Combination Effects Of Droxinostat And Cisplatin On Cell Proliferation And Apoptosis Of Hepatocellular Carcinoma Cells In Vitro

BACKGROUND:Histone deacetylase inhibitors (HDACIs) can suppress tumor development and progression. Many studies have found droxinostat can anti-tumor and characterized by low toxicity and thus was taken more and more attention, but it has anti-cancer effects on HCC has not been reported. Cisplatin (DDP) chemotherapy as first-line treatment of hepatocellular carcinoma (HCC), however, its resistance phenomenon and toxicities making the practicality is not satisfactory. In our study, we evaluated the potential combinative effect of droxinostat and cisplatin on HCC cell lines.OBJECTIVE:In this study, we explored the anti-neoplastic effects of droxinostat and DDP on HCC cell lines HepG2and SMC-7721in vitro, and explore the synergistic anti-neoplastic efficiency, focused on cell proliferation, apoptosis and explored its relevant mechanism. This study aimed at providing a theoretical strategy for the application of combination theoretical strategy in HCC.METHODS:HepG2and SMMC-7721cells lines were used in this study.(1) By using MTT assay, droxinostat and DDP treated HCC cells respectively with different concentrations, in order to choose low-dose cisplatin concentration and the appropriate concentration of droxinostat.(2)By using the Real Time Cellular Analysis (RTCA) and MTT assay, we detected cells proliferation of droxinostat combined with low-dose cisplatin, and to explore whether the two drugs have a synergistic effect.(3)Cells apoptosis rate was measured by flow cytometry.(4) HDAC3, p53Bcl-2, Bax mRNA expression were assessed by using the q RT-PCR.(5) HDAC3, histone acetylation levels and mitochondrial apoptosis pathway expression were analysised by Western Blot.RESULTS:Both SMMC-7721cells and HepG2were sensitive to Droxinostat and DDP respectively in time and dose dependent manner. Compared with either Droxinostat or low-dose DDP treated alone, combination therapy could inhibit HCC cell proliferation (P <0.05) and induce apoptosis (P<0.05); Droxinostat combine with low-dose DDP can inhibit the expression of HDAC3, enhance the expression of histone acetylation levels, and increase activation of the mitochondrial apoptotic pathway.CONCLUSION:Our studies showed that histone deacetylase inhibitor Droxinostat can inhibite cell proliferation and induce cell apoptosis. Its potential mechanism may be related to the suppression HDAC3, increasing acetylation of histone expression, achieved by the mitochondrial apoptosis pathway. Droxinostat can effectively enhance cisplatin on HCC on the effects of inhibiting cell proliferation and inducing cell apoptosis. This study suggests that Droxinostat and cisplatin were worthy of further exploration for therapy of HCC.