miR-222 promotes retinoblastoma cell proliferation and invasion by targeting RB1 / 中国癌症杂志

ABSTRACT

Background and purpose:A large number of studies have showed that retinoblastoma gene 1 (RB1) can inhibit the occurrence and development of many tumors, including neuroblastoma, small cell lung cancer, osteosar-coma, pancreatic cancer, breast cancer and so on. RB1 is also closely related to the regulation of cell cycle, differentia-tion, senescence, apoptosis, growth inhibition, etc. The goal of this article is to elucidate whether miR-222 promotes cell proliferation and invasion by targeting RB1, further to explore the molecular mechanism that miR-222 functions as an oncogene in retinoblastoma cells.Methods:miR-222 (miR-222 mimics) and RB1-wt, miR-NC and RB1-wt, miR-222 and RB1-mut, miR-NC (a controlled miR-222 mimics) and RB1-mut were co-transfected into Y79 cells, and luciferase activity was detected by single photon. Retinoblastoma cells were transfected with miR-222 mimics and miR-NC, and the expressions of RB1 protein were detected by Western blot. Retinoblastoma cell proliferation assays were performed by MTS assay when miR-222, miR-NC, RB1 (pcDNA3.1-RB1), vector (pcDNA3.1), miR-222+RB1 and miR-NC+vec-tor were transfected into Y79 cells. The growth and invasion ability of Y79 cells with ectopic expression of miR-222 were evaluated by MTS and Transwell invasion assays.Results:This study demonstrated that miR-222 could promote the luciferase activity of RB1-wt. The expression levels of luciferase reporter gene activity in Y79 cells after transfection with miR-222+RB1-wt were higher than those in the negative control cells (miR-NC+RB1-wt) (P0.05). After transfection with miR-222 mimics for 48 h, Transwell invasion assay showed that the number of cells through the basement membrane was (193±10). Compared with the control group (144±11), it could signiifcantly accelerate the invasion of Y79 cells (P0.05).Conclusion:miR-222 promotes cell proliferation and invasion by targeting RB1 expression in retinoblastoma cells.