Role of cancer stem cells and microRNA in resistance to chemotherapy in patients with ovarian cancer.

Despite the introduction of "the golden standard" in chemotherapy for ovarian cancer (taxanes/platinum), a relapse of the disease is noted in 80% of women treated in this manner. Studies on ovarian cancer stem cells (CSCs) and attempts at treatment using salinomycin, isolated from Streptonzyces albus and endotoxin of Clostridium peifringens, are promising, in particular because CSC markers have been identified. Resistence of ovarian cancer cells to paclitaxel and cisplatin is associated with a reduced expression of miR-30c, miR-130, and miR335, which results in activation of M-CSF, the known factor of resistance to cytostatic drugs. In clear cell ovarian cancer, a reduced expression of miR-449 was detected, which may lead to overexpression of MET phenotype, typical for chemoresistant ovarian cancer. MicroRNAs remain in investigations, but their involvement in the control of genes linked to the development of the cancer and its progression seems to offer the promise of a targeted therapy.