Knockdown of p62/sequestosome enhances ginsenoside Rh2-induced apoptosis in cervical cancer HeLa cells with no effect on autophagy

Abstract

p62/sequestosome is a multifunctional adaptor protein that participates in a wide variety of cellular processes. 20(S)-Ginsenoside Rh2 (G-Rh2) has various biological effects, including anticancer activity. We found that G-Rh2 can induce apoptosis and autophagy in HeLa cells. G-Rh2 significantly enhanced the transcriptional level of p62. A siRNA was constructed to knock down p62 and assess its effect on apoptosis induced by G-Rh2. p62 protein levels were successfully downregulated in cells transfected with the p62-specific siRNA. Silencing of p62 further decreased cell viability while also enhancing cell apoptosis, reactive oxygen species generation, the ratio of Bax to Bcl-2, and the cleavage of PARP. p62 knockdown decreased expression levels of Nrf2. Moreover, silencing of p62 had no significant effect on autophagy induced by G-Rh2. These results suggest that combining G-Rh2 treatment with inhibition of p62 may be a potential treatment strategy for cervical cancer.

Keywords: apoptosis; autophagy; ginsenoside G-Rh2; p62.