Different cytotoxic and apoptotic responses of MCF-7 and HT1080 cells to MnO 2 nanoparticles are based on similar mode of action.

•MnO2 NPs induced dose-dependent cytotoxicity in MCF-7 and HT1080 cells.•MnO2 NPs disturbed the redox homeostasis of both MCF-7 and HT1080 cells.•MnO2 NPs induced up-regulation of p53 gene and low MMP in MCF-7 and HT1080 cells.•HT1080 cells showed higher susceptibility against MnO2 NPs as compared to MCF-7.•HT1080 cells showed higher uptake of MnO2 NPs than those of MCF-7 cells.