Chromodomain Helicase DNA-Binding Protein 5 Inhibits Renal Cell Carcinoma Tumorigenesis by Activation of the p53 and RB Pathways

Chromodomain helicase DNA-binding protein 5 (CHD5) plays a crucial tumor suppressor role in multiple types of tumors. For this study, we investigated its clinical significance and the molecular mechanism(s) underlying tumorigenesis in renal cell carcinoma (RCC). Initially, CHD5 expression was assessed in primary tumor tissue and in tissue array. Correlations among CHD5 expression and clinicopathological characteristics were analyzed. Next, lentivirus-mediated CHD5 overexpression in the ACHN and 769-P cells was used to assess effects on proliferation, migration, invasion ability, and the regulation of the p14(ARF)/p53 and p16(INK4a)/RB signaling pathways. Finally, a xenograft mouse model was used to verify its impact on tumor growth in vivo. Results demonstrated that CHD5 was downregulated in tumor tissues and that low CHD5 expression was correlated with advanced TNM stage, high Fuhrman grade, lymph node metastasis, and poor survival. Overexpression of CHD5 inhibited proliferation, migration, and invasion in vitro; prompted cell cycle G1 phase arrest; induced apoptosis; and suppressed tumor growth in vivo. Furthermore, we confirmed that CHD5 activates the p53 and RB pathways to inhibit tumorigenesis in RCC. In summary, CHD5 is involved in the initiation and progression of RCC and may serve as a diagnostic biomarker and a potential therapeutic target for RCC.