Down regulation of lactate dehydrogenase initiates apoptosis in HeLa and MCF-7 cancer cells through increased voltage-dependent anion channel protein and inhibition of BCL2

// Suhail Al-Salam 1 , Karthishwaran Kandhan 1 and Manjusha Sudhadevi 1 1 Department of Pathology, College of Medicine & Health Sciences, United Arab Emirates University, AlAin, UAE Correspondence to: Suhail Al-Salam, email: suhaila@uaeu.ac.ae Keywords: cancer metabolism; LDHA; apoptosis; VDAC Received: February 23, 2021     Accepted: March 25, 2021     Published: April 27, 2021 Copyright: © 2021 Al-Salam et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ABSTRACT Malignant cells commonly use aerobic glycolysis for ATP production; this is known as the Warburg effect, where pyruvate is converted to lactate, by enzyme lactate dehydrogenase A (LDH-A). In this study, we have investigated the effect of inhibition of LDH-A on cells viability and identifying the mechanism of cell death in HeLa and MCF-7 cancer cells. Human cervical cancer HeLa cell line and breast cancer MCF-7 cell line were used to investigate the effect of inhibition of LDH-A by sodium oxamate on cell survival and proliferation using western blot, spectrophotometry, and immunofluorescent study. There was significant reduction in LDH-A ( P < 0.001) and cell viability ( P < 0.001) in a dose-dependent mode in both HeLa and MCF-7 SO-treated cancer cells. The voltage-dependent anion channel (VDAC) protein was significantly increased ( P < 0.001) in association with decreased LDH-A. The proapoptotic proteins; cytochrome C ( P < 0.001), BAX ( P < 0.001), cleaved caspase-3 ( P < 0.001), cleaved caspase-8 ( P < 0.001), and cleaved caspase-9 ( P < 0.001) were significantly increased in association with decreased LDH-A. While, the anti-apoptotic protein Bcl2 was significantly decreased ( P < 0.001) in association with decreased LDH-A. We conclude that Inhibition of LDH-A can decrease cells viability through activation of intrinsic apoptotic pathway via increased VDAC protein and inhibition of Bcl2 as well as activation of the extrinsic apoptotic pathway through activation of caspase-8.