Histone demethylase JMJD1A promotes alternative splicing of AR variant 7 (AR-V7) in prostate cancer cells

L Fan, F Zhang, S Xu, X Cui… - Proceedings of the …, 2018 - National Acad Sciences
L Fan, F Zhang, S Xu, X Cui, A Hussain, L Fazli, M Gleave, X Dong, J Qi
Proceedings of the National Academy of Sciences, 2018National Acad Sciences
Formation of the androgen receptor splicing variant 7 (AR-V7) is one of the major
mechanisms by which resistance of prostate cancer to androgen deprivation therapy occurs.
The histone demethylase JMJD1A (Jumonji domain containing 1A) functions as a key
coactivator for AR by epigenetic regulation of H3K9 methylation marks. Here, we describe a
role for JMJD1A in AR-V7 expression. While JMJD1A knockdown had no effect on full-length
AR (AR-FL), it reduced AR-V7 levels in prostate cancer cells. Reexpression of AR-V7 in the …
Formation of the androgen receptor splicing variant 7 (AR-V7) is one of the major mechanisms by which resistance of prostate cancer to androgen deprivation therapy occurs. The histone demethylase JMJD1A (Jumonji domain containing 1A) functions as a key coactivator for AR by epigenetic regulation of H3K9 methylation marks. Here, we describe a role for JMJD1A in AR-V7 expression. While JMJD1A knockdown had no effect on full-length AR (AR-FL), it reduced AR-V7 levels in prostate cancer cells. Reexpression of AR-V7 in the JMJD1A-knockdown cells elevated expression of select AR targets and partially rescued prostate cancer cell growth in vitro and in vivo. The AR-V7 protein level correlated positively with JMJD1A in a subset of human prostate cancer specimens. Mechanistically, we found that JMJD1A promoted alternative splicing of AR-V7 through heterogeneous nuclear ribonucleoprotein F (HNRNPF), a splicing factor known to regulate exon inclusion. Knockdown of JMJD1A or HNRNPF inhibited splicing of AR-V7, but not AR-FL, in a minigene reporter assay. JMJD1A was found to interact with and promote the recruitment of HNRNPF to a cryptic exon 3b on AR pre-mRNA for the generation of AR-V7. Taken together, the role of JMJD1A in AR-FL coactivation and AR-V7 alternative splicing highlights JMJD1A as a potentially promising target for prostate cancer therapy.
National Acad Sciences