Nearly 50% of prostate cancers harbor gene fusions that lead to overexpression of the transcription factor ERG, while a mutually exclusive 10% of prostate cancers harbor recurrent mutations in the gene encoding the E3 ubiquitin ligase SPOP. Recent reports suggest that SPOP acts as a ubiquitin ligase for ERG and propose that ERG stabilization is the oncogenic effector of SPOP mutation. Here, we used human prostate cancer samples and showed that the vast majority of human SPOP-mutant cancers do not express ERG. Comparison of SPOP-mutant and ERG-fusion organoid models showed evidence of divergent, rather than common, transcriptional programs. Furthermore, expression of prostate cancer–associated SPOP mutations in genetically engineered mouse models of SPOP-mutant prostate cancer did not result in the expression of ERG protein in histologically normal prostate glands, high-grade prostatic intraepithelial neoplasia, invasive adenocarcinoma, or prostate organoids. In summary, we found no evidence that ERG is an effector of SPOP mutation in human prostate cancer or mouse models.
Jonathan Shoag, Deli Liu, Mirjam Blattner, Andrea Sboner, Kyung Park, Lesa Deonarine, Brian D. Robinson, Juan Miguel Mosquera, Yu Chen, Mark A. Rubin, Christopher E. Barbieri
Guidelines: The Editorial Board will only consider letters that we deem relevant and of interest to our readers. We will not post data that have not been subjected to peer review, nor will we post letters that are essentially a reiteration of another letter. We reserve the right to edit any letter for length, content, and clarity. Authors will be notified by e-mail if their letters were accepted. No appeals will be considered.
Specific requirements: All letters must be 400 words or fewer. You may enter the letter as plain text or HTML. The author's name and e-mail address are required, and will be posted with the letter. All possible conflicts of interest must be noted, even if they are not posted. If you wish to include a figure (keep in mind that non-peer-reviewed data will not be posted), please contact the editors directly at email@example.com.