Abstract
Ovarian cancer (OC) is the 2nd most prevalent gynaecological cancer in New Zealand with approximately 300 diagnosed and 208 deaths per year. Epithelial ovarian cancer (EOC) accounts for approximately 90% of OC, and high-grade serous ovarian carcinoma (HGSOC) accounts for 70% of all EOC.
The PI3K/AKT/mTOR and Integrin/FAK/Src pathways are critical to cell functions, and dysregulation contributes to sustained proliferation, apoptotic resistance, and metastasis, making these pathways attractive targets for cancer therapies. Inhibitors (i), Alpelisib (PI3Ki) and defactinib (FAKi), are FDA-approved for other cancers, have not been combined for OC treatment. We hypothesise that combining alpelisib and defactinib will significantly improve the therapeutic effects by inhibiting the growth of OC cell lines in vitro.
SKOV3, OVCAR5, and OVCAR8 OC cell lines were selected as models for this research. Characterisation of the cell lines using western blot revealed AKT, FAK, and p-FAK presence in all cell lines; p-AKT was detected only in OVCAR5 and OVCAR8 OC cells. cBioPortal analysis revealed deletions/mutations in the PI3K/AKT/mTOR pathway potentially resulting in p-AKT levels being below the limit of detection in SKOV3.
Quantifying alpelisib/defactinib effectiveness as single agents on SKOV3, OVCAR5, and OVCAR8 cells revealed IC50s of 5 ± 1µM, 9 ± 2µM, and 50 ± 23µM for alpelisib-treated, and 5 ± 1µM, 4 ± 1µM and 4 ± 2µM for defactinib-treated cells, respectively. OVCAR5 cells were then treated with defactinib at the average IC50 dose of 4 µM (medium), and low (2µM) and high (8 µM) doses to observe dose-dependent inhibition. This was done using western blot, which showed a dose dependent inhibition of AKT, p-AKT, and FAK, but not p-FAK. Combined treatment of alpelisib and defactinib on OVCAR5 cells preliminarily demonstrated increased growth inhibition versus single agents. However, more comprehensive studies are required to assess the validity of the observed findings.