RBBP6 aggravates the progression of ovarian cancer by targeting PIK3R6.

Objective RBBP6 is identified to be a cancer-associated gene by bioinformatics analysis. This study aims to explore the role of RBBP6 in regulating proliferation and metastasis in ovarian cancer, thus providing theoretical references for ovarian cancer treatment. Patients and methods Differential expressions of RBBP6 in ovarian cancer and normal ones were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between RBBP6 and prognosis in ovarian cancer patients was analyzed. The interaction between RBBP6 and PIK3R6 was detected by bioinformatics analysis and Dual-Luciferase reporter assay. Moreover, regulatory effects of RBBP6 and PIK3R6 on proliferative and migratory potentials in A2780 and CAOV3 cells were examined by Cell Counting Kit-8 (CCK-8) and transwell assay, respectively. Finally, tumorigenicity assay was conducted in nude mice to illustrate the in vivo regulations of PBBP6 and PIK3R6 on ovarian cancer growth. Results RBBP6 was upregulated in ovarian cancer tissues than normal ones. RBBP6 was irrelevant to age, tumor size and tumor node metastasis (TNM) staging in ovarian cancer patients, but correlated to lymphatic metastasis and distant metastasis. RBBP6 was abundantly expressed in ovarian cancer cells, and among the tested cell lines, CAOV3 and A2780 expressed the highest level of RBBP6. Knockdown of RBBP6 attenuated in vitro proliferative and migratory potentials in CAOV3 and A2780 cells. PIK3R6 was the target gene binding RBBP6, which was positively regulated by RBBP6. Overexpression of PIK3R6 could abolish the inhibited proliferative and migratory potentials in ovarian cancer cells with RBBP6 knockdown. In addition, the knockdown of RBBP6 slowed the in vivo growth of ovarian cancer in nude mice, and the alleviated cancer progression was reversed by overexpression of PIK3R6. Conclusions RBBP6 is highly expressed in ovarian cancer cases, which stimulates proliferative and migratory potentials by targeting PIK3R6. RBBP6 may be a novel therapeutic target for ovarian cancer.