Role of long non-coding RNA maternally expressed gene 3 on cell proliferation and apoptosis of clear cell renal cell carcinoma

Abstract

Objective To examine the expression of long non-coding RNA maternally expressed gene 3 (MEG3) in human clear cell renal cell carcinoma tissues (ccRCC) and cell lines. And to analyze the effects of MEG3 overexpression on the proliferation and apoptosis of ccRCC cells. Methods Real-time quantitative polymerase chain reaction (Real-time PCR) was carried out to measure the expression level of MEG3 in ccRCC specimens and cell lines compared with respective controls. After MEG3 was stabilized overexpressed in 786-O cells, methyl thiazol tetrazolium (MTT) and flow-cytometric assays were performed to evaluate the effects of MEG3 on cell proliferation and apoptosis. Protein levels of growth-or apoptosis-related molecules were then determined by Western blotting. Results MEG3 expression was decreased in ccRCC specimens and cell lines compared with respective controls. Overexpression of MEG3 in ccRCC cell line 786-O [0.51±0.02 vs. 11.26±1.89 for pcDNA3.1 and pcDNA3.1-MEG3 cell lie respectively with statistical difference (P<0.05)] resulted in delayed cell proliferation rate and induction of cell apoptosis[(7.02±1.21)% vs. (13.95±5.48)%] in vitro. Cyclin D1 and B cell lymphoma/leukemia-2 associated X protein (bax) protein levels were affected by MEG3 overexpression in these cell lines. Conclusion MEG3 was down-regulated in ccRCC, in which it functions as a potent tumor suppressor by regulating cell proliferation and apoptosis processes. Key words: Long non-coding RNA; Maternally expressed gene 3; Clear cell renal cell carcinoma; Cell proliferation; Apoptosis