Human ovarian cancer multicellular spheroids: a model for testing antiproliferation activity of Devil's club (Oplopanax horridus) and anticancer agents.

This study was conducted to employ an ovarian cancer Ovcar 10 three-dimensional model to assess the antiproliferation activity of the medicinal plant Devil's club, Oplopanax horridus, and its active compound, alone and in combination, with chemotherapeutic agents compared to Ovcar 10 two-dimensional cells grown as monolayer cells. Ovcar 10 three-dimensional spheroids were prepared with a rotary cell culture system. Cell counting kit-8 assessed the antiproliferation activity. Apoptosis-related gene expression in three-dimensional spheroids and two- dimensional cells was analyzed with an apoptosis antibody array. Flow cytometry was used to analyze the cell cycle. Ovcar 10 cells formed compact three-dimensional spheroids after 5 days of culture in a rotary culture system. Ovcar 10 three-dimensional spheroids were significantly more resistant to killing by Devil's club extract, its active compound alone, gemcitabine, and paclitaxel, but not cisplatin compared to two-dimensional cells, with IC50 levels closer to that observed in vivo. Devil's club extract and its active compound alone significantly enhanced the antiproliferation activity of cisplatin and gemcitabine at some concentrations, but did not affect the activity of paclitaxel. A number of apoptosis-related genes were differentially expressed in three-dimensional spheroids, two-dimensional cells, and cells treated with Devil's club extract compared to untreated controls. In three-dimensional spheroids, the proportion of cells in the G2/M phase was slightly increased and the S phase was slightly decreased compared to two-dimensional cells. Ovcar 10 cells in three-dimensional spheroids altered the expression of multiple apoptosis-related genes, which may have contributed to the increased resistance of the cells to some drugs.