title: Cisplatin-resistant prostate cancer model: Differences in antioxidant system, apoptosis and cell cycle.
abstract: Differences in the antioxidant system, apoptotic mechanism and in cell cycle between prostatic cell lines could partially elucidate the development of cisplatin resistance. The aim of this study was to identify the most characteristic parameter for a particular cell line and/or a particular cisplatin treatment using a general regression model and to assess whether it is possible to use measured parameters as markers of cisplatin resistance. This study integrates the results of viability, antioxidant, flow cytometric and quantitative PCR assays in order to characterize the resistance of prostate cancer to cisplatin. Cell growth using metabolic- (MTT) and impedance-based assays, the expression of key cell death signaling proteins (p53, Bax and Bcl-2), cell cycle, activity of antioxidant system-related proteins (superoxide dismutase, glutathione peroxidase, glutathione reductase and metallothionein) and free radical scavenging capacity assays [free radicals (FR), ferric reducing antioxidant power (FRAP), ABTS] were analyzed in the cell lines 22Rv1, PC-3 and PNT1A with respect to rising concentrations (0-150 µM) and different length of cisplatin treatment (12-72 h). The non-functional-p53 PC-3 cell line showed decreased BAX (p<0.05) and, in contrast to PNT1A and 22Rv1, no cisplatin-induced effects on cell cycle. All cell lines showed increasing levels of free radical scavenging activity by ABTS, FRAP and FR assays in a time- and dose-dependent manner (r>0.76 at p<0.001 for ABTS, FRAP and FR at p<0.001). PC-3 showed increased (p<0.05) levels of free radical scavenging activity by ABTS and FR methods. These findings, together with significantly elevated MT, decreased p53 and Bax indicate PC-3 to be cisplatin-resistant. The differences in the antioxidant system and apoptotic mechanisms in PC-3 cells may elucidate the development of cisplatin resistance and indicate that this cell line may be further studied as a model of cytostatic resistance.
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Jaromir
authors.initials: J
authors.lastname: Gumulec
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Balvan
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Marketa
authors.initials: M
authors.lastname: Sztalmachova
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Raudenska
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Veronika
authors.initials: V
authors.lastname: Dvorakova
authors.affiliation: Department of Experimental Biology, Faculty of Science, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Lucia
authors.initials: L
authors.lastname: Knopfova
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Polanska
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Kristyna
authors.initials: K
authors.lastname: Hudcova
authors.affiliation: Department of Chemistry and Biochemistry, Mendel University in Brno, CZ-613 00 Brno, Czech Republic.
authors.forename: Branislav
authors.initials: B
authors.lastname: Ruttkay-Nedecky
authors.affiliation: Department of Natural Drugs, Faculty of Pharmacy, University of Veterinary and Pharmaceutical Sciences, CZ-612 42 Brno, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Babula
authors.affiliation: Department of Chemistry and Biochemistry, Mendel University in Brno, CZ-613 00 Brno, Czech Republic.
authors.forename: Vojtech
authors.initials: V
authors.lastname: Adam
authors.affiliation: Department of Chemistry and Biochemistry, Mendel University in Brno, CZ-613 00 Brno, Czech Republic.
authors.forename: Rene
authors.initials: R
authors.lastname: Kizek
authors.affiliation: Department of Biochemistry, Faculty of Science, Charles University, CZ-128 40 Prague 2, Czech Republic.
authors.forename: Marie
authors.initials: M
authors.lastname: Stiborova
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University, CZ-625 00 Brno, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Masarik
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000627:therapeutic use*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D015398:Signal Transduction / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
chemical_list: D000975:Antioxidants; D016159:Tumor Suppressor Protein p53; D002945:Cisplatin