Project description:A subpopulation of prostate luminal epithelial cells has been previously reported to be sufficient to regenerate prostatic architecture following consecutive rounds of androgen deprivation/repletion. This functional characteristic suggest prostate luminal epithelial cells as the putative cell-of-origin for castration-resistant prostate cancer - which more notizable fenotype is the lack of response to androgen deprivation thereapy. We used microarrays to profile the androgen-induced transcripts in luminal prostate epithelial cells involved in a cycle of prostate regression/regeneration in Hoxb13-rtTA|TetO-H2BGFP transgenic mice.
Project description:Immuno-stained (keratin 14+ basal marker) frozen prostate sections were subjected to laser-guided microdissection to isolate basal and luminal epithelial prostate cells for expression profiling. RNA was amplified using the AmpTec TRinucleotide kit (AmpTec GmBH). Expression profiling performed using the Invitrogen post-labelling kit and the CRUK whole genome array (WGA) gene set. Keywords: repeat sample
Project description:Transcription factors are one of the major groups of proteins whose suppression leads to tumor growth arrest. Different types of cancer express a specific set of transcription factors that establish and maintain specific gene expression patterns. In prostate cancer cells, one of the key transcriptional regulators is the HOXB13 protein, but its function has not been well characterized. In the present study, we searched for protein partners of HOXB13 by co-immunoprecipitation followed by high-throughput mass spectrometric analysis (IP/LC-MS) using the PC3 cell line as a source. This analysis revealed that the major partners of HOXB13 were transcription factors with different types of DNA-binding domains.
Project description:Subset of adult prostate basal cells and fetal prostate epithelial cells have enhanced tubule-initiating capability in vivo. Features associated with this process may be co-opted in cancer cells We used microarrays to contrast gene expression profiles of fetal and adult tubule-initiating cells compared to basal and luminal epithelial cells that can be isolated from bening prostate tissue specimens.
Project description:Transcriptome analysis of lineage marked AR-deleted and wild type luminal prostate epithelial cells from prostates from 4 week old males, and bulk wild-type prostates from 3 week old male mice.
Project description:To identify potential cofactors of HOXB13 in suppressing lipogenic programs in prostate cancer cells, we performed tandem affinity purification followed by mass spectrometry analysis of WT and G84E HOXB13 expressed in LNCaP cells. Out of the HOXB13-enriched proteins are previously reported interactors such as AR and its cofactors FOXA1, GATA2, and NKX3. However, these interactions were not disrupted by G84E as compared to WT HOXB13. Interestingly, we found strong interactions of HOXB13 with HDAC1/3 and their corepressors NCoR1/2 and TBL1X. Notably, these interactions were drastically reduced by G84E mutation.
Project description:While tissue and lineage-specific super-enhancers (SEs) regulate cell fate decision during development, the nature of Castration Resistant Prostate Cancer (CRPC)-specific SEs (CSEs) that drive resistance to AR-targeted therapies is unknown. Herein we report the lysine 13 (K13)-acetylation of Homeodomain transcription factor HOXB13 as a critical feature underlying CSE exclusivity. The histone acetyltransferase (HAT) CBP/p300 specifically acetylates HOXB13 (acK13-HOXB13) in prostate cancer cells. The acK13-HOXB13 enriched CSEs sprout at critical lineage genes such as the NKX3-1, Androgen receptor (AR), AR regulator ACK1/TNK2 a tyrosine-kinase and tyrosine kinase ligands associated with angiogenesis, including VEGFA and ANGPT2/ANGPTL3 to expedite prostate tumor autonomy.
Project description:Treatment induced-resistance of CRPC is an imminent undesirable outcome in patients. Tissue and lineage-specific super-enhancers (SEs) determine cell fate and plasticity during development and disease respectively. However, the identity and function of CRPC-specific SEs (CSEs) regulated genes is unknown. Herein we report the lysine 13 acetylation of the prostate-enriched transcription factor HOXB13 (acK13-HOXB13) mediated by the histone acetyl transferase (HAT) CBP/p300 as a critical mechanism of CSE establishment. Mechanistically, acK13-HOXB13 establishes the CRPC enhanceosome comprising chromatin remodeling bromo-domain proteins SMARCA2/BAZ2B and the HAT p300/CBP which enable histone and non-histone protein acetylation at CSEs. Such CSEs sprout at tyrosine kinase genes encoding ACK1/TNK2, VEGFA, and ANGPT2/ANGPTL3 to increase pathogenic output in primary human tumors. These tyrosine kinase mediated signaling cascades establish robust networks to conduce growth, survival and androgen-bypass. Consistently, the loss of function acK13-HOXB13 mutants show significant reduction of proliferation, spheroid formation, and xenograft tumor growth that correlates with the high sensitivity to the AR-antagonist Enzalutamide. Targeting HOXB13 acetylation mediated CRPC-SE establishment at critical tyrosine kinase genes could therefore have significant clinical implications in preventing PC recurrence.
Project description:While tissue and lineage-specific super-enhancers (SEs) regulate cell fate decision during development, the nature of Castration Resistant Prostate Cancer (CRPC)-specific SEs (CSEs) is unknown. Herein we report the lysine 13 (K13) acetylation of HOXB13 mediated by the histone acetyltransferase CBP/p300 regulates prostate tumor autonomy. The acK13-HOXB13 shadows H3K27ac at lineage specific SEs and surpasses it at CSEs. In contrast, mutation of HOXB13 at K13 sensitizes CRPCs to Enzalutamide, disables spheroid and xenograft tumor formation. Mechanistically, the acK13-HOXB13 interacts with chromatin remodeling bromodomain proteins to regulate tumor-specific CSE selection. These CSEs sprout at critical lineage genes NKX3-1, Androgen receptor (AR), AR regulator ACK1 tyrosine kinase and tyrosine kinase ligands regulating angiogenesis. Single-cell transcriptomic analysis of human prostate tumor organoids reveal ACK1 expression underlies sensitivity to the small molecule inhibitor (R)-9b over AR-targeted agents. Collectively, our studies reveal acK13-HOXB13 regulated epigenome as a key cog in prostate cancer cell autonomy.
Project description:Homeobox-B13 (HOXB13) is a master transcriptional regulator which is exclusively expressed in the prostate tissue and has been shown to be crucial for its embryonic development. There is extensive clinical and experimental evidence to support the role of HOXB13 in prostate cancer (PCa). Yet, despite this critical role, the function of HOXB13 remains controversial with some studies supporting an oncogenic role and others demonstrating a tumor-suppressive role. While there is a clear relationship between HOXB13 and AR there are conflicting studies if HOXB13 is itself regulated by AR. Interrogating various AR +ve and AR -ve in-vivo and in-vitro models, in this study, we demonstrate that HOXB13 is crucial for the growth and proliferation of PCa regardless of its androgen dependency. We show that HOXB13 activity in these different models is mediated via interactions with cell-specific transcription factors. Yet despite the diverse transcription factor interactions, HOXB13 activity is commonly modulated by SMARCD2, a member of the mSWI/SNF chromatin remodeling complex. The HOXB13/SMARCD2 interaction is stabilized through interactions with transcription factors. This interaction alters the chromatin accessibility at HOXB13 binding sites which leads to increased proliferation in PCa.