| Objective: The morbidity and mortality of gastric cancer have been high in a long time.The incidence of gastric adenocarcinoma accounts for 95% of gastric malignant tumors,which is the most common type of gastric cancer in histology.At present,some researchers had proved that long non-coding RNAs is related to pathogenesis of gastric adenocarcinoma.The purpose of this study was to discover a new lncRNA,explore its expression in gastric adenocarcinoma tissues and cell lines,and combine the clinical and pathological data corresponding to the samples to initially reveal its molecular role in the pathogenesis of gastric adenocarcinoma.The functions it plays are looking for new in vitro markers for early diagnosis of gastric cancer and potential targets for targeted treatment of gastric cancer.Methods:(1)The high-throughput expression profiling chip technology was used to detect gastric adenocarcinoma and corresponding adjacent tissues by the research team in the early stage,and differentially expressed lncRNAs were obtained.Combined with information such as the multiple of lncRNA differential expression,preliminary screening the lncRNA has not been reported in the literature at home and abroad is used as the target lncRNA.(2)Verify the expression of the target lncRNA in89 pairs of gastric adenocarcinoma and corresponding adjacent tissues,as well as gastric adenocarcinoma cell lines by real-time fluorescent quantitative PCR(RT-qPCR)technology,and evaluate whether the results are consistent with the chip expression profile.(3)Two cell lines with low expression of the target lncRNA were initially selected,and the lentivirus was used to construct the overexpression vector of the target lncRNA,so that the target cells showed more than twice the expression before the lentivirus infection.(4)Evaluate the effect of the target lncRNA on the biological behavior of gastric adenocarcinoma cells including invasion and metastasis through cell function measurements and animal experiments.Results:(1)The target lncRNA RP3-333A15.1 was screened from the expression profile of the previous chip,and the sample size of RP3-333A15.1 in gastric adenocarcinoma and adjacent tissues was verified by expanding the sample’s amount by qPCR technology.The down-regulated expression rate was 78.7%(70/89),and the difference was statistically significant(p <0.001)for obviously down-regulated expression.(2)Differential expression of lncRNA RP3-333A15.1 combined with clinicopathological data showed that: the expression of lncRNA RP3-333A15.1 in gastric adenocarcinoma and adjacent tissues of 89 patients was no related to the age,gender,tumor site,the degree of differentiation,depth of invasion,lymph node metastasis,peripheral nerve invasion or not,and surgical options(P>0.05),by contrast,it was related to tumor size and vascular invasion(P<0.05).(3)Overexpression of lncRNA RP3-333A15.1 in vitro gastric adenocarcinoma cell lines SGC-7901 and MGC-803 significantly inhibited their biological behaviors such as metastasis and proliferation.The subcutaneous tumor-bearing experiment in nude mice confirmed that lncRNA RP3-333A15.1 has the effect of inhibiting the growth of gastric adenocarcinoma cell SGC-7901 in vivo.Conclusion: After 89 pairs of gastric adenocarcinomas and adjacent tissues were verified by RT-qPCR,lncRNA RP3-333A15.1 was down-regulated in gastric adenocarcinoma tissues,which was consistent with the results of previous microarray detection.In vitro cell experiments and animal experiments confirmed that overexpression of lncRNA RP3-333A15.1 significantly inhibited gastric adenocarcinoma cell proliferation,invasion,metastasis and other biological behaviors.The expression of lncRNA RP3-333A15.1 in gastric adenocarcinomas and adjacent tissues is obviously associated with tumor size and vascular invasion.In summary,lncRNA RP3-333A15.1 has clinical value as a new detection marker in vitro for early diagnosis of gastric cancer and a potential target for targeted therapy of gastric cancer. |
PDF Full Text Request