The role of cancer stem cells in progressive growth and resistance of ovarian cancer: true or fiction?

Growing evidence indicates that biological heterogeneity of ovarian cancer is associated with a small subpopulation of cancer cells existing within tumor tissue and defined as cancer stem cells (CSCs). This small group of ovarian cells possesses the capacity of self-renewal. Recent data revealed that progression, metastasis and relapse of ovarian cancers are related to the behavior of cancer stem cells. However, how ovarian CSCs maintain their migration properties is still unclear. The clinical relevance of CSCs has been supported by emerging evidence, showing that CSCs are resistant to conventional chemotherapy of ovarian cancer. Identification of biomarkers of ovarian cancer stem cells seems to be important for target therapy. Therapeutic strategies aimed at eliminating CSCs in ovarian cancers might extend disease survival and limit recurrence. This review will describe the current knowledge of ovarian CSCs biology and contribution of these cells to metastasis and chemoresistance of ovarian cancer as well as the possibility to use target therapy of ovarian CSCs.