Recent studies have shown that docetaxel-based chemotherapy confers a survival benefit in patients with castration-resistant prostate cancer (PC). Also epidermal growth factor receptor (EGFR) was found to have multiple roles in prostatic tumorigenesis. However, the EGFR-mediated chemoresistance mechanism in human PC was not well delineated. In this study, we explored the mechanism of EGFR-mediated docetaxel resistance in PC. A series of stable docetaxel-resistant PC/DX sublines were established at our laboratory. The docetaxel IC50s of PC3 and PC/DX25 cells were 0.01 and 1.33 μM, respectively. Cellular resistance to docetaxel was significantly associated with increased EGFR and EGFR activation in PC/DX25. There was a dose-dependent increase in EGFR expression associated with the magnitude of docetaxel resistance. Expression of EGFR in PC/DX25 was higher than that in PC3, RWPE-1 and LNCaP cells. Similar results were also found in human PC tissues by immunohistochemical staining. We showed that docetaxel sensitivity can be stored in PC/DX25 cells by knockdown and inactivation of EGFR expression through EGFR siRNA and specific inhibitors, respectively. Contrarily, overexpression of EGFR or recombinant EGF protein treatment could rescue PC3 cells from docetaxel-mediated cytotoxicity. Gefitninb (ZD1839) significantly inhibited the growth of PC/DX25 cells by MTT in vitro and on xenografted nude mice in vivo. Moreover, EGFR-mediated docetaxel resistance occurred through the Akt-dependent ABCB1 expression in PC cells. These findings demonstrated EGFR played an important role in docetaxel-resistant PC and EGFR inhibition may enhance the therapeutic efficacy of docetaxel-based treatment.

SILC is safe and efficacious for patients with acute cholecystitis. The main benefit is a faster recovery than that achieved with 3ILC.

SILCBDE is as safe and efficacious as standard LCBDE in experienced hands. Choledochoscope manipulation and bile duct repair are the key skills. Long-term follow-up and further prospective randomized trials are anticipated.

A spacer-enhanced FITC-labeled peptide self-assembled onto AuNPs was fabricated as a chymotrypsin activated fluorescent AuNP probe and was used for the diagnosis of pancreatitis with fecal specimens.