Hsp60 Chaperonin Acts as Barrier to Pharmacologically Induced Oxidative Stress Mediated Apoptosis in Tumor Cells with Differential Stress Response

Authors

  • Upasana Sarangi Authors contributed equally.
  • Manish Kumar Singh Authors contributed equally.
  • Kanugovi Vijaya Vittal Abhijnya CSIR—Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, Andhra Pradesh, India.
  • Lebaka Prasanna Anjaneya Reddy CSIR—Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, Andhra Pradesh, India.
  • Badabagni Siva Prasad CSIR—Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, Andhra Pradesh, India.
  • Vikrant Vinay Pitke CSIR—Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, Andhra Pradesh, India.
  • Khanderao Paithankar CSIR—Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, Andhra Pradesh, India.
  • Amere Subbarao Sreedhar CSIR—Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, Andhra Pradesh, India.

DOI:

https://doi.org/10.33393/dti.2013.1348

Keywords:

Hsp60, mitochondria, rotenone, oxidative stress, tumor cells

Abstract

Mitochondrial functions play a central role in energy metabolism and provide survival fitness to both normal and tumor cells. Mitochondrial chaperonin Hsp60 is involved in both pro- and anti-apoptotic functions, but how Hsp60 senses the mitochondria selective oxidative stress response is unknown. In this study, by using rotenone, an irreversible inhibitor of oxidative phosphorylation against IMR-32 and BC-8 tumor cells containing differential heat shock transcriptional machinery, we studied whether the oxidative stress response is related to Hsp60. The accelerated cytotoxicity in response to rotenone has been correlated with enhanced production of O2●-, H2O2, reactive oxygen species, and Hsp60 translocation from the mitochondria to the cytoplasm. The inability of cells to resist oxidative stress mediated Hsp60 translocation appeared to depend on mitochondrial oxyradical scavenging system and Bax translocation. A delayed oxidative stress response in hsp60 shRNA-treated cells was found to be due to increased mitochondrial translocation of Hsp60 on shRNA pre-sensitization. Overexpression of Hsp60 failed to protect cells from oxidative stress due to a lack of its mitochondrial retention upon post-rotenone treatment. These results also revealed that Hsp60 mitochondrial localization is indispensable for decreasing O2●- levels, but not H2O2 and ROS levels. However, cycloheximide treatment alone induced Hsp60 translocation, while rotenone combination delayed this translocation. In contrast to oxidative stress, MG132 and 17AAG treatments showed mitochondrial retention of Hsp60; however, MG132 combination either with hsp60 shRNA or 17AAG induced its translocation. Additionally, overexpression of Huntingtin gene also resulted in Hsp60 mitochondrial accumulation. We suggest that Hsp60 may act as a barrier to pharmacological targeting of mitochondria.

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Published

2015-09-01

How to Cite

1.
Sarangi U, Singh MK, Abhijnya KVV, Reddy LPA, Prasad BS, Pitke VV, Paithankar K, Sreedhar AS. Hsp60 Chaperonin Acts as Barrier to Pharmacologically Induced Oxidative Stress Mediated Apoptosis in Tumor Cells with Differential Stress Response. dti [Internet]. 2015 Sep. 1 [cited 2021 Oct. 15];7(1). Available from: https://journals.aboutscience.eu/index.php/dti/article/view/1348

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Original Research Article

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