Forced migration is occurring at unprecedented levels. Forced migrants may be at risk for substance use for reasons including coping with traumatic experiences, co-morbid mental health disorders, acculturation challenges and social and economic inequality. This paper aimed to systematically review the literature examining substance use among forced migrants, and identify priority areas for intervention and future research.Seven medical, allied health and social science databases were searched from inception to September 2015 in accordance with PRISMA guidelines to identify original peer-reviewed articles describing any findings relating to alcohol and/or illicit drug use among refugees, internally displaced people (IDPs), asylum seekers, people displaced by disasters and deportees. A descriptive synthesis of evidence from quantitative studies was conducted, focusing primarily on studies which used validated measures of substance use. Synthesis of evidence from qualitative studies focused on identifying prominent themes relating to the contexts and consequences of substance use. Critical Appraisal Skills Programme (CASP) checklists were used to assess methodological quality of included studies.Forty-four quantitative , 16 qualitative and three mixed-methods studies were included. Ten studies were rated as high methodological quality (16%), 39 as moderate quality (62%) and 14 as low quality (22%). The majority of research was conducted among refugees, IDPs and asylum seekers , predominantly in high-income settings. The highest-quality prevalence estimates of hazardous/harmful alcohol use ranged from 17%-36% in camp settings and 4%-7% in community settings. Few studies collected validated measures of illicit drug use. Seven studies compared substance use among forced migrants to other migrant or native-born samples. Among eight studies which conducted multivariable analysis, male sex, trauma exposure and symptoms of mental illness were commonly identified correlates of substance use.Our understanding of substance use among forced migrants remains limited, particularly regarding persons displaced due to disasters, development and deportation. Despite a growing body of work among refugee-background populations, few studies include refugees in low and middle-income countries, where over 80% of the global refugee population resides. Findings suggest a need to integrate substance use prevention and treatment into services offered to forced migrants, particularly in camp settings. Efforts to develop and evaluate interventions to reduce substance use and related harms are needed. The International Organisation for Migration (IOM) defines forced migration as “a migratory movement in which an element of coercion exists, including threats to life and livelihood, whether arising from natural or man-made causes” . Three mAlthough the number of active conflicts globally decreased from 63 in 2008 to 42 in 2014 . No. No64]. Our review approach was guided by three overarching questions:What does available research tell us about the magnitude, and risk and protective factors for substance use and related harms among forced migrants?What are the contextual factors which underlie substance use among forced migrants?What evidence is available to inform the design and implementation of interventions to address harmful substance use among forced migrants?The research questions and our subsequent search strategy were developed using the SPIDER tool, which has been designed for reviews incorporating qualitative and mixed-methods literature . Our SPISeven medical, allied health and social science databases  were searched from inception to May 2015. Search terms, developed in consultation with a medical librarian, covered the key domains of forced migration and substance use (Domains S and PI of SPIDER), and were modified slightly for each database . ArticleStudies were considered eligible for inclusion in the review if they described any findings related to alcohol or illicit drug use among forced migrant populations (defined using the IOM definition ). RelevaArticles were excluded if they were not original peer-reviewed research, were not published in English, French or Spanish, did not clearly identify the population as forced migrants or did not provide separate results for forced migrants, or did not report any relevant findings. Multiple reports from the same study were excluded unless they reported additional relevant data.Following an initial screen of titles and abstracts, potentially relevant articles were selected for full text review. A random 10% of full-text articles were checked by a second reviewer and showed high inter-rater agreement on inclusion/exclusion decision .From included articles, article publication characteristics , study procedures , participant characteristics  and substance use findings were extracted into a purpose-designed Microsoft Access database by JM and RF, and independently reviewed by DH.A quality assessment was conducted using the Critical Appraisal Skills Programme (CASP) checklists for cohort studies, case-control studies and qualitative studies . The cheDue to the heterogeneity of study designs, populations and outcome measures, a meta-analytical approach was considered inappropriate. Synthesis of evidence from quantitative studies was descriptive; results presented focus primarily on studies which used validated measures. 95% Confidence Intervals for prevalence estimates were calculated using Stata 13.1 . Synthesis of evidence from qualitative studies focused on identifying prominent themes relating to the contexts and consequences of substance use.A total of 63 relevant articles were included in the review . The mosThe majority of included articles examined substance use among refugee, IDP and asylum seeker populations , 16 studies utilised qualitative methods and three studies used mixed-methods. The majority of quantitative studies used cross-sectional study designs (82%). Half of the quantitative studies used probability sampling methods  and almost two thirds  included samples of 200 or more participants. Sixteen studies included a comparison sample of native-born or non-forced migrants. Qualitative studies employed a range of methods, including participant interviews and focus groups, key expert interviews and ethnographic methods. Ten studies were rated as high methodological quality , 39 as moderate quality (62%) and 14 as low quality (22%).Studies collected alcohol use prevalence estimates over the lifetime (n = 4), past year (n = 2) and past month (n = 4). Lifetime alcohol use prevalence estimates were all among refugee communities in the US and ranged from 13% among Iraqi refugees  to 38% aTwelve studies measured the prevalence of hazardous/harmful alcohol use, of which six collected this information using validated measures, all using the Alcohol Use Disorders Identification Test (AUDIT ). In camOnly two studies reported on prevalence of drug use. Among a sample of Afghan refugees in Pakistan, 23% had ever used drugs and 7% had ever injected drugs  and amonA small number of studies reported findings related to specific drug types, most commonly cannabis, cocaine, heroin and methamphetamine. One study used the Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV to measure lifetime prevalence of substance use disorders among refugees in the US, finding a prevalence of 4% for cannabis use disorder, and below 1% for cocaine, hallucinogens, amphetamines, and opioids/heroin use disorder . Among dOf the 16 studies which included a comparison sample of non-forced migrants, only seven conducted statistical analysis examining differences in alcohol or drug use outcomes . In the Two studies compared patterns of drug use and related risk behaviour between drug-using forced migrant and non-forced migrant samples. No significant differences in the proportion of participants reporting opiates as the first drug injected or reporting current injecting drug use was found between Afghan refugees and native Pakistanis . Among pSeven studies conducted statistical analysis to identify correlates associated with alcohol outcomes, including current/past-month drinking, increasing alcohol & tobacco use post-disaster, and hazardous/harmful drinking . In fiveStudies examining correlates of drug use outcomes were limited to two studies of regular drug users, one among deportees and one among people displaced by a hurricane . FactorsOnly one intervention study was identified—a screening and brief intervention for high-risk alcohol use in a refugee camp setting in Thailand . AlthougSubstance use was commonly examined in the context of mental health. Two case studies described use of drugs including opiates, cocaine and cannabis to self-medicate symptoms of PTSD among refugees and asylum seekers ,98, and Several studies focused on substances that were traditionally used in migrants’ countries of origin. Among the Burmese refugee community in Wollongong, Australia, betel quid chewing was seen as a benign social habit . SimilarEleven studies examined the unique context of refugee camp settings. Within these studies the important role of alcohol production and sales as a source of income for these vulnerable communities was acknowledged ,81. WithOur global systematic review shows that despite substantial growth in research examining substance use among forced migrants in recent years, the available body of evidence remains limited. On the basis of the available evidence however, we draw attention to several findings with important implications for public health.A major finding of this review is that there is substantial heterogeneity in patterns of substance use across included studies. In studies using validated measures, the prevalence of hazardous/harmful alcohol use ranged from 4%-36%, alcohol dependence ranged from <1%-42% and drug dependence ranged from 1%-20%. Further, among studies including comparison samples, some found lower rates of substance use among forced compared with non-forced migrant samples, some found no statistically significant differences, and one study detected associations in different directions among male and female participants. The heterogeneity in findings likely reflects regional and global differences in patterns of substance use, which may be influenced by local context factors such as availability of substances and social norms ,129. ThiA particularly notable finding is that if we consider the upper limits of these estimates, as many as one in three forced migrants may be using alcohol in harmful or hazardous ways, and, when measured among current drinkers only, this estimate may be as high as two in three. Importantly, these figures may actually underestimate the true prevalence of harmful drinking as stigma has been shown to influence non-response and underreporting of substance use among culturally diverse communities –133. In A second key finding of this review relates to substance use among resettled forced migrants in Western settings. Although the prevalences of alcohol and illicit drug use tended to be relatively low in studies included in this review, there was substantial variation in the recorded estimates and the time points post-migration at which these measurements were captured. Given the high rates of alcohol use occurring in refugee camp settings, it is likely that substance use among newly-arriving refugees may be occurring at higher levels than what is being detected. Although current evidence-based clinical guidelines for screening and treating newly-arrived immigrants and refugees do not specifically address substance use we suggest that, consistent with the recommendations for PTSD and intimate partner violence, clinicians should be alert for signs and symptoms of substance use, and investigate further where appropriate . Given aA final key finding is that the single longitudinal study included in this systematic review detected a statistically significant increase in the prevalence of lifetime alcohol use among newly-arrived refugees in the US over a 12-month period , suggestEarlier reviews of substance use among displaced persons identified methodological issues such as small sample sizes, use of non-probability sampling methods and lack of comparison groups as major limitations of existing research ,63. The First, the representativeness of study samples is limited. With the overwhelming focus on refugee populations, knowledge of substance use among persons displaced due to disasters, development and deportation remains extremely limited. These groups may represent a particularly vulnerable subset of forced migrants as they commonly lack the protections and supports that are afforded to refugees and IDPs under internationally recognised treaties. Moreover, current research has focused predominantly on resettled refugees in high-income settings, and findings may not be generalisable to refugee populations in low and middle-income settings, which is a major concern given that over 80% of the global refugee population resides in these settings . ImportaThe heterogeneity of included studies in terms of populations, settings and outcome measures precluded pooling of data in a meta-analytic manner, and makes it difficult to draw definitive conclusions. The search strategy used focused specifically on substance use. It is possible that articles broadly examining the health or mental health of forced migrants which included substance use measures but did not include substance use terms in the article title, abstract or key words may not have been identified. The review was limited to studies published in English, French, or Spanish. Although few articles were excluded due to this eligibility criteria, it is possible that findings in excluded studies were in a different direction from those included, potentially biasing the results. This review was also limited to peer-reviewed published literature as it was not feasible to conduct grey literature searches due to limited resources. Finally, a large number of sources were reviewed by a small research team in a short period of time, and although internal checks were conducted to minimise errors in data coding and entry, some unintended errors may have occurred.Many important questions regarding substance use among forced migrants remain unanswered. Further research is needed to robustly assess the burden of substance use and dependence in low and middle-income countries, as well as among other sub-groups of forced migrants who have been under-studied, such as people displaced by disasters, and deportees. Importantly, as the bulk of existing research has focused on alcohol use, there is a need for additional research examining illicit drug use, including measures of individual drug types rather than unspecified ‘drug use’, and examination of transitions between different routes of drug administration. Multi-country studies which incorporate standardised recruitment, data collection and analysis across diverse settings (such as the work done on intimate partner violence in Asia and the Pacific ) would bIn addition to measuring prevalence and identifying risk factors for substance use, it is essential to conduct research to identify factors which are protective against substance use. Drawing on the broader epidemiological literature, particularly research conducted among migrant and minority communities, factors warranting exploration include individual-level factors such as agency, resilience, and coping skills, community-level factors such as community cohesion, social network systems, and norms about substance use, environment-level factors such as availability of alcohol and illicit drugs, and policy-level factors such as rights to obtain citizenship, and legal, economic and social integration –151. BetFuture research should be designed to ensure inclusion of under-represented groups at high risk of substance use, such young people, and should employ longitudinal methods, in order to examine changes in substance use at different time points in the migration and resettlement trajectory. In particular, prospective cohort studies are crucial in identifying new-onset substance use and changes in individuals’ patterns of substance use over time. Although there are inherent challenges in conducting cohort studies with migrant populations, such as ongoing insecurity and population mobility which may impede follow-up, strategies which have had some demonstrated success include employing dynamic and adaptive methodological approaches, collaboration with established services, ongoing community engagement and utilising the capacity of information and communication technologies –156. RepMost importantly, the major gap in knowledge regarding effective, culturally competent interventions to prevent substance use and reduce related harms must be addressed. Recent research has noted that brief community-based interventions for alcohol use disorder have been shown to be effective in high-income settings ; exploraIn summary, findings from this systematic review draw attention to our limited understanding of the epidemiology of substance use among forced migrant populations, particularly among persons displaced due to disasters, development and deportation, as well as among refugees in low and middle-income countries, where over 80% of the global refugee population resides. Findings suggest a need to integrate substance use prevention and treatment into services offered to forced migrants, particularly in camp settings. Given the recent and continuing projected increases in forced migration globally, longitudinal research to improve our understanding of substance use across the migration trajectory, and efforts to develop and evaluate interventions to reduce substance use and related harms are needed.S1 File(DOC)Click here for additional data file.S2 File(DOCX)Click here for additional data file.


The Middle East respiratory syndrome (MERS) outbreak in Korea in 2015 may be attributable to poor nosocomial infection control procedures implemented. Strict infection control measures were taken in the hospital where an imported case with MERS was treated in southern China and 53 health care workers were confirmed to be MERS-CoV negative. Infection control in healthcare settings, in which patients with emerging infectious diseases such as MERS, Ebola virus disease, and the severe acute respiratory syndrome (SARS) are diagnosed and treated, are often imperfect. When it comes to emerging or unknown infectious diseases, before the imported case was finally identified or community transmission was reported, cases have often occurred in clusters in healthcare settings. Nosocomial infection control measures should be further strengthened among the workers and inpatients in designated healthcare settings that accommodate suspected cases suffering from emerging or unknown infectious diseases.The online version of this article (doi:10.1186/s40249-016-0118-9) contains supplementary material, which is available to authorized users. Please see Additional file Which intervention and control measures should be immediately taken when suspected Middle East respiratory syndrome (MERS) case(s) are imported from abroad? High priority should be given to the prevention of nosocomial infections among the workers and inpatients in the healthcare settings. Since the first human case of MERS coronavirus (MERS-CoV) was reported in Saudi Arabia in 2012, 1684 laboratory-confirmed cases and 600 related deaths have been recorded  . AlthougOn May 27, 2015, a suspected human case of MERS with a fever of 39.7 °C, who had travelled from South Korea to Huizhou city, Southern China, was notified by the World Health Organization (WHO). This suspected case was then quarantined in a negatively pressurized room and confirmed to be infected with MERS on May 29. Strict infection control measures were taken in the hospital where the case was treated to reduce the risk of further transmission. On June 10, serum samples were collected from 53 healthcare workers who used personal protective equipment when treating this patient, and all were confirmed to be MERS-CoV negative [The first imported case of MERS in Korea was reported on May 20, 2015. Over the following weeks, the number of secondary and subsequent cases from this patient increased, leading it to become the largest case cluster of MERS outside the Middle East. All cases (excluding the index case) have been linked to a single chain of transmission and were associated with healthcare facilities . Of thesWhen it comes to emerging infectious diseases such as the severe acute respiratory syndrome (SARS), Ebola virus disease, and MERS, before the imported case was finally identified or community transmission was reported, cases have often occurred in clusters in healthcare settings. In March 2003, for example, 19 medical staff members, one inpatient, and one family number were infected with SARS-CoV by the same index SARS patient in a hospital in Guangdong . In a BeIn many countries including China, nosocomial infection regulations have been established nationally, in order to ensure routine infection control operation in healthcare settings. However, in healthcare settings where patients with emerging or unknown infectious diseases are diagnosed and treated, especially those operated by local governments, infection control methods against severe infectious diseases such as MERS are often imperfect. For example, a survey of device-associated healthcare-associated infection (DA-HAI) rates in 398 ICUs in Shanghai, China, reported a high number of DA-HAIs, which posed a major threat to patient safety . TherefoProper control measures should be taken to ensure that nosocomial infections do not occur in designated healthcare settings that accommodate suspected cases suffering from emerging infectious diseases. To this end, a comprehensive and detailed evaluation of nosocomial infection control should be conducted in each designated healthcare setting. Negative-pressure quarantine ICUs and wards should be built in accordance with the demand in the area. Regulations, standards, procedures, and operational instructions on protection against infections from emerging respiratory, gastrointestinal, body fluid, and insect-borne infectious diseases should be established. Periodical regular trainings for the knowledge of prevention and control emerging or unknown infectious diseases, and emergency exercises regarding nosocomial infection events among medics can also help to strengthen the infection control system.


It has become increasingly clear that microbes form close associations with the vast majority of animal species, especially insects. In fact, an array of diverse microbes is known to form shared metabolic pathways with their insect hosts. A growing area of research in insect-microbe interactions, notably for hemipteran insects and their mutualistic symbionts, is to elucidate the regulation of this inter-domain metabolism. This review examines two new emerging mechanisms of gene regulation and their importance in host-microbe interactions. Specifically, we highlight how the incipient areas of research on regulatory “dark matter” such as epigenomics and small RNAs, can play a pivotal role in the evolution of both insect and microbe gene regulation. We then propose specific models of how these dynamic forms of gene regulation can influence insect-symbiont-plant interactions. Future studies in this area of research will give us a systematic understanding of how these symbiotic microbes and animals reciprocally respond to and regulate their shared metabolic processes. Microbial associates that interact with insects can produce a wide array of metabolic products that complement the metabolic needs of their herbivorous hosts , such as plant sap, present a nutritional challenge to consumers. Most insect herbivores that feed on a phloem or xylem sap diet are able to feed on this essential amino acid-deficient niche because they harbor one or more nutritional symbionts . Now more than ever, DNA methylation has become more tractable to study due to the recent advancement in sequencing technology and bioinformatics. In turn the field of epigenomics is more accessible to researchers for both model and non-model organisms. As such the number of research articles on DNA methylation has been steadily increasing  and Drosophila melanogaster (fruit fly) DNA methylation is not functional, because of lineage specific losses of DMNTs  dinucleotide sites Bird, . HoweverC. elegans and D. melanogaster, do not have active copies of DNMTs (detailed above). Nevertheless, DNA methylation has been observed in a diversity of other invertebrate species. For example, in the Pacific oyster Crassostrea gigas, different levels of CpG methylation have been observed that correlate with gene functions  of the genome, whereas intergenic regions remain largely unmethylated  is silenced in larvae that feed on protein-rich royal jelly these larvae develop into fertile queens with fully developed ovaries  with variable levels of methylation between worker and nurse bees was strongly correlated with the alternative splicing of its gene product. The direct consequences of this alternative splicing however are unclear . This photoperiodic response allows the larvae to survive throughout winter. Knock-down of either DNMT1a or DNMT3 in N. vitripennis parents disrupted the photoperiod-induced developmental arrest of their larvae. Although the exact mechanisms are yet to be elucidated, these results suggest that environmentally induced diapause in N. vitripennis are linked to DNA methylation.In the parasitoid wasp M. persicae, individuals resistant to an organophosphate pesticide encode a differentially methylated esterase gene that confers the resistant phenotype . Furthermore, the authors identified correlations between CpG island methylation and growth rate, morph development, and pigmentation of the aphid population by pharmacologically inhibiting the DNA methyltransferases  infects the mosquito, Aedes aegypti, the mosquito is hypomethylated because Wolbachia suppresses DNMT2  alter host phenotypes. We hypothesize that this ability is widespread in insect symbionts, particularly among co-evolved insect symbionts. These intimate partners may influence methylation of their insect hosts with functional DNA methylation systems by modulating their host's immune responses to microbes. For example, attenuating immune responses so as to permit their intracellular persistence. In addition, these symbionts can encode novel biosynthetic pathways, which may contribute microbially derived metabolites, such as folate; folate is a key source of the one carbon group used to methylate DNA Table . MoreoveIn recent years, there has been a rapid increase in the identification of non-coding, regulatory RNAs in Bacteria, Archaea, and Eukaryotes , as such they often have partial complementarity with their targets. Trans-encoded sRNAs are generally dependent on the RNA chaperone Hfq  and small-interfering RNAs (siRNAs). Within eukaryotes, the RNAi pathway is responsible for the regulation of a diversity of endogenous genes via miRNAs, and for protecting the organism from invasive genetic material, such as viruses and transposable elements via siRNAs Hannon, . These strans-encoded sRNAs. Plant miRNAs on the other hand have high sequence complementarity , trans-acting siRNAs (tasiRNAs), and natural antisense transcript-derived siRNAs , elevated mutation rates and the fixation of deleterious and neutral mutations due to genetic drift, ultimately resulting in gene inactivation and loss . In Buchnera's close relatives, such as E. coli, Vibrio spp., and Pseudomonas spp., 3′ CCA is encoded in all tRNA genes that are present in Buchnera; most likely to maintain efficient translation. Nevertheless, only half of Buchnera tRNA genes encode 3′ CCA  co-opt existing machinery to compensate for core regulatory processes and (2) maintain existing machinery to conserve essential regulatory functions.One example of how reduced genomes compensate to maintain essential gene expression processes comes from previous research on Organelles represent the most dramatic example of tiny genomes that express regulatory sRNAs. Within eukaryotes there are two general types of organelles that have a unique evolutionary history with a microbial origin, such as mitochondria and plastids . From these studies, we can see a potential trend emerging that organelle sRNAs expressed either from the organelle genome or the nuclear genome of their hosts are important for the regulation of these small, eroded genomes.In mammals, besides providing energy for cellular functioning, mitochondria are also important in apoptosis  cell lines, it has been found to express sRNAs that potentially increase bacterial fitness by upregulating host genes that help facilitate its own replication  pathways in response to aphid nutritional demand  to process these sRNAs. There is evidence that shows that bacteria can produce sRNAs that target eukaryotic genes, suggesting that these sRNAs either mimic eukaryotic sRNAs or can be co-opted into the RNAi pathway. This type of trans-kingdom communication via sRNAs has also been observed in fungal plant pathogens (Weiberg et al., Recent studies on epigenomic and small-RNA regulation in eukaryotes and bacteria have challenged historical preconceptions of how these genomes are regulated and evolve. The implications of these new studies on the understanding of the regulation of shared animal-microbe metabolic processes warrant further investigation in future studies. Such studies are critical because of the importance these regulatory mechanisms have in the evolution and maintenance of these widespread herbivore symbioses. To this end, we conclude this review by proposing future directions that will aid in teasing apart the regulatory underpinnings and dynamics of shared metabolic processes that are ubiquitous between insect herbivores and their microbial symbionts.Elucidating the mechanisms and patterns of DNA methylation and its inheritance is important for understanding the molecular biology, ecology, and the evolution of non-model animals. For example, methylation patterns are linked not only to numerous human diseases (Robertson, D. melanogaster, S. cervisiae, C. elegans; Goll and Bestor, A. pisum can be reared in culture, maintained asexually or sexually, have short generation times, have co-evolved microbial symbionts, and exhibit a wide range of host plant interactions. Thus, aphids are ideally suited for characterizing novel aspects of epigenetic regulation. Results produced from this research can thus be important for understanding insect nutrition specifically, as well as the ecology and evolution of insect-host plant interactions and symbiosis more generally. In addition, many obligate symbionts in insect systems produce folate and/or other methyl- groups, which may influence insect host DNA-methylation patterns (Table Aphids are an attractive and tractable model for studying epigenetic regulation of shared herbivore-microbe metabolisms. Aphids display functional DNA methylation (Walsh et al., ns Table . In turnns Table  can now Buchnera are still autonomous bacterial cells, however some of these minimal genomes can regulate gene expression at the post-transcriptional level (Hansen and Degnan, Insect taxa in several of the most diverse insect orders are known to harbor obligate symbionts with reduced genomes. Most of these symbionts have been characterized in blood and sap-feeding insects; the smallest known bacterial genome is a symbiont from a sap-feeding insect (Bennett and Moran, DK, MT, and AH all substantially wrote and edited the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Telomere biology is central to the maintenance of genomic stability and telomeric dysfunction is thought to be an early stage in carcinogenesis. Reports of telomere lengths and their ascribed colorectal cancer (CRC) risks have been discordant, with both very short and very long telomeres implicated. Nevertheless, telomeres appear to play a very central role in cancer initiation. Telomere length changes also appear to impact disease burden, progression, and overall survival. This review covers contemporary views on telomere biology and CRC risk, with a brief overview of analytical methods employed in telomere measurement. We conclude with arguments in favor of including telomere assessment in the molecular profiling of CRCs. Telomeres are repeat TTAGGG sequences at the end of linear chromosomes, which guard against loss of genetic material during cellular replication. Due to an inherent end replication problem, chromosomes are exposed to a potential loss of genetic material, with telomeres acting as a buffer against loss of chromatin. Repeated cell cycles eventually lead to a critically shortened telomere length, signaling cellular senescence, and triggering apoptosis. This arrest in proliferation is thought to protect against malignant transformation and a failure to do so results in catastrophic genomic instability and carcinogenesis. Telomeres are thus important in managing genomic stability. This central role in genome maintenance makes telomeres key players in carcinogenesis and an attractive candidate for tumor profiling at the molecular level.Telomere length changes have been linked to numerous cancers, including colorectal cancer (CRC). Results from studies analyzing telomere lengths in CRC have been discordant, presenting evidence that both ends of the spectrum (shorter and longer lengths) have a possible role in CRC occurrence –3. MoreoThe tumor micro-environment may also contribute to carcinogenesis. Shortened telomeres in stromal cells may participate in epithelial changes leading to cancer via autocrine or paracrine mechanisms. Thus as stromal cells undergo senescence, they exhibit a secretory phenotype that may trigger neighboring cells with shortened telomeres to by-pass the senescence signal and termination, setting the stage for chromosomal instability and malignant transformation . This thEpidemiological studies evaluating the relationship between telomere lengths and CRC risks have produced conflicting results. Although telomere attrition is classically thought of as a risk for CRC, reports of longer telomere lengths, and a predisposition to CRC have emerged , 16–18. in situ hybridization (flow-FISH), quantitative FISH (Q-FISH), and single or universal single telomere length analysis (STELA) , flow cytometry with fluorescence  (STELA) . Souther (STELA) . Further (STELA) . Cancer  (STELA) . The tel (STELA) . qPCR do (STELA) . Telomer (STELA) . Alterna (STELA) . hTERT m (STELA) , 26. Giv (STELA) . A standThe lack of consensus on telomere length changes and the conferred risk for CRC could point toward the existence of distinct molecular subclasses of CRC. Telomere dysfunction may represent an alternative pathway in CRC carcinogenesis, a shift from the two classic genomic instabilities observed: chromosomal and microsatellite instability (MSI). In a study assessing telomere attrition in microsatellite stable (MSS) and chromosomally stable (CIN−) rectal cancers, Boardman et al. revealed evidence of molecular heterogeneity within MSS cancers, in regards to their CIN status and telomere maintenance mechanism . Of inteStudies looking into the relationship between MSI and telomere lengths have been sparse. Telomeres may be considered a form of super microsatellite given their tandem repeat nature and it may be reasonable to assume that defects in MMR genes impact telomere length. In an experiment studying the effect of down-regulating MSH2 in fibroblast cell lines, Mendez-Bermudez et al. report a statistically significant increase in telomere attrition rate compared to control cell lines . HoweverThe impetus for adding telomere lengths to the molecular profiling of CRC lies in the possibility of tailored therapy. Differences in molecular profiles often translate into distinct clinical progression, as in the case for CIN− and CIN+ CRC. Genetic CRC may also benefit from a telomeric subclassification, as telomere length changes have been suggested as risk modifiers in mutation carriers and therefore may serve as a marker of prediction . The assThere has been intense interest in anti-telomerase drugs and their potential as a targeted chemotherapeutic drug , 39. TarVery like the chicken or egg causality dilemma, the timeline of events involving telomeres, genomic instability, and CRC remain unclear. While distinct molecular mechanisms are conceivable, synergistic effects between different components and the interactions of alternative pathways cannot be ignored. Differences in analytic measures have been implicated in the varying results seen suggesting the need for a standardized measurement technique. The difference in results could also reflect a reverse-causation effect. Larger prospective studies are imperative to validate previously published data. Moreover, given the duality in findings, a healthy range of telomere lengths may need to be established. Nevertheless, a subclassification of CRC to include telomere status could carry significant value in predicting disease severity, progression and overall prognosis, and in directing treatment. A telomere subclassification represents an important step forward in individualized medicine and is, therefore, an important avenue to explore.Lisa A. Boardman is supported by the National Cancer Institute (RO-1 CA132718 and RO-1 CA 170357) and the National Institute of Diabetes and Digestive and Kidney Diseases . The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.


Swietenia macrophylla) and tree species diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves). We found that both forms of plant diversity had positive effects on stem (but not leaf) defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s) of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer diversity effects on plant chemical defenses.Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among species than among genotypes within a given species, so plant species diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and species diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany ( Ecological research conducted over the last decade has shown that plant intra- and inter-specific diversity have large effects on ecosystem processes, such as decomposition rates and productivity Although plant diversity effects on plant biomass (via resource use) and consumers are well-documented, little information is available about the effects of plant diversity on anti-herbivore defenses. Diversity effects on plant defenses are extremely important because they might influence herbivory and explain over-yielding There are two possible mechanisms by which producer diversity may influence plant defenses. First, plant diversity is known to increase plant growth via more efficient resource use Plantago lanceolata plants growing in patches of high species diversity exhibited a lower concentration of foliar aucubin and total iridoid glycoside, but a greater concentration of catalpol, another important defensive compound. In addition, Moreira and colleagues Despite these appealing predictions, few studies have directly evaluated the effects of plant diversity on anti-herbivore defenses Importantly, the mechanisms by which producer diversity influences plant defenses may vary depending on the source of plant diversity. For instance, the magnitude of trait variation underlying diversity effects is usually greater among species than among genotypes within a given species, therefore we would expect that plant species diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects Swietenia macrophylla) as well as tree species diversity, and evaluated the effects of diversity on mahogany growth , herbivore damage , and chemical defensive traits (polyphenolics and condensed tannins in stem and leaves). We focused on H. grandella because it is the most important herbivore (in terms of abundance and amount of damage inflicted) of mahogany in our system . Larvae of this herbivore carve tunnels through the terminal shoots of juvenile plants  comparing the relative importance of these two source of plant diversity (following the prediction of stronger effects of species diversity), and (b) evaluating the mechanisms for such effects, namely if diversity effects were mediated via changes in plant growth (due to underlying growth-defense trade-offs) or herbivore damage. To address this, we performed a large-scale field experiment where we manipulated genotypic diversity of the tropical tree big-leaf mahogany  is a large-statured tree with a patchy distribution throughout much of southern Mexico, Central America, and South America H. grandella  Big-leaf mahogany (Tabebuia rosea (Bertol.) DC. (Bignonaceae), Ceiba pentandra (L.) Gaertn. , Enterolobium cyclocarpum (Jacq.) Griseb. (Fabaceae), Piscidia piscipula (L.) Sarg. (Fabaceae), and Cordia dodecandra A. DC. (Boraginaceae). These species are long-lived, deciduous, and adult trees reach from 20 m (P. piscipula) to 40 m (C. pentandra) In tropical forests of the Yucatan Peninsula, big-leaf mahogany co-occurs with five other tree species In December 2011, we established 74 plots of 21×21 m each at a planting density of 64 plants per plot, 3 m spacing among trees, for a total of 4780 plants. Isles between plots were 6-m wide, and the experiment covered a total area of 7.2 ha Mahogany was planted in 59 of these plots which were classified into four types, depending on the diversity treatment combination: a) mahogany monocultures of one genotype , b) mahogany monocultures of four genotypes , c) polycultures of four species within which all mahogany saplings were of one genotype , and d) polycultures of four species within which mahogany plants were represented by four genotypes (15 plots). For these four plot types, treatments of both species and genotypic diversity included equal numbers of individuals of four species  and four mahogany genotypes drawn from pools of six species or six genotypes, respectively. All non-mahogany species were equally represented across polycultures (each species present in six polyculture plots). Likewise, mahogany genotypes were represented in a similar number of mahogany monocultures of four genotypes (8–9 plots per genotype), and also in a similar number of species polycultures where mahogany plants were of four genotypes (9–10 plots per genotype).In this study, we sampled a subset of these 59 plots where mahogany was present (see following two sections) and within these plots we restricted our sampling only to mahogany.For measurements of growth and stem borer damage, we randomly selected eight mahogany plants allocated across plot types as follows : 12 genotypic monoculture plots, 20 genotypic polyculture plots, and 12 species polyculture plots where mahogany was represented by one genotype; we did not sample species polyculture plots with four genotypes. From January 2011 to March 2011, we collected seeds of each tree species from adult plants located in southern Quintana Roo (SE México), and germinated at the INIFAP  in Mocochá . For all species, we collected seed from six mother trees, and distance among trees ranged from 0.5 to 50 km. In the case of mahogany, distance among mother trees ranged from 3 to 50 km which is within the distance range used by previous studies to define genetically distinct populations of this species H. grandella damage by examining the apical and axilar meristems of plants in search of attack sites (easily identified by the presence of frass) H. grandella attacks per plant.In late July 2013, we recorded mahogany growth by measuring total height, as well as H. grandella larval performance and survival As a proxy of quantitative chemical defences, we measured polyphenolics and condensed tannins in stems and leaves. In late July 2013, we randomly sampled four out of the eight previously mentioned mahogany plants sampled per plot for growth and stem borer attack , allocated across plot types as follows: 12  genotypic monocultures, 12 (out of the 20) genotypic polycultures, and 12  species polycultures; again, we did not sample polycultures with four mahogany genotypes. Polyphenolics are carbon-based compounds, non-nutritious, and unpalatable for herbivores because they inhibit herbivore digestion by binding to consumed plant proteins Polyphenolics were extracted and analysed as described by Moreira et al. Condensed tannins were determined by the acid butanol method H. grandella attacks per plant), and chemical defenses . For each response variable, we performed two separate models: First, to test the effect of mahogany genotype diversity, we compared genotypic monocultures and genotypic polycultures, and second, to test for a species diversity effect, we compared genotypic monocultures and species polycultures (hereafter “Model 0” in each case). Then, we departed from these initial models and constructed “mechanistic” models which included additional covariates aimed at testing if each source of diversity influenced mahogany defenses via effects on mahogany growth and H. grandella attack: (i) “Model 1” tested an effect of genotypic or species diversity on mahogany defenses via trade-offs between growth and defense by including plant height as a covariate. If diversity effects on defenses are mediated by growth-defense trade-offs via increased growth, then a significant effect of diversity on defenses should become non-significant once plant size is accounted for in the model; (ii) “Model 2” tested an effect of genotypic or species diversity via changes in herbivory by including H. grandella attack as a covariate in the model. If diversity effects on defenses are mediated by higher or lower attack of H. grandella at high diversity, then a significant effect of diversity on defenses should become non-significant once herbivory is accounted for in the model. Normality was met in all cases, and we report least square means ± standard errors as descriptive statistics. All models were performed with PROC MIXED in SAS  using plot and genotype as random effects. The former accounted for non-independence of plants sampled from the same plot, while the latter controlled for variation in growth and defenses among maternal sources. We also performed models using plot as the level of replication (results not shown) and all results were qualitatively idential.We performed general linear mixed models to test for plant diversity effects on plant growth, herbivore damage (number of H. grandella. Although attack was lower in genotypic and species polycultures (30% in both cases) relative to genotypic monocultures, we were not able to detect a significant effect of either source of plant diversity on attack by this herbivore  anti-herbivore defenses in big-leaf mahogany, namely the concentration of stem polyphenolics and condensed tannins. In addition, the effects of these two sources of plant diversity on defenses were similar in magnitude. Contrarily to our expectations, positive effects from both sources of plant diversity were not mediated by the effects of diversity on plant growth or herbivore damage. Although the mechanism(s) of diversity effects on plant defenses in this study are yet to be determined, our study is one of the few to test for and show producer diversity effects on plant chemical defenses (i.e. secondary compounds). Such effects were particularly strong and are likely to play an important role in mediating plant diversity effects on higher trophic levels and ecosystem function.Ammophila breviligulata, a dominant species in dune ecosystems. Similarly, Cook-Patton et al. Oenothera biennis). Nonetheless, further research in other systems comparing the effects of plant intra- and inter-specific diversity is necessary in order to assess the relative importance and mechanisms by which different forms of plant diversity shape anti-herbivore defenses in plants, and in turn potentially explain differential effects on arthropod faunas.To the best of our knowledge, there are no previous studies testing the relative contribution of plant intra- and inter-specific diversity on plant defense allocation patterns. Our results showed that plant genotypic and species diversity effects on mahogany anti-herbivore defenses tended to be similar in magnitude, despite the presumption that greater magnitude of trait variation among species than among genotypes should lead to stronger effects of species diversity (relative to genotypic diversity) on producers. Moreover, for stem tannins we even observed a stronger effect of genotypic diversity relative to species diversity. Accordingly, these findings agree with recent work showing that plant intra- and inter-specific diversity effects on ecosystem function and arthropod communities can be of similar importance Oenothera biennis (via complementarity effects) at high genotypic diversity resulted in reduced resistance to an exotic leaf herbivore P. lanceolata were only weakly related to changes in herbivory across levels of diversity. Our results showed a tendency for a negative effect of plant diversity on H. grandella attack, suggesting that some unknown mechanism drove an increase in plant defenses, and that such effect in turn could have negatively influenced stem borer attack. However, this argument remains speculative as reductions in attack by this specialist herbivore may have also responded to resource concentration effects with increasing genotypic or species diversity, as suggested by previous findings in this system . Regardless of the mechanism at work, evidence for diversity effects on plant defenses remains limited and further research is needed to derive general patterns and determine which mechanisms and defensive compounds are more important and under what conditions.Our finding that diversity did not influence plant defenses via growth-defense trade-offs is not surprising, given that neither source of diversity influenced mahogany growth. Contrary to our findings, results from a previous study by McArt & Thaler H. grandella attack or via growth-defense trade-offs, these mechanisms cannot be entirely discarded. First, it is possible that our measure of H. grandella abundance (i.e. number of attack sites per plant) was not predictive of the amount of damage (and thus defense induction) experienced by each plant. Second, and related also to the effects of diversity on herbivory, previous work in our system (during 2012) has shown that attack by H. grandella was significantly lower in species polycultures at the middle of the rainy season (early September), but this pattern reversed towards the end of the rainy season (late October) . Therefore, whereas we associated plant defenses with current patterns of herbivory (tissue samples taken during the same month as herbivore measurements), it is possible that stem-borer attack levels during previous months would have been a better predictor of defensive investment. Third, although results suggest that diversity effects on defenses via growth-defense trade-offs are not occurring at present in this system, our measurements were conducted at an early time point in the experiment. Accordingly, it is possible that such trade-offs may arise subsequently, once diversity effects on plant growth presumably become stronger Although we found that plant diversity effects on anti-herbivore defenses were not mediated by diversity effects on It is important to note that some authors have suggested that producer diversity may influence plant defenses in the absence of effects on plant growth and growth-defense trade-offs In summary, the results from this study demonstrated that both plant inter- and intra-specific diversity can cause important changes in allocation to chemical defenses by plants, but that such effects were not driven by changes in plant growth (and thus growth-defense trade-offs) or herbivore damage. We suggest that additional abiotic factors (e.g. nutrient availability and uptake) and mechanisms should be considered in future studies in order to fully understand the observed patterns. Understanding the mechanisms by which plant diversity influences traits of importance to herbivores, in particular plant secondary metabolites, will contribute to a better understanding of plant diversity effects on consumers and ecosystem function.


Microbial interaction is an integral component of microbial ecology studies, yet the role, extent, and relevance of microbial interaction in community functioning remains unclear, particularly in the context of global biogeochemical cycles. While many studies have shed light on the physico-chemical cues affecting specific processes, (micro)biotic controls and interactions potentially steering microbial communities leading to altered functioning are less known. Yet, recent accumulating evidence suggests that the concerted actions of a community can be significantly different from the combined effects of individual microorganisms, giving rise to emergent properties. Here, we exemplify the importance of microbial interaction for ecosystem processes by analysis of a reasonably well-understood microbial guild, namely, aerobic methane-oxidizing bacteria (MOB). We reviewed the literature which provided compelling evidence for the relevance of microbial interaction in modulating methane oxidation. Support for microbial associations within methane-fed communities is sought by a re-analysis of literature data derived from stable isotope probing studies of various complex environmental settings. Putative positive interactions between active MOB and other microbes were assessed by a correlation network-based analysis with datasets covering diverse environments where closely interacting members of a consortium can potentially alter the methane oxidation activity. Although, methanotrophy is used as a model system, the fundamentals of our postulations may be applicable to other microbial guilds mediating other biogeochemical processes. Natural microbial communities are characterized by complex networks of microbial populations forming intricate relationships of synergistic, antagonistic, and/or neutral nature. Accumulating evidence stresses the relevance of microbial interactions and their role in altering microbial mediated processes, referred here as community/ecosystem functioning , enabling the comparison and interpretation of networks built for different environments revealing (in) consistent associations of MOB with other microbes. We argue that incorporating mechanistic knowledge on biotic interactions in community functioning is a step forward in linking microbial diversity and abundance to ecosystem functioning, facilitating predictions of ecosystem functioning under disturbance.Interdependent relationships between microorganisms due to nutritional reliance between community members are well known  for the MOB may occur  where light penetrated to the anoxic zone, aerobic methane oxidation was fuelled by molecular oxygen produced in situ by photosynthetic algae organisms, and actively interact to form tight associations with their biotic environment. A mutually beneficial interaction occurs in ombrotrophic peatlands where MOB-Rhizobium sp.) are thought to provide MOB with essential nutrients  under oxygen limitation , the coupling of 13C–CH4 labeling to a network analysis provides a direct link through a shared substrate and cross-feeding between interacting microorganisms. Hence, while previous work provided direct evidence for interaction-induced modulation of methane oxidation in simplified ecosystems  were found to be associated to both MOB subgroups , we focused on the communities which appear to be specific to the gammaproteobacterial and alphaproteobacterial MOB at the order level where some members seemingly converged after incubation , whereas the non-MOB community associated with gammaproteobacterial MOB was more diverse with Pseudomonadales occurring in both sites. Although the accompanying non-MOB community differs, this trend was consistent in the sediment from the geothermal spring where Rhodospirillales was the only dominant order (>1% relative abundance) associated to Methylosinus  was rather site-specific and not consistent; habitat-overarching set of genera was associated with the MOB. Interestingly, in some study sites  and MOB in all sites, which is in accordance with a previous study where a high relative abundance  was found in a methane-enriched community. It is often hypothesized that the co-detection of methylotrophs and methanotrophs in SIP studies are caused by cross-feeding; the methylotrophs feed on the methanol derived from methane oxidation. While cross-feeding is likely a cause for the co-occurrence of methylotrophs and MOB, the detection of other active microorganisms associated to the different MOB subgroups within each site may not be a stochastic event, but supports the notion of a selection of specific accompanying community members , although an antagonistic interaction (nature of the interaction) may also occur . Biotic interactions can exert a direct and/or indirect effect, modulating process rates , and help predicting ecological interactions ; because functional traits among MOB vary  between microorganisms drives their co-occurrence , this “parameter” is not as well integrated in biogeochemical models designed to predict ecosystem functioning as well as processes (van de Leemput et al., In lieu of determining the growth response of all combinations of the co-cultures, the values were inferred using the predictive model (Stock et al., Disentangling biotic interaction from other environmental parameters altering process rates is challenging. Nevertheless, this challenge may be partly circumvented by experimental setups capitalizing on artificially assembled communities (De Roy et al., Accordingly, microbial interaction may become important under certain conditions Figure . For insAH, PB conceived the review and analysis. RA performed the analyses with input from AD, AH, and PB. AH wrote the initial manuscript. RA, AV, AD, ZJ, SK, FK, NB, and PB critically revised and approved the manuscript. All authors are accountable for all aspects of the work.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Plants undergo continuous exposure to various biotic and abiotic stresses in their natural environment. To survive under such conditions, plants exhibit stress tolerance or stress avoidance through acclimation and adaptation mechanisms that ultimately reestablish cellular and organismal homeostasis or reduce episodic shock effects. These abilities involve intricate and complex mechanisms of perception, transduction, and transmission of stress stimuli, allowing optimal response to environmental conditions. The perception of stimuli and their expansion in cells involves signaling molecules such as intracellular calcium and reactive oxygen species, which intensify the action of particular signaling pathways. To date, the molecular mechanisms that are involved in each stress have been revealed comparatively independently, and so our understanding of convergence points between biotic and abiotic stress signaling pathways remains rudimentary. However, recent studies have revealed several molecules as promising candidates for common players that are involved in crosstalk between stress signaling pathways.This special issue aimed to join original research and review articles related to understanding of plant responses to abiotic and biotic stress conditions, identifying novel players involved in plant responses to stress conditions, biotechnological strategies to increase plant tolerance to abiotic and biotic stresses, and understanding molecular interactions and crosstalks among different stress conditions. omic studies to understand the response of single cell types to environmental stresses in order to clearly depict the contribution of each cell type composing the sample in response to stress. Cellular complexity of entire organs masks cell-specific responses to environmental stresses and logically leads to the dilution of the molecular changes occurring in each cell type composing the tissue/organ/plant in response to the stress. Specifically, the authors highlight that combining one or two omic analyses to look at single cell system biology can provide more precise molecular characterization and more dynamic models of the interactions between the plant and its environment.M. Nourbakhsh-Rey and M. Libault in “Decipher the Molecular Response of Plant Single Cell Types to Environmental Stresses” explore Cerasus humilis Seedlings” describe the correlation between the activities of antioxidant enzymes and drought tolerance. By exploring drought-resistant and drought-susceptible C. humilis accessions, they compare the abilities of the contrasting genotypes to induce antioxidant defense under drought conditions. Their manuscript presents original data indicating that plants exhibiting a more efficient reactive oxygen species scavenging system in response to drought conditions have enhanced membrane protection, an ability that could be directly linked to their higher adaptation to drought.J. Ren et al. in “Drought Tolerance Is Correlated with the Activity of Antioxidant Enzymes in Kosteletzkya virginica under Salt Stress” employed RT-qPCR to select the most stable reference gene of the perennial halophytic plant K. virginica under salinity stresses. The stable reference gene selected in this study will be very helpful for revealing the gene expression profiles of K. virginica under salt stress, allowing a better understanding of the salt-resistant mechanisms in halophyte plants.X. Tang et al. in “Reference Gene Selection for qPCR Normalization ofY. Oono et al. in “Genome-Wide Transcriptome Analysis of Cadmium Stress in Rice” used RNAseq strategy to elucidate the molecular basis of the rice response to cadmium (Cd) stress, a widespread heavy metal pollutant that is highly toxic to living cells, negatively affecting nutrient uptake and homeostasis in plants. In this work, rice plants were hydroponically treated with low Cd concentrations, revealing novel Cd-responsive transporters by analyzing gene expression under different Cd concentrations. This study could help to develop novel strategies for improving tolerance to Cd exposure in rice and other cereal crops.J. S. Rohila et al. in “Leaf Proteome Analysis Reveals Prospective Drought and Heat Stress Response Mechanisms in Soybean” investigate the effect of drought, heat, and cooccurring drought and heat stresses in the leaf proteome of two contrasting soybean genotypes. The authors identified genes involved in photosynthesis that were differentially expressed during drought and heat stress conditions, suggesting that photosynthesis-related proteins could be affecting RuBisCO regulation, electron transport, and Calvin cycle during abiotic stress, which ultimately alter the carbon fixation in leaves. The authors discuss the role of heat shock-related proteins and ROS detoxification capacity via carbonic anhydrase as heat and drought tolerance mechanisms, respectively.J. M. Garcia-Mina et al. in “Involvement of Hormone- and ROS-Signaling Pathways in the Beneficial Action of Humic Substances on Plants Growing under Normal and Stressing Conditions” review our current knowledge about the mechanisms by which soil humus affects soil fertility. In particular, they discuss the relationships between two main signaling pathway families that are affected by humic substances within the plant: hormone- and ROS-mediated signaling pathways. The authors aim to integrate these events in a more comprehensive model and point out future research directions to unveil the complete mechanisms of regulation.γ-ECS1) in Latex Production in Hevea brasiliensis” isolated a γ-ECS gene from the rubber tree and investigated its function linked to thiol content in latex. To understand the relation between γ-ECS and thiols and to correlate these findings to latex flow, the authors conducted RT-qPCR analysis and found that the expression levels of Hbγ-ECS1 were induced by tapping and ethrel stimulation, and the expression was related to thiols content in the latex. When looking at long-term flowing latex, the gene was related to the duration of latex flow. This work may have important biotechnological applications, since rubber tree is a major commercial source of latex, which is used for rubber production.W. Fang et al. in “Cloning and Expression Analysis of One Gamma-Glutamylcysteine Synthetase Gene  on different essential plant metabolic activities, such as reactive oxygen species metabolism, Krebs cycle, pentose phosphate pathway, chlorophyll content, and terpene emission. They found that not only are most of these pathways indeed modified by HF-EMF exposure, but also radiation brings about alterations in gene expression and plant growth. The authors propose to consider nonionizing HF-EMF radiation as a noninjurious, albeit influential environmental factor that induces significant changes in plant metabolism.


Selenium (Se) at very low doses has crucial functions in humans and animals. Since plants represent the main dietary source of this element, Se-containing crops may be used as a means to deliver Se to consumers (biofortification). Several strategies have been exploited to increase plant Se content. Selenium assimilation in plants affects both sulfur (S) and nitrogen (N) metabolic pathways, which is why recent research has also focused on the effect of Se fertilization on the production of S- and N- secondary metabolites with putative health benefits. In this review we discuss the function of Se in plant and human nutrition and the progress in the genetic engineering of Se metabolism to increase the levels and bioavailability of this element in food crops. Particular attention is paid to Se biofortification and the synthesis of compounds with beneficial effects on health. Selenium is an essential trace element for humans and animals, and some organic forms like methyl-selenocysteine (MeSeCys) appear to be particularly effective sources of dietary Se. Selenium is incorporated as selenocysteine (SeCys) at the active site of a wide range of selenoproteins involved in major metabolic pathways, such as thyroid hormone metabolism, antioxidant defense and immune function . Low intWhile there is no proof of essentiality for Se in plants , Se is r–1 soil, may vary over 100-fold between plant species , a key enzyme for selenate-to-selenite transition, resulted in enhanced selenate reduction: the transgenic APS plants accumulated organic Se (likely methyl-SeCys) when supplied with selenate, while wildtype controls accumulated selenate , which function in plant defense against insects and herbivores Figure . The hydBecause S nutrition is strictly associated with N metabolism, Se can exert an additional effect on the synthesis of proteins and amino acids, as well as on N-secondary compounds with free radical scavenging activities, like phenolics Figure . Amino aSolanum lycopersicon L.) plants and Brassica species in particular, contain high levels of phenolic compounds. Additionally, Brassica spp. are rich in glucosinolates (GLSs).Several studies examined how Se enrichment of plants affects their content in these phytochemicals . Tomato Brassica oleracea L.), Se fertilization was shown to reduce the amount of total phenolic acids, without altering the profile distribution of specific compounds  in Se-deficient areas. Finally, since different plant species appear to be able to influence their neighboring plants’ Se accumulation and perhaps speciation , it willThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Recent successful endovascular stroke trials have provided unequivocal support for these therapies in selected patients with large-vessel occlusive acute ischemic stroke. In this piece, we briefly review these trials and their utilization of advanced neuroimaging techniques that played a pivotal role in their success through targeted patient selection. In this context, the unique challenges and opportunity for advancement in current stroke networks’ routine delivery of care created by these trials are discussed and recommendations to change current national stroke system guidelines are proposed. Recent clinical trials have endorsed a variety of advanced neuroimaging approaches to reiterate the now unequivocal superiority of combined thrombolytic and endovascular therapy for improving outcomes in acute ischemic stroke (AIS) patients with large-vessel occlusion (LVO). Heralding a new era, this momentous advance in treatment has, on the one hand, created a novel challenge to current routine clinical practice and, on the other, a tremendous opportunity to modernize current stroke systems of care: the necessary and inevitable incorporation of advanced imaging techniques into acute stroke. Such integration and utilization, as these trials have demonstrated, holds the key for stroke care providers to save more brain and more stroke patients.a priori determined favorable perfusion/ischemic mismatch profile within the affected vascular territory , Trial and Cost Effectiveness Evaluation of Intra-arterial Thrombectomy in Acute Ischemic Stroke (THRACE), and Assess the Penumbra System in the Treatment of Acute Stroke (THERAPY) all required imaging evidence of LVO for enrollment –3. Even erritory . Endovaserritory , 6. Simierritory , 8.As a consequence of these trials’ requisite inclusion of vascular imaging, their image profiles reflected a more comprehensive, informative assessment of acute stroke than those obtained in routine clinical practice: one not only of tissue status but also of vascular status. More importantly, because these trials enrolled patients with LVO across a wide range of clinical scenarios, their results demonstrated that acute stroke imaging profiles enhanced with vascular status invaluably expanded eligibility for and established treatment of LVO-AIS in its diverse array of clinical impairment beyond what routine practice has offered.3), a region of hypoperfusion, and a vascular occlusion were required for entry, demonstrated a high-revascularization rate  , it now Current stroke systems of care predominantly implement a hub-and-spoke model that links multiple primary stroke centers (PSCs) with a comprehensive stroke center (CSC) . This moConsequently, these requirements already provide challenge to current consensus positions on early management of LVO-AIS. The 2013 AHA/ASA Guidelines for the Early Management of Patients with AIS include the following recommendations: intracranial vascular imaging when endovascular therapy is considered  and perfusion-based methods for reperfusion therapies when event duration exceeds thrombolytic eligibility windows  . This cha priori bypassing of centers without access to vascular imaging and/or additional transfer to those with it leading to the disuse of certain centers and an overburdening on and stressing of a network’s remaining available sites, services, and resources to accommodate this need.Without updating this requirement for PSC designation, the current framework within which stroke care is delivered faces significant challenges. For one, currently designated PSCs without at least vascular imaging capability and vascular neurology expertise available for its interpretation run the grave risk of becoming obsolete. Although these sites can administer thrombolytic therapy and clinically infer presence of LVO, without vascular imaging and its expert evaluation, they can no longer provide a definitive, complete assessment of acute stroke rendering them ineffective within an acute stroke system of care. In fact, a recent analysis of over 11,000 patients in the SITS-International Stroke Thrombolysis Register demonstrated that an NIHSS of 11 was moderately predictive of LVO, though the sensitivity of this measure was only 64.5% , in lineWith these concepts in mind, we suggest that PSC certification (or re-certification) mandate the following new key elements: (1) immediate availability of vascular imaging with either contrast-enhanced CT angiography or time of flight magnetic resonance angiography for all patients presenting with acute stroke; (2) immediate availability of vascular neurology expertise via in-person or telemedicine for clinical and radiologic evaluation of acute stroke; and (3) in-place protocols within acute stroke networks of care for rapid identification, stabilization, and transfer of LVO-AIS patients to CSCs or facilities of equivalence in care.The colossal efforts to advance acute stroke care have yielded a tremendous opportunity that should not be forsaken. More imaging, incorporating non-invasive angiography and multimodal CT or MRI, beyond the current standard of non-contrast CT at PSCs will facilitate triage of stroke patients for current state-of-the-art therapies to save more brain and to extend this opportunity to more patients at greatest risk of long-term disability. Such modernization of stroke systems of care through incorporation of advanced imaging methods and their timely interpretation in clinical context is not just an opportunity, but an inevitable next step that recent trial success has galvanized with a clear message: we must image more to save more.AT – conceived of, principally wrote, and revised the manuscript. JH – conceived of, principally wrote, and revised the manuscript. KN – intellectual contribution through drafting or revising the manuscript for intellectual content. MC-A – intellectual contribution through drafting or revising the manuscript for intellectual content. RM – intellectual contribution through drafting or revising the manuscript for intellectual content. FC – analyzed data. DL – conceived of, principally wrote, and revised the manuscript.Neurocritical and Neurohospitalist Care, a section of the journal Frontiers in Neurology. Dr. Jason D. Hinman reports the following disclosures: He serves as an editorial board member of Journal of Neurological Disorders and Neurocritical and Neurohospitalist Care, a section of the journal Frontiers in Neurology; and is supported by NIH grant #NS083740. Dr. Kwan L. Ng reports the following disclosures: He is supported by the American Heart Association grant #14BFSC17760005 ASA-Bugher Stroke Center. Dr. Mateo Calderon-Arnulphi, Dr. Royya Modir and Ms. Fiona Chatfield report no disclosures. Dr. David S. Liebeskind reports the following disclosures: He is a paid consultant for Stryker and Covidien, and is supported by NIH grant #K24NS072272.Dr. Aaron P. Tansy reports the following disclosures: He serves as an editorial board member of


In this review we introduce the concept of the tumor macroenvironment and explore it in the context of metabolism. Tumor cells interact with the tumor microenvironment including immune cells. Blood and lymph vessels are the critical components that deliver nutrients to the tumor and also connect the tumor to the macroenvironment. Several factors are then released from the tumor itself but potentially also from the tumor microenvironment, influencing the metabolism of distant tissues and organs. Amino acids, and distinct lipid and lipoprotein species can be essential for further tumor growth. The role of glucose in tumor metabolism has been studied extensively. Cancer-associated cachexia is the most important tumor-associated systemic syndrome and not only affects the quality of life of patients with various malignancies but is estimated to be the cause of death in 15%–20% of all cancer patients. On the other hand, systemic metabolic diseases such as obesity and diabetes are known to influence tumor development. Furthermore, the clinical implications of the tumor macroenvironment are explored in the context of the patient’s outcome with special consideration for pediatric tumors. Finally, ways to target the tumor macroenvironment that will provide new approaches for therapeutic concepts are described. Complications of a malignant tumor can be either (1) local due to direct effects of the primary tumor or metastatic lesions on the surrounding tissues, or (2) systemic. Tumors may cause systemic effects by releasing soluble factors into blood or lymph vesselsWith recent advances in cancer therapy, patients live longer and, therefore, it is of utmost importance to improve the quality of life during this time. In this context, addressing systemic complications as a target for intensive research and development of treatment options is imperative. This review aims to introduce the concept of tumor macroenvironment, explore it in the context of the tumor microenvironment, and discuss the clinical and therapeutic implications of this concept.Before discussing a definition of the tumor macroenvironment, we will briefly explore the cellular elements of the tumor microenvironment and consider their local and systemic interactions.As early as 1863 Rudolf Virchow observed that tumor tissues are infiltrated by immune cells; he was also the first to hypothesize a direct link between inflammation and cancer.The local effect of cytokines released into the tumor microenvironment has been reviewed extensively.Unlike in normal tissue, cellular proliferation in tumors is an uncontrolled process. During the early stages of tumorigenesis, two main signaling types dominate in the tumor microenvironment to support tumor cell proliferation. The first type of signaling increasing proliferation constitutes autocrine stimulation among tumor cells themselves. Tumor cells may release growth factor ligands that bind to receptors on the surface of tumor cells, thereby stimulating proliferation.To survive in this hostile environment, tumor cells deregulate their intrinsic metabolic machinery and, via paracrine signaling, remodel the tumor microenvironment to activate tumor-associated angiogenesis. Though tumor cells are master regulators of the tumor microenvironment, each type of cell in this environment may interact with other neighboring cells.14C-glycine decreased in normal tissues during the rapid growth phase of Flexner-Jobling carcinoma. Conversely, total radioactivity in tumors increased both in fasted and fed animals, indicating that tumors do not lose protein content during starvation, forming a “one-way passage”.Increased whole-body protein turnover is often associated with tumor growth. This has been well documented in cachecticOn the cellular level, protein and amino acid metabolism is also deregulated in cancer cells. In contrast to decreased protein synthesis in muscle cells, tumor cells exhibit increased protein synthesis.In line with the experimental observations mentioned above showing that amino acids are important building blocks for tumors, several reports demonstrate that tumors directly influence plasma free amino acid (PFAA) profiles. Threonine, serine, and glycine are significantly reduced in the serum of lung cancer patients. PFAA are tumor type–specific, as there was no decrease in these three FAA in breast cancer patients.14C-glycine,Taken together, the experimental findings from in vitro and in vivo studies using Dysregulated lipid metabolism is a hallmark of cancer. Lipids serve as the structural and functional domains on the scaffold of proteins, as fat depots, and as signaling molecules. Functions of lipids are critical in malignant tumors as they are necessary not only for providing the membrane constituents of proliferating cells but also for energetic, biophysical, and signaling pathways that drive tumorigenesis.In 1953 Medes et al found that cancer tissues are able to synthesize lipids de novo, in particular enormous amounts of FA and phospholipids. They also demonstrated that the amount of lipid synthesis in cancer tissue is comparable to that in liver.Since the pivotal observation of the important role of fatty acid synthase in cancer cell growth,De novo lipogenesis is considered to be the primary source of FA available for lipid synthesis in cancer cells. However, cancer cells do not solely rely on de novo lipogenesis but also use exogenous FA for membrane synthesis and for the synthesis of oncogenic signalling lipids such as ceramide-1-phosphate (C1P), platelet-activating factor (PAF), diacylglycerol (DAG), and lysophosphatidic acid (LPA).Breast cancer has been shown to be associated with increased plasma FFA concentrations. Linoleic acid does not only induce PAI-1 (a prognostic marker for breast cancer) secretion through SMAD4 (similar to mothers against decapentaplegic-4) but also enhances the migratory potential of the highly invasive MDA-MA-468 breast cancer cell line.Since lipids play a substantial role in maintaining cellular integrity, it is not surprising that altered lipoprotein patterns also have been associated with malignancies. Patients suffering from various types of hematological neoplasia exhibit significantly lower plasma cholesterol, high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C) levels and higher triglyceride (TG) concentrations than body mass index (BMI)-matched healthy controls.In general, low plasma LDL-C levels are robustly correlated with cancer. Surprisingly, however, genetically decreased LDL-C in patients with three polymorphic genotypes—proprotein convertase subtilisin/kexin (PCSK) type 9, ATP-binding cassette sub-family G (ABCG) member 8, and apolipoprotein (APO)E—was not seen.Cancer-associated cachexia (CAC) is a multi-factorial syndrome characterized by progressive loss of skeletal muscle mass with or without loss of fat mass that cannot be reversed by conventional nutritional support.2-glycoprotein [ZAG]); and (2) factors released by the host as a response ,Clinically, cachexia should be suspected if an involuntary weight loss of>5% of the premorbid weight occurs within a 6-month period. While anorexia also may occur concomitantly, the drop in caloric intake alone does not explain the body composition changes seen in cachexia. Moreover, cachexia may progress even in the absence of anorexia.Many lines of investigations prove beyond a reasonable doubt that a multifactorial in situ network of inflammation governs various intricate signaling processes that advance tumor development and progression. In addition to microenvironmental effects, inflammatory responses in the macroenvironment are associated with increased levels of inflammatory mediators The mechanistic interaction between systemic inflammation and tumor development in patients has not yet been fully elucidated. There is, however, increasing experimental evidence for a causal relationship between systemic inflammation and features of CAC. In experimental CAC models, administration of many of the cytokines listed above led to anorexia, weight loss, acute-phase protein response, protein and fat breakdown, and increased levels of cortisol and glucagon, as well as decreased insulin levels, insulin resistance, anemia, fever, and elevated energy expenditure.Loss of adipose tissue is one of the hallmarks of CAC. A remarkable decrease in size of adipocytes was observed in cachectic miceAdipose tissue is a potent source of energy, constituting about 90% of adult fuel reserves. Instead of being viewed as a passive calorie reservoir, it is now recognized as a highly active metabolic as well as endocrine organ profoundly impacting on the host energy metabolism via adipokines.2+-dependent mechanism, and the ATP-ubiquitin–dependent proteolytic pathway (UPP). The latter is considered to be preferentially activated.Cachexia-related muscle wasting results from a disturbance of the tightly regulated balance of muscle protein breakdown and synthesis.Cytokines such as those mentioned above induce systemic inflammation. Indeed, insulin resistance and sensitivity to systemic inflammation were observed in patients with various types of tumors and were associated with CAC.Besides protein breakdown, a reduction in the rate of muscle protein synthesis in weight-losing cancer patients also has been described in cancer patients. In some cases, muscle protein synthesis decreased dramatically compared with healthy controls, whereas whole body rates of protein synthesis and degradation do not differ significantly.Human obesity is a complex disease resulting from a combination of elevated caloric intake and a relative lack of physical activity. Hippocrates was the first one to note the relation between obesity and reduced life expectancy. In one of his medical works he stated that “Sudden death is more common in those who are naturally fat than in the lean”. Various studies have provided ample evidence that obesity is risk factor linked with chronic illnesses, and is not only restricted to diabetes, heart diseases, dyslipidemia, inflammatory diseases, and hypertension. In 2003, a landmark study was performed by the American Cancer Society analyzing the influence of excess body weight on the risk of cancer-related deaths in a large population of 900,000 American adults. The prospective investigation showed that men and women with a BMI of at least 40.0 had a death rate from all cancers combined of 52%, which was 88% higher than their normal-weight counterparts.The basic mechanism(s) linking obesity to tumor-initiating events remain largely elusive. Two main mechanistic connections have been suggested that may causally link obesity and increased fat mass with cancer progression: (1) altered signaling events, and (2) changes in the local and systemic levels of adipocyte-derived factors. This altered physiological state may induce an enhanced mitogeneic effect shaping the tumor microenvironment through autocrine and paracrine signaling combined with infiltration of immune cells and inflammation.Epidemiological data suggest that there is an association between the incidence of a wide variety of malignancies and diabetes. A causative relationship has not been proven so far, but biological mechanisms that support this theory have been found. However, it has to be kept in mind that diabetes and malignant tumors have common risk factors.A meta-analysis of case-control and cohort studies indicated an association of diabetes mellitus with an increased risk for colon cancer in both men and women, whereas rectal cancer showed this association only in male patients. Analysis of the seven studies that controlled for known confounders such as smoking or obesity still showed this association, which was also independent of physical activity.In a meta-analysis of 36 studies stratified by study design, diabetes mellitus was associated with a higher incidence of bladder cancer in case-control and cohort studies with an even higher risk within the first 5 years.The association of diabetes mellitus and malignancies of the gastrointestinal tract also has been investigated in a large number of studies. In a cohort study of 929 diabetic patients and 1,126 controls, a 2.75-fold increase of gastrointestinal malignancies, including gastric, hepatic, colon, and pancreatic cancers, was demonstrated.The mechanisms leading to this increased risk of malignant tumors in the diabetic population have been investigated and a number of genetic pathways have been implicated in this process. Hyperglycemia itself, however, also interacts with tumor cells. High glucose levels have a direct effect on cancer cells leading to increased proliferation, inducing mutations of various genes, augmenting invasion and migration, and resetting signaling pathways in tumor cells.In contrast to the large number of studies described above, diabetes appears to have an opposite effect on the pathogenesis of prostate cancer. In a prospective cohort study, a diabetic metabolic state was associated with a risk reduction of 25% of prostate cancer.Until now, cancer-staging systems and prognostic stratification tools for patients exclusively rely on tumor-related clinical or histopathological factors. Tumor size, number, and location of metastatic lesions, tumor grading, or other histomorphological features like vascular invasion or tumor necrosis provide the basis for individual risk assessment in daily clinical routine.Basic principles of adulthood cancer do not necessarily apply to solid pediatric tumors such as hepatoblastoma (HB), the most common liver tumor in infancy, or neuroblastoma (NB), the most common extracranial solid tumor in children. These entities are of embryological origin, and have distinct genetic alterations, unique growth patterns, and specific prognoses. NB may have different genetic clones within one individual lesion and either may progress to a chemotherapy-resistant malignancy or mature to a “benign” ganglioneuroma. Consequently, it must be assumed that environmental factors influencing each specific lesion could be distinctly different from adulthood cancer. This section elucidates current knowledge about the macro- and microenvironment in children with solid pediatric tumors and focuses on major principles and potential therapeutic strategies for pediatric oncology in the future.As early as 1930 Warburg described the dependence of tumors cells on glycolysis even in the presence of adequate oxygen supply (“aerobic glycolysis”). Today we understand that this disproportional metabolism of glucose into lactateUsing neuroblastoma cells (SH-SY5Y and SK-N-BE) Navratilova et al demonstrated that tetrathiomolybdate (TMD), a drug that exhibits anti-angiogenic and tumor-suppressing effects increased glucose uptake, production of lactate, and activation of Akt and AMPK signaling pathways as angiogenic “escape strategies” of NB cells under low glucose conditions.CAC represents a hypercatabolic syndrome characterized by depletion of adipose and protein tissues.Tumor cells can manage to escape the anti-tumor immune responses. Revealing the underlying mechanisms for solid pediatric tumors could foster development of tumor-specific and immunologic anti-cancer therapies. The tumor microenvironment certainly plays a central role in this context as it presents the “stage” for the interaction between proliferating tumor cells, tumor stroma on the one hand and blood vessels supplying soluble anti-cancer factors or inflammatory cells on the other hand.For NB, Pistoia et alThe fate of tumor cells reaching distant organs depends on local factors within the “new” microenvironment. Such tissue-derived factors can influence the viability, proliferation, cell adhesion and motility, chemotaxis, or apoptosis.In the previous sections we delineated various tumor-induced effects on the macroenvironment, such as tumor-induced systemic inflammation, that potentially modulate metabolism and induce cachexia. Therapeutic efforts to block the actions of, for example, macrophage-secreted substances, may slow the progression of tumor effects on the macroenvironment such as cachexia. Anti-inflammatory compounds, such as cyclo-oxygenase 2 inhibitors, appear to be efficacious in the reduction of cachexia in animals,Dietary modification such as caloric restriction has been shown to decrease tumor initiation and progression in model systems of cancer. In breast tumor-bearing mice, it induced metabolic and signaling changes that affect stroma and tumor cells, resulting in reduction of tumor proliferation and consequent metastases.HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase is the rate-limiting enzyme in the biosynthesis of isoprenoid compounds, including cholesterol, dolichol, and ubiquinone.This review is intended to provide convincing arguments for the tumor macroenvironment concept since we believe it to be very useful to explore the effects tumors exert on the entire complex organism. The multiple interfaces between tumor cells, tumor stroma, including vasculature and immune cells, and the surrounding tissue and organs are a fascinating environment to study the interplay of the various components. This will help to understand the biology and the properties of malignant tumors much better and will undoubtedly support the establishment of new therapy and prevention concepts.