Characteristics of in vitro model systems for ovarian cancer studies

Nowadays, targeted therapy plays a growing role in oncological treatment. In ovarian cancer, particularly promising results are achieved with poly (ADP-ribose) polymerase (PARP) inhibitors. Recent clinical trials have shown that PARP inhibitors can result in significantly longer progression-free survival. These results encourage the search for other targeted therapies and bring hope that ovarian cancer can soon become a manageable chronic disease. The main problem in ovarian cancer research is the heterogeneity of this disease. Recent studies have shown that different histological types of ovarian cancer can originate from distinct tissues. According to the recent knowledge, ovarian cancer is an artificial term for distinct invasive malignancies localised within the pelvis. Genetic and immunophenotype analyses have shown that high-grade serous ovarian cancer, the most frequent histological type and the one with the worst prognosis, originates mainly from fallopian tube epithelium, while endometrioid and clear-cell cancers originate from the endometrium. For these reasons, in basic and preclinical studies on ovarian cancer, one has to carefully choose a well-defined model system, corresponding to the histological type of interest. In this article, we discuss ovarian cancer cell lines most frequently used in in vitro studies. Our aim is to indicate the advantages and disadvantages of different models, encompassing primary and established cell cultures, two- and three-dimensional models, etc. In particular, we would like to alert researchers to the fact that the most popular cell lines SKOV3 and A2780 do not represent a suitable model for studies on high-grade serous ovarian cancer.