Abstract 2788: Characterization of an in vivo generated subpopulation of human LnCaP prostate cancer cells as an improved testosterone-dependent in vivo mouse xenograft model for compound testing.

Abstract

Prostate cancer is one of the most frequently diagnosed cancer entities in men. It can be estimated that in 80% of all men reaching the age of 80 years prostate tumors are present. Since a depletion of testosterone in prostate cancer therapies is often performed, androgen-dependent and -independent prostate carcinoma cell lines have been widely used to establish mouse in vivo xenograft models in order to identify novel drugs helping to eliminate prostate tumors. A commercially available LnCaP cell line was shown to be androgen-dependent since addition of synthetic androgens to androgen-free culture medium was able to restore proper cell proliferation in cell culture. However, when implanted in SCID mice in order to establish a xenograft model, the take rate turned out to be very low and tumor growth was highly heterogeneously. Therefore, we resected and recultivated one of the few well-growing tumors and reimplanted the arising subpopulation subcutaneously in mice. After performing two rounds of this “subpopulationing” procedure we could generate a new cell line, LnCaP-Z2, which was able to form tumors in mice with a take rate of nearly 100%, but still shows heterogenous tumor growth similar to other subcutaneously implanted prostate cancer cells (e.g. PC-3). In order to demonstrate an androgen dependency of our new LnCaP subpopulation model in vivo we used castrated mice and implanted them subcutaneously with two different prostate cancer cell lines in the absence or presence of also subcutaneously inoculated testosterone pellets. Whereas no influence of testosterone was detectable on the growth behavior of subcutaneous PC-3 xenograft tumors, the development of the LnCaP-Z2 xenografts was strictly dependent on testosterone release. Finally, treatment of Bicalutamide, a typical member of the class of anti-androgens, which is frequently used in the treatment of prostate cancer, led to significant inhibition of tumor growth using our improved subpopulation LnCaP-Z2 in vivo model. Thus, we could demonstrate the model's potency as a testosterone-dependent in vivo tool suitable for screening and development of novel anti-prostate cancer drugs. Citation Format: Andreas Lingnau, Steffen Hoffmann, Cynthia Schaefer-Obodozie, Ulrike Leisegang, Andreas Klotzbuecher, Christoph Schaechtele. Characterization of an in vivo generated subpopulation of human LnCaP prostate cancer cells as an improved testosterone-dependent in vivo mouse xenograft model for compound testing. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2788. doi:10.1158/1538-7445.AM2013-2788