JS-K, a glutathione/glutathione S-transferase-activated nitric oxide releasing prodrug inhibits androgen receptor and WNT-signaling in prostate cancer cells

BMC Cancer

Research Article

Mark Schrader¹  Marcus V Cronauer¹  Andres J Schrader¹  Martin Laschak²  Andrea Hessenauer²  Klaus-Dieter Spindler²  Wolfgang Streicher³ 

[1] Department of Urology, Ulm University, Prittwitzstrasse 43, 89075, Ulm, Germany;Institute for General Zoology and Endocrinology, Ulm University, Albert Einstein Allee 23, 89069, Ulm, Germany;Institute for General Zoology and Endocrinology, Ulm University, Albert Einstein Allee 23, 89069, Ulm, Germany;Department of Urology, Ulm University, Prittwitzstrasse 43, 89075, Ulm, Germany;

关键词: Nitric Oxide;    Androgen Receptor;    LNCaP Cell;    Nitrotyrosine;    Castration Resistant Prostate Cancer;   

DOI  :  10.1186/1471-2407-12-130

 received in 2011-11-04, accepted in 2012-03-30,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundNitric oxide (NO) and its oxidative reaction products have been repeatedly shown to block steroid receptor function via nitrosation of zinc finger structures in the DNA-binding domain (DBD). In consequence NO-donors could be of special interest for the treatment of deregulated androgen receptor(AR)-signaling in castration resistant prostate cancer (CRPC).MethodsProstate cancer (PCa) cells were treated with JS-K, a diazeniumdiolate derivate capable of generating large amounts of intracellular NO following activation by glutathione S-transferase. Generation of NO was determined indirectly by the detection of nitrate in tissue culture medium or by immunodetection of nitrotyrosine in the cytoplasm. Effects of JS-K on intracellular AR-levels were determined by western blotting. AR-dimerization was analyzed by mammalian two hybrid assay, nuclear translocation of the AR was visualized in PCa cells transfected with a green fluorescent AR-Eos fusion protein using fluorescence microscopy. Modulation of AR- and WNT-signalling by JS-K was investigated using reporter gene assays. Tumor cell proliferation following JS-K treatment was measured by MTT-Assay.ResultsThe NO-releasing compound JS-K was shown to inhibit AR-mediated reporter gene activity in 22Rv1 CRPC cells. Inhibition of AR signaling was neither due to an inhibition of nuclear import nor to a reduction in AR-dimerization. In contrast to previously tested NO-donors, JS-K was able to reduce the intracellular concentration of functional AR. This could be attributed to the generation of extremely high intracellular levels of the free radical NO as demonstrated indirectly by high levels of nitrotyrosine in JS-K treated cells. Moreover, JS-K diminished WNT-signaling in AR-positive 22Rv1 cells. In line with these observations, castration resistant 22Rv1 cells were found to be more susceptible to the growth inhibitory effects of JS-K than the androgen dependent LNCaP which do not exhibit an active WNT-signaling pathway.ConclusionsOur results suggest that small molecules able to inhibit WNT- and AR-signaling via NO-release represent a promising platform for the development of new compounds for the treatment of CRPC.

【 授权许可】

Unknown   
© Laschak et al; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.