Targeting Phosphoinositide 3-Kinase to Reduce the Progression of Ovarian Cancer Cells in a 3D Collagen Model

Ovarian cancer remains a major cause of mortality in women aged 74 years and under. Dysregulation of the PI3K/AKT/mTOR and NFκB signaling pathways has been associated with poor outcomes and treatment resistance. This study evaluated three potential anticancer agents targeting these pathways: buparlisib (a pan-PI3K/mTORC1 inhibitor), SN32976 (a PI3K p110α inhibitor), and pterostilbene (a resveratrol analogue that downregulates PI3K/AKT and NFκB signaling). Their efficacy was tested in 3D collagen models of ovarian cancer, using SKOV3 and OVCAR8 cell lines, activated by tumor necrosis factor-alpha (TNFα) and lysophosphatidic acid (LPA). Using concentrations derived from 2D assays, viability, collagen gel sizes, secretion of interleukin 6/8 (IL-6/8) and signal pathway proteins were analyzed. All compounds were less effective in 3D models than in 2D cultures, with high cell viability maintained. TNFα and LPA did not significantly alter drug sensitivity, and collagen gel contraction was largely unaffected. While the compounds did not consistently change signaling protein levels, they generally reduced secretion of pro-inflammatory cytokines IL-6 and IL-8. Growth in 3D collagen gels conferred drug resistance on OVCAR8 but not SKOV3 models. Overall, these findings provide preclinical support for further investigation of SN32976 and pterostilbene in ovarian cancer models.