Radiosensitizing effect and mechanism of 2'-hydroxyflavanone in prostate cancer cells

Abstract

Objective To study the radiosensitizing effect of 2'-hydroxyflavanone (2'-HF) on prostate cancer cells, and to preliminarily investigate its mechanism. Methods Colony formation assay, tert-butylhydroperoxide (TBHP) oxidative stress assay, Hoechst staining, and apoptosis flow cytometry using Annexin V-FITC and propidium iodide (PI) were performed to measure the impact of 2'-HF on the radiosensitivity of VCaP prostate cancer cells. Western blot was used to determine the effects of 2'-HF on expression of AKT, phosphorylated AKT (p-AKT), and aldo-keto reductase 1C3(AKR1C3) in VCaP cells and preliminarily investigate the mechanism. Data were analyzed by t test and factorial analysis of variance. Results The results of colony formation assay indicated that after exposure to radiation, VCaP cells treated with 2'-HF had a significantly lower proliferation level than cells in the control group (P=0.010), yielding a sensitization enhancement ratio of 1.19. The results of TBHP oxidative stress assay suggested that VCaP cells treated with 2'-HF had significantly weaker anti-oxidative capacity than cells in the control group (P=0.015). Hoechst staining and apoptosis flow cytometry with Annexin V-FITC and PI indicated that 2'-HF treatment plus irradiation significantly enhanced apoptosis in VCaP cells (P=0.001. The results of Western blot suggested that 2'-HF treatment significantly inhibited the protein expression of p-AKT and AKR1C3 in VCaP cells (P=0.013 and P=0.016). Conclusions 2'-HF can enhance the radiosensitivity of prostate cancer cells, which is probably associated with its inhibitory effects on AKT pathway and AKR1C3 expression in prostate cancer cells. Key words: 2'-hydroxyflavanone; Radiosensibility; Prostate cancer cells line