Mechanisms determining sensitivity to cisplatin in three mutant Chinese hamster ovary cell lines

Effects of Aulosira fertilisima against cisplatin-induced nephrotoxicity and oxidative stress in rats

Oxidative stress due to abnormal production of reactive oxygen molecules (ROM) is believed to be involved in the etiology of toxicities of many xenobiotics. Evidence suggested that ROM is involved in the nephrotoxicity of a widely used synthetic anticancer drug cisplatin. The nephroprotective effects of ethanol extract of Aulosira fertilisima Ghose (EEA) was evaluated using cisplatin (5 mg/kg(-1) i.p.)-induced renal damage in rats. EEA showed higher significant effect on DPPH radical scavenging activity as compared with methanol extract of A. fertilisima (MEA) and water extract of A. fertilisima (WEA). Thus, EEA was selected for further in vivo studies. The serum urea and creatinine levels in the cisplatin alone-treated group were significantly elevated with respect to normal group of animals. The levels were reduced in the EEA (100 mg/kg, p.o) plus cisplatin-treated groups. Renal oxidative stress was determined by renal TBARS, CD and reduced glutathione levels, and by enzymatic activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione transferase (GST). A single dose of cisplatin-produced marked renal oxidative and nitrosative stress and significantly deranged renal functions. Chronic EEA treatment significantly and dose-dependently restored renal functions, reduced lipid peroxidation, and enhanced reduced glutathione levels, superoxide dismutase, and catalase activities. The results of the study indicated that A. fertilisima significantly and dose-dependently protected the nephrotoxicity induced by cisplatin. This protection is mediated either by preventing the cisplatin-induced decline of renal antioxidant defense system or by their direct free radical scavenging activity.

Ankyrin repeat domain 1, ANKRD1, a novel determinant of cisplatin sensitivity expressed in ovarian cancer

PURPOSE

The standard of care for ovarian cancer includes platinum-based chemotherapy. It is not possible, however, to predict clinical platinum sensitivity or to design rational strategies to overcome resistance. We used a novel approach to identify altered gene expression associated with high sensitivity to cisplatin, to define novel targets to sensitize tumor cells to platins and ultimately improve the effectiveness of this widely used class of chemotherapeutics.

EXPERIMENTAL DESIGN

Using differential display PCR, we identified genes differentially expressed in a mutagenized cell line with unusual sensitivity to cisplatin. The most highly differentially expressed gene was selected, and its role in determining cisplatin sensitivity was validated by gene transfection and small interfering RNA (siRNA) approaches, by association of expression levels with cisplatin sensitivity in cell lines, and by association of tumor expression levels with survival in a retrospective cohort of 71 patients with serous ovarian adenocarcinoma.

RESULTS

The most highly differently expressed gene identified was ANKRD1, ankyrin repeat domain 1 (cardiac muscle). ANKRD1 mRNA levels were correlated with platinum sensitivity in cell lines, and most significantly, decreasing ANKRD1 using siRNA increased cisplatin sensitivity >2-fold. ANKRD1 was expressed in the majority of ovarian adenocarcinomas tested (62/71, 87%), and higher tumor levels of ANKRD1 were found in patients with worse outcome (overall survival, P=0.013).

CONCLUSIONS

These findings suggest that ANKRD1, a gene not previously associated with ovarian cancer or with response to chemotherapy, is associated with treatment outcome, and decreasing ANKRD1 expression, or function, is a potential strategy to sensitize tumors to platinum-based drugs.

Protective effects of vitamin c against cisplatin-induced nephrotoxicity and lipid peroxidation in adult rats: a dose-dependent study

Cisplatin is one of the most active cytotoxic agents in the treatment of cancer, but its clinical use is associated with nephrotoxicity. In the present study we report the effects of different amounts of vitamin C (50, 100 or 200 mg kg(-1)body wt.) in rat kidneys treated with cisplatin (5 mg kg(-1)body wt.), using single doses of both compounds. Cisplatin administration induced lipid peroxidation which was accompanied by a decrease in renal glutathione level in animals killed 7 days after treatments. Furthermore, an increase in serum creatinine has been observed. Treatment of animals with vitamin C 10 min prior to the cisplatin inhibited cisplatin-mediated damage. Seven days after vitamin C plus cisplatin treatments, the depleted level of glutathione and changes in the creatinine clearance recovered to significant levels (P<0.05). Similarly, the enhanced serum creatinine levels which are indicative of renal injury showed a significant reduction (P<0.05) with the three doses of vitamin C tested. The protective effect of vitamin C was dose-dependent. The results suggest that vitamin C is an effective chemoprotective agent against nephrotoxicity induced by the antitumoral cisplatin in Wistar adult rats.