Anti-ErbB4 targeted therapy combined with radiation therapy in prostate cancer: Results of in-vitro and in-vivo studies

AKIVA VEXLER, GHALIB LIDAWI, VERED LOEW, ITAY BARNEA, VICTORIYA KARAUSH, ALEXANDER SHTABSKY and RAMI BEN-YOSEF

volume 7 | issue 7

July 2008
Pages: 1090 - 1094

Purchase article for $19

Subscribe to this journal for $129/year

» Log in

Purpose: To evaluate the efficiency of anti ErbB4 targeted therapy combined with irradiation (XRT) over each modality alone in prostate cancer. Methods: Clones with low and high expression of ErbB4 isolated by a limited dilution technique from an androgen independent Cl-1 cell line were used. The cells from these clones were exposed to XRT (single dose of 2-6 Gy) and to anti-ErbB4 monoclonal antibody (mAb). The XTT test was used to measure cell survival. In addition, tumor bearing nude mice were treated either by XRT, mAb or by a combined treatment. Tumor sizes were recorded at given time points. Results: Clones with high ErbB4 expression grew faster than those with low ErbB4 expression. XRT inhibited the growth of both expressive and non-expressive ErbB4 cells, while mAb inhibited only high ErbB4 expressing cells. The combination of XRT and mAb resulted in a 30% reduction of the survival of high ErbB4 expressing cells over XRT alone (p=0.013). In tumor bearing mice the tumor size in the combined arm was 1mm at 4 weeks compared to 2-3 mm and 4-5 mm in the radiation and mAb arms ( p' value of 0.02 and 0.087 respectively) Conclusion: Anti ErbB4 combined with XRT is possibly more effective than each modality alone in prostate cancer.