Abstract
The aim of the present study was to investigate the activities of novel synthetic epidermal growth factor receptor (EGFR) inhibitors (ZINC05463076, ZINC2102846 and ZINC19901103) against prostate tumors, in vitro models and investigate the potential underlying mechanisms. A panel of prostate tumor cell lines (LNCaP, DU-145, PC-3 and LNCaP-AI cells) were used to evaluate antitumor activity of ZINC05463076, ZINC2102846, and ZINC19901103 in vitro. Cell growth and clonal formation were determined by MTT assay and Soft agar colony formation assay, respectively. An EGFR kinase assay following treatment of the compounds was performed by ELISA. Cell cycle-regulating proteins, including cyclin-dependent kinase (CDK)1, CKD2, CKD4 and inhibitory effects of these compounds on downstream signaling were analyzed by western blotting. Flow cytometry was performed to investigate apoptosis and cell cycle phases of the treated cells. It was revealed that all compounds synthesized in the present study demonstrated significant EGFR inhibition abilities, compared with approved EGFR inhibitor drug gefitinib. Treatment of LNCaP, DU-145, PC3 and LNCaP-AI cells with these compounds revealed cell proliferation inhibition and colony formation suppression dose-dependently in vitro. The agents impaired phosphorylation of EGFR and extracellular signal-regulated kinase 1/2 and suppressed their downstream signaling. In addition, these novel synthetic agents decreased the expression level of survivin, which may induce G1 cell cycle phase arrest and cell apoptosis in PCa cells subsequently. Collectively, ZINC05463076, ZINC2102846 and ZINC19901103 exhibited significant antitumor activity in human prostate tumors in vitro, by inhibiting EGFR and promoting apoptosis, which suggested a rationale for clinical development in prostate tumor therapy.