Mayo Clinic Laboratory and Pathology Research Roundup: Aug. 21

The Research Roundup provides an overview of the past week’s research from Mayo Medical Laboratories consultants, including featured abstracts and complete list of published studies and reviews.


Featured Abstract

Intrinsic BET Inhibitor Resistance in SPOP-Mutated Prostate Cancer Is Mediated by BET Protein Stabilization and AKT-mTORC1 Activation

Bromodomain and extraterminal domain (BET) protein inhibitors are emerging as promising anticancer therapies. The gene encoding the E3 ubiquitin ligase substrate-binding adaptor speckle-type POZ protein (SPOP) is the most frequently mutated in primary prostate cancer. Mayo Clinic researchers demonstrated that wild-type SPOP binds to and induces ubiquitination and proteasomal degradation of BET proteins (BRD2, BRD3 and BRD4) by recognizing a degron motif common among them. In contrast, prostate cancer-associated SPOP mutants show impaired binding to BET proteins, resulting in decreased proteasomal degradation and accumulation of these proteins in prostate cancer cell lines and patient specimens and causing resistance to BET inhibitors. Transcriptome and BRD4 cistrome analyses reveal enhanced expression of the GTPase RAC1 and cholesterol-biosynthesis-associated genes together with activation of AKT-mTORC1 signaling as a consequence of BRD4 stabilization. This data show that resistance to BET inhibitors in SPOP-mutant prostate cancer can be overcome by combination with AKT inhibitors and further support the evaluation of SPOP mutations as biomarkers to guide BET-inhibitor-oriented therapy in patients with prostate cancer. The study was published in Nature Medicine.


Published to PubMed This Week

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Kelley Schreiber

Kelley Schreiber is a Marketing Channel Manager at Mayo Medical Laboratories. She is the principle editor and writer of Insights and leads social media and direct marketing strategy. Kelley has worked at Mayo Clinic since 2013. Outside of work, you can find Kelley running, traveling, playing with her new kitten, and exploring new foods.