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Altered glutathione metabolism in oxaliplatin resistant ovarian carcinoma cells.
Cancer Lett. 1996 Jul 19; 105(1):5-14.CL

Abstract

Elevation of glutathione (GSH) is commonly observed in cellular resistance to a number of anticancer agents. Most frequently reported change in GSH metabolism that is associated with the elevated GSH levels is increased mRNA expression and activity of gamma-glutamyl cysteine synthetase (gamma GCS), the first enzyme of the GSH biosynthetic pathway. We have isolated sublines of the A2780 ovarian carcinoma cell line (C10 and C25) that are 8- and 12-fold resistant to oxaliplatin by repeatedly exposing the cells to increasing concentrations of the platinum agent. The GSH levels in C10 and C25 cell sublines are 3.1- and 3.8-fold higher than the parent A2780 cell line. The mRNA levels and activities for gamma GCS and that for gamma-glutamyl transpeptidase (gamma GT), the GSH salvage pathway enzyme, were measured in these cells. The mRNA for gamma GT and gamma GCS were measured by RT-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 and gamma GCS activity were measured by HPLC assays and gamma GT activity by a colorimetric assay. The increase in GSH in C10 and C25 was associated with an elevation in gamma GT mRNA (2.5- and 8-fold) and gamma GT activity (2.7- and 2.8-fold). No changes were observed in gamma GCS mRNA levels or activity. The data indicate that alterations in GSH metabolism leading to elevations in cellular GSH in A2780 ovarian carcinoma cells selected for low levels of resistance to oxaliplatin are mediated by gamma GT, the "salvage' pathway, rather than an increase in GSH biosynthesis.

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 availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

8689632

Citation

el-akawi, Z, et al. "Altered Glutathione Metabolism in Oxaliplatin Resistant Ovarian Carcinoma Cells." Cancer Letters, vol. 105, no. 1, 1996, pp. 5-14.
el-akawi Z, Abu-hadid M, Perez R, et al. Altered glutathione metabolism in oxaliplatin resistant ovarian carcinoma cells. Cancer Lett. 1996;105(1):5-14.
el-akawi, Z., Abu-hadid, M., Perez, R., Glavy, J., Zdanowicz, J., Creaven, P. J., & Pendyala, L. (1996). Altered glutathione metabolism in oxaliplatin resistant ovarian carcinoma cells. Cancer Letters, 105(1), 5-14.
el-akawi Z, et al. Altered Glutathione Metabolism in Oxaliplatin Resistant Ovarian Carcinoma Cells. Cancer Lett. 1996 Jul 19;105(1):5-14. PubMed PMID: 8689632.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Altered glutathione metabolism in oxaliplatin resistant ovarian carcinoma cells. AU - el-akawi,Z, AU - Abu-hadid,M, AU - Perez,R, AU - Glavy,J, AU - Zdanowicz,J, AU - Creaven,P J, AU - Pendyala,L, PY - 1996/7/19/pubmed PY - 1996/7/19/medline PY - 1996/7/19/entrez SP - 5 EP - 14 JF - Cancer letters JO - Cancer Lett. VL - 105 IS - 1 N2 - Elevation of glutathione (GSH) is commonly observed in cellular resistance to a number of anticancer agents. Most frequently reported change in GSH metabolism that is associated with the elevated GSH levels is increased mRNA expression and activity of gamma-glutamyl cysteine synthetase (gamma GCS), the first enzyme of the GSH biosynthetic pathway. We have isolated sublines of the A2780 ovarian carcinoma cell line (C10 and C25) that are 8- and 12-fold resistant to oxaliplatin by repeatedly exposing the cells to increasing concentrations of the platinum agent. The GSH levels in C10 and C25 cell sublines are 3.1- and 3.8-fold higher than the parent A2780 cell line. The mRNA levels and activities for gamma GCS and that for gamma-glutamyl transpeptidase (gamma GT), the GSH salvage pathway enzyme, were measured in these cells. The mRNA for gamma GT and gamma GCS were measured by RT-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 and gamma GCS activity were measured by HPLC assays and gamma GT activity by a colorimetric assay. The increase in GSH in C10 and C25 was associated with an elevation in gamma GT mRNA (2.5- and 8-fold) and gamma GT activity (2.7- and 2.8-fold). No changes were observed in gamma GCS mRNA levels or activity. The data indicate that alterations in GSH metabolism leading to elevations in cellular GSH in A2780 ovarian carcinoma cells selected for low levels of resistance to oxaliplatin are mediated by gamma GT, the "salvage' pathway, rather than an increase in GSH biosynthesis. SN - 0304-3835 UR - https://www.unboundmedicine.com/medline/citation/8689632/Altered_glutathione_metabolism_in_oxaliplatin_resistant_ovarian_carcinoma_cells_ L2 - https://linkinghub.elsevier.com/retrieve/pii/0304383596042450 DB - PRIME DP - Unbound Medicine ER -