Steroids affect collateral sensitivity to gemcitabine of multidrug-resistant human lung cancer cells
Introduction
2′,2′-Difluorodeoxycytidine (gemcitabine) is a deoxycytidine analog which is active against non-small cell lung cancer (NSCLC), in patients and in tumor models, both in vitro and in vivo Hertel et al., 1990, Boven et al., 1993, Abratt et al., 1994. Gemcitabine and deoxycytidine are phosphorylated by deoxycytidine kinase to their monophosphates. Also the mitochondrial enzyme thymidine kinase 2 phosphorylates deoxycytidine and gemcitabine, however, to a lesser extent than deoxycytidine kinase Bergman et al., 1999, Eriksson et al., 1991. The monophosphates of gemcitabine and deoxycytidine are subsequently phosphorylated to their triphosphates, which are incorporated into DNA, resulting in DNA damage (Huang et al., 1991). Since gemcitabine requires passage through the S-phase in order to be incorporated, this antimetabolite is predominantly active in fast growing tumors (Huang and Plunkett, 1995).
Steroids, like the natural corticosteroid cortisol and the synthetic steroid dexamethasone, inhibit the proliferation of many cell types including lung cancer cell lines Nakane et al., 1990, Croxtall and Flower, 1992. Although steroids are known to induce discrete changes in gene expression and protein synthesis (Ivarie and O'Farrell, 1978), the molecular mechanisms involved in cell growth control have not been clarified yet. Several studies report a decrease in thymidine kinase activity, most likely the cytosolic thymidine kinase 1, as a result of corticosteroid exposure in rat and chicken Tesoriere et al., 1989, Herzfeld and Raper, 1980, Naray et al., 1977, Sakata, 1975. Corticosteroids might have a similar effect on deoxycytidine kinase activity.
In patients, side effects of gemcitabine treatment include nausea and vomiting. The adverse effects of treatment of lung carcinoma is prevented by combinations of anti-emetics and dexamethasone (Cleri et al., 1995). However, not much is known about interaction of cytostatic therapy and dexamethasone. Since steroids inhibit cell proliferation and gemcitabine is S-phase dependent, theoretically, steroids would decrease sensitivity to gemcitabine.
It is known that some of the steroid hormones such as cortisol, progesterone and aldosterone are substrates for the plasma membrane drug efflux pumps P-glycoprotein and multidrug resistance-associated protein (MRP) Endicott and Ling, 1989, Grant et al., 1994, Van Kalken et al., 1993, Mulder et al., 1996. This pump function can be blocked by verapamil (Cornwell et al., 1987). In our previous study an increased sensitivity to gemcitabine was found in P-glycoprotein and MRP overexpressing NSCLC cells, which was related to an increased deoxycytidine kinase activity (Bergman et al., 1998). It was hypothesized that a decrease of intracellular cortisol and dexamethasone concentration as a result of P-glycoprotein or MRP activity might result in an increase in gemcitabine phosphorylation and eventually sensitivity.
In this study we determined whether steroids interact with sensitivity to gemcitabine in cells with a MRP and P-glycoprotein overexpression and whether changes in deoxycytidine kinase and thymidine kinase 2 activity are involved.
Section snippets
Chemicals and reagents
Dulbecco's Modified Eagle's Medium (DMEM) was purchased from Flow Laboratories (Irvine, UK) and fetal calf serum from Gibco (New York, USA), trichloroacetic acid, glutamine and gentamicin from Merck (Darmstadt, Germany), trypsin, sulforhodamine B, cortisol and dexamethasone from Sigma (St. Louis, USA). [5-3H]deoxycytidine (21.9 Ci/mmol) was from Moravek, Brea, CA. All other chemicals were of analytical grade and commercially available.
Cell culture
The in vitro experiments were performed with the human NSCLC
Effect of cortisol, dexamethasone and verapamil on sensitivity to gemcitabine and proliferation rate of SW1573 and its MDR variants
To investigate the effect of cortisol and dexamethasone on sensitivity to gemcitabine, cells were exposed to gemcitabine with or without corticosteroids. Sensitivities of the cells relative to their sensitivities to gemcitabine alone are depicted in Fig. 1. Cortisol (5 μM) decreased sensitivity to gemcitabine 1.8- and 1.5-fold in SW1573 and 2R160 cells, respectively. However, 2R120 cells were two-fold more sensitive to gemcitabine during cortisol exposure. Cortisol did not affect doubling time
Discussion
In this paper, we describe a decrease in gemcitabine sensitivity by steroid exposure in wild-type NSCLC cells. This is in agreement with a study of Rieger et al. (1999) who described a reduction of gemcitabine sensitivity of cultured human glioma cells by clinically relevant concentrations of dexamethasone. However, in the P-glycoprotein and MRP overexpressing variants no effect was found, which might be mediated by a decrease of steroid concentrations by the action of the membrane efflux
References (35)
- et al.
Decreased resistance to gemcitabine of cytosine arabinoside resistant myeloblastic murine and rat leukemia cell lines: role of altered activity and substrate specificity of deoxycytidine kinase
Biochem. Pharmacol.
(1999) - et al.
Certain calcium channel blockers bind specifically to multidrug-resistant human KB carcinoma membrane vesicles and inhibit drug binding to P-glycoprotein
J. Biol. Chem.
(1987) - et al.
The mitochondrion as a primary site of action of glucocorticoids: the interaction of the glucocorticoid receptor with mitochondrial DNA sequences showing partial similarity to the nuclear glucocorticoid responsive elements
J. Steroid Biochem. Mol. Biol.
(1995) - et al.
Comparison of the substrate specificities of human thymidine kinase 1 and 2 and deoxycytidine kinase toward antiviral and cytostatic nucleoside analogs
Biochem. Biophys. Res. Comm.
(1991) - et al.
Glucocorticoid regulation of thymidine kinase (TK-1) expression in L929 cells
J. Biol. Chem.
(1993) - et al.
The glucocorticoid domain: steroid-mediated changes in the rate of synthesis of rat hepatoma proteins
Cell
(1978) - et al.
Comparison of the Sulforhodamine B Protein and tetrazolium (MTT) assays for in vitro chemosensitivity testing
Eur. J. Cancer
(1991) - et al.
Gemcitabine cytotoxicity of human malignant glioma cells: modulation by antioxidants, bcl-2 and dexamethasone
Eur. J. Pharmacol.
(1999) - et al.
Treatment of normal and malignant cells with nucleoside analogues and etoposide enhances deoxycytidine kinase activity
Eur. J. Cancer
(1999) - et al.
Human thymidine kinase 2: molecular cloning and characterisation of the enzyme activity with antiviral and cytostatic nucleoside substrates
FEBS Lett.
(1999)
Efficacy and safety profile of gemcitabine in non-small cell lung cancer. Phase II study
J. Clin. Oncol.
Glucocorticoid regulation of the genes encoding thymidine kinase, thymidylate synthase, and ornithine decarboxylase in P1798 cells
Mol. Endocrinol.
Increased sensitivity to gemcitabine of P-glycoprotein and MRP overexpressing human non-small cell lung cancer cell lines
Adv. Exp. Med. Biol.
The influence of the schedule and the dose of gemcitabine on the anti-tumour efficacy in experimental human cancer
Br. J. Cancer
Oral combination antiemetics in patients receiving cisplatin or cyclophosphamide plus doxorubicin
Cancer
Lipocortin 1 mediates dexamethasone-induced growth arrest of the A549 lung adenocarcinoma cell line
Proc. Natl. Acad. Sci. U. S. A.
The biochemistry of P-glycoprotein-mediated multidrug resistance
Annu. Rev. Biochem.
Cited by (25)
The single nucleotide variant rs2868371 associates with the risk of mortality in non-small cell lung cancer patients: A multicenter prospective validation
2019, Radiotherapy and OncologyCitation Excerpt :Because of its profound anti-inflammatory property, glucocorticoids and their synthetic analogs are widely prescribed in lung cancer treatment. However, glucocorticoids sensitivity and actions vary considerably among individuals and tissues promoting or inhibiting tumor progression and regulating radio(chemo)therapy-induced cell apoptosis existing an incomplete understanding of the underlying mechanism in each case [41,42]. We validated the association between the rs2868371 SNP and survival in NSCLC patients in a multicenter prospective setting.
New dimension of glucocorticoids in cancer treatment
2016, SteroidsCitation Excerpt :Whether the action of GCs promotes or inhibits tumor progression is controversial in non-hematologic cancer types. Prior studies have demonstrated that GCs can suppress tumor progression and metastasis [29,32–39], whereas other investigations reported that GCs inhibit chemotherapy-induced cell apoptosis [40–51]. This controversial phenomenon may result from different cancer subtypes, differential GR levels, and the dosage of GCs given.
Optimizing pemetrexed-gemcitabine combination in patients with advanced non-small cell lung cancer: A pharmacogenetic approach
2011, Journal of Thoracic OncologyCitation Excerpt :Nevertheless, the present research is limited by its exploratory nature and the investigation of the changes in gemcitabine uptake, and intracellular activation would require further experiments and the study of how these changes might improve drug efficacy would need further clinical trials. Preclinical and clinical studies show how dexamethasone might result in altered gene expression23,24 and reduce sensitivity of lung cancer cells to gemcitabine.25 In the current experience, the modulation of the dCK and hENT1 expressions, induced by pemetrexed, was highly reproducible among all 19 patients, although receiving dexamethasone premedication, as mandatory in clinical practice.
Tumor and host factors that may limit efficacy of chemotherapy in non-small cell and small cell lung cancer
2010, Critical Reviews in Oncology/HematologyCitation Excerpt :MRP1 expression was associated with increased deoxycytidine kinase expression and with augmented sensitivity to gemcitabine, and antagonism of MRP1 by verapamil reduced sensitivity to gemcitabine, possibly be decreasing expression of deoxycytidine kinase [139,268]. Corticosteroids alone decreased deoxycytidine kinase activity and also decreased gemcitabine efficacy in NSCLC cell lines [268]. Synergism between gemcitabine and pemetrexed in NSCLC cell lines appears to be mediated in part through the up-regulation of expression of deoxycytidine kinase expression by pemetrexed [135,267], although up-regulation of expression of the gemcitabine transporter (hENT1) and decreased phosphorylation of Akt may also play a role [267].
Drug-drug interactions in oncology: Why are they important and can they be minimized?
2005, Critical Reviews in Oncology/Hematology