?.Study On The Roles And Mechanisms Of LncRNA TRERNA1 In Migaration-invasion Of GC Cells ?.An Associate Study Of Functional TagSNP Rs7560488 In DNMT3A Promoter To The Susceptibility Of Gastric Cancer In Chinese

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Study on the roles and mechanisms of IncRNA TRERNA1 in migration-invasion of GC cellsGastric cancer(GC)is the third leading cause of cancer-related deaths worldwide expecially in East Asia.The disease is generally asymptomatic and is diagnosed often at an advanced and even terminal stage.In spite of the improvement in chemotherapy,radiotherapy,molecular therapies and surgical techniques,the five-years overall survival rate of gastric cancer patients remains has not been significantly improved over the past few decades.One of the most important reasons is that more than half of GC patients were diagnosed at an advanced stage accompanied by malignant proliferation or lymphatic metastasis.However,the molecular mechanisms underlying the invasion and metastasis of advanced gastric carcinomas are still poorly understood.Previous studies mainly focused on protein-coding genes dysregulation and their functions,but the protein-coding genes dysregulation could not elucidate the complexity of GC.Epigenetic regulators and non-coding RNAs have recently gained significant attention in delineating the complex mechanisms underlying malignant cancer cells metastasis,lots of evidence have shown that ncRNAs play an important role in cancer carcinogenesis,invasion and metastasis,and could provide new insights into the malignant biological behavior of gastric cancer.The present research aims to explore the potential roles and mechanism of eRNATRERANA1 on malignant proliferation,migration and invasion in GC cells.The relative expression of TRERNA1 was detected by qPCR in clinical tissue samples and cell lines of gastric cancer,and the relationship between the expression levels of TRERNA1 and clinicopathological features of GC patients was evaluated as well.Employinge wound healing assay,transwell migration assay,matrigel invasion assay,CCK-8 assay and flow cytometry,we analyzed the function of TRERNA1 on the migration,invasion and proliferation of GC cells.Using Chromatin immunoprecipitation(ChIP)assay,RNA immunoprecipitation(RIP)assay and molecular biology technology such as qPCR and western blot,we try to unveil the molecular mechanisms underlying the migration and invasion induced by TRERNA1.Finally,to explore the mechanisms governing the expression of TRERNA1,ChIP technology,bioinformatics analysis,dual-luciferase reporter assay and clinical pathology analysis were adopted.Our data implied the following:1)Increased expression of TRERNA1 was positively correlated with lymph node metastasis in gastric cancer.2)TRERANA1 promoted the cell invasion and migration instead of cell proliferation in GC in vitro.3)TRERNA1 activated SNAIl to suppress CDH1 expression during cell invasion and migration in GC cells.4)TRERNA1 decreased CDH1 transcription by binding to EZH2 to increase H3K27me3 level of CDH1 during cell invasion and migration in GC cells.5)TRERNA1 deduced CDH1 translation through interacting with RNA-binding proteins hnRNP K,FXR1 and FXR2.6)TRERNA1 was regulated by transcription factor TFAP4 by binding directly to the E-box motif in the promoter of TRERNA1In summary,these results indicated that eRNA TRERNA1 is an oncogenic lncRNA that involved in the invasion and migration of GC cells,and leads us to propose that TRERNA1 may serve as key regulatory molecular in GC metastasis.Our provide new views and landscapes to understand the complex network of TRERNA1 in GC metastasis,and potential new strategies for the potential diagnostic and prognostic markers as well as therapeutic targets in gastric cancer.? An associate study of functional tagSNP rs7560488 in DNMT3A promoter to the susceptibility of gastric cancer in ChineseGastric cancer(GC)is one of the most common malignant tumors worldwide,especially in China.Epidemiologic studies have shown that people have been exposed to the same environmental risk factors,only a fraction of exposed individuals develop GC suggesting that there is inter-individual variation in genetic susceptibility to GC.DNMT3A which contains DNMT3A1 and DNMT3A2 are two de novo DNA methyltransferases plays a crucial role in embryonic development and aberrant DNA methylation in carcinogenesis.Polymorphisms of the DNMT3A gene may regulate gene expression,influence its enzymatic activity and may contribute to susceptibility to cancer.In the present study,we evaluate the associations between the genetic variants in the DNMT3A1 and GC risk and also reveal the biological mechanism of GC in a Chinese population.Our study would help for reveal the pathogenesis of gastric cancer and identify an optimal therapeutic target for precision medicine,and would provide innovative perspectives on GC study and new theoretical basis for early diagnosis,prevention,personalized treatment and medicine guide.We conducted a case-control study of 405 GC cases and 408 cancer-free controls,using the linkage disequilibrium(LD)-based tagging SNPs approach identified tagSNPs in the DNMT3A1 promoter,and then examined the functionality of promoter tagSNPs in DNMT31 by using the report gene assay,electrophoretic mobility shift assay(EMSA),and quantitative real-time RT-PCR.We screened two potentially functional tagSNPs rs7560488 and rs 1550117,and selected the novel tagSNP rs7560488 in DNMT3A1 promoter to evaluate the association with GC and further examined the functionality in GC.As a result,we found that the tagSNP rs7560488 T>C polymorphism in the DNMT3A1 promoter region was associated with risk of gastric cancer.Specifically,compared with the TT genotype,the TC/CC genotype is associated with a significantly increased risk of GC(OR=1.65,95%CI =1.118-2.877),the risk was 1.74 times who carries allele C than allele T(OR = 1.744,95%CI = 1.310-2.321).Subjects who were TC/CC genotype exhibited a reduced expression of DNMT3A1 than TT genotype in vivo.Furthermore,stratified analysis showed that individual who harbored TC or CC genotypes less than 60 years old were more susceptible to GC(OR=1.794,95%CI =1.118-2.877).In vitro functional analyses by luciferase reporter assay and electrophoretic mobility shift assay(EMSA)indicated that the tagSNP rs7560488 T>C substantially altered transcriptional activity of DNMT3A1 gene via influencing the binding of some transcriptional factor,although a definite transcriptional factors remains to be identified.Our results suggest that the genetic variations in the DNMT3A promoter contribute to the susceptibility to GC by modulating promoter activity,and also provide an insight that tagSNP rs7560488 T>C may be a promising biomarker for predicting GC genetic susceptibility and a valuable information in GC pathogenesis in Jiangsu province.