Background: Study of the mechanisms of apoptosis in tumor cells is an important field of tumor therapy and cancer molecular biology. Apoptosis triggered by activation of the mitochondrial-dependent caspase pathway represents the main programmed cell death mechanism. The mitochondrial-dependent apoptosis pathway is activated by various intracellular stresses that induce permeabilization of the mitochondrial membrane, leading to cytochrome C release. This study was to investigate the anti-tumor effects of Dioscin from traditional Chinese anti-snake venom medicine Paris chinensis (PCD) and correlated mechanisms regarding apoptosis in human ovarian cancer SKOV3 cells.
Methods: Cell viability was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyl-tetrazolium bromide (MTT) assay. Cell apoptosis was evaluated by flow cytometry and Laser Scanning Confocal Microscope (LSCM) using Annexin-V/PI staining. Intracellular calcium ions were detected using fluorescence microscopy. The expression of apoptosis-related proteins cytochrome C and caspase-3 was measured by immunohistochemical staining.
Results: PCD had an anti-proliferation effect on human ovarian cancer SKOV3 cells in a dose- and time-dependent manner. After treatment with PCD, the apoptotic rate significantly increased, and accompanied with the increased levels of caspase-3 and cytochrome C protein in SKOV3 cells. Morphological changes typical of apoptosis were also observed with LSCM by Annexin V/PI staining. Moreover, intracellular calcium accumulation occurred in PCD-treated cells.
Conclusions: The molecular determinants of inhibition of cell proliferation as well as apoptosis of PCD may be associated with the activation of Ca2+-related m itochondrion pathway in SKOV3 cells.