The apoptosis of OVCAR-3 induced by TNF-α plus IFN-γ co-immobilized polylactic acid copolymers

Abstract

The cell cycle arrest and apoptosis of human ovarian cancer OVCAR-3 cells, induced by three kinds of co-immobilized polylactic acid copolymer materials, compared with the corresponding control groups and free groups, are investigated in vitro. The three kinds of polylactic acid copolymers are PLGA (poly(lactic-co-glycolic acid)), PDLLA (poly(DL-lactic acid)), and PEG-PLGA (polyethylene glycol-poly(lactic-co-glycolic acid) copolymers). They are respectively photo-immobilized with TNF-α plus IFN-γ as the co-immobilized group, respectively mixed with TNF-α plus IFN-γ as the free group. First, the co-immobilized groups are prepared and examined by Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), and electron spectroscopy for chemical analysis (ESCA). Second, the cell morphology, cell mortality, and cell cycle arrest of OVCAR-3 cells induced by the co-immobilized group are analyzed by ematoxylin staining and flow cytometry. Third, western immunoblot analysis of the protein expression of p53, Bax, and Bcl-2 and immunofluorescence analysis of the protein location of caspase-3 in the induced OVCAR-3 cells were also performed. The results show that the co-immobilized group shows more visible inhibition activity towards OVCAR-3 cells than the control group and free group, after a time of 48 hours and at a concentration level of 20 ng ml⁻¹. The OVCAR-3 cells mediated by the co-immobilized group are individually arrested in the G₁, G₂, and S phases. Moreover, the western blotting and immunofluorescence analysis reveals that the treatment of OVCAR-3 cells by the co-immobilized group remarkably enhances the cellular expression of activated p53, Bax, and caspase-3, suggesting that the mitochondrial pathway of apoptosis may be significant. Our data thus provide the microscopic surface characterization and cell biology basis for utilizing the TNF-α plus IFN-γ co-immobilized polylactic acid copolymers as potential antitumorigenic targeted drugs.