BACKGROUND: We explored multiple molecular mechanisms of the combination of docetaxel and an oncolytic prostate-restricted replication competent adenovirus (Ad) (PRRA) in advanced prostate cancer (PCa) models. The combinational therapy has potential to overcome the therapeutic limitations of poor virus distribution inside solid tumors. METHODS: We evaluated the effect of docetaxel on the antitumor efficacy and efficiency of virus transduction, transgene expression and virus distribution of PRRA in a prostate-specific antigen/prostate-specific membrane antigen-positive tumor xenograft model. We also evaluated the effect of docetaxel on apoptosis induction, cell killing and the efficiency of transgene expression and virus replication in vitro. RESULTS: Tumor growth inhibition was significantly enhanced when docetaxel was administrated before intratumor injection of PRRA. In vivo dual-photon microscopy and ex vivo fluorescence microscopy and immunohistochemistry showed that docetaxel increased transgene expression and expanded virus distribution. The combination of docetaxel and PRRA also increased cell apoptosis. In vitro, docetaxel significantly increased cell killing in PRRA-treated PCa cells. Docetaxel significantly increased Ad-mediated trangene expression independent of Ad binding receptors and replication capability. Docetaxel increased the activity of cytomegalovirus (CMV) promoter but not of a chimeric prostate-specific enhancer, resulting in higher transgene expression. The enhanced CMV promoter activity resulted from activation of p38 mitogen-activated protein kinase (MAPK) because inhibition of p38 MAPK blocked the docetaxel-induced increase in CMV promoter activity. CONCLUSIONS: Combining docetaxel with an oncolytic PRRA improved therapeutic potential by expanding virus distribution and enhancing cell apoptosis and killing. These studies suggested a novel mechanism for enhancing the effect of therapeutic genes delivered by a PRRA.
BACKGROUND: We explored multiple molecular mechanisms of the combination of docetaxel and an oncolytic prostate-restricted replication competent adenovirus (Ad) (PRRA) in advanced prostate cancer (PCa) models. The combinational therapy has potential to overcome the therapeutic limitations of poor virus distribution inside solid tumors. METHODS: We evaluated the effect of docetaxel on the antitumor efficacy and efficiency of virus transduction, transgene expression and virus distribution of PRRA in a prostate-specific antigen/prostate-specific membrane antigen-positive tumor xenograft model. We also evaluated the effect of docetaxel on apoptosis induction, cell killing and the efficiency of transgene expression and virus replication in vitro. RESULTS: Tumor growth inhibition was significantly enhanced when docetaxel was administrated before intratumor injection of PRRA. In vivo dual-photon microscopy and ex vivo fluorescence microscopy and immunohistochemistry showed that docetaxel increased transgene expression and expanded virus distribution. The combination of docetaxel and PRRA also increased cell apoptosis. In vitro, docetaxel significantly increased cell killing in PRRA-treated PCa cells. Docetaxel significantly increased Ad-mediated trangene expression independent of Ad binding receptors and replication capability. Docetaxel increased the activity of cytomegalovirus (CMV) promoter but not of a chimeric prostate-specific enhancer, resulting in higher transgene expression. The enhanced CMV promoter activity resulted from activation of p38 mitogen-activated protein kinase (MAPK) because inhibition of p38 MAPK blocked the docetaxel-induced increase in CMV promoter activity. CONCLUSIONS: Combining docetaxel with an oncolytic PRRA improved therapeutic potential by expanding virus distribution and enhancing cell apoptosis and killing. These studies suggested a novel mechanism for enhancing the effect of therapeutic genes delivered by a PRRA.
Authors: Svend O Freytag; Hans Stricker; James Peabody; Jan Pegg; Dell Paielli; Benjamin Movsas; Kenneth N Barton; Stephen L Brown; Mei Lu; Jae Ho Kim Journal: Mol Ther Date: 2007-01-16 Impact factor: 11.454
Authors: Mohan Hingorani; Christine L White; Shane Zaidi; Andrew Merron; Inge Peerlinck; Martin E Gore; Christopher M Nutting; Hardev S Pandha; Alan A Melcher; Richard G Vile; Georges Vassaux; Kevin J Harrington Journal: Clin Cancer Res Date: 2008-08-01 Impact factor: 12.531
Authors: K J Kelly; Ruben M Sandoval; Kenneth W Dunn; Bruce A Molitoris; Pierre C Dagher Journal: Am J Physiol Cell Physiol Date: 2002-12-21 Impact factor: 4.249
Authors: Xiong Li; You-Hong Liu; Sang-Jin Lee; Thomas A Gardner; Meei-Huey Jeng; Chinghai Kao Journal: Clin Cancer Res Date: 2008-01-01 Impact factor: 12.531
Authors: Kwang Il Kim; Joo Hyun Kang; June-Key Chung; Yong Jin Lee; Jae Min Jeong; Dong Soo Lee; Myung Chul Lee Journal: J Nucl Med Date: 2007-08-17 Impact factor: 10.057