Targeted inhibition of mitochondrial Hsp90 induces mitochondrial elongation in Hep3B hepatocellular carcinoma cells undergoing apoptosis by increasing the ROS level
Abstract
Previous studies reported that a Gamitrinib variant containing triphenylphosphonium (G-TPP) binds to mitochondrial Hsp90 and rapidly inhibits its activity to induce apoptosis. We investigated the mechanisms underlying the antitumor activity of G-TPP in Hep3B hepatocellular carcinoma cells. Contrary to our predictions, we observed mitochondrial elongation in the G-TPP-treated Hep3B cells undergoing apoptosis. We found that the G-TPP-induced mitochondrial elongation in Hep3B cells was caused by a decrease in the mitochondrial fission-regulating protein Drp1 rather than by changes in the mitochondrial fusion machinery proteins Mfn1 and Opa1. Furthermore, G-TPP induced G2-M phase cell cycle arrest by reducing the interaction between CDK1 and cyclin B1. Additionally, reactive oxygen species (ROS) played a pivotal role in G-TPP-induced cell death and mitochondrial elongation in Hep3B cells, and these processes are mediated by the reduced association of CDK1 with cyclin B1 and the suppressed phosphorylation of Drp1 (Ser616). Thus, G-TPP induces cell death and causes Drp1-mediated mitochondrial elongation in Hep3B cells by increasing the ROS level.
References
A hyperfused mitochondrial state achieved at G1-S regulates cyclin E buildup and entry into S phase.
Parkin-independent mitophagy requires Drp1 and maintains the integrity of mammalian heart and brain.
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Carcinoma, Hepatocellular
Hepatocellular Carcinoma is a malignant cancer in liver epithelial cells. Discover the latest research on Hepatocellular Carcinoma here.
Apoptosis
Apoptosis is a specific process that leads to programmed cell death through the activation of an evolutionary conserved intracellular pathway leading to pathognomic cellular changes distinct from cellular necrosis