Abstract:

Objective  To investigate the inhibitory effect of Gefitinib in the treatment of hormone independent prostate cancer (HIPC) in vitro and in vivo Methods  The HIPC cell line PC-3 was treated with Gefitinib indifferent concentrations for 24-120?h, and then the cellinhibition ratio (CIR) was measured with MTT and expression levels of proteins, such as epidermal growth factor receptor (EGFR), protein kinase B (Akt), mitogen aetivatedprotein kinase (MAPK) and protein kinase C (PKC) were determined by Western blot. Results  The inhibitoryeffect of Gefitinib on PC-3 cells′ growth showed a time and density- dependence, and the ideal inhibitory concentration and time were 5?ng/mL and 72?h, in which the CIR of PC-3 cells was 50%-60%. Compared with the control group, expression levels of protein EGFR and Akt were significantly decreased by 70.44% and 59.01% in PC-3 cells in the Gefitinib group; expression levels of MAPK and PKC was decreased by 34.83% and 33.40%. In an in vivo experiment, compared with the control group, the growth of HIPC tumors in the Gefitinib group was significantly inhibited by 53.95%.Conclusion  Gefitinib could significantly induce inhibitory effects on growth of HIPC in vitro- and in vivo by down-regulation of expressions of EGFR and its intra-cellular effective proteins Akt in PC-3 cells.

Key words: Hormone independence prostate cancer; Gefitinib; Epidermal growth factor receptor; Intracellular effective protein