Study Of Apoptosis In Human Laryngeal Carcinoma Hep-2 Cells Induced Arsenic Trioxide

Objective: To investigate the possibility and mechanism of human laryngeal carcinoma Hep-2 cells induced arsenic trioxide.Methods: After treatment with arsenic trioxide, Hep-2 cells growth inhibition were assessed by MTT colorimetric assay and apoptotic rate by flow cytometry. We observed morphological characters of apoptosis by electron microscope and assessed endonucleolysis by electronphoresis. We also observe the expression of bcl-2 by flow cytometry and in-direct immunofluorescence.Results: Arsenic trioxide inhibited the growth of Hep-2 cells in dose-dependent manner in a certain range of dose, and the IC50of As2O3 for12h, 24h, 36h, 48h, is 1.75μmol/L, 1.35μmol/L, 1.05μmol/L, 0.85 μmol/L; At dose of 0.25μmol/L, 0.5μmol/L, 1μmol/L, 2μmol/L, arsenic trioxide apparently inhibited growth of Hep-2 cells for 48h is 15%, 33%, 65%, 82%, flow cytometry showed apoptotic rate is 21.7%, 19%, 5.2%, 4.6%.The marked morphological changes included condensed charomatin, nuclear fragmentation and apoptotic body. Agarose gel electronphoresis of DNA revealed ladder pattern. The expression of bax was measured to increase with increase of drug dose by FCM.Conclusion: Arsenic trioxide may induce apoptosis of human laryngeal carcinoma Hep-2 cells, and the up-regulation of bax expression was one of the most important role in apoptosis.