title: Inhibition of aldose reductase enhances HeLa cell sensitivity to chemotherapeutic drugs and involves activation of extracellular signal-regulated kinases.
abstract: Changes in glucose metabolism during diabetes are linked to an increased risk for the development of cancer. Increased activity of aldose reductase, the rate-limiting polyol pathway enzyme that converts glucose into sorbitol, mediates pathologies associated with diabetes and is thought to be involved in increased resistance to chemotherapeutic drugs. Thus, increased intracellular sorbitol levels may serve a protective function in cancer cells. In these studies we determined whether an inhibitor of aldose reductase could enhance the effectiveness of anticancer agents. Our findings indicate that treatment with the aldose reductase inhibitor, ethyl 1-benzyl-3-hydroxy-2(5H)-oxopyrrole-4-carboxylate (EBPC), enhances the cytotoxic effects of the anticancer agents doxorubicin and cisplatin in HeLa cervical carcinoma cells. To establish a mechanistic basis for the increased cytotoxicity by EBPC, we examined the activity of the extracellular signal-regulated kinase (ERK) pathway, which is an important regulator of cell growth. Interestingly, treatment with EBPC in combination with the chemotherapeutic drugs increased ERK activity as compared to treatment with the chemotherapeutic drugs, suggesting a possible role for the ERK pathway in mediating doxorubicin- or cisplatin-induced cell death. Consistent with this possibility, inhibition of ERK activation by the MEK inhibitor, U0126, reversed the EBPC-mediated enhancement of cell death. In summary, these data provide evidence that adjuvant therapy with aldose reductase inhibitors improves the effectiveness of chemotherapeutic drugs, possibly through an ERK pathway-mediated mechanism.
authors.affiliation: Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Univeristy of Maryland School of Medicine, Baltimore 21201, USA.
authors.forename: Eun Kyoung
authors.initials: EK
authors.lastname: Lee
authors.forename: William T
authors.initials: WT
authors.lastname: Regenold
authors.forename: Paul
authors.initials: P
authors.lastname: Shapiro
mesh_terms: D000449:Aldehyde Reductase / Q000037:antagonists & inhibitors*; D002945:Cisplatin / Q000494:pharmacology; D004317:Doxorubicin / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; C067822:ethyl 1-benzyl-3-hydroxy-2(5H)-oxopyrrole-4-carboxylate; D004317:Doxorubicin; D000449:Aldehyde Reductase; D011065:Poly(ADP-ribose) Polymerases; D020928:Mitogen-Activated Protein Kinases; D002945:Cisplatin; D011761:Pyrrolidonecarboxylic Acid