Effect of Cytostatic Drugs on the mRNA Expression Levels of Ribonuclease in Breast and Ovarian Cancer Cells

Breast and ovarian cancers remain a major public health issue, constituting a major cause of female morbidity and mortality worldwide. Even though systemic chemotherapy remains the main course of action for both types of cancer, current research studies aim at the discovery of novel therapeutic targets. Ribonucleases, due to their apparent implication in gene expression regulation, may serve as potential anticancer drugs. Human RNase kappa is an endoribonuclease belonging in a recently identified family of proteins. Recent data from expression microarray studies reveal that the RNase kappa gene is found either up- or downregulated in a number of human cancers, indicating a possible diagnostic and/or prognostic utility. The aim of this study was to investigate modulations in the expression levels of RNase kappa gene, in breast and ovarian cancer cells, as a response to treatment with different chemotherapeutic agents. BT-20 breast cancer cells and SKOV-3 ovarian cancer cells were treated with the cytotoxic drugs paclitaxel, docetaxel, cisplatin, carboplatin, epirubicin and vinorelbine. Gene expression analysis was performed by the comparative C-T method also known as 2(-Delta Delta CT) method. The results revealed a distinct increase in the expression levels of RNase kappa mRNA (up to 9-fold) after treatment with the antineoplastic agent paclitaxel in both cell lines, while treatment with the remaining anticancer drugs did not alter drastically the mRNA levels of RNase kappa. Based on the fact that paclitaxel exerts its cytotoxic action by inducing apoptosis, the results could be indicative of a potential implication of RNase in apoptosis-related pathways.