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Induction of gamma-glutamyl transpeptidase mRNA by platinum complexes in a human ovarian carcinoma cell line.
Oncol Res 1996; 8(10-11):415-23OR

Abstract

Elevation of glutathione (GSH) is widely observed in cellular resistance to platinum agents. Our previous studies have shown that sublines of human ovarian carcinoma cell line A2780, which exhibited low levels of resistance to oxaliplatin, showed elevated steady state levels of mRNA and activity of gamma-glutamyl transpeptidase (gamma-GT, EC 2.3.2.2), but not of gamma-glutamylcysteine synthetase (gamma-GCS, EC 6.3.2.2) [El-akawi et al., Cancer Lett. 105:5-14; 1966]. To understand this phenomenon better, we have studied the effect of single exposures of oxaliplatin or cisplatin on the mRNA expression of gamma-GT and gamma-GCS in A2780 cells. The mRNAs of gamma-GT and gamma-GCS were measured by reverse transcriptase PCR, with quantitation of the PCR product by HPLC; mRNA levels are expressed as ratios to beta-actin mRNA, used as an endogenous standard. GSH was measured by HPLC. The gamma-GT activity was measured by a colorimetric assay. Single exposures of cells to oxaliplatin induced a time- and concentration-dependent increase in the mRNA of gamma-GT, but not of gamma-GCS. Cisplatin also induced an elevation in gamma-GT mRNA, but to a lower degree. The gamma-GT enzyme activity increased corresponding to the elevation in mRNA expression. The gamma-GT-induced cells showed an increase in cellular GSH when incubated in medium containing GSH. The data suggest that a) single, brief exposures to pharmacologically relevant concentrations of platinum complexes induce elevation in mRNA of gamma-GT, b) elevation in gamma-GT mRNA translates into elevated gamma-GT activity and increase in GSH salvage, and c) the degree of induction of gamma-GT mRNA differs between platinum complexes.

Authors+Show Affiliations

Department of Investigational Therapeutics, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

9114434

Citation

el-akawi, Z, et al. "Induction of Gamma-glutamyl Transpeptidase mRNA By Platinum Complexes in a Human Ovarian Carcinoma Cell Line." Oncology Research, vol. 8, no. 10-11, 1996, pp. 415-23.
el-akawi Z, Zdanowicz J, Creaven PJ, et al. Induction of gamma-glutamyl transpeptidase mRNA by platinum complexes in a human ovarian carcinoma cell line. Oncol Res. 1996;8(10-11):415-23.
el-akawi, Z., Zdanowicz, J., Creaven, P. J., Abu-hadid, M., Perez, R., & Pendyala, L. (1996). Induction of gamma-glutamyl transpeptidase mRNA by platinum complexes in a human ovarian carcinoma cell line. Oncology Research, 8(10-11), pp. 415-23.
el-akawi Z, et al. Induction of Gamma-glutamyl Transpeptidase mRNA By Platinum Complexes in a Human Ovarian Carcinoma Cell Line. Oncol Res. 1996;8(10-11):415-23. PubMed PMID: 9114434.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Induction of gamma-glutamyl transpeptidase mRNA by platinum complexes in a human ovarian carcinoma cell line. AU - el-akawi,Z, AU - Zdanowicz,J, AU - Creaven,P J, AU - Abu-hadid,M, AU - Perez,R, AU - Pendyala,L, PY - 1996/1/1/pubmed PY - 1996/1/1/medline PY - 1996/1/1/entrez SP - 415 EP - 23 JF - Oncology research JO - Oncol. Res. VL - 8 IS - 10-11 N2 - Elevation of glutathione (GSH) is widely observed in cellular resistance to platinum agents. Our previous studies have shown that sublines of human ovarian carcinoma cell line A2780, which exhibited low levels of resistance to oxaliplatin, showed elevated steady state levels of mRNA and activity of gamma-glutamyl transpeptidase (gamma-GT, EC 2.3.2.2), but not of gamma-glutamylcysteine synthetase (gamma-GCS, EC 6.3.2.2) [El-akawi et al., Cancer Lett. 105:5-14; 1966]. To understand this phenomenon better, we have studied the effect of single exposures of oxaliplatin or cisplatin on the mRNA expression of gamma-GT and gamma-GCS in A2780 cells. The mRNAs of gamma-GT and gamma-GCS were measured by reverse transcriptase PCR, with quantitation of the PCR product by HPLC; mRNA levels are expressed as ratios to beta-actin mRNA, used as an endogenous standard. GSH was measured by HPLC. The gamma-GT activity was measured by a colorimetric assay. Single exposures of cells to oxaliplatin induced a time- and concentration-dependent increase in the mRNA of gamma-GT, but not of gamma-GCS. Cisplatin also induced an elevation in gamma-GT mRNA, but to a lower degree. The gamma-GT enzyme activity increased corresponding to the elevation in mRNA expression. The gamma-GT-induced cells showed an increase in cellular GSH when incubated in medium containing GSH. The data suggest that a) single, brief exposures to pharmacologically relevant concentrations of platinum complexes induce elevation in mRNA of gamma-GT, b) elevation in gamma-GT mRNA translates into elevated gamma-GT activity and increase in GSH salvage, and c) the degree of induction of gamma-GT mRNA differs between platinum complexes. SN - 0965-0407 UR - https://www.unboundmedicine.com/medline/citation/9114434/Induction_of_gamma_glutamyl_transpeptidase_mRNA_by_platinum_complexes_in_a_human_ovarian_carcinoma_cell_line_ L2 - https://medlineplus.gov/ovariancancer.html DB - PRIME DP - Unbound Medicine ER -