RESUMO
@#Objective: To explore the mechanism of lncRNA XIST (XIST) regulating the biological behaviors of colorectal cancer HCT-8 cells via miR-32-5p/EZH2 (enhancer of Zeste homolog 2) axis. Methods:Atotal of 28 pairs of cancer tissues and corresponding para-cancerous tissues form colorectal cancer patients with complete clinical data were collected from the Colorectal and Anal Surgery, Xiangya Hospital of Central South University during July 2014 and August 2018. The expression levels of lncRNA XIST and miR-325p in colorectal cancer tissues and cell lines were detected by qPCR. The targeted relationship between lncRNA XIST, miR-32-5p and EZH2 was verified by dual luciferase reporter gene, and the expression level of EZH2 was further detected by WB. The proliferation, migration and apoptosis of HCT-8 cells were detected by CCK-8, Transwell and flow cytometry with Annexin V-FITC/PI staining, respectively. Results: lncRNAXIST was highly expressed in colorectal cancer tissues and cell lines with the highest expression in HCT-8 cells (P<0.05 or P<0.01). Dual luciferase reporter gene assay validated that lncRNA XIST negatively regulated miR-32-5p (P<0.05), and EZH2 was a target gene of miR-32-5p. Knockdown of lncRNAXIST inhibited proliferation and migration and induced apoptosis of HCT-8 cells (P<0.05 or P<0.01). Further experiments demonstrated that knockdown of lncRNA XIST up-regulated the expression of miR-32-5p and further down-regulated the expression level of EZH2, thereby inhibiting the proliferation and migration of HCT-8 cells and inducing apoptosis. Conclusion: lncRNAXIST promotes proliferation, migration and inhibits apoptosis of HCT-8 cells via miR-325p/EZH2 axis.
RESUMO
@# Objective: To investigate the mechanism of lncRNA XIST (XIST) on modulating gastric cancer progression via regulating miR-337-3p/HOXC8 axis. Methods: A total of 58 cases of gastric cancer tissues and corresponding para-cancerous tissues resected from March 2013 to January 2018 in Department of General Surgery, Kailuan General Hospital of Tangshan City were collected for this study; in addition, human gastric cancer cell lines (AGS, MGC803, HGC27) and human gastric mucosal GES-1 cells were also collected. qPCR was used to detect the expressions of XIST and miR-337-3p in above mentioned gastric tissues and cell lines. XIST-knockdown vectors, miR-337-3p mimics, miR-337-3p inhibitor and HOXC8-overexpression vectors were transfected into AGS cells. The proliferation and invasion of AGS cells were detected by CCK-8 and Transwell experiments respectively, and the expression levels of HOXC8, E-cadherin, N-cadherin and vimentin were detected by WB. The targeting relationships between XIST, miR337-3p and HOXC8 were verified by dual-luciferase reporter gene assay. Results: XIST was up-regulated in gastric cancer tissues and cell lines (all P<0.01). XIST knockdown significantly inhibited proliferation, invasion and EMT of AGS cells (P<0.05 or P<0.01). Moreover, XIST directly interacted with miR-337-3p and down-regulated its expression, while HOXC8 was the target gene of miR-3373p. Furthermore, XIST knockdown suppressed proliferation, invasion and EMT ofAGS cells through up-regulating the inhibitory effect of miR-337-3p on HOXC8 (P<0.05 or P<0.01). Conclusion: XIST knockdown can suppress the proliferation, invasion and EMT of AGS cells, which may be related with down-regulation of HOXC8 by targeting miR-337-3p.
RESUMO
@# Objective: To investigate the molecular mechanisms of lncRNA XIST/miR-34a-5p/SIRT6 axis regulating the proliferation and metastasis of oral squamous cell carcinoma (OSCC) cells. Methods: Specimens of tumor tissues and paracancer tissues of 47 patients with OSCC, who visited the Qingdao Stomatological Hospital from March 2013 to March 2018, were enrolled in this study. qPCR was performed to measure the mRNA expressions of lncRNA XIST, miR-34a-5p and SIRT6 in OSCC tissues and cell lines. WB was performed to measure the protein levels of SIRT6, Ki67, pcDNA, cleaved-caspase3, cleaved-caspase8, E-cadherin and vimentin in OSCC tissues and cell lines. CCK-8 assay was performed to observe the effect of lncRNA XIST knockdown on proliferation of Cal-27 and Tca-8113 cells; Tanswell assay was performed to detect migration and invasion of Cal-27 and Tca-8113 cells; flow cytometry was performed to detect the apoptosis of Cal-27 and Tca-8113 cells; and dual luciferase reporter assay was performed to verify the relationship between lncRNAXIST and miR-34a, or miR-34a and SIRT6. Results: Expressions of lncRNAXIST and SIRT6 were up-regulated in OSCC tissues and cell lines (all P<0.05), reversely, miR-34a-5p was down-regulated in OSCC tissues and cell lines (P<0.01). lncRNA XIST knockdown significantly suppressed OSCC cells proliferation, migration and invasion, and induced apoptosis of OSCC cells (all P<0.01); however, simultaneous transfection with miR-34a-5p inhibitor or pcDNA-SIRT6 vector exerted opposite effect. lncRNA XIST knockdown significantly increased cell proliferation and metastasis related protein expression in OSCC cells (all P< 0.01), and simultaneous transfection with miR-34a-5p inhibitor or pcDNA-SIRT6 vector exerted opposite effect. In addition, lncRNA XIST directly targeted miR-34a-5p, and miR-34a-5p targeted SIRT6, lncRNA XIST upregulated SIRT6 expression via inhibiting miR34a-5p (P<0.01). Conclusion: Taken together, lncRNA XIST/miR-34a-5p/SIRT6 axis regulates the proliferation and metastasis of OSCC cells and provides potential therapeutic targets for OSCC.