To investigate the temporal ordering of cognitive and functional declines separately in older adults with or without Alzheimer’s disease (AD).A community-based longitudinal study of aging and dementia in Northern Manhattan (Washington Heights/Hamilton Heights Inwood Columbia Aging Project) and a multicenter, clinic-based longitudinal study of prevalent AD at Columbia University Medical Center, Johns Hopkins School of Medicine, Massachusetts General Hospital, and the Hôpital de la Salpêtrière in Paris, France (the Predictors Study).3,443 initially non-demented older adults  and 517 patients with AD.Cognitive measures included the modified Mini-Mental State Exam and composite scores of memory and language derived from a standardized neuropsychological battery. Function was measured with the Blessed Dementia Rating Scale, completed by the participant (in the sample of non-demented older adults) or an informant . Data were analyzed with autoregressive cross-lagged panel analysis.Cognitive scores more consistently predicted subsequent functional abilities than vice versa in non-demented older adults, participants with eventual incident dementia, and patients with prevalent AD.Cognitive declines appear to precede and cause functional declines prior to and following dementia diagnosis. Standardized neuropsychological tests are valid predictors of later functional changes in both non-demented and demented older adults. Empirical investigation into the temporal ordering of Alzheimer’s disease (AD) signs has largely focused on cerebrospinal fluid and structural magnetic resonance imaging biomarkers ,2. BehavMany investigators have assumed that cognitive changes precede functional changes prior to AD diagnosis . Indeed,There have been few direct investigations of the temporal ordering of cognitive and functional declines prior to AD. Amieva and colleagues reported descriptively that declines in semantic memory and conceptual formation appeared to precede declines in activities of daily living in a sample of 350 AD converters . In contfollowing AD diagnosis has largely been ignored. We recently demonstrated strong coupling of cognitive and functional declines both between and within patients diagnosed with probable AD [The temporal ordering of cognitive and functional declines bable AD . HoweverThe purpose of this study was to investigate the temporal ordering of cognitive and functional declines separately in older adults with or without AD. In both samples, cognition was measured with neuropsychological tests, and function was measured using a self-report questionnaire completed by either the individual (in the sample of non-demented older adults) or an informant (in the sample of AD patients). We used autoregressive cross-lagged panel analysis to compare the predictive abilities of the cognitive variables for function versus functional variables for cognition. This approach allows for an exploration of reciprocal causality between cognition and function.Data from two longitudinal studies were used in the present analyses. A sample of initially non-demented older adults was drawn from the Washington Heights/Hamilton Heights Inwood Columbia Aging Project (WHICAP) ,14. A saThe local Institutional Review Board (IRB) at Columbia University approved the WHICAP study. Written informed consent was obtained from all WHICAP participants. Local IRB at all participating sites approved The Predictors Study. Written informed consent was obtained directly from patients at study entry. Patient assent was documented at each subsequent visit in accordance with IRB requirements.WHICAP is a prospective, community-based study of aging and dementia in a racially and ethnically diverse sample of Medicare-eligible residents of Northern Manhattan. Participants were identified from Medicare records and recruited in two waves: 1992  and 1999 . Ongoing follow-up occurs at 18-24 month intervals and includes a battery of cognitive, functional, and health measures administered in the participant’s preferred language (English or Spanish). We have previously demonstrated acceptable measurement and structural invariance of our neuropsychological battery across English and Spanish speakers .Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria [The current sample included 3,443 participants who did not meet criteria for dementia at their initial study visit. Dementia was determined by a consensus of a group of neurologists and neuropsychologists using criteria . To maxiCognition was evaluated with tests of episodic memory and language. Episodic memory was chosen due to its central role in dementia progression. Language was chosen based on evidence that verbal fluency and verbal abstraction evidence the earliest declines prior to dementia diagnosis . Tests wThe episodic memory domain included measures from the Selective Reminding Test (SRT) . ParticiThe language domain included measures of naming, verbal fluency, verbal abstraction, repetition, and comprehension. Naming ability was quantified as the number of spontaneously-identified objects on a 15-item version of the Boston Naming Test . Verbal Functional abilities were assessed with items from the Blessed Dementia Rating Scale (BDRS) . In WHICIn line with prior work with this dataset, models controlled for age, sex, race, ethnicity, education, recruitment year, and illness burden. Race and ethnicity were determined via self-report using the format of the 2000 US Census. To quantify illness burden at each occasion, one point was assigned for the presence of each of the following conditions: heart disease, hypertension, stroke, diabetes, pulmonary disease, thyroid disease, liver disease, renal insufficiency, peptic ulcer disease, peripheral vascular disease, cancer, Parkinson’s disease, Essential Tremor, Multiple Sclerosis, and arthritis. These points were summed to create an index of illness burden at each occasion.The current sample included 517 patients with probable AD recruited in two waves beginning in 1989 (N=252) or 1998 (N=265) from clinics at four sites: Columbia University Medical Center (N=208), Johns Hopkins School of Medicine (N=147), Massachusetts General Hospital (N=124), and the Hôpital de la Salpêtrière in Paris, France (N=38). Diagnoses of probable AD were made using NINCDS-ADRDA criteria  at conseCognition was measured using the Modified Mini Mental State Exam (mMMS) . In addiFunctional abilities were assessed with items from the BDRS . In The In line with prior work with this dataset, the Predictors model controlled for age, sex, education, and recruitment site. In a subset of 265 participants recruited in 1998, data were available to quantify illness burden at each occasion. Specifically, one point was assigned for the presence of each of the following conditions: hypertension, diabetes, myocardial infarction, congestive heart failure, valvular heart disease, angina, atrial fibrillation, other cardiac arrhythmia, hypercholesterolemia, hypertriglyceridemia, epilepsy, head trauma with loss of consciousness, pulmonary disease, thyroid disease, chronic liver disease, chronic renal disease, systemic malignancy, autoimmune disorder, and syphilis. These points were summed to create an index of illness burden at each occasion.Descriptive statistics were computed in SPSS version 19 . Bivariate autoregressive cross-lagged panel analyses were conducted in Mplus version 7  using maximum likelihood estimation. Missing data were managed with full information maximum likelihood (FIML), which uses all available data for parameter estimation.In the cross-lagged models, each variable at each occasion was regressed onto the same variable at the previous occasion (autoregressive paths) as well as the other variable of interest at the previous occasion (cross-lagged paths). In addition, occasion-specific correlations between the two variables of interest were estimated. A schematic of the general model is shown in In the current study, three cross-lagged models were estimated. The first two examined relationships between function and one of the two cognitive abilities in WHICAP  over an average of five years. In addition, these models were re-run on the subset of 612 individuals who converted to dementia during the study period in order to more specifically examine temporal ordering prior to confirmed dementia onset. The third model examined the relationship between function and global cognitive status in The Predictors Study over 5.5 years. In the subset of 265 participants recruited in 1998, a supplementary model was run in which a time-varying covariate reflecting illness burden was added to the model to confirm that results were not dramatically altered by the consideration of comorbid health conditions. Due to this smaller sample size used in this analysis, only 2.5 years of data were evaluated. Model fit was evaluated with the root mean square error of approximation (RMSEA<0.08), standardized root mean square residual (SRMR<0.05), and the comparative fit index (CFI>.95).r=-0.32; all p’s<.001) and language  scores at all four visits. Autoregressive and cross-lagged paths in the two models are shown in Memory  and language  models fit well. After controlling for covariates, better functional ability was associated with higher concomitant memory . At the first visit, the association between function and memory was not significant . Better functional ability was also associated with higher language scores at the all four visits . With regard to cross-lagged paths, memory and language scores predicted subsequent functional ability at follow-up visits 3  and 4 . In contrast, functional ability did not predict subsequent memory or language scores at any of the follow-up visits .In the restricted sample of incident dementia cases, memory  and language  models fit well. After controlling covariates, better functional ability was associated with higher memory scores at visits 2 through 4 . With regard to the autoregressive paths, previous functional ability predicted subsequent functional ability at each visit . Similarly, previous global cognitive status predicted subsequent global cognitive status at each visit . Cross-lagged paths are shown in The model fit well . At all twelve occasions, better functional ability was associated with higher global cognitive status . With regard to the autoregressive paths, previous functional ability predicted subsequent functional ability at each visit . Similarly, previous global cognitive status predicted subsequent global cognitive status at each visit . With regard to cross-lagged paths, global cognitive status predicted functional ability at each subsequent visit . In contrast, functional ability only predicted global cognitive status at the second visit . Standardized regression coefficients were larger for the prediction of functional ability by cognition at each visit.A supplementary model was run in the subset of 265 participants recruited in 1998 adding a time-varying covariate reflecting illness burden. This model fit well . Better functional ability was associated with higher global cognitive status at the first five occasions . Among non-demented older adults, composites scores of memory or language reliably predicted self-reported functional ability at every subsequent visit, whereas self-reported functional ability only predicted subsequent cognitive scores two-thirds of the time. In addition, standardized regression coefficients were larger for the prediction of functional ability by cognitive domain. Restricting the sample to incident dementia cases, cognitive score predicted subsequent functional ability at two of the three follow-up visits, while functional scores did not predict subsequent cognitive scores at any visit. Among patients with prevalent AD, cognitive score predicted informant-rated functional ability at each subsequent visit, whereas functional ability only predicted subsequent cognition at three out of 11 follow-up visits. Further, the magnitude of association between cognitive score and subsequent functional ability was larger than that between functional score and subsequent cognition for every visit. These findings were independent of chronic illness burden and are most consistent with the view that cognitive declines precede functional declines.These results validate the use of neuropsychological tests for functional prognosis among older adults with and without AD. It is notable that a previous study reporting poor prognostic ability of neuropsychological tests did not examine cognitive abilities assessed in the present study: word list learning, basic language ability, and verbal abstraction . TogetheResults provide minimal evidence for reciprocal causality between cognition and function and clarify our earlier demonstration of tight coupling of cognitive and functional declines over the course of AD by showing that decrements in the ability to perform tasks of daily living temporally follow and are predicted by decrements in cognition . Thus, iImportantly, our finding that cognitive declines preceded functional declines in the sample of initially non-demented older adults was replicated, and even more pronounced, in the subset of participants who went on to develop dementia. The interaction between cognitive and functional decline appears to begin prior to formal dementia diagnosis. It has been suggested that the Clinical Dementia Rating (CDR), a comprehensive clinical interview focusing on real-world functioning, is sufficient to diagnose dementia prior to the inflection point of cognitive decline . HoweverThere were minimal differences in the observed temporal associations in the two populations studied . In the initially non-demented sample, associations between cognition and subsequent function were somewhat stronger for later time points, perhaps because these variables became more coupled as cognitive and functional abilities declined. Indeed, the magnitudes of association between the cognitive variables and subsequent functioning at these later time points were similar to those seen between global cognitive status and subsequent functioning in the prevalent AD sample.predicted functional scores at subsequent visits. While the magnitudes of the associations between cognition and subsequent function were similar at later visits, language scores at the initial study visit appeared to be a stronger predictor of functioning at the second visit than memory scores. These results may be consistent with those of Amieva et al. (2008), who reported that verbal fluency and verbal abstraction, both of which were included in our language composite, were the first tests to evidence declines prior to AD conversion in their French sample. Alternatively, function could have been more sensitive to declines in language than memory if both domains declined similarly in the present study.Amieva and colleagues 2008) have descriptively shown that declines in cognitive performance appear to precede declines in activities of daily living prior to AD diagnosis [ have desA main strength of this study is its large numbers of older adults both prior to and following dementia onset. Another strength is the use of panel analysis, which allowed for a direct examination of the temporal ordering of cognitive and functional changes. While cognitive scores were limited to a single measure of global cognitive status in the AD sample, we were able to replicate our results with composite scores of memory and language tests in the sample of initially non-demented older adults. A limitation of analyses on the WHICAP sample was the lack of an informant-based measure of function, as the presence of a reliable informant was not an inclusion criterion for this community-based study. It should be noted that the same pattern of results  was found in the Predictors sample, in which function was measured via informant report.In conclusion, the present study supports the view that cognitive declines precede and cause functional declines in late life. In addition, standardized neuropsychological tests represent a useful marker of functional prognosis during all stages of dementia. While the current study cannot address the temporal ordering of biomarkers as described by Jack et al. 2010, 2013) [0, 2013 [


Initiating neoplastic cell transformation events are of paramount importance for the comprehension of regeneration and vanguard oncogenic processes but are difficult to characterize and frequently clinically overlooked. In epithelia, pre-neoplastic transformation stages are often distinguished by the appearance of phenotypic features of another differentiated tissue, termed metaplasia. In haemato/lymphopoietic malignancies, cell lineage ambiguity is increasingly recorded. Both, metaplasia and biphenotypic leukaemia/lymphoma represent examples of dysregulated cell differentiation that reflect a history of trans-differentiation and/or epigenetic reprogramming. Here we compare the similarity between molecular events of experimental cell trans-differentiation as an emerging therapeutic concept, with lineage confusion, as in metaplasia and dysplasia forecasting tumour development. Observations of trans-differentiation in tissue culture were initially regarded merely as the result of artificial manipulation, with no physiological correspondence. Meanwhile, reprogramming cell differentiation has advanced as a promising option for future therapeutic approaches. Reprogramming experiments have shown that a few transcription factors may instruct alternative cell differentiation outcomes, yet many of the same factors are often activated in neoplastic tissue that may give rise to cancer. How incoherent cell differentiation states emerge in pre-neoplastic tissue and how they contribute to tumourigenesis is still far from being understood. Clinical observations of epithelial metaplasia and haematopoietic ‘lineage infidelity’ and ‘lineage promiscuity’ are renowned phenomena and biphenotypic leukaemia/lymphoma echo the remarkable data set collected in the past years on experimental cell reprogramming. Here, we review the possibility that in neoplastic transformation aberrantly regulated transcription factors mediate de-/and trans-differentiation steps that may confer selective advantages to the evolving cancer cell. The possibility is discussed that multi-lineage phenotypes and epithelial metaplasia are disease-relevant physiological counterparts of experimental reprogramming.Previously scorned as tissue culture artefact, the concept of cellular reprogramming meanwhile struggled its way to mainstream scientific acceptance. The field of cell reprogramming entails the potential to revolutionize pharmacological screening approaches and feeds hopes for development of new cell based therapies for degenerative diseases. In a breakthrough experiment, genes coding for four transcription factors  were ectopically expressed in normal fibroblasts, granting them properties very similar to embryonic stem cells (Takahashi & Yamanaka, With the emerging concept of lineage-specifying transcription factors, the question arose of what would be the outcome of inappropriate activation or inactivation of ‘lineage-specific’ transcription factors. The results of many experiments clearly showed that lineage committed precursors were more flexible than initially anticipated, and in several cases gave rise to alternative cell types. Studies with GATA1 for instance, showed that ectopic expression in myeloid progenitors or common lymphoid progenitors redirected their development into the megakaryocytic/erythroid lineages (Iwasaki et al, A remarkable reprogramming and trans-differentiation potential was discovered for C/EBP transcription factors . Early sin vitro originating insulin producing islet cells. Exocrine pancreatic cells, as well as keratinocytes, fibroblasts and hepatocytes were found to be reprogrammable into insulin producing cells by transcription factors including Pdx1, MafA and Ngn3 (Aviv et al, Beyond pure academic interest, recent developments have now fuelled hope of direct reprogramming of one cell type into another lineage as an alternative and circumventing the induced pluripotent state. Direct reprogramming might provide the quintessential therapeutic answer to some of the most afflicting illnesses of our time (Robinton & Daley, Despite all promises of experimental reprogramming, scanning the literature for physiological naturally occurring equivalents of cell fate plasticity reveals a much darker side of the concept. One where transforming cells in cancer development may profit from lineage confusion by aberrantly expressed transcription factors, promoting tumourigenesis. Examples of this are found in leukaemia and in epithelial trans-differentiation, or metaplasia.Some 2–5% of aggressive types of leukaemia and lymphoma are characterized by blast populations that simultaneously express myeloid and lymphoid lineage markers (Swerdlow et al, Early demonstration of B-cell to myeloid reprogramming was achieved by retroviral encoded signalling oncogenes, such as Ras or Raf that also activate C/EBPβ (Klinken et al, Markers of various haematopoietic cell lineages have also been observed in multiple myeloma (Epstein et al, in vivo (Shen et al, For a time, research sought evidence of physiological reprogramming or trans-differentiation, as a proof that it not only represents an experimental artefact, but also occurs in the organism. It was clear from early on, that if somewhere, physiological reprogramming would be encountered in the context of tissue damage and regeneration. The plasticity of pancreatic cells in the regenerating pancreas has been know since the early eighties, in particular their ability to trans-differentiate into hepatocytes Several groups attempted to show that circulating haematopoietic cells were capable of trans-differentiation, but this was subsequently contested mostly as the reflection of extremely rare events and quite often related to cell fusion, instead of true lineage conversion (Wagers & Weissman, de novo expression of key transcription factors that re-direct epithelial differentiation to a different fate, similar to biphenotypic haematopoiesis and to experimental reprogramming. Accordingly, pathologically relevant trans-differentiation and mixed lineage features might not be reserved to leukaemia/lymphoma but might also be relevant to epithelial neoplastic transformation.Known to pathologists for decades, metaplasia is a clinical entity defined as the transformation of patches of a differentiated epithelium into another type of differentiated epithelium (Slack & Tosh, Adult epithelial tissues, similar to its haematopoietic counterparts, arise through highly controlled mechanisms of cell differentiation. Somatic stem cells, embedded in the tissues and sheltered in specialized niches of mesenchymal cells, give rise to progeny that will ultimately differentiate into functional cells to repopulate the tissue. The specific outcome of this differentiation process depends on transcription factor networks and on cellular signalling pathways, mostly controlled by neighbouring cells, defined during embryogenesis, and persisting in adulthood as regenerative potential (Blanpain et al, in vivo plasticity of pancreatic and hepatic cells. For instance, squamous metaplasia of the lung is associated with long-term exposure to cigarette smoke, gastric acid reflux with Barrett's oesophagus, H. pylori infection with intestinal metaplasia of the stomach, and pancreatitis triggers the development of acinar-to-ductal metaplasia (Husain & Thrower, If in experimental reprogramming artificial induction of master switch transcription factors and selection of reprogrammed cells is mandatory to the success, how would comparable changes be physiologically attained in trans-differentiating metaplastic epithelium? The consensus is that metaplasia is intimately related to chronic injury, inflammation, regeneration and healing, as hinted by the Metaplasia also generally occurs between cell types that arise from neighbouring regions in the adult or in the developing embryo Slack, . As in hIn any case and independently of the onset mechanisms, metaplastic tissue is thought to promote appearance of neoplastic foci, although it remains unclear how emerging tumour cells take advantage of lineage confusion for their own benefit. A recent set of publications has now disclosed that tumours, despite presenting markers from a given tissue, do not forcibly derive from stem cells specific for that given tissue. The group of Blanpain has highlighted the plasticity of epidermal stem cells, by showing that basal cell tumours, despite expressing hair follicle markers in the early stages do not derive from hair follicle progenitors, but from basal stem cells that are reprogrammed into hair follicle progenitors. As basal cell tumourigenesis is WNT dependent, and basal stem cells carry a number of WNT inhibitors, reprogramming might allow the cancer cells to circumvent this inhibitory effect (Youssef et al, P63: is a transcription factor that shares high similarity with its eminent homolog, the p53 tumour suppressor gene. P63 deficient mice display a striking generalized defect in stratified epithelium, indicating crucial roles in maintaining stem cell populations in squamous and other stratified epithelia (Yang et al, Although associated with the expression of squamous keratins and differentiation markers, the mechanism of how p63 drives squamous differentiation remains largely unknown. A recent report suggested that p63 deficient mice develop Barrett's oesophagus not through transdifferentiation events, but by competition between stem sell lineages, and reactivation of residual embryonic stem cells with alternative differentiation potential (Wang et al, CDX2: is a homeobox transcription factor that together with its homolog CDX1, plays an important role in the development and specification of gastrointestinal tissues. In adulthood, both CDX1 and CDX2 are predominately expressed in the colon and small intestine and are absent from the stomach and the oesophagus (Barros et al, The initial connection between CDX2 and metaplasia was established by the observation that, intestinal metaplasia of the stomach and Barrett's oesophagus, both express CDX2 (Bai et al, SOX9: is a member of the SOX family of transcription factors, and plays a wide role in embryogenesis and the differentiation of several tissues. SOX9 is ectopically expressed in acinar-to-ductal metaplasia together with HNF6, repressing acinar genes and inducing ductal differentiation in acinar cells (Prevot et al, H. pylori was shown to lead to alteration of DNA-repair machinery and to a ‘mutator’ phenotype. How exactly H. pylori infection induces genetic instability, however, remains to be resolved. Yet, large amounts of bio-reactive free-radicals are produced in the context of chronic inflammation that may cause DNA damage (Machado et al, Although the induction of signalling pathways by chronic inflammation in both epithelial and mesenchymal cells might play a role in the early development of metaplasia, genetic and/or epigenetic alterations are likely required for prolonged maintenance of a reprogrammed state that eventually progresses into tumourigenesis. The effects of inflammation are difficult to analyse and quantify, however, it is evident that chronic inflammation has deleterious effects on stem cell equilibrium (Quante & Wang, H. pylori is often suggested to be a facultative intracellular parasite (Dubois & Boren, H. pylori infection and gastric metaplastic reprogramming.An additional, unexpected connection between host–pathogen interaction and physiological reprogramming thus emerges: intracellular parasites have long been suspected to remodel host cell gene expression in order to achieve an optimal niche to complete parasite life cycle. Masaki and collaborators have now shown that the Leprosy Bacilli reprograms Schwann cells to a state of mesenchymal progenitor-like cells. This mechanism entails epigenetic changes at the DNA level of the reprogrammed cell, and promotes bacterial dissemination (Masaki et al, Mutations in tumour suppressor genes, including P53 and APC or c-MYC amplification as observed in intestinal metaplasia or Barrett's oesophagus, are considered as consequences of carcinogen/inflammation-induced genetic instability (Dolan et al, Few reports have specifically addressed the subject of histone modifications in metaplasia, although one study refers to deacetylated histone H4 in areas of intestinal metaplasia of the stomach (Ono et al, Transcription factors with nodal functions are involved in generation of somatic stem cells and steering precursor cells from an immature state into a fully functional mature and specialized state. Experimentally induced changes in the expression of transcription factors showed that it is possible to re-direct differentiation pathways in an artificial procedure coined reprogramming. Accumulating evidence suggests that reprogramming or trans-differentiation events are also ubiquitous in neoplastic conversion. The conceptual relationships between reprogramming and trans-differentiation cues are summarized in A set of data shows that key transcription factors are often deregulated during leukaemogenesis and lymphomagenesis in conjunction with an ambiguous phenotype. In epithelia, cell fate is altered by inflammation-induced changes, involving key transcription factors that may be instrumental to formation of metaplastic foci that are since long thought of as sites of epithelial cancer initiation. A large body of circumstantial information suggests that such ambivalent phenotypes may be considered to play a crucial role in tumour initiation, although it remains to be resolved whether and how exactly a developing cancer cell profits from lineage promiscuity/ambiguity. A central question then is whether ‘reprogramming’ into a lineage promiscuous state only reflects the meltdown of epigenetic memory and/or confer selective advantages to tumour cells. In the case of biphenotypic leukaemia/lymphoma, lineage confused cells may combine the best out of two worlds, such as gain of growth factor autonomy by assimilating lineage divergent lymphoid/myeloid signalling pathways and growth factor sources, or/and by enhancing resistance to stress and apoptosis (Ding & Morrison, To what extent is trans-differentiation and lineage confusion a common feature of cancer onset and progression, of which metaplasia and leukaemic lineage ambiguities are the most observable reflexions?Can we restrict tumour progression by targeting the lineage specific transcription factors responsible for this phenomenon?Can therapeutic approaches take advantage by targeting multi-lineage features?Haematopoiesis is the process of formation of several blood cell lineages through differentiation from haematopoietic stem cells. It occurs in adult humans mainly in the bone marrow, but can also occur in secondary lymphoid organs such as the thymus or spleen.Rrefers to a feature of some cancer cells displaying lineage infidelity/promiscuity/trans-differentiation that might confer a selective advantage to tumour growth.McCulloch has introduced the term in 1983 (Smith et al, Transient bi- or multiphenotypic stem cell stages that are preserved as a relic in leukaemic blast populations due to the primary oncogenic event that is involved in maturation arrest (Greaves et al, A type of trans-differentiation, is the pre-neoplastic but often reversible physiological conversion of a given cell type into another in the context of tissue injury or chronic inflammation. Metaplasia gives rise to patches of a differentiated tissue amidst another tissue. Barrett's oesophagus, gastric intestinal metaplasia, squamous lung metaplasia or acinar-to-ductal metaplasia of the pancreas, are examples of metaplasia.Although several definitions have been advanced, here trans-differentiation and reprogramming are mostly treated as analogous concepts of changing cell fate. All terms can be defined as the conversion of one differentiated cell type into another. While reprogramming solely is a concept of experimental manipulation that converts cells back to a quasi-embryonic like state, direct reprogramming brings forth a new differentiated phenotype, similar to trans-differentiation that may also occur under physiological or pathological conditions in the organism.


Animals as distinct as fruit flies and humans can repair and replace cells in their nervous system after damage caused by injuries or diseases. To support healing, cells called glia increase in number near damaged areas, engulf cellular debris, and restore neuronal function by wrapping around axons, long projections that conduct electrical impulses. Cell growth must be tightly regulated during regeneration so that tumors don't develop, but how genes orchestrate this process has not been explained by past studies.PLoS Biology, a research team led by Alicia Hidalgo, a neuroscientist at the University of Birmingham in the United Kingdom, reveals a gene network that underlies glial responses to injury in the central nervous system of the fruit fly (Drosophila melanogaster). This network consists of two feedback loops that promote regeneration and repair, but then put the brakes on cell division to prevent uncontrolled growth.In the current issue of Through a series of genetic experiments, the team found that a protein called Prospero engages in a tug-of-war with two cell signaling pathways, Notch and Dorsal/NF-kappaB. Prospero inhibits cell proliferation, while Notch and Dorsal/NF-kappaB activate it. Because these opposing signals boost each other's activity, they keep glia on the brink of dividing under normal conditions.But when the researchers stabbed the ventral nerve cord of flies with a needle, glia became more abundant close to the wounds. Raising levels of Prospero through genetic modifications resulted in fewer glia after injury, but boosting either Notch or Dorsal/NF-kappaB signaling intensified glial proliferation.Next, the researchers tested what happens when the negative feedback breaks down. Disrupting the balance between the opposing signals by enhancing either Notch or Dorsal/NF-kappaB signaling in mutant flies lacking Prospero resulted in tumor-like overgrowths.The interplay between Notch and Prospero also regulates regeneration and repair. A surge in Notch signaling caused wounds to shrink and glia to encircle damaged axons, and Prospero enabled the clearance of cellular debris. But lesions were larger in flies with no Prospero, too much Prospero, decreased Notch activity, or a deficiency in Prospero combined with overstimulation of the Notch pathway.This gene network may allow cells to adapt to changes in their environment during the normal course of development and throughout life, thus preserving the stability of the nervous system. Through these pathways, cells could multiply or form connections during learning without disturbing the brain's structure and function.In addition to potentially explaining how the nervous system maintains equilibrium, this research could lead to new therapeutic strategies for regeneration in the adult mammalian central nervous system, which does not undergo extensive repair. If this gene network exists in humans, it might be possible to manipulate the genes and transplant cells into patients with spinal cord injuries or certain neurological disorders.Kato K, Forero MG, Fenton JC, Hidalgo A (2011) The Glial Regenerative Response to Central Nervous System Injury Is Enabled by Pros-Notch and Pros-NFκB Feedback. doi:10.1371/journal.pbio.1001133


Acromegaly is caused by hypersecretion of growth hormone (GH) and consequently of insulin-like growth factor-I (IGF-1) due to pituitary tumor. Other causes, such as increased growth-hormone releasing hormone (GHRH) production, ectopic GHRH production, and ectopic GH secretion, are rare. Growth hormone and IGF-1 play a role in the regulation of bone metabolism, but accurate effect of growth hormone excess on bone is not fully explained. The issue of osteoarticular manifestations is still very actual, due to development of complications in the majority of patients with acromegaly. Traditionally, acromegaly is considered as a cause of secondary osteoporosis. Nowadays, it is discussed if BMD as predictor of osteoporotic fractures in acromegalic patient is decreased or even normal. Thus, bone quality remains to be more important in assessment of fracture risk. GH excess leads to increased bone turnover, defined by changes of bone markers. The articular manifestations are frequent clinical complications and may be present as the earliest symptom in a significant proportion of acromegalic patients. Articular manifestations are the main causes of morbidity and immobility of these patients, and they are persistent even after successful treatment. Quick recognition of osteoarticular changes and aiming the therapy lead to decrease in complication number. Acromegaly is a chronic endocrinopathy caused by hypersecretion of growth hormone (GH) and consequently of insulin-like growth factor-I IGF-1) due to pituitary tumor. Other causes, such as increased growth hormone-releasing hormone production from hypothalamic tumors, ectopic growth hormone-releasing hormone production, and ectopic GH secretion from nonendocrine tumors, are rare. Growth hormone (GH) and its peripheral mediator, insulin-like growth factor-1 (IGF-1), play a significant role in the regulation of bone metabolism. While adult growth hormone deficiency has been shown to be involved in determining bone loss and osteoporosis, the effects of growth hormone excess on bone are unexplained and uncertain. It remains unclear whether the overall increase in BMD observed in patients with acromegaly is associated with a decrease in fracture risk  due to p. Early din vitro and in vivo. GH and IGF-1 are important regulators of bone homeostasis through life. They are acting in autocrine and paracrine ways, stimulate proliferation, differentiation, and extracellular matrix production in osteoblastic like-cell lines and finally bone formation. GH also stimulates recruitment and bone resorption activity in osteoclastic-like cells . Al. Alin viUeland et al.  evaluateParkinson et al.  evaluateTo summarize, active acromegaly leads to increase in bone turnover markers. GH excess inhibits differentiation and activity of osteoclasts through the RANK-RANK-l—OPG system. Independent predictors of bone turnover markers are values of GH, IGF-I as well as age of the patient. Studies have proven correlation between bone resorption and formation, suggesting coupling between bone turnover markers. After treatment with somatostatin analogues (pegvisomant and octreotide) bone markers and IGF-I normalize. Study of transsphenoidal surgery effect on bone turnover is missing.Z-score below −2SD in almost 30% of study patients with acromegaly, and almost 40% patients over 50 years were osteoporotic. There was no difference in Z-score and T-score between groups with active or controlled acromegaly. Giuseppina et al. [T-score of femoral neck, regardless of gonadal status. Study by Madiera et al. [T-score was observed in eugonadal patients with active acromegaly compared to controlled hypogonadal patients and the most of osteoporotic patients were hypogonadal. The effect of gonadal status on BMD in acromegalic patients is ambiguous. Some studies [The whole effect of growth hormone excess on bone mineral density is not fully explained. GH/IGF-1 axis might play an important role in the maintenance of bone mass, what was described by few past studies . It was a et al.  brought  studies , 21 have studies , 23 have studies . Associa studies . We have studies . There wIn conclusion, GH/IGF-1 axis plays clearly an important role in maintenance of bone mass. It was described that cortical bone in acromegaly changes in opposite to trabecular bone. Results of few past studies remain controversial. Recent studies suggest that BMD decreases in patients with active controlled disease. As it was described in previous text influence of gonadal status plays also the role in bone mass acquisition, proving that hypogonadal patients with controlled disease have higher prevalence of osteoporosis in comparison to eugonadal noncontrolled acromegalic patients. According to gonadal status also gender difference was described in acromegalic patients, supported by studies with GH deficient patients treated with recombinant human growth hormone. Less discussed, but very important, was BMD measurement technique in past studies. It suggested that two-dimensional DXA is distorted because it is not counting with perpendicular scan bone density. Thus, other techniques should be used for assessment of BMD. At last, the clinical access to acromegalic patient should be individual with emphasis to state of disease, gonadal status, gender, age, measured site of bone measuring technique.2) regardless of gender. Based on these findings an insufficient quality of bone should be the most important factor of bone health, and it is influenced by gonadal status, disease activity, and gender. Full-understanding of the problematic of osteoporotic fractures in patients with acromegaly requires other studies with higher number of patients.Only in one study  increaseThe articular manifestations of acromegaly are one of the most frequent clinical complications and may be present as the earliest symptom of acromegaly. Its prevalence and severity worsen with the duration of uncontrolled disease and often result in significant disability. The pathogenesis of arthropathy in acromegaly is comprised of two mechanisms: initial endocrine and subsequent mechanical changes . RadioloThe radiological appearance of arthropathy in acromegaly was mostly studied in small noncontrolled groups of patients with untreated and treated but active disease. These studies have suggested that more severe radiological abnormalities were related to biochemically more active acromegaly and longer disease duration . Further common complaints relate to limited range of movement, joint instability, and joint deformation. The presence of radiologic abnormalities and clinical manifestations of arthropathy are not correlated, unless joints are severely affected as in long-standing disease .There were few studies evaluating prevalence of joint changes in acromegalic patients. Recent study evaluated 89 acromegalic patients with adequate long-term disease control for prevalence and radiological characteristics of arthropathy. They found evidence for radiological arthritis in a least one joint in all patients and clinical arthritis in two-thirds of patients. The most prevalent manifestation was axial osteoarthritis, affecting the cervical and lumbar areas, even at young ages. The characteristic radiological changes observed were wide joint spaces and severe osteophytosis .In early phase of the disease widened intervertebral spaces and vertebral enlargement may be present in the spine X-ray. Ossification of the anterior surface of vertebral bodies is relatively common and in more severe cases can bridge the disc space resembling diffuse idiopathic skeletal hyperostosis syndrome. Biermasz et al. , 31 repoOsteoarticular manifestations of acromegaly are the most frequent clinical complications and may be present as the earliest symptom in a significant proportion of patients with acromegaly. Many patients with joint complaints are misdiagnosed as a generalized osteoarthritis. Early diagnosis of acromegalic arthropathy and aiming the therapy could lead to decrease in severe joint complications, a disability. With ongoing disease arthropathy becomes irreversible and biochemical control of acromegaly, as documented by a normal IGF-I, will have a very small efficacy in improving the clinical status.The effects of growth hormone excess on bone turnover and bone density are not fully explained, but GH/IGF-1 axis plays an important role in the maintenance of bone mass. This effect is proved by high levels of bone turnover markers in active acromegaly, and correlation between IGF-I and bone remodeling was proven by few past studies. Traditionally, acromegaly is considered as a cause of secondary osteoporosis. Nowadays, it is frequently discussed if BMD as predictor of osteoporotic fractures in patient with acromegaly is unchanged according to earlier studies or decreased according to few recent studies. It was shown that GH excess has effect on trabecular bone but no effect on cortical bone, thus quality of bone remains to be more important in osteoporotic fracture risk, but another studies are needed. Supposed increased fracture risk cannot be fully explained by changes in bone mineral density. It seems that bone quality plays the most important role in fracture risk regardless of BMD. Nowadays, in clinical practice noninvasive methods to asses bone quality are missing. Adequately designed studies focusing on different parameters of bone quality in patient with acromegaly are required. Assessment of patient risk profile could be helpful in stratification of patients with high risk of fracture. In clinical practice beside BMD testing and bone turnover evaluation fracture risk assessment using FRAX calculator could be helpful in fracture risk prediction. Prevalence and severity of arthropathy worsen with the duration of uncontrolled disease and often result in significant disability. Studies have suggested more severe joint abnormalities related to biochemically more active and longer duration of acromegaly thus quick obtaining of diagnosis and aiming the therapy lead to decrease in fatal complication number.


Drought is one of the most serious production constraint for world agriculture and is projected to worsen with anticipated climate change. Inter-disciplinary scientists have been trying to understand and dissect the mechanisms of plant tolerance to drought stress using a variety of approaches; however, success has been limited. Modern genomics and genetic approaches coupled with advances in precise phenotyping and breeding methodologies are expected to more effectively unravel the genes and metabolic pathways that confer drought tolerance in crops. This article discusses the most recent advances in plant physiology for precision phenotyping of drought response, a vital step before implementing the genetic and molecular-physiological strategies to unravel the complex multilayered drought tolerance mechanism and further exploration using molecular breeding approaches for crop improvement. Emphasis has been given to molecular dissection of drought tolerance by QTL or gene discovery through linkage and association mapping, QTL cloning, candidate gene identification, transcriptomics and functional genomics. Molecular breeding approaches such as marker-assisted backcrossing, marker-assisted recurrent selection and genome-wide selection have been suggested to be integrated in crop improvement strategies to develop drought-tolerant cultivars that will enhance food security in the context of a changing and more variable climate. Drought is the most devastating abiotic stress affecting crop productivity, which is caused by insufficient rainfall and/or altered precipitation patterns . The importance of multifaceted strategies including genetic engineering  Among the various abiotic stresses that curtail crop productivity, drought is the most recalcitrant to breeding  in a breeding programme, either by direct selection or through a surrogate such as molecular markers, depends on their relative genetic correlation with yield, extent of genetic variation, heritability and genotype × environment interactions. For instance, in drought environments, osmotic adjustment, accumulation and remobilization of stem reserves, superior photosynthesis, heat- and desiccation-tolerant enzymes, etc. are important PTs. However, it is important to establish their heritability and genetic correlation with yield in target environments. Identification of drought-adaptive PTs and mechanisms is time consuming and costly; however, if successful, the benefits are likely to be substantial. The information on important PTs can be collected on potential parental lines involving screening of entire crossing block, or a set of commonly used parents, thus producing a catalogue of useful PTs. This information can be used strategically in designing crosses, thereby increasing the likelihood of transgressive segregation events, which bring together desirable traits. However, if enough resources are available, screening for PTs could be applied to segregating generations in yield trials, or any intermediate stage, depending on when genetic gains from selection are optimal Reynolds .It is important to note that using specific traits, breeding strategies are effective only when these traits are properly defined in terms of the stage of crop development at which they are relevant, the specific attributes of the target environment for which they are adaptive and their potential contribution to yield   of leaves, and WUE of spike photosynthesis associated with refixation of respiratory CO2, (4) photoprotection including energy dissipation, anti-oxidant systems and anatomical traits such as leaf wax. The model is used to assist in taking breeding decisions by permitting a strategic approach of accumulating drought-adaptive alleles by crossing parents with contrasting drought-adaptive mechanisms. Accumulation of soluble stem carbohydrates and their remobilization during the post-anthesis drought period help to supply surplus assimilates for grain growth during grain filling , genotypes with deeper, more profuse roots have an advantage through better water extraction deeper in the soil profile  characterization of crossing block lines for stress-adaptive mechanisms, (2) strategic crossing among parents with different but potentially complementary PT expression, thus ensuring cumulative gene action in selected progeny, and (3) early generation selection (EGS) of bulks for canopy temperature (CT). This type of physiological characterization is used to assess variation and thereby increases the rates of genetic gains , several traits can be determined on the basis of a single spectrum  estimate the effects of environmental perturbations, such as changing atmospheric composition, on canopy structure and function . Quantitative MRI and PET data not only help to study differences between species, but also provide a phenotype within a species, the growth pattern, water relations and/or translocation properties of assimilates  to investigate root/shoot systems growing in sand or soil which allow to assess structure, transport routes and the translocation dynamics of recently fixed photoassimilates labelled with short-lived radioactive carbon isotope (δ11C (only 20 min) limits the utility of MRI to study source–sink relationships in minute structures such as developing seeds . The platform has the capacity to measure almost unlimited sets of parameters easily, allows comprehensive screening and provides statistics on various plant traits in a dynamic way. Depending on the degree of automatization, plants are manually placed in the Scanalyzer 3D or transported on conveyor belts directly from the greenhouses to the imaging chambers. Such chambers provide top and side imaging of both shoot and root systems to quantify plant height/width, biomass and plant architecture. Application of different camera and acquisition modes—from visual light to near infrared (NIR/SWIR), infrared (IR) and fluorescence imaging—opens new perspectives for visualization using non-destructive quantification. The key application is in the fast developing domain of plant functional genomics. These automated systems will increase our understanding of plant growth kinetics and help improve plant models for systems biology or breeding programmes.One of the high-throughput integrated phenotyping platforms that includes the pipeline of imaging, image processing automatization and data handling modules was developed by LemnaTec, a German company , followed by tiers of more sophisticated screens of decreasing numbers of genotypes have been proposed Sinclair , Fig. 3.In several genetic studies, drought tolerance has been found to be a complex quantitative trait controlled by a large number of minor genes/QTLs  development of mapping populations segregating for drought tolerance-related traits, (2) identification of polymorphic markers, (3) genotyping of the mapping populations with polymorphic markers, (4) construction of genetic maps, (5) precise phenotyping for drought tolerance-related traits, as mentioned above, and (6) QTL mapping using both genotypic and phenotypic data. This process is commonly called linkage mapping/linkage analysis-based QTL mapping -based association mapping, initially used in human genetics, has been suggested as an alternative approach for QTL mapping in crop species . Most of the identified QTLs for drought traits explain a relatively small portion of total phenotypic variation. As a result, their direct deployment in breeding programmes through marker-assisted selection (MAS) may not be very effective.In summary, QTLs for drought tolerance have been identified for several major and important crop species like rice, maize, wheat, barley, sorghum, pearl millet, soybean and chickpea  with causal effect on the trait is like finding a ‘needle’ in the ‘genomic haystack’. Therefore, to identify the causal gene(s), positional cloning of QTLs have been undertaken in several crop species  full transporter was cloned from eibi1 mutation responsible for leaf water conservation in wild barley and rice  involved in cell expansion within the expected intervals of QTL for root traits in rice  PCR-based differential display PCR (DDRT-PCR) analysis  have also been developed in maize  into elite, less drought-tolerant cultivars or breeding lines (recipient parents) without transfer of undesirable or deleterious genes from the donors (linkage drag). The process is commonly referred to as marker-assisted backcrossing (MABC). Superior lines or cultivars are developed that contain only the major gene/QTL from the donor parent, while retaining the whole genome of the recurrent parent Hospital . AlthougThe relatively low success of MABC for improving drought tolerance can be attributed to the complex nature of drought. In many instances, the expression of drought tolerance is controlled by minor main-effect QTLs or epistatic QTLs. For instance, QTLs with ~10 % phenotypic variation for drought tolerance have been identified in maize . Similar MARS breeding programmes are being conducted at several other international institutes including ICRISAT, the French Centre for International Agricultural Research (CIRAD) and University of California-Riverside, USA for improving drought tolerance in chickpea, sorghum and cowpea, respectively  or genomic selection (GS) is another important approach to develop superior germplasm lines with overall excellent performance in a target environment.Genome-wide marker genotyping is used for GWS rather than selected markers showing significant associations (as in case of MARS) with the traits of interest. In summary, individuals in a phenotyped population  are genotyped using genome-wide markers and breeding values of alternative alleles of all the markers are fitted as random effects in a linear model. Individuals in subsequent recurrent selection generations are then selected based purely on the sum of those breeding values [genomic estimated breeding value (GEBV); Meuwissen et al. It is evident that precise phenotyping is essential to screen larger core collection/mapping population for identifying the most appropriate QTL and candidate genes for use in plant breeding. A number of phenotyping approaches are available and this area of research is currently referred to as ‘phenomics’. Nevertheless, re-integration of the pieces of the ‘phenomics’ puzzle into a comprehensive and relevant crop improvement framework of ‘seed yield stability’ will involve crop modelling (Tardieu and Tuberosa In summary, it is essential to integrate crop physiology, genomics and breeding approaches to dissect complex drought tolerance traits, understand the molecular basis of drought tolerance and develop the next-generation crops for our changing climate. Although work is ongoing in some major crops, it is anticipated that integrated physiology, genomics and breeding approaches will be initiated/accelerated in the so-called orphan crops that are important for food security in many developing countries.


HIV care providers may be optimally positioned to promote smoking behaviour change in their patients, among whom smoking is both highly prevalent and uniquely harmful. Yet research on this front is scant, particularly in the developing country context. Hence, this study describes smoking behaviour among people living with HIV/AIDS (PLWHA) in the Kathmandu Valley of Nepal, and assesses the association between experience of physician-delivered smoking status assessment and readiness to quit among HIV-positive smokers.We conducted a cross-sectional survey of PLWHA residing in the Kathmandu Valley, Nepal. Data from 321 adult PLWHA were analyzed using multiple logistic regression for correlates of current smoking and, among current smokers, of motivational readiness to quit based on the transtheoretical model (TTM) of behaviour change.Overall, 47% of participants were current smokers, with significantly higher rates among men (72%), ever- injecting drug users (IDUs), recent (30-day) alcohol consumers, those without any formal education, and those with higher HIV symptom burdens. Of 151 current smokers, 34% were thinking seriously of quitting within the next 6 months (contemplation or preparation stage of behaviour change). Adjusting for potential confounders, experience of physician-delivered smoking status assessment during any visit to a hospital or clinic in the past 12 months was associated with greater readiness to quit smoking .Roughly one-third of HIV-positive smokers residing in the Kathmandu Valley, Nepal, are at the contemplation or preparation stage of smoking behaviour change, with rates significantly higher among those whose physicians have asked about their smoking status during any clinical interaction over the past year. Systematic screening for smoking by physicians during routine HIV care may help to reduce the heavy burden of smoking and smoking-related morbidity and mortality within HIV-positive populations in Nepal and similar settings. As expanding global application of antiretroviral therapy (ART) heralds a paradigm shift in HIV-related morbidity and mortality -5, the tYet even for individuals with protracted tobacco use histories, cessation brings almost immediate health benefits and can, over time, reduce the risk of premature death to a level approaching that of a lifetime non-smoker ,23. FromA key component and predictor of successful outcomes in the process of smoking cessation is motivational readiness to change ,30, descOne promising vehicle for reaching HIV-positive smokers may lie in the frequent contact between HIV-positive smokers and their physicians facilitated by the need for regular immunologic monitoring and, for many, ART support. Given this heightened level of interaction and trust , HIV medWithin the general population, even simple interventions delivered by physicians in the form of brief encouragement or advice to quit smoking can have a significant impact on short-term movement through the stages of change  and on fDespite the exceptional health risks associated with tobacco smoking and the clear benefits of quitting for HIV-positive smokers, attention to smoking behaviour and motivational readiness to quit has been inadequate in this important smoking subgroup. Moreover, although over 90% of the world's HIV-positive population resides in the developing world , data onWe therefore explored factors associated with current smoking status and readiness to quit among PLWHA residing in the Kathmandu Valley of Nepal, among the least developed countries in South Asia. In particular, this study examined the association between experience of physician-delivered smoking status assessment and motivational readiness to quit in HIV-positive smokers.This cross-sectional study surveyed a community-based sample of 321 HIV-positive residents of the Kathmandu Valley, Nepal. Since the country's first case of HIV was reported in 1988, Nepal has been facing a burgeoning concentrated epidemic, with prevalence especially high among injecting drug users (IDUs) . In the We recruited 322 participants through purposive, convenience sampling techniques. Potential participants were referred through staff members of five local non-governmental organizations (NGOs) working within HIV-positive communities in the Kathmandu Valley. Individuals recruited for participation fulfilled the following inclusion criteria: (1) 16 to 60 years of age, (2) self-reported diagnosis of HIV-positive status, and (3) willing provision of written informed consent for voluntary participation.Data collection was undertaken during February and March 2010 in the wider context of the baseline phase of a longitudinal healthy living intervention overseen by the second author (KCP). The survey was based on a structured, pre-tested Nepali language questionnaire. Trained interviewers administered the questionnaire face-to-face in a private setting, with each interview lasting approximately 45-60 minutes. All participants were informed about the study procedures using a prepared information sheet, and signed informed consent forms prior to being interviewed. To enhance confidentiality, interviewers reassured participants that numerical codes would be used in place of names in all records. The study protocol was reviewed and ethical approval granted by the Institutional Review Board of the Graduate School of Medicine at the University of Tokyo and by the Nepal Health Research Council.Standard single questionnaire items assessed basic sociodemographic and HIV-specific clinical variables. We used the HIV Symptom Index (HSI) , which aA modified 7-item version of the AIDS-related Stigma Scale  was usedcurrent smokers if they reported smoking "every day" or "some days" at the time of survey. Participants who had smoked at least 100 cigarettes in their lifetime but had quit smoking at the time of the interview were considered former smokers, while those reporting never smoking or smoking fewer than 100 cigarettes in their lifetime were considered never smokers.Current smoking status was assessed by single items asking participants about smoking frequency at the time of the survey and about amount smoked both daily and cumulatively. Based on definitions set forth by the CDC , we claslight smokers (≤ 10 cigarettes/day) or moderate-to-heavy smokers (> 10 cigarettes/day) [Frequency of smoking as a measure of smoking intensity was assessed by asking current smokers how many cigarettes they smoked in a typical day. Current smokers were then categorized as tes/day) . Currenttes/day) . We idenExperience of smoking status assessment by a health care provider was measured by first asking all participants their frequency of visits to a hospital or clinic for any reason over the 12 months preceding the time of survey. Those reporting at least one visit to a hospital or clinic during that time (n = 302) then responded to three items inquiring whether a physician, paramedic, or nurse had ever asked about their smoking status during any such visit.pre-contemplation stage, while those reporting an intention to quit in the next 1-6 months were classified as falling within the contemplation stage. Those expressing an intention to quit within the next 30 days and also reporting a previous quit attempt in the past 12 months were categorized in the preparation stage of change.Current smokers' readiness to quit smoking was assessed based on the following question: "Are you seriously thinking of quitting smoking?" According to the conventions of the TTM , particiOf 322 eligible participants, data from one male participant was incomplete and thus excluded from analysis. The remaining 321 HIV-positive individuals  constituted our study sample.Multiple logistic regression analysis was used to explore factors associated with smoking status and to examine the association between experience of physician-delivered smoking status assessment and readiness to quit smoking, comparing current smokers in lower (pre-contemplators) and higher (contemplators and preparators) stages of change in terms of potential covariates. Independent variables were entered into each regression using a direct (simultaneous) entry method. Major sociodemographic characteristics and other mediators having previously established or theoretically feasible associations with the dependent variables were included as covariates or potential confounders in the analyses. Multicollinearity was also assessed for each model, and the variance inflation factor (VIF) of all variables was less than 3.0. All statistical tests were 2-sided, considered significant at the p < 0.05 level, and performed using SPSS version 18.0 for Windows .The surveyed group was 57% male and had a median age of 33  years; 81% of participants had at least some formal education , and roughly half (51%) were moderate-to-heavy smokers  had reached or surpassed the contemplation stage of change, with some thought of quitting within the next six months. Roughly half (52%) of current smokers had made at least one quit attempt within the past 12 months; the most commonly cited reason for relapse was "Addiction/Habit" (45%), followed by "Boredom" (32%).Among the 137 current smokers reporting at least one visit to a hospital or clinic within the past 12 months, 73% reported experience of physician-delivered smoking status assessment during any such visit. Further, 26% reported experience of paramedic- or nurse-delivered smoking status assessment within the same parameters.less likely than those without any formal education to be current smokers .Men were over nine times more likely than women to be current smokers   , the prevalence of smoking among HIV-positive men was over twice the corresponding national rate (34.8%) . IdentifIn terms of motivational readiness to quit, the proportion of participants still in the precontemplative stage of behaviour change was high relative to previous findings on HIV-positive smokers in developed countries ,33,34. VOur study is the first to report on formal education as a potential barrier to quitting readiness among HIV-positive smokers. Given the strong positive linear correlation between education and the quit ratio (proportion of ever smokers who had quit smoking) demonstrated by Wetter et al. , it may Similarly, though data from developed countries suggest that smokers attempting to quit may be less successful and more susceptible to relapse with the presence of another smoker in the household ,56, our We further found that history of at least one smoking cessation attempt was associated with greater quitting readiness. This finding is consistent with the TTM, by which the probability of successful change increases with the number of change attempts , and is less likely to recognize current smoking in their patients [Finally, our research opens up a new and previously unexplored space for the role and effectiveness of basic smoking status screening administered by physicians treating PLWHA. Because the HIV practice pattern typically consists of regular contact over an extended period of time, physicians treating PLWHA have enhanced opportunities to build rapport and trust and to better tailor the tone to the individual patient. Yet there is evidence that HIV care providers may actually be patients ,58. ThisNotably, we found significantly higher motivational readiness for cessation among individuals reporting smoking status assessment by a physician, though not among individuals reporting such assessment by a paramedic or nurse. This implies that, in the context of this study setting, the words of a physician may be imbued with greater meaning or weight when it comes to issues of health behaviour change. Specifically, paramedics and nurses might be perceived more as peers, as they are frequently available for consultation in the NGO clinics. In contrast, interactions with physicians typically occur in more formal settings, where they may more likely be perceived as expert service providers and their words afforded greater value.Drawing smokers' attention to their smoking behaviour is a form of feedback to the patient and might in itself be sufficient to effect behaviour change when administered by a trusted and valued health professional. While more intensive, multifaceted counselling interventions may be the ideal, they are not always feasible in busy primary care or clinical settings, particularly in low-resource environments, where health care providers' time is at a premium. From a public health perspective, even given a small effect size for facilitation of smoking cessation through brief physician intervention, the net effect can still be substantial, provided large numbers of physicians follow such a practice systematically .These results should be considered within the context of several study limitations. First, although this study surveyed a large group of participants from multiple NGO outreach networks across the Kathmandu Valley, findings are specifically representative of PLWHA falling within the network of our partner NGOs. Importantly, our sample contained only two non-heterosexual participants, though men who have sex with men represent an important risk group in the HIV epidemic nationally. Second, this study relies on self-report of all measures, leaving room for several types of bias. Because information was collected through face-to-face interviews, a social desirability bias may have been introduced, though a confidential and sensitive method of survey administration was designed to limit this tendency. Although we did not verify smoking status biochemically for those who reported being nonsmokers, there is empirical evidence that self-report is a sufficient, reliable, and valid means to assess smoking status .Third, measurement of smoking status assessment experiences in this study only covered the existence of such an interaction and did not address potential variability in the specific content or quality of the discussions on smoking taking place between patients and their physicians. Finally, though previous research has established that stage of behaviour change effectively predicts both smoking cessation attempts and actual cessation ,30, the Roughly one-third of HIV-positive smokers residing in the Kathmandu Valley, Nepal, are at the contemplation or preparation stage of smoking behaviour change, with rates significantly higher among those whose physicians have asked about their smoking status during any clinical interaction over the past year. Although longitudinal studies will be necessary to draw decisive conclusions, our findings suggest an important role for physicians in raising awareness and catalyzing change among their currently smoking HIV-positive patients. Particularly in an era of pervasive ART, the prevention of chronic, tobacco-related disease represents an increasingly critical component of HIV medicine globally. Even through the most minimal investment of time and resources, HIV health care systems show promise as a gateway for effective delivery of smoking cessation interventions to the critical though neglected population of HIV-positive smokers.The authors declare that they have no competing interests.RMA conceived of the study, contributed to the study design, conducted the statistical analyses, and drafted the article. KCP helped to conceptualize the study and contributed to the design of the study, the interpretation of results, and the revisions of the article. RMA, KCP, and KPT oversaw the data collection. JK and BDP assisted in the implementation of the study. MJ monitored and supervised the study progress. All authors contributed to critical revision of and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2458/11/677/prepub


The first joint meeting of the International Society for Cellular Oncology (ISCO) and the European Workshop on Cytogenetics and Molecular Genetics of Solid Tumors (EWCMST), organized by Bauke Ylstra, Juan Cigudosa and Nick Gilbert, was held from 4 to 8 March, 2012 in Palma de Mallorca, Spain. This meeting provided a novel and unique opportunity to jointly present the latest updates on the genetics of cancer and its implications for diagnosis, prognosis and therapy, now and in the future. Various aspects were highlighted, including the identification of effective therapeutic targets, the role of cellular senescence in tumor development and therapy, chromosome translocations in leukemias and solid tumors, mechanisms underlying fragile sites and chromosome instability, tumor-associated ‘omics’ landscapes, genetic and epidemiologic risk factors, the role of tissue and cancer stem cells, angiogenesis and the tumor micro-environment, and the epigenetics of cancer. In this report, new insights and clinical advancements related to these various topics are provided, based on information presented at the meeting. Over the last years substantial advances in the treatment of solid tumors have been made. Molecular markers, e.g. Her2/neu, KRAS, EGFR and BRAF, which can predict the therapeutic success of some monoclonal antibodies and tyrosine kinase inhibitors, are now used in clinical practice. As a result, selected patients with breast, gastro-esophageal, colorectal and non-small cell lung cancer can be treated substantially more effective.The transcription factor MYC coordinates the expression of a vast and functionally diverse repertoire of genes that, together, are required for the orderly proliferation of somatic cells. These include genes that govern processes such as the cell division cycle and cell survival, as well as a multitude of processes that proliferating cells need to engage in their surrounding microenvironment, such as the generation of blood vessels, tissue remodeling and the recruitment of cells loaded with enzymes and growth factors needed to do this. MYC is functionally non-redundant and absolutely required for the efficient proliferation of normal and cancer cells. The control of MYC expression in cancer cells is almost always compromised, which turns MYC into a compelling candidate cancer drug target . As of yIn his keynote lecture, Gerard Evans reported the development of a switchable genetic mouse model in which endogenous MYC function can be systematically and reversibly inhibited in normal and tumor tissue in vivo. Using this model, he showed that inhibiting MYC has indeed a remarkably efficacious and durable therapeutic impact on multiple cancer types while eliciting only mild, reversible side effects. Since the requirement of MYC cannot be circumvented, the emergence of resistant clones was not observed. Similarly, switchable genetics was used to model the therapeutic efficacy of restoring p53 gene function in various cancer types and at various stages of their evolution. These latter studies uncovered inherent limits in the efficacy of p53-restoration as a targeted cancer therapy.+ T-cells. They further extrapolated their findings to human disease by analyzing the livers of patients infected with hepatitis C virus (HCV). In agreement with the mouse data, they found that senescent cells were cleared in patients infected with HCV alone, but not in those infected with both HCV and HIV. Of note, HIV infection and immunosuppressant therapy are associated with an increased risk of liver cancer [High levels of cellular stress are intrinsically associated with the process of tumorigenesis. Also, chemotherapy and cancer regression are based on the infliction of high levels of cellular stress. For years, it has been assumed that apoptosis was the relevant cellular response. Challenging this long held assumption, current accumulated evidence indicates that senescence is the most prevalent cellular response to stress, implicated in both protecting from cancer emergence and triggering cancer regression. The fate of senescent cells within tissues has, however, long been uncertain. Some show extremely lengthy residency times in vivo. For example, moles formed by senescent melanocytic cells can reside in human skin for decades . Until rr cancer . The repr cancer . iPS celr cancer ).Chromosome translocations may occur as somatic, primary events in various forms of cancer, including leukemias, lymphomas, sarcomas and carcinomas. These aberrant chromosomes have major consequences for cancer initiating cells. Genomic studies of translocation breakpoints have revealed mechanisms involving unresolved double strand breaks and non-homologous end joining, sometimes accompanied by regional inversion of sequences at the breakpoints. Terry Rabbitts and co-workers have been interested in developing integrated technologies to evaluate the role of translocations in cancer development and to assess the therapeutic promise of translocation-encoded oncogenic proteins. To this end, mouse preclinical models that emulate chromosomal translocations have been designed (chromosome translocations à la carte). These allow the dissection of the genetic and transcriptomic steps involved from cancer initiation (translocations) to overt disease. For therapeutic target validation, they have developed a series of methods to select antibody fragments that interfere with protein-protein interactions inside cells for target validation and to gain insight into transcription factor complex formation . The chrFor a long time, a common misconception has been that fusion genes such as BCR-ABL were found in leukemias, lymphomas and sarcomas, but not in common epithelial cancers. This view has changed dramatically since the discovery of TMPRSS-ERG gene fusions in ~50 % of prostate cancers . Paul EdCommon fragile sites (CFSs) are large chromosomal regions prone to breakage upon replication stress, which is considered to be a driving force of oncogenesis. CFSs were long believed to contain sequences blocking replication fork progression, thus impeding replication completion and leading to DNA breaks upon chromosome condensation. Recently, Michelle Debatisse and co-workers have shown that the fragility of FRA3B and FRA16D, the most active CFSs in human lymphocytes, rather depends on the presence of large initiation-poor regions in the core of the sites . As expeFaithful chromosome segregation is required for cell viability and relies on both the mitotic spindle assembly checkpoint and the machinery that corrects kinetochore-microtubule attachment errors . Most soChromosome segregation errors can also result in structural chromosome aberrations. Chromosomes that mis-segregate are frequently damaged during cytokinesis, triggering a DNA double-strand break response in the respective daughter cells involving ATM, CHK2, and p53. Rita Maia and co-workers reported that these double-strand breaks can lead to unbalanced translocations in the daughter cells .Next generation sequencing technologies are increasingly being used to uncover the spectrum of genomic, transcriptomic and epigenomic variants present in solid tumors . Susie Chttp://R2.amc.nl). This platform allows the integrative analysis of high throughput data in combination with publicly available data. The analysis of structural defects led to the identification of local shredding of chromosomes, known as chromothripsis, in 18 % of high-stage neuroblastomas. These tumors are associated with a poor clinical outcome. Structural alterations recurrently affected ODZ3, PTPRD and CSMD1, which are involved in neuronal growth cone stabilization. In addition, ATRX, TIAM1 and a series of regulators of the Rac/Rho pathway were found to be mutated, further implicating defects in neuritogenesis in neuroblastoma. The genomic landscape of neuroblastoma thus reveals two novel defects, chromothripsis and neuritogenesis alterations [Neuroblastoma is a childhood tumor of the peripheral sympathetic nervous system. The pathogenesis has for a long time been quite enigmatic, as only very few gene defects were identified in this often lethal tumor. Until recently, frequently detected gene alterations included MYCN amplifications and ALK activations. Jan Molenaar and co-workers applied microarray-based mRNA profiling, qPCR-based microRNA profiling, DNA copy number profiling using aCGH and SNP arrays and, very recently, whole genome sequencing to a large series of primary neuroblastoma tumors of all stages, with the aim to identify new tumor driving aberrations that may be employed for the development of targeted therapies. The vast amount of data has been made available through a web-based platform , risk. The heritable component of CRC variance is ~35 %, but <5 % of cases are attributable to known highly penetrant mutations. Our understanding of the genetic basis of CRC has moved forward considerably in recent years, and Malcolm Dunlop and co-workers recently reported the assessment of a set of single nucleotide polymorphisms (SNPs) near 157 DNA repair genes in three CRC genome wide association studies . AlthouWhile the major risk factor for the development of oropharyngeal cancers is a history of smoking and drinking, there is a rapidly growing group of younger patients developing this cancer without these risk factors. This is probably due to high rates of human papillomavirus (HPV) in these cancers. To characterize the distinct molecular alterations that occur in different oropharyngeal cancers David Smith and co-workers performed RNA and whole exome sequencing and, in addition, profiled a number of oropharyngeal cancers using methlyation arrays. Tumors and matched normal tissues were analyzed from the same patients to characterize tumor-specific alterations that occurred during cancer development. Three different groups of oropharyngeal cancer patients were compared: (i) current smokers, (ii) non-smokers and (iii) ex-smokers with at least 10 years of smoking cessation. It was observed that tumors derived from the current smoking group had both much greater variability in the number and types of alterations and many more alterations than tumors from the other two groups. It was also found that after at least 10 years of smoking cessation, gene expression and methylation patterns in both matched normal tissue and oropharyngeal tumor tissue were more similar to the non-smokers than the current smokers. In addition, a group of interesting genes was found that was inactivated by hyper-methylation only in the current smoking group. These same genes showed lower expression levels in the tumors as compared to their matched normal tissues, but again only from the current smoking group. Pathway analysis revealed alterations in the expression of genes involved in the p53 DNA damage-repair pathway, including CHECK2 and ATR, which displayed patterns of increased expression that were associated with HPV-negative current smokers rather than former never smokers . CurrentAs of yet, it is not entirely clear why targeting any specific gene results in tumor regression. One emerging concept that attempts to explain tumor regression upon the inactivation or repair of a single mutant gene product is the idea of oncogene addiction, first described by Weinstein . By thisTissue stem cells are responsible for tissue homeostasis and repair and have been hypothesized to be at the origin of CSCs. However, for the vast majority of cancers the cell of origin is still unknown. Two epithelial skin cancers are frequent in human populations: basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Cédric Blanpain and co-workers developed new genetic approaches to identify the cells of origin of BCC and SCC. Using mice conditionally expressing constitutively active Smoothened mutant (SmoM2) or KRAS mutant (G12D), they were able to activate hedgehog or RAS signaling in different cellular compartments of the skin epidermis, and to determine from which epidermal compartments oncogene expression induces cancer formation. Using clonal analyses, they found that SmoM2-induced BCCs arise from long-term resident progenitor cells of the inter-follicular epidermis. In contrast, expression of mutant KRAS in hair follicle bulge stem cells, but not in their transient amplifying progeny, led to benign squamous skin tumor (papilloma). Whereas no malignant tumor was observed following KRASG12D expression alone, expression of KRASG12D combined with loss of p53 induced invasive SCC formation. These studies have uncovered the cells at the origin of SmoM2-induced BCCs and KRAS-induced SCCs in mice, and have demonstrated that the expression of differentiation markers in tumor cells is not necessary predictive for cancer initiating cells. Therefore, they developed a novel strategy to isolate, by flow cytometry, tumor initiating cells at different time points following oncogene expression and determined the molecular changes associated with tumor initiation and progression. The functional relevance of these changes in the regulation of epidermal stem cells and human skin cancer development was discussed .Hematopoietic stem cells (HSCs), the best understood adult stem cells, function to sustain all blood lineages. Using HSC as a stem cell model system, Boyi Gan and co-workers have sought to understand the role of tumor suppressors involved in cancer metabolism and the regulation of stem cell homeostasis, including TSC, a key negative regulator of mTORC1 activation and cell growth, and LKB1, a critical component controlling energy metabolism . They foThe formation of metastasis is a multi-step process with several rate-limiting steps. While dissemination of tumor cells appears to be an early and frequent event, successful initiation of metastatic growth, a process termed ‘metastatic colonization’, is rather inefficient for many cancer types and accomplished only by a minority of cancer cells that reach distant sites. Prevalent target sites are characteristic for many tumor entities. Ilaria Malanchi and co-workers have shown that a small population of CSCs in a mammary gland tumor model is critical for metastatic colonization. These CSCs represent a stable population of tumor cells which selectively survive and proliferate upon metastatic seeding, thereby driving the initial expansion of cancer cells at the secondary site .Angiogenesis is known to play a pivotal role in the etiology and progression of several cancers, including epithelial ovarian cancer (EOC). In a recent phase 3 trial the effect of bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor, on survival of women with this disease was examined . It was Intra-vital microscopy has revealed an abnormal organization, structure and function of the tumor microvasculature . These abnormalities result in elevated interstitial fluid pressure and hinder the delivery of therapeutic agents to tumors. Furthermore, they induce a hostile microenvironment in tumors characterized by hypoxia and acidosis. The abnormal microenvironment further lowers the effectiveness of anti-tumor treatment such as radiation and chemotherapy. However, one can also exploit the aberrant microenvironment for the treatment of tumors, i.e., enhanced permeability and retention effects of the tumor vasculature may allow a selective delivery of nanoparticles to tumors. Such nanoparticles not only increase the therapeutic index but also allow the targeted delivery of toxic agents and hydrophobic drugs to tumors. Until recently, however, there was a crucial drawback of this approach, i.e., these nanoparticles could not penetrate into tumor tissues after extravasation from blood vessels. Dai Fukumura and co-workers have proposed to solve this dichotomy using a multistage nanoparticle delivery system . To thisFor the development of strategies distinct from targeting the VEGF signaling axis, the identification of specific markers of tumor endothelial cells and the design of high-affinity specific drugs targeting these markers, are needed. To this end, Arjan Griffioen and co-workers set out to profile the antigenic make-up of tumor endothelial cells. For the identification of tumor-specific angiogenesis markers, they performed yeast 2-hybrid screens using existing angiogenesis inhibitors as baits, in conjunction with transcriptome subtraction techniques using RNA from angiogenic endothelial cells isolated from both malignant and normal angiogenic tissues and of resting endothelial cells. By doing so, they identified a series of genes that showed specific over-expression in tumor endothelium but not in angiogenic endothelium of normal tissues, thus creating a therapeutic window for tumor vasculature specific targeting. Antibody targeting of four cell-surface expressed or secreted products  inhibited angiogenesis in vitro and in vivo , 40 and Epigenetic changes represent common and functionally important alterations that contribute to carcinogenesis . AberranInfection with high-risk human papillomavirus (hrHPV) is a necessary but insufficient cause of cervical cancer. Progression of hrHPV-induced cervical intraepithelial neoplasia to invasive cancer is a rare event driven by (epi)genetic alterations in the host cell genome. Current developments in population-based cervical screening by primary hrHPV testing ask for objective biomarkers for risk stratification of hrHPV-positive women. Renske Steenbergen and co-workers reported on DNA methylation events associated with HPV-induced malignant transformation. Both a longitudinal in vitro model system and tissue specimens were analyzed for DNA methylation alterations using quantitative methylation-specific PCR (qMSP). Following functional studies in HPV-transformed keratinocytes, the diagnostic potential of most promising methylation markers was evaluated on hrHPV-positive cervical scrapes. An increasing number of genes was found to become methylated during hrHPV-induced carcinogenesis, including Wnt-pathway regulators, novel tumor suppressor genes, miRNAs and viral DNA. For CADM1, MAL and miRNA-124-2 DNA methylation-based gene silencing was demonstrated to functionally contribute to hrHPV-induced transformation. Based on their distinct onset during transformation and extensive evaluation on tissue specimens the combination of CADM and MAL methylation was tested on hrHPV-positive cervical scrapes collected during population-based cervical screening studies using a training and independent validation set. Testing for CADM1/MAL methylation appeared as least as discriminatory for high-grade cervical intraepithelial neoplasia as the currently proposed method, i.e. cytology either or not combined with HPV16/18 genotyping. Steenbergen and co-workers conclude that testing for DNA methylation alterations provides an objective triage tool for hrHPV-positive women. This opens up the possibility for complete cervical screening by objective, non-morphological molecular methods applicable to both conventional scrapes and self-sampled cervico-vaginal specimens.Aberrant DNA methylation and histone modification also play an important role in the malignant transformation of hematopoietic cells. In the past years, novel mutations have been described in genes from the epigenetic machinery  as well as in metabolic genes (IDH1 and IDH2), which impact the epigenetic status of the leukemic blasts –47. By uIt is anticipated that with the continuously increasing power of cellular, functional and genetic screens, including the application of next-generation sequencing, cancer-causing genes and/or mechanisms will be elucidated at an increasingly rapid pace. This, in turn, will provide further insights into the etiology of cancer and opportunities to improve diagnosis, prognosis and  therapy.