RNA-seq in LNCaP with inducible expression of MACC constructs.
Ontology highlight
ABSTRACT: The androgen receptor (AR) is the central determinant of prostate tissue identity and differentiation, controlling normal, growth-suppressive prostate-specific gene expression. It is also a key driver of prostate tumorigenesis, becoming “hijacked” to drive oncogenic transcription. However, the regulatory elements determining the execution of the growth suppressive AR transcriptional program, and whether this can be reactivated in prostate cancer (PCa) cells remains unclear. Canonical androgen response element (ARE) motifs are the classic DNA binding element for AR. Here, we used a genome-wide strategy to modulate regulatory elements containing AREs to define distinct AR transcriptional programs. We find that activation of these AREs is specifically associated with differentiation and growth suppressive transcription, and this can be reactivated to cause death in AR+ PCa cells. In contrast, repression of AREs is well tolerated by PCa cells, but deleterious to normal prostate cells. Finally, gene expression signatures driven by ARE activity are associated with improved prognosis and luminal phenotypes in human PCa patients. This study demonstrates that canonical AREs are responsible for a normal, growth-suppressive, lineage-specific transcriptional program, that this can be reengaged in PCa cells for potential therapeutic benefit, and genes controlled by this mechanism are clinically relevant in human PCa patients.
Project description:The androgen receptor (AR) is the central determinant of prostate tissue identity and differentiation, controlling normal, growth-suppressive prostate-specific gene expression. It is also a key driver of prostate tumorigenesis, becoming “hijacked” to drive oncogenic transcription. However, the regulatory elements determining the execution of the growth suppressive AR transcriptional program, and whether this can be reactivated in prostate cancer (PCa) cells remains unclear. Canonical androgen response element (ARE) motifs are the classic DNA binding element for AR. Here, we used a genome-wide strategy to modulate regulatory elements containing AREs to define distinct AR transcriptional programs. We find that activation of these AREs is specifically associated with differentiation and growth suppressive transcription, and this can be reactivated to cause death in AR+ PCa cells. In contrast, repression of AREs is well tolerated by PCa cells, but deleterious to normal prostate cells. Finally, gene expression signatures driven by ARE activity are associated with improved prognosis and luminal phenotypes in human PCa patients. This study demonstrates that canonical AREs are responsible for a normal, growth-suppressive, lineage-specific transcriptional program, that this can be reengaged in PCa cells for potential therapeutic benefit, and genes controlled by this mechanism are clinically relevant in human PCa patients.
Project description:The androgen receptor (AR) is the central determinant of prostate tissue identity and differentiation, controlling normal, growth-suppressive prostate-specific gene expression. It is also a key driver of prostate tumorigenesis, becoming “hijacked” to drive oncogenic transcription. However, the regulatory elements determining the execution of the growth suppressive AR transcriptional program, and whether this can be reactivated in prostate cancer (PCa) cells remains unclear. Canonical androgen response element (ARE) motifs are the classic DNA binding element for AR. Here, we used a genome-wide strategy to modulate regulatory elements containing AREs to define distinct AR transcriptional programs. We find that activation of these AREs is specifically associated with differentiation and growth suppressive transcription, and this can be reactivated to cause death in AR+ PCa cells. In contrast, repression of AREs is well tolerated by PCa cells, but deleterious to normal prostate cells. Finally, gene expression signatures driven by ARE activity are associated with improved prognosis and luminal phenotypes in human PCa patients. This study demonstrates that canonical AREs are responsible for a normal, growth-suppressive, lineage-specific transcriptional program, that this can be reengaged in PCa cells for potential therapeutic benefit, and genes controlled by this mechanism are clinically relevant in human PCa patients.
Project description:The androgen receptor (AR) mediates the action of androgens by binding to androgen-responsive elements (AREs) and subsequently regulating target genes involved in prostate carcinogenesis. The precise locations, true nature, and functional roles of AREs in human prostate cancer are still unknown. Here we redefine AREs by motif-resolution AR chromatin immunoprecipitation-exonuclease (ChIP-exo) assay in human prostate cancer cells and tumors. Surprisingly, we find that, in addition to canonical full-length AREs and half-site-like AREs, a significant portion of the four redefined ARE categories comprises non-canonical full-length AREs. The redefined AREs in enhanced AR binding regions in prostate tumors versus paired non-malignant adjacent tissues regulate a prostate cancer-relevant gene network not only centered on AR, but more interestingly, on novel AR target genes mTOR, BIRC5 and BCL2L1 involved in prostate cancer cell growth and survival. The precise redefinition of AREs has important implications for understanding how AR contributes to prostate carcinogenesis. To examine the differential AR binding in LNCaP cells before and after androgen stimulation, ChIP-Seq of androgen receptor is performed in LNCaP cells under the two conditions. To profile histone modification status in control LNCaP cells, MNase-Seq is performed with five different antibodies specific to certain histone marks. Each experiment includes two replicates.
Project description:The androgen receptor (AR) mediates the action of androgens by binding to androgen-responsive elements (AREs) and subsequently regulating target genes involved in prostate carcinogenesis. The precise locations, true nature, and functional roles of AREs in human prostate cancer are still unknown. Here we redefine AREs by motif-resolution AR chromatin immunoprecipitation-exonuclease (ChIP-exo) assay in human prostate cancer cells and tumors. Surprisingly, we find that, in addition to canonical full-length AREs and half-site-like AREs, a significant portion of the four redefined ARE categories comprises non-canonical full-length AREs. The redefined AREs in enhanced AR binding regions in prostate tumors versus paired non-malignant adjacent tissues regulate a prostate cancer-relevant gene network not only centered on AR, but more interestingly, on novel AR target genes mTOR, BIRC5 and BCL2L1 involved in prostate cancer cell growth and survival. The precise redefinition of AREs has important implications for understanding how AR contributes to prostate carcinogenesis. FOXA1 ChIP-exo
Project description:The androgen receptor (AR) mediates the action of androgens by binding to androgen-responsive elements (AREs) and subsequently regulating target genes involved in prostate carcinogenesis. The precise locations, true nature, and functional roles of AREs in human prostate cancer are still unknown. Here we redefine AREs by motif-resolution AR chromatin immunoprecipitation-exonuclease (ChIP-exo) assay in human prostate cancer cells and tumors. Surprisingly, we find that, in addition to canonical full-length AREs and half-site-like AREs, a significant portion of the four redefined ARE categories comprises non-canonical full-length AREs. The redefined AREs in enhanced AR binding regions in prostate tumors versus paired non-malignant adjacent tissues regulate a prostate cancer-relevant gene network not only centered on AR, but more interestingly, on novel AR target genes mTOR, BIRC5 and BCL2L1 involved in prostate cancer cell growth and survival. The precise redefinition of AREs has important implications for understanding how AR contributes to prostate carcinogenesis.
Project description:The androgen receptor (AR) mediates the action of androgens by binding to androgen-responsive elements (AREs) and subsequently regulating target genes involved in prostate carcinogenesis. The precise locations, true nature, and functional roles of AREs in human prostate cancer are still unknown. Here we redefine AREs by motif-resolution AR chromatin immunoprecipitation-exonuclease (ChIP-exo) assay in human prostate cancer cells and tumors. Surprisingly, we find that, in addition to canonical full-length AREs and half-site-like AREs, a significant portion of the four redefined ARE categories comprises non-canonical full-length AREs. The redefined AREs in enhanced AR binding regions in prostate tumors versus paired non-malignant adjacent tissues regulate a prostate cancer-relevant gene network not only centered on AR, but more interestingly, on novel AR target genes mTOR, BIRC5 and BCL2L1 involved in prostate cancer cell growth and survival. The precise redefinition of AREs has important implications for understanding how AR contributes to prostate carcinogenesis.
Project description:The androgen receptor (AR) mediates the action of androgens by binding to androgen-responsive elements (AREs) and subsequently regulating target genes involved in prostate carcinogenesis. The precise locations, true nature, and functional roles of AREs in human prostate cancer are still unknown. Here we redefine AREs by motif-resolution AR chromatin immunoprecipitation-exonuclease (ChIP-exo) assay in human prostate cancer cells and tumors. Surprisingly, we find that, in addition to canonical full-length AREs and half-site-like AREs, a significant portion of the four redefined ARE categories comprises non-canonical full-length AREs. The redefined AREs in enhanced AR binding regions in prostate tumors versus paired non-malignant adjacent tissues regulate a prostate cancer-relevant gene network not only centered on AR, but more interestingly, on novel AR target genes mTOR, BIRC5 and BCL2L1 involved in prostate cancer cell growth and survival. The precise redefinition of AREs has important implications for understanding how AR contributes to prostate carcinogenesis.
Project description:The androgen receptor (AR) mediates the action of androgens by binding to androgen-responsive elements (AREs) and subsequently regulating target genes involved in prostate carcinogenesis. The precise locations, true nature, and functional roles of AREs in human prostate cancer are still unknown. Here we redefine AREs by motif-resolution AR chromatin immunoprecipitation-exonuclease (ChIP-exo) assay in human prostate cancer cells and tumors. Surprisingly, we find that, in addition to canonical full-length AREs and half-site-like AREs, a significant portion of the four redefined ARE categories comprises non-canonical full-length AREs. The redefined AREs in enhanced AR binding regions in prostate tumors versus paired non-malignant adjacent tissues regulate a prostate cancer-relevant gene network not only centered on AR, but more interestingly, on novel AR target genes mTOR, BIRC5 and BCL2L1 involved in prostate cancer cell growth and survival. The precise redefinition of AREs has important implications for understanding how AR contributes to prostate carcinogenesis.
Project description:The androgen receptor (AR) is a therapeutic target of prostate cancer (PCa). Targeted AR therapy commonly uses androgen deprivation therapy (ADT) and AR antagonists to reduce androgen levels and inhibit tumor growth. Surprisingly, treatment with supraphysiological androgen level (SAL) can also inhibit the growth of PCa. SAL (R1881) was shown to induce cellular senescence in PCa. Knockdown of BHLHE40 in C4-2 and LNCaP cell lines indicates that BHLHE40 mediates SAL-induced cellular senescence as a possible tumor suppressive pathway. The RNA-seq from BHLHE40 knocked down C4-2 cells confirmed that BHLHE40 regulates cellular senescence and associated pathways. Interestingly, a large overlap of differentially expressed gene sets was identified between BHLHE40 regulated transcriptome and the SAL-changed transcriptome leading to four classes of up-and downregulated BHLHE40 transcriptome landscapes overlapping with that of AR. Further RNA-seq analyses revealed that the tumor suppressive cyclin G2 (CCNG2) emerged as a novel downstream target of BHLHE40. Knockdown of CCNG2 suggests that it mediates SAL-induced cellular senescence providing evidence of a novel pathway by the AR-BHLHE40-CCNG2 axis to mediate androgen-induced cellular senescence as a novel tumor suppressive pathway in PCa cells.
Project description:Androgen receptor (AR) signaling remains the key therapeutic target in the management of hormone-naïve advanced prostate cancer (PCa) and castration-resistant PCa (CRPC). Recently, landmark molecular features have been reported for CRPC, including the expression of constitutively active AR variants that lack the ligand-binding domain. Besides their role in CRPC, AR variants lead to the expression of genes involved in tumor progression. However, little is known about the specificity of their mode of action compared with that of wild-type AR (AR-WT). We performed AR transcriptome analyses in an androgen-dependent PCa cell line as well as cross-analyses with publicly available RNA-seq dataset and established that transcriptional repression capacity that was marked for AR-WT was pathologically lost by AR variants. Functional enrichment analyses allowed us to associate AR-WT repressive function to a panel of genes involved in cell adhesion and epithelial-to-mesenchymal transition. So, we postulate that a less documented AR-WT normal function in prostate epithelial cells could be the repression of a panel of genes linked to cell plasticity, and that this repressive function could be pathologically abrogated by AR variants in PCA.