Revista de toxicología clínica y experimental


Novel benzoxazole derived genotoxicity apoptogenic effects in hepatoma cell.

Yaoqing Chen, Yang Wang, Xueli Xie, Abhay Pratap Singh, Jian Fu

The hepatocellular carcinoma represent significant drug resistance to impediment effective treatment. The novel benzoxazole derivatives and the cytotoxicity effect toward hepatocellular carcinoma displayed critical regulatory process to cause cellular apoptosis. In this study, we investigated synthesized novel benzoxazole derivative dosage and time dependent bioaviability and morphology apoptosis in hepatoma cell (SMMC-7721). The derivative induced exposure of phosphatidylserine, DNA fragmentation and cleave of cysteine-aspartic acid protease expression in the execution of cell apoptosis were evaluated. The novel benzoxazole derivative dosage dependent SMMC-7721 cell membrane phosphatidylserine sensing to annexin a5 affinity were investigated by annexin a5 and propidium iodide dual staining flow cytometry. Cellular morphology of apoptosis were identified by Hoechst33258 stained adenine and thymine riches double-stranded DNA. The cytotoxicity induced DNA fragmentation in SMMC-7721 cell were analyzed by TdT-mediated dUTP nick-end labeling and agarose gel electrophoresis. Apoptosis relative cleaved cysteine-aspartic acid protease expression were quantified by westernblot. The results inducated that 2.5 μmol/L and 5 μmol/L was the optimum low dosage in genotoxicity of SMMC-7721 cell, however the significant decreasing of cellular viability in SMMC-7721 recognized in high dosages. The derivative induced phosphatidylserine sensing to annexin a5 affinity were increased 300% in the high dosage of 30 μmol/L. 24 hours incubation was the optimum time to obtain cellular morphological apoptosis and the significantly DNA ladder in optimum low dosage 5 μmol/L. DNA fragmentation were observed after 48 hours incubation in optimum low dosage. The A preliminaryprocaspase-3 and -9 down-regulated and the activated cleaved caspase-3, -9 up-regulated were recognized in the moderate dosage of 10 μmol/L, morevover become too significant in maximum dosage of 30 μmol/L. However, Poly (ADP-ribose) polymerase were preliminary significantly inhibited in the moderate dosage of 20 μmol/L. Conclusions: In vitro synthesized novel benzoxazole derived hepatocellular carcinoma SMMC-7721 cell morphological apoptosis were dosage-dependent that were observable in the lowest dosage of 2.5 μmol/L, however cellular phosphatidylserine exposure were presented in quadrupling of this lowest dosage. The derivative intervene manifested as DNA double strain chain breaks, DNA fragmentation and single-strand DNA breaks in low dosages, while decreasing the expression and cleaving of procaspase-3 and -9 in moderate dosages. Based on the above results, it can be concluded that synthesized novel benzoxazole derivative was the compound to introduce the genotoxicity in SMMC-7721 cell, further inducing apoptogenic effectiveness. This the important mechanism for this new structure benzoxazole toovercome the hepatic carcinoma drug resistance.