Low tristetraprolin expression activates phenotypic plasticity and primes transition to lethal prostate cancer in mice

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Abstract

Phenotypic plasticity is a hallmark of cancer and is increasingly realized as a mechanism of resistance to androgen receptor–targeted (AR-targeted) therapy. Now that many prostate cancer (PCa) patients are treated upfront with AR-targeted agents, it is critical to identify actionable mechanisms that drive phenotypic plasticity, to prevent the emergence of resistance. We showed that loss of tristetraprolin (TTP; gene ZFP36) increased NF-κB activation, and was associated with higher rates of aggressive disease and early recurrence in primary PCa. We also examined the clinical and biological impact of ZFP36 loss with co-loss of PTEN, a known driver of PCa. Analysis of multiple independent primary PCa cohorts demonstrated that PTEN and ZFP36 co-loss was associated with increased recurrence risk. Engineering prostate-specific Zfp36 deletion in vivo induced prostatic intraepithelial neoplasia, and, with Pten codeletion, resulted in rapid progression to castration-resistant adenocarcinoma. Zfp36 loss altered the cell state driven by Pten loss, as demonstrated by enrichment of epithelial–mesenchymal transition (EMT), inflammation, TNF-α/NF-κB, and IL-6–JAK/STAT3 gene sets. Additionally, our work revealed that ZFP36 loss also induced enrichment of multiple gene sets involved in mononuclear cell migration, chemotaxis, and proliferation. Use of the NF-κB inhibitor dimethylaminoparthenolide (DMAPT) induced marked therapeutic responses in tumors with PTEN and ZFP36 co-loss and reversed castration resistance.

Authors

Katherine L. Morel, Beatriz Germán, Anis A. Hamid, Jagpreet S. Nanda, Simon Linder, Andries M. Bergman, Henk van der Poel, Ingrid Hofland, Elise M. Bekers, Shana Y. Trostel, Deborah L. Burkhart, Scott Wilkinson, Anson T. Ku, Minhyung Kim, Jina Kim, Duanduan Ma, Jasmine T. Plummer, Sungyong You, Xiaofeng A. Su, Wilbert Zwart, Adam G. Sowalsky, Christopher J. Sweeney, Leigh Ellis