Studies of the anti-cancer potential of flavonoids in Human Nasopharyngeal carcinoma cells

ONG CHYE SUN

Publication

Studies of the anti-cancer potential of flavonoids in Human Nasopharyngeal carcinoma cells

ONG CHYE SUN

Abstract

In this study, we aim to determine the molecular mechanisms underlying the anti-tumour property of two flavonoids namely luteolin and quercetin on nasopharyngeal carcinoma (NPC) using two NPC cell lines, HK1 and CNE2. We first identified the mechanisms leading to quercetin-mediated cell cycle arrest in NPC cells. Quercetin was able to inhibit E2F-1 transcriptional activity, thus preventing the expression of cyclin E. In addition, quercetin induced apoptosis by up-regulating the expression of Bad and Bax in HK1 and CNE2 cells. In the second part of our study, luteolin was found to inhibit cell cycle progression at G1 phase via enhanced protein phosphorylation and proteasomal degradation of cyclin D1, which is mediated by suppression of the Akt-glycogen synthase kinase-3beta (GSK-3?)-cyclin D1 signaling pathway. In the last third part of this study we examined the sensitisation effect of quercetin and luteolin, both used at sub-cytotoxic concentrations on apoptosis induced by vincristine, a commonly used cancer therapeutic agents, in both CNE2 and HK1 cells. Taken together, data from this part of our study thus provide experimental evidence for potential application of combination therapy using these two flavonoids.