circ_0005075 promotes proliferation and invasion of liver cancer HCCC9810 cells by sponging miR-335 / 中国肿瘤生物治疗杂志

ABSTRACT

@#Objective: To explore the effect of circ_0005075 on the proliferation and invasion of liver cancer cells and its underlying mechanism. Methods:Atotal of 35 cases of cancer tissues and corresponding para-cancerous tissues from liver cancer patients, who underwent surgical resection in Tangshan Workers’Hospital from March 2015 to March 2018, were collected for this study. qPCR was used to detect the expression levels of circ_0005075 and miR-335 in liver cancer tissues, para-cancerous tissues, liver cancer cell lines (HCCC9810, HepG2, HLE and hepatic epithelial THLE-3 cells). Dual luciferase reporter gene assay was used to verify the targeting relationship among circ 0005075, mir-335 and CCND1. By using liposome-mediated method, Sh-circ_0005075, miR-335 mimics, miR335 mimics+pcDNA-CCND1, sh-circ_0005075+pcDNA-CCND1, pcDNA-circ_0005075+miR-335 mimics, sh-CCND1+pcDNA-circ_ 0005075 were transfected into HCCC9810 cells, respectively. The effects of circ_0005075/miR-335/CCND1 molecular axis on the proliferation and invasion of HCCC9810 cells were detected by MTT and Transwell methods. Results: circ_0005075 was highly expressed in liver cancer tissues and cell lines (P<0.01) ,and the highest expression in HCCC9810 cells (P<0.05). Dual luciferase reporter gene results showed that circ_0005075 negatively regulated miR-335 (P<0.05), and CCND1 was a target gene of miR-335 (P<0.05). Further experiments proved that knockdown of circ_0005075 or overexpression of miR-335 could inhibit the proliferation and invasion of HCCC9810 cells by regulating CCND1（P<0.05 or P<0.01） . Conclusion: Circ_0005075 upregulates the expression level of CCND1 by sponging miR-335, thereby promoting the proliferation and invasion of HCCC9810 cells.