Back to Search Start Over

p44/42 MAP kinase-dependent regulation of catalase by autocrine human growth hormone protects human mammary carcinoma cells from oxidative stress-induced apoptosis.

Authors :
Zhu Z
Mukhina S
Zhu T
Mertani HC
Lee KO
Lobie PE
Source :
Oncogene [Oncogene] 2005 May 26; Vol. 24 (23), pp. 3774-85.
Publication Year :
2005

Abstract

Previous microarray expression analyses have indicated autocrine human growth hormone (hGH) regulation of genes involved in the oxidative stress response. Expression analysis of antioxidant enzymes revealed that autocrine hGH increased both the mRNA and protein levels of catalase, superoxide dismutase 1 (SOD1), glutathione peroxidase and glutamylcysteine synthetase but not that of SOD2. As a consequence, autocrine hGH increased the antioxidant capacity of mammary carcinoma cells and protected against oxidative stress-induced apoptosis. Catalase activity was increased by autocrine production of hGH in mammary carcinoma cells and a catalase inhibitor abrogated protection from oxidative stress afforded by autocrine hGH. Autocrine hGH transcriptionally regulated catalase gene expression in a p44/42 MAP kinase-dependent manner and inhibition of MEK concordantly abrogated the protective effect of autocrine hGH against oxidative stress-induced apoptosis. Given that increased cellular oxidative stress is a key effector mechanism of specific chemotherapeutic agents, we propose that antagonism of autocrine hGH will improve the efficacy of chemotherapeutic regimes utilized for human mammary carcinoma.

Details

Language :
English
ISSN :
0950-9232
Volume :
24
Issue :
23
Database :
MEDLINE
Journal :
Oncogene
Publication Type :
Academic Journal
Accession number :
15782123
Full Text :
https://doi.org/10.1038/sj.onc.1208541