Ovarian cancer (OC) is the most frequent cause of mortality among gynecological malignancies, with a 5-year survival rate of approximately 30%. The standard regimen for OC therapy includes a platinum agent combined with a taxane, to which the patients frequently acquire resistance. Resistance arises from the oxidation of anticancer drugs by CYP1B1, a cytochrome P450 enzyme overexpressed in malignant OC. The aim of the present study was to determine the role of CYP1B1 expression in the drug resistance of OC to the taxane, paclitaxel (PTX). Immunohistochemical staining was used to assess CYP1B1 expression in a panel of ovarian samples (53 primary cancer samples, 14 samples of metastastic cancer, 30 benign tumor samples and 19 normal tissue samples). Semi-quantitative RT-PCR was also performed to determine CYP1B1 expression in several OC cell lines. Finally, we used proliferation and toxicity assays, as well as a mouse xenograft model using nude mice to determine whether α-naphthoflavone (ANF), a CYP1B1 specific inhibitor, reduces resistance to PTX. CYP1B1 was overexpressed in the samples from primary and metastatic loci of epithelial ovarian cancers. In some cell lines, PTX induced CYP1B1 expression, which resulted in drug resistance. Exposure to ANF reduced drug resistance and enhanced the sensitivity of OC cells to PTX in vitro and in vivo. The expression profile of CYP1B1 suggests that it has the potential to be a useful diagnostic marker and prognostic factor for malignant OC. The inhibition of CYP1B1 expression by specific agents may provide a novel therapeutic strategy for the treatment of patients resistant to PTX and may improve the prognosis of these patients.
The primary aim of this study is to evaluate the clinical significance of E-cadherin protein expression and the methylation status in CDH1 promoter in endometrial cancer. The expression of E-cadherin and methylation in its promoter region was analyzed, retrospectively, in 152 clinical tissue samples from patients with endometrial lesions. We found that the hypermethylation of CDH1 promoter, which caused low expression of E-cadherin in endometrial cancer, was associated with not only clinicopathological progress of endometrial cancer but also with the overall 5-year clinical survival rate. The findings provide the potential therapeutic and prognostic target molecule for patients with endomethrial cancer.
Differentially expressed proteins between cervical cancer tissues pre- and post-NAC with TP were identified by comparative proteomic approach. The NAC therapy with TP down-regulated proteins involved in energy production (glycolytic enzymes) and chaperones but up-regulated proteins involved in apoptosis. These findings shed new light on biomarkers associated with effect of chemotherapy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.