Comparative Effect of Sodium Butyrate and Sodium Propionate on Proliferation, Cell Cycle and Apoptosis in Ovarian Cancer Cells

Abstract

Short-chain fatty acids (SCFAs) are ubiquitous lipids produced by the gut microbiome through the fermentation of dietary fibers and non-digestible carbohydrates. Over the years, SCFAs have received considerable interest as possible regulators of many types of cancer, mainly colorectal cancer. However, their role and underlying mechanisms in ovarian cancer are yet to be elucidated. This study aimed to investigate and compare the anti-tumor effects of NaB and NaP in two distinctive ovarian cancer cell lines, SKOV-3 and PA-1. The effect of NaB and NaP on proliferation was assessed in 2D and 3D through MTT assay, colony formation assay, and spheroid hanging drop method. Alterations in the cell cycle were evaluated by Propidium Iodide (P.I) staining with flow cytometry, followed by evaluation of cyclin A2, B1, D2, and E2 expression by RT-qPCR. The mechanism of cell death induced by NaB and NaP was assessed using Annexin V/P. I and western blot analysis of proteins that regulate and initiate apoptosis, namely PARP1, Caspase 3, Bcl-2, and Bax. Our results revealed that NaB and NaP inhibit proliferation and impaired spheroid formation of SKOV-3 and PA-1 cells in a dose- and time-dependent manner. Moreover, both NaB and NaP induced cell cycle arrest at the G2/M phase, which was further supported by the downregulation of cyclin A2 and B1. Finally, the mode of cell death exerted by NaB and NaP was through apoptosis, as seen by the increased percentage of early/late apoptotic cells and the elevation of Bax/Bcl-2 ratio in treated cells. When compared to NaP, NaB showed a lower IC50 and a significantly greater apoptotic activity, indicating that NaB has a more potent anti-tumor effect than NaP. In conclusion, our findings underline the inhibitory effect of NaB and NaP in different subtypes of ovarian cancer, thus highlighting their therapeutic potential in cancer.