Long non-coding RNA GATA6-AS1 is mediated by N6-methyladenosine methylation and inhibits the proliferation and metastasis of gastric cancer

BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 plays a role as an anti-oncogene in the occurrence and development of gastric cancer.Further experi-ments confirmed that the overexpression of fat mass and obesity-associated protein(FTO)inhibited the expression of GATA6-AS1,thereby promoting the occurrence and development of gastric cancer.AIM To investigate the effects of GATA6-AS1 on the proliferation,invasion and migration of gastric cancer cells and its mechanism of action.METHODS We used bioinformatics methods to analyze the Cancer Genome Atlas(https://portal.gdc.cancer.gov/.The Cancer Genome Atlas)and download expression data for GATA6-AS1 in gastric cancer tissue and normal tissue.We also constructed a GATA6-AS1 lentivirus overexpression vector which was transfected into gastric cancer cells to investigate its effects on proliferation,migration and invasion,and thereby clarify the expression of GATA6-AS1 in gastric cancer and its biological role in the genesis and development of gastric cancer.Next,we used a database(http://starbase.sysu.edu.cn/starbase2/)to analysis GATA6-AS1 whether by m6A methylation modify regulation and predict the methyltransferases that may methylate GATA6-AS1.Furthermore,RNA immunoprecipitation experiments confirmed that GATA6-AS1 was able to bind to the m6A methylation modification enzyme.These data allowed us to clarify the ability of m6A methylase to influence the action of GATA6-AS1 and its role in the occurrence and development of gastric cancer.RESULTS Low expression levels of GATA6-AS1 were detected in gastric cancer.We also determined the effects of GATA6-AS1 overexpression on the biological function of gastric cancer cells.GATA6-AS1 had strong binding ability with the m6A demethylase FTO,which was expressed at high levels in gastric cancer and negatively correlated with the expression of GATA6-AS1.Following transfection with siRNA to knock down the expression of FTO,the expression levels of GATA6-AS1 were up-regulated.Finally,the proliferation,migration and invasion of gastric cancer cells were all inhibited following the knockdown of FTO expression.CONCLUSION During the occurrence and development of gastric cancer,the overexpression of FTO may inhibit the expression of GATA6-AS1,thus promoting the proliferation and metastasis of gastric cancer.

Prognostic value of the long noncoding RNA AFAP1-AS1 in cancers

Objective This meta-analysis explored whether the expression of actin filament-associated protein 1 antisense RNA 1(AFAP1-AS1)is related to the prognosis and clinicopathological features of patients with cancer.Methods PubMed,EMBASE,and Cochrane Library were systematically searched.Hazard ratios(HRs)with 95%confidence intervals(CIs)were used to assess the prognostic value based on overall survival(OS),disease-free survival(DFS),and progression-free survival(PFS).Odds ratios(ORs)with 95%CIs were used to determine the relationships between AFAP1-AS1 and clinicopathological features,such as large tumor size(LTS),high tumor stage(HTS),poor histological grade(PHG),lymph node metastasis(LNM),and distant metastasis(DM).Results Thirty-five eligible articles and 3433 cases were analyzed.High AFAP1-AS1 expression,compared to low AFAP1-AS1 expression,correlated with significantly shorter OS(HR=2.15,95%CI=1.97-2.34,P<0.001),DFS(HR=1.37,95%CI=1.19-1.57,P<0.001),and PFS(HR=1.97,95%CI=1.56-2.50,P<0.001)in patients with cancer.In various cancers,elevated AFAP1-AS1 expression was significantly associated with LTS(OR=2.76,95%CI=2.16-3.53,P<0.001),HTS(OR=2.23,95%CI=1.83-2.71,P<0.001),and PHG(OR=1.39,95%CI=1.08-1.79,P=0.01)but not LNM(OR=1.59,95%CI=0.88-2.85,P=0.12)or DM(OR=1.81,95%CI=0.90-3.66,P=0.10).Conclusion High AFAP1-AS1 expression was associated with prognostic and clinicopathological features,suggesting that AFAP1-AS1 is a prognostic biomarker for human cancers.

Basic Study Long non-coding RNA TP73-AS1 promotes pancreatic cancer growth and metastasis through miRNA-128-3p/GOLM1 axis

BACKGROUND Previous studies have suggested that long non-coding RNAs(lncRNA)TP73-AS1 is significantly upregulated in several cancers.However,the biological role and clinical significance of TP73-AS1 in pancreatic cancer(PC)remain unclear.AIM To investigate the role of TP73-AS1 in the growth and metastasis of PC.METHODS The expression of lncRNA TP73-AS1,miR-128-3p,and GOLM1 in PC tissues and cells was detected by quantitative real-time polymerase chain reaction.The bioinformatics prediction software ENCORI was used to predict the putative binding sites of miR-128-3p.The regulatory roles of TP73-AS1 and miR-128-3p in cell proliferation,migration,and invasion abilities were verified by Cell Counting Kit-8,wound-healing,and transwell assays,as well as flow cytometry and Western blot analysis.The interactions among TP73-AS1,miR-128-3p,and GOLM1 were explored by bioinformatics prediction,luciferase assay,and Western blot.RESULTS The expression of TP73-AS1 and miRNA-128-3p was dysregulated in PC tissues and cells.High TP73-AS1 expression was correlated with a poor prognosis.TP73-AS1 silencing inhibited PC cell proliferation,migration,and invasion in vitro as well as suppressed tumor growth in vivo.Mechanistically,TP73-AS1 was validated to promote PC progression through GOLM1 upregulation by competitively binding to miR-128-3p.CONCLUSION Our results demonstrated that TP73-AS1 promotes PC progression by regulating the miR-128-3p/GOLM1 axis,which might provide a potential treatment strategy for patients with PC.