23 Molecular and Cellular Biochemistry 170: 23–30, 1997. © 1997 Kluwer Academic Publishers. Printed in the Netherlands. Differential effect of glucose deprivation on MAPK activation in drug sensitive human breast carcinoma MCF-7 and multidrug resistant MCF-7/ADR cells Anjali K. Gupta, 1 Yong J. Lee, 1 Sandra S. Galoforo, 1 Christine M. Berns, 1 Alvaro A. Martinez, 1 Peter M. Corry, 1 Xiao-yu Wu 2 and Kun-Liang Guan 2 1 Department of Radiation Oncology, Research Laboratories, William Beaumont Hospital, 3601 West Thirteen Mile Road, Royal Oak, Michigan 48073; 2 Department of Biological Chemistry and Institute of Gerontology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA Received 4 July 1996; accepted 25 October 1996 Abstract We have investigated the effect of glucose deprivation treatment on the activation of mitogen activated protein kinases (MAPKs) in the drug-sensitive human breast carcinoma cells (MCF-7) and its drug resistant variant (MCF-7/ADR) cells. Western blots and in-gel kinase assays showed that glucose free medium was a strong stimulus for the activation of MAPK in MCF-7/ADR cells. No activation was seen in MCF-7 cells. MAPK was activated within 3 min of being in glucose free medium and it re- mained activated for over 1 h in MCF-7/ADR cells. After being returned to complete medium, 1 h was required for the MAPK to become deactivated. To investigate whether alternative sources of ATP could inhibit glucose deprivation induced MAPK activation, we added glutamine and glutamate to glucose deprived medium. The addition of glutamine did not reverse glucose deprivation induced MAPK activation in MCF-7/ADR cells. The addition of glutamate, however, decreased the MAPK acti- vation and the length of time of activation. We observed an increase greater than three fold in MEK, Raf, Ras, and PKC activ- ity with glucose deprivation in MCF-7/ADR cells. This suggests that glucose deprivation-induced MAPK activation is mediated through this signal transduction pathway. (Mol Cell Biochem 170: 23–30, 1997) Key words: glucose deprivation, MAPK, MCF-7, MCF-7/ADR, signal transduction Address for offprints: Y. J. Lee, Department of Radiation Oncology Research Laboratories, William Beaumont Hospital, 3601 West Thirteen Mile Road, Royal Oak, MI 48073, USA Introduction Angiogenic factor-related genes such as basic fibroblast growth factor (bFGF) contain AP-1 cis -acting regulatory elements (TPA response elements; TRE) in their promoter region [1]. These regulatory elements are recognized by AP- 1 transcription factors (Jun and Fos family proteins) [2]. The induction of jun and fos gene transcripts and post-transla- tional modification of their products regulates the activity of AP-1 transcription factor [3]. Environmental stresses such as heat shock exposure [4], UV-irradiation [5], ionizing radia- tion exposure [6, 7], and treatment with chemical agents [4, 5] have been shown to induce c-jun and c-fos gene expres- sion in mammalian cells. Recent work from this laboratory has shown that stress induced bFGF gene expression is me- diated through the activation of protein kinase C (PKC) and AP-1 transcription factors (Jun and Fos) [8, 9]. A fundamental question that remains unanswered is how