Susceptibility of HPV-18 Cancer Cells to HIV Protease Inhibitors

Cervical cancer cases continue to rise despite all the advanced screening and preventative measures put in place, which include human papillomavirus (HPV) vaccination. These soaring numbers can be attributed to the lack of effective anticancer drugs against cervical cancer; thus, repurposing the human immunodeficiency virus protease inhibitors is an attractive innovation. Therefore, this work was aimed at evaluating the potential anticancer activities of HIV-PIs against cervical cancer cells. The MTT viability assay was used to evaluate the effect of HIV protease inhibitors on the viability of cervical cancer cells (HeLa) and non-cancerous cells (HEK-293). Further confirmation of the MTT assay was performed by confirming the IC₅₀s of these HIV protease inhibitors on cervical cancer cells and non-cancerous cells using the Muse™ Count and Viability assay. To confirm the mode of death induced by HIV protease inhibitors in the HPV-associated cervical cancer cell line, apoptosis was performed using Annexin V assay. In addition, the Muse™ Cell Cycle assay was used to check whether the HIV protease inhibitors promote or halt cell cycle progression in cervical cancer cells. HIV protease inhibitors did not affect the viability of non-cancerous cells (HEK-293), but they decreased the viability of HeLa cervical cancer cells in a dose-dependent manner. HIV protease inhibitors induced apoptosis in HPV-related cervical cancer cells. Furthermore, they also induced cell cycle arrest, thus halting cell cycle progression. Therefore, the use of HIV drugs, particularly HIV-1 protease inhibitors, as potential cancer therapeutics represents a promising strategy. This is supported by our study demonstrating their anticancer properties, notably in HPV-associated cervical cancer cell line.