@article {STOPE4921, author = {MATTHIAS B. STOPE and JULIANE BRADL and STEFANIE PETERS and ANDREAS STREITB{\"O}RGER and MARTIN WEISS and UWE ZIMMERMANN and REINHARD WALTHER and CHRISTOPHER H. LILLIG and MARTIN BURCHARDT}, title = {Shortened Isoforms of the Androgen Receptor Are Regulated by the Cytoprotective Heat-shock Protein HSPB1 and the Tumor-suppressive MicroRNA miR-1 in Prostate Cancer Cells}, volume = {33}, number = {11}, pages = {4921--4926}, year = {2013}, publisher = {International Institute of Anticancer Research}, abstract = {Background: Shortened, constitutively active androgen receptor (AR) isoforms have been characterized and linked to tumor progression and chemoresistance in prostate cancer (PCa). We examined the regulation of shortened AR isoforms by a newly-identified AR regulatory signaling pathway involving heat-shock protein HSPB1 and microRNA miR-1. Materials and Methods: HSPB1 and miR-1 were modulated by overexpression and knock-down approaches utilizing the model PCa system, 22Rv1. Subsequently, AR isoform expression levels were quantified by western blot analysis. Results: HSPB1 was identified as an inducer and miR-1 as an inhibitor of AR variants, with no detectable discrimination between long and short AR isoform regulation. Conclusion: In 22Rv1 cells, all AR isoforms were co-regulated by the cytoprotective factor HSPB1 and the tumor suppressor miR-1. Notably, our data provide evidence that HSPB1 inhibition is able to target expression of long as well as of short AR isoforms.}, issn = {0250-7005}, URL = {https://ar.iiarjournals.org/content/33/11/4921}, eprint = {https://ar.iiarjournals.org/content/33/11/4921.full.pdf}, journal = {Anticancer Research} }