Function And Mechanism Of Long Non-coding RNA-ROR In Gastric Cancer

Background:Long intergenic non-coding RNA reg?lator of reprogramming(LincRNA-ROR),is a newly identified long non-coding RNA,was initially found to reg?late the process of reprogramming.Present studies indicated that it played important roles in development and progression of hepatocell?lar carcinoma,breast cancer and glioma.However,the role of ROR in gastric cancer is rarely known.The conclusion below has been demonstrated by our previous study.1)The levels of ROR was significantly down-reg?lated in 50 tissues of gastric cancer.2)Over-expression of ROR in gastric cancer cells co?ld significantly induced apoptosis,suppressed invasion and migration,while had little effect on cell proliferation.3)ROR co ? Id induce epithelial-to-mesenchymal transition to inhibt metastasis of gastric cancer cells.The experiments based on previous data are to testify the proposed function and mechanism of ROR in the negative.Firstly,the gastric cancer tissues added up to 65 cases are used for the subsequent research.Secondly,knockdown experiment was used to study biological behaviors and mechanism of ROR.Methods:1.Quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect the expression levels of ROR in 65 gastric cancer tissues and its paired adjacent normal tissues,analyzing the relationship between the expression of ROR and its Clinicopathological features.2.knockdown trial was used to lower ROR expression,the transfection efficiency was verified by qRT-PCR.3.The effect on proliferation and apoptosis after down-reg?lating expression of R07R was evaluated by CCK-8 assay and flow cytometry.Transwell assay was performed to detect the ability of migration and invasion in gastric cancer cells.4.Western blotting was used to detect the markers of epithelial-to-mesenchymal transition(EMT).Res?lts:1.The levels of ROR were significantly down-reg?lated in gastric cancer compared with paired adjacent normal tissues(P<0.001).2.The ROR expression was down-reg?lated in MGC-803 and SGC-7901 cells after knockdown experiment(p<0.001).3.CCK-8 assay,flow cytometry,transwell assay indicated that it co?ld promote cell proliferation(P<0.01),significantly inhibited apoptosis(P<0.05),promote invasion and migration(P<0.05)after knockdown of ROR.4.Westem blotting has discovered the epithelial markers(E-cadherin)were down-reg ? lated after knock-down of ROR,whereas the mesenchymal markers(Vimentin?N-cadherin?a-SMA)and p-AKT were increased when we examined the protein markers.The corresponding markers show an opposite trend after pathway inhibitors added.Conclusion:The levels of ROR was significantly down-reg?lated in gastric cancer tissues.Moreover,ROR in gastric cancer cells co?ld suppress cell invasion and migration,significantly promote cell apoptosis.ROR had little effect on cell proliferation by overexpression,however,it co?ld promote cell proliferation by knockdown.Additionally,ROR co ? Id suppress invasion and migration partly because of the influence of AKT signal pathway on EMT in gastric cancer cell lines.