Bacterial extracellular vesicles induced oxidative stress and mitophagy through mTOR pathways in colon cancer cells, HT-29: Implications for bioactivity

Abstract

Bacterial-extracellular-vesicles (BEVs) derived from Escherichia coli, strain-A5922, were used as a therapeutic tool to treat colon cancer cells, HT-29. BEVs induced oxidative stress, and observed mitochondrial autophagy, known as mitophagy, were crucial in initiation of treatment. The mitophagy, induced by the BEVs in HT-29 cells, produced adenocarcinomic cytotoxicity, and stopped the cells growth. The trigger for mitophagy, and an increase in productions of reactive oxygen species led to cellular oxidative stress, that eventually led to cells death. A reduction in the mitochondrial membrane potential, and an increase in the PINK1 expressions confirmed the oxidative stress involvements. The BEVs triggered cytotoxicity, and mitophagy in the HT-29 carcinoid cells, channelized through the Akt/mTOR pathways connecting the cellular oxidative stress, effectively played its part to cause cells death. These findings substantiated the BEVs' potential as a plausible tool for treating, and possibly preventing the colorectal cancer.

Keywords: Anticancer; Autophagy; BEVs; Bacterial extracellular vesicles; Cancer cell-line; Cytotoxicity; E. coli; HT-29 cells; Mitophagy; OIMVs; OMVs; Outer inner membrane vesicles; Outer membrane vesicles; Oxidation; Oxidative stress; ROS; Reactive oxygen species; Strain A 5922.