[Effect of RNF152 on NO induced apoptosis of colon cancer cells]

Objective: To investigate the role and mechanism of ring finger protein 152 (RNF152) in the development of colitis-associated colon cancer (CAC). Methods: CAC was induced by azoxymethane (AOM) and dextran sulfate sodium (DSS) in C57BL/6 mice. Three different stages of mice during the development of colon cancer were obtained, named AD1, AD2 and AD3, respectively. A control group of mice without any treatment was set up as well. The expression of RNF152 in mouse colon tissues was measured by real-time quantitative polymerase chain reaction (RT-qPCR). The effects of RNF152 overexpression on apoptosis and nitric oxide (NO) induced apoptosis was examined by flow cytometry. The expressions of Bcl-2 and Bcl-XL were detected by western blot. Results: CAC was effectively induced by AOM and DSS in C57BL/6 mice. The tumor incidence rate of AD3 group was 100%. The whole genome expression microarray data from mouse AOM-DSS model indicated that the mRNA level of RNF152 was gradually decreased during the development of colon cancer. The RT-qPCR results showed that RNF152 mRNA level in AD3 was 1.23±0.18, higher than 0.52±0.08 in negative control (P<0.01). Flow cytometry analysis showed that overexpression of RNF152 increased the apoptosis of RKO cells (P<0.01). The apoptotic rate of RKO-RNF152 cells treated with NO donor DETA NONOate was (31.2±3.1)%, higher than (14.2±2.1)% in RKO-PCDB cells (P<0.001). Overexpression of RNF152 significantly decreased the protein expressions of Bcl-XL and Bcl-2. Conclusion: Downregulation of RNF152 may facilitate the development of CAC by inhibiting the cell apoptosis.