Olive: A potential suppressor for cervical cancer by upregulation of p21

Abstract Background Cervical cancer (CC) is the second deadliest for women between the ages of 20 to 39 years. Even with prevention tactics for screening, incident rates and mortality of CC remain high. Olive has been shown to have many beneficial effects in humans concerning cardiovascular disease and inflammation. Despite these promising benefits, little is known about its effect on CC. This study examined the effects and mechanism of effects of olive extract (OE) on the HeLa cervical cancer cell line. Methods We utilized clonogenic survival assay, quick cell proliferation assay, and caspase-3 activity to investigate the effect of OE on proliferation and apoptosis of CC cell line HeLa. To investigate the mechanisms behind these findings, RT-PCR and immunohistochemistry (IHC) were performed. Results OE inhibited the growth and proliferation of HeLa cells. In comparison to the control, the percentage of colonies as well as the optical density of the CC cells was found to be decreased. In addition, the relative activity of caspase-3, a marker for apoptosis, was increased after treatment with OE. The anti-proliferative effect of OE on HeLa cells correlated with the increase of an anti-proliferative molecule p21. However, the pro-apoptotic effect of OE was not correlated with change of major pro-apoptotic or anti-apoptotic molecules examined in this study. Conclusion Our study suggests that OE inhibits growth of HeLa CC cells by upregulation of p21. Further study on the effects of OE on CC and other cancers is warranted by these results.