Objective: To detect the expression of heparanase (HPA) in cervical cancer cells and investigate the impact of quercetin on the expression of HPA, and the molecular mechanism that quercetin inhibits the growth of cervical cancer cells.
Methods: The experimental groups included cervical cancer cell lines (HeLa and Caski) exposed to different concentrations of quercetin (20, 40 and 80 µmol/L) in the culture medium. The control groups included a negative control group, which was cultured with RPMI 1640 only, and a positive control group, in which cervical cancer cells were transfected with HPA small interference RNA (siRNA) to silence HPA expression. The cellular expression levels of HPA were detected with fluorescence quantitative real-time PCR and western blot analysis at 24, 48 and 72 hours after treatment.
Results: (1) HPA was significantly expressed in both cervical cancer cell lines (HeLa and Caski), and it exists both nucleus and cytoplasm. (2) The real-time PCR shows as follows: as the quercetin concentration increased (20, 40 and 80 µmol/L), the mRNA expression level of HPA decreased (P < 0.01), in which the inhibition of HPA expression was concentration dependent. In addition, the inhibition of HPA expression was also time dependent. As time growth, the expression level of HPA mRNA (24, 48 and 72 hours) in HeLa and Caski cells decreased (P < 0.01). Compared with negative control group, the expression level of HPA mRNA decreased in different concentrations of quercetin (40 and 80 µmol/L) in both HeLa and Caski cells (all P < 0.05); Compared with positive control group, the expression level of HPA mRNA expressed no obvious difference in quercetin (80 µmol/L) group (P > 0.05) in HeLa cells, while it was opposite in Caski cells (P < 0.01). (3) The result of western blot shown that, as the quercetin concentration increased (20, 40 and 80 µmol/L) and time growth (24, 48 and 72 hours), the expression level of HPA protein decreased (P < 0.01), and the inhibition of HPA protein expression was concentration and time dependent. Compared with negative control group, the expression level of HPA protein decreased in different concentrations of quercetin (40 and 80 µmol/L) in both HeLa and Caski cells (all P < 0.05); Compared with positive control group, the expression level of HPA protein expressed no obvious difference in quercetin (80 µmol/L) group (all P > 0.05) in both HeLa cells and Caski cells (all P > 0.05).
Conclusion: Quercetin could inhibits the expression of HPA in cervical carcinoma cell lines, which inhibition is concentration and time dependent.