Down-regulation of Polη expression leads to increased DNA damage, apoptosis and enhanced S phase arrest in L-02 cells exposed to hydroquinone

摘要: Abstract DNA polymerase eta (Polη), the product of xeroderma pigmentosum variant gene, is required for translesion synthesis, and plays a pivotal role in preventing genome instability after damage induced by genotoxic agents. Studies have previously suggested link between Polη susceptibility to hydroquinone (HQ)-induced toxicity. To further address response L-02 cells HQ, we employed RNA interference silence expression examined these Polη-deficient toxic effects HQ. In this study, cell survival rate was determined using MTT assay, Comet apoptosis cycle distribution were flow cytometry, mRNA levels real-time PCR, protein γ-H2AX Western blot, foci visualized confocal laser scanning fluorescence microscopy exposed HQ at various concentrations 24 h vitro. The results showed that stable Polη-knockdown successfully constructed more than 80% inhibition confirmed. also down-regulation led decrease proliferation an enhanced HQ-induced cytotoxicity. 2-fold sensitive when compared with nonspecific siRNA control cells. Moreover, Polη-silenced treated displayed increased level double-strand breaks as measured olive tail moment, elevated indicated induction γ-H2AX. addition, knockdown resulted pronounced S phase arrest following treatment. Together, show important damage.