The Rs4938723 Polymorphism Reduces Expression of MicroRNA-34b and Increases the Risk of Recurrence after Endoscopic Dissection in Early Gastric Cancer.
BACKGROUND
In respect to the effect of MET1 upon the recurrence of Early gastric cancer (EGC) after endoscopic dissection (ESD) treatment, we aimed to investigate the molecular mechanism, including the potential regulator and signaling pathways of MET1 in this study.


METHODS
We searched the miRNA database online (www.mirdb.org) with the "seed sequence" located within the 3'-UTR of the target gene, and then validated MET1 to be the direct gene via luciferase reporter assay system. Real-time PCR and western-blot were used to determine the expression of miR-34b mRNA and MET1 mRNA and protein in different treating group.


RESULTS
MET1 was the direct gene of miR-34b by searching the miRNA database online and constructing luciferase reporter. We also investigated the negative regulatory relationship between miR-34b and MET1 via studying the relative luciferase activity at different concentrations of miR-34b mimics. Further, since rs4938723 polymorphism was previously reported to be interfering with the expression of miR-34b, we investigated the expression level of different genotypes including TT (N=20), TC (N=9) and CC (N=3), which supported the hypothesis that the presence of minor allele (C) of rs4938723 polymorphism compromised the expression of miR-34b. Meanwhile, we also conducted real time PCR and Western blot analysis to study the mRNA and protein expression level of MET1 among different genotypes or cells treated with different concentration of miR-34b mimics/inhibitors, indicating the negative regulatory relationship between miR-34b and MET1.We also investigated the relative viability of EGC cells when transfected with miR-34b mimics (50nM and 100nM) and miR-34b inhibitors (100nM) to validate miR-34b to be negatively interfering with the viability of EGC cells.


CONCLUSION
These data confirmed miR-34b rs4938723 polymorphism was also recognized as a biomarker to predict recurrence after ESD in EGC patients via analysis upon the recurrence-free rate among different genotypes of EGC patients.
['Yu|Kuaiyun|K|']
D020413:3' Untranslated Regions D000483:Alleles D000070416:Antagomirs D001483:Base Sequence D014408:Biomarkers, Tumor D045744:Cell Line, Tumor D030541:Databases, Genetic D005773:Gastroscopy D005838:Genotype D006801:Humans D035683:MicroRNAs D009364:Neoplasm Recurrence, Local D009367:Neoplasm Staging D020641:Polymorphism, Single Nucleotide D016016:Proportional Hazards Models D019859:Proto-Oncogene Proteins c-met D012333:RNA, Messenger D060888:Real-Time Polymerase Chain Reaction D012307:Risk Factors D016415:Sequence Alignment D013274:Stomach Neoplasms D015996:Survival Rate
Rs4938723 MicroRNA-34b Recurrence Endoscopic dissection Early gastric cancer Apoptosis MET