RESUMO
@# To investigate the role of long chain non-coding RNA00707 (lncRNA00707) and micro RNA-613 (miR-613) in regulating the proliferation and metastasis of gastric cancer cells and its underlying mechanisms. Methods: Eighty-nine pairs of primary gastric cancer tissues and corresponding prar-cancerous tissues were collected from the Department of Surgical Oncology, Qinghai Provincial People's Hospital during January 2014 and June 2018 for this study. The expressions of lncRNA00707 and miR-613 in gastric cancer tissues and cells were detected by qPCR. The lncRNA00707 low expression and over-expression models of MGC-803 and SGC-7901 cells were established; The proliferation of gastric cancer cells was monitored by CCK-8 assay, and Transwell assay was performed to determine the migration and invasion of gastric cancer cells. Dual luciferase gene reporter assay was adopted to validate the relationship between lncRNA 00707 and miR-613. Results: Compared with para-cancerous tissues and normal cell line GES-1, the expression of lncRNA 00707 was significantly up-regulated in cancer tissues and cell lines, and the expression of lncRNA00707 was positively correlated with WHO stage (all P<0.05). Down-regulation of lncRNA 00707 significantly inhibited the proliferation and migration of SGC-7901 cells, while overexpression of lncRNA00707 exerted the opposite effect (all P<0.05). Compared with negative control group, lncRNA00707 over-expression significantly reduced the luciferase activity of miR-613; in the contrary, the luciferase activity of miR-163 was significantly increased in MGC-803 and SGC-7901 cells with lncRNA 00707 knockdown (all P<0.01). Conclusion: lncRNA 00707 facilitates the proliferation, migration and invasion of gastric cancer cells by inhibiting the function of miR-613, which exerts a protumorigenic effect in gastric cancer.
RESUMO
This study was designed to explore the effect and mechanism of miR-206/miR-613 on the expression of OATP1B1 gene. Bioinformatic analysis was used to predict the potential miRNAs target sites in 3'-untranslated region (3'-UTR) of OATP1B1 mRNA. The expression level of miR-206/miR-613 and OATP1B1 mRNA and protein was determined with RT-qPCR and Western blot, respectively. Luciferase assay was used to explore the exact mechanism of the effect of miR-206/miR-613 on the expression of OATP1B1 mRNA and protein. The results showed that the seed sequences of miR-206/miR-613 has perfect complementary with 3'-UTR of OATP1B1 mRNA in terms of sequence specificity. The secondary structure between miR-206/miR-613 and 3'-UTR of OATP1B1 mRNA was rather stable. The OATP1B1 protein level was down-regulated by 24.7%, 38.8% by overexpression of miR-206/miR-613. The expression was up-regulated by 25%, 38.2% by inhibition of miR-206/miR-613. However, overexpression or inhibition of miR-206/miR-613 had no effect on the expression of OATP1B1 mRNA. The luciferase activity of pMIR/OATP1B1-WT luciferase reporter gene was decreased by 35% and 30% through overexpression of miR-206/miR-613. The expression was increased by 33.1% and 32.5% through inhibition of miR-206/miR-613. When the binding sites in the 3'-UTR of OATP1B1 mRNA complementary with miR-206/miR-613 was mutated, overexpression or inhibition of miR-206/miR-613 had no effect on the luciferase activity. Collectively, miR-206/miR-613 post-transcriptionally regulates the expression of OATP1B1 protein by directly targeting the 3'-UTR of OATP1B1 mRNA.