scholarly journals MED19 alters AR occupancy and gene expression in prostate cancer cells, driving MAOA expression and growth under low androgen

PLoS Genetics ◽  
2021 ◽  
Vol 17 (1) ◽  
pp. e1008540
Author(s):  
Hannah Weber ◽  
Rachel Ruoff ◽  
Michael J. Garabedian
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Cancer Cells ◽  
Androgen Deprivation ◽  
Monoamine Oxidase A ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
Cancer Cell Growth ◽  
Androgen Independence ◽  
Androgen Independent

Androgen deprivation therapy (ADT) is a mainstay of prostate cancer treatment, given the dependence of prostate cells on androgen and the androgen receptor (AR). However, tumors become ADT-resistant, and there is a need to understand the mechanism. One possible mechanism is the upregulation of AR co-regulators, although only a handful have been definitively linked to disease. We previously identified the Mediator subunit MED19 as an AR co-regulator, and reported that MED19 depletion inhibits AR transcriptional activity and growth of androgen-insensitive LNCaP-abl cells. Therefore, we proposed that MED19 upregulation would promote AR activity and drive androgen-independent growth. Here, we show that stable overexpression of MED19 in androgen-dependent LNCaP cells promotes growth under conditions of androgen deprivation. To delineate the mechanism, we determined the MED19 and AR transcriptomes and cistromes in control and MED19-overexpressing LNCaP cells. We also examined genome-wide H3K27 acetylation. MED19 overexpression selectively alters AR occupancy, H3K27 acetylation, and gene expression. Under conditions of androgen deprivation, genes regulated by MED19 correspond to genes regulated by ELK1, a transcription factor that binds the AR N-terminus to induce select AR target gene expression and proliferation, and genomic sites occupied by MED19 and AR are enriched for motifs associated with ELK1. Strikingly, MED19 upregulates expression of monoamine oxidase A (MAOA), a factor that promotes prostate cancer growth. MAOA depletion reduces androgen-independent growth. MED19 and AR occupy the MAOA promoter, with MED19 overexpression enhancing AR occupancy and H3K27 acetylation. Furthermore, MED19 overexpression increases ELK1 occupancy at the MAOA promoter, and ELK1 depletion reduces MAOA expression and androgen-independent growth. This suggests that MED19 cooperates with ELK1 to regulate AR occupancy and H3K27 acetylation at MAOA, upregulating its expression and driving androgen independence in prostate cancer cells. This study provides important insight into the mechanisms of prostate cancer cell growth under low androgen, and underscores the importance of the MED19-MAOA axis in this process.

scholarly journals MED19 alters AR occupancy and gene expression in prostate cancer cells, driving MAOA expression and growth under low androgen

2019 ◽  
Author(s):  
Hannah Weber ◽  
Rachel Ruoff ◽  
Michael J. Garabedian
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Cancer Cells ◽  
Androgen Deprivation Therapy ◽  
Androgen Deprivation ◽  
Cancer Growth ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
Insight Into ◽  
Androgen Independent

AbstractAndrogen deprivation therapy (ADT) is a mainstay of prostate cancer treatment, given the dependence of prostate cells on androgen and the androgen receptor (AR). However, tumors become ADT-resistant, and there is a need to understand the mechanism. One possible mechanism is the upregulation of AR co-regulators, although only a handful have been definitively linked to disease. We previously identified the Mediator subunit MED19 as an AR co-regulator, and reported that MED19 depletion inhibits AR transcriptional activity and growth of androgen-insensitive LNCaP-abl cells. Therefore, we proposed that MED19 upregulation would promote AR activity and drive androgen-independent growth. Here, we show that stable overexpression of MED19 in androgen-dependent LNCaP cells promotes growth under conditions of androgen deprivation. To delineate the mechanism, we determined the MED19 and AR transcriptomes and cistromes in control and MED19 LNCaP cells. We also examined H3K27 acetylation genome-wide. MED19 overexpression selectively alters AR occupancy, H3K27 acetylation, and gene expression. Under conditions of androgen deprivation, genes regulated by MED19 and genomic sites occupied by MED19 and AR are enriched for ELK1, a transcription factor that binds the AR N-terminus to promote select AR-target gene expression. Strikingly, MED19 upregulates expression of monoamine oxidase A (MAOA), a factor that promotes prostate cancer growth. MAOA depletion reduces androgen-independent growth. MED19 and AR occupy the MAOA promoter, with MED19 overexpression enhancing AR occupancy and H3K27 acetylation. Furthermore, MED19 overexpression increases ELK1 occupancy at the MAOA promoter, and ELK1 depletion reduces MAOA expression and androgen-independent growth. This suggests that MED19 cooperates with ELK1 to regulate AR occupancy and H3K27 acetylation at MAOA, upregulating its expression and driving androgen independence in prostate cancer cells. This study provides important insight into the mechanisms of prostate cancer cell growth under low androgen, and underscores the importance of the MED19-MAOA axis in this process.Author summaryProstate cancer is one of the most common cancers worldwide, and androgen hormones are essential for prostate cancer growth. Androgens exert their effects through a protein called the androgen receptor (AR), which turns on and off genes that regulate prostate cancer growth. Powerful drugs that block AR action by lowering androgen levels – so-called androgen deprivation therapy - are used to treat prostate cancer patients, and these yield initial success in reducing tumor growth. However, over time, tumors circumvent androgen deprivation therapy and patients relapse; in many cases, this occurs because AR becomes re-activated. The factors responsible for re-activating AR and promoting growth under androgen deprivation are not well understood. Here, we demonstrate that a subunit of the Mediator transcriptional regulatory complex, called MED19, promotes growth of prostate cancer cells under low androgen conditions, mimicking the ability of tumors to grow under androgen deprivation in prostate cancer patients. MED19 promotes androgen-independent growth by working with a transcription factor that interacts with AR, called ELK1, to induce the expression of genes regulated by AR that promote prostate cancer growth. This study provides important insight into how prostate cancer cells can maintain growth under androgen deprivation through MED19.

scholarly journals SHH-N non-canonically sustains androgen receptor activity in androgen-independent prostate cancer cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diana Trnski ◽  
Maja Sabol ◽  
Sanja Tomić ◽  
Ivan Štefanac ◽  
Milanka Mrčela ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Therapy Resistance ◽  
Androgen Deprivation ◽  
Prostate Cancer Cells ◽  
Androgen Independence ◽  
Androgen Receptor Activity ◽  
Signaling Activation ◽  
Androgen Independent

AbstractProstate cancer is the second most frequent cancer diagnosed in men worldwide. Localized disease can be successfully treated, but advanced cases are more problematic. After initial effectiveness of androgen deprivation therapy, resistance quickly occurs. Therefore, we aimed to investigate the role of Hedgehog-GLI (HH-GLI) signaling in sustaining androgen-independent growth of prostate cancer cells. We found various modes of HH-GLI signaling activation in prostate cancer cells depending on androgen availability. When androgen was not deprived, we found evidence of non-canonical SMO signaling through the SRC kinase. After short-term androgen deprivation canonical HH-GLI signaling was activated, but we found little evidence of canonical HH-GLI signaling activity in androgen-independent prostate cancer cells. We show that in androgen-independent cells the pathway ligand, SHH-N, non-canonically binds to the androgen receptor through its cholesterol modification. Inhibition of this interaction leads to androgen receptor signaling downregulation. This implies that SHH-N activates the androgen receptor and sustains androgen-independence. Targeting this interaction might prove to be a valuable strategy for advanced prostate cancer treatment. Also, other non-canonical aspects of this signaling pathway should be investigated in more detail and considered when developing potential therapies.

Phenethyl isothiocyanate in combination with dibenzoylmethane inhibits the androgen-independent growth of prostate cancer cells

2018 ◽  
Vol 9 (4) ◽  
pp. 2398-2408 ◽  
Author(s):  
Huarong Huang ◽  
Yan He ◽  
Lanyue Zhang ◽  
Hongping Xiang ◽  
Dongli Li ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Inhibitory Effect ◽  
Phenethyl Isothiocyanate ◽  
Prostate Cancer Cells ◽  
Prostate Tumors ◽  
Androgen Independence ◽  
Androgen Independent

This study investigates the inhibitory effect of PEITC and DBM in combination on the progression of androgen-dependent VCaP prostate tumors to androgen independence.

scholarly journals The Impact of Ang-(1-9) and Ang-(3-7) on the Biological Properties of Prostate Cancer Cells by Modulation of Inflammatory and Steroidogenesis Pathway Genes

2020 ◽  
Vol 21 (17) ◽  
pp. 6227
Author(s):  
Kamila Domińska ◽  
Karolina Kowalska ◽  
Kinga Anna Urbanek ◽  
Dominika Ewa Habrowska-Górczyńska ◽  
Tomasz Ochędalski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Cancer Cells ◽  
Renin Angiotensin System ◽  
Biological Properties ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
M Cell ◽  
Pc3 Cells ◽  
The Impact

The local renin–angiotensin system (RAS) plays an important role in the pathophysiology of the prostate, including cancer development and progression. The Ang-(1-9) and Ang-(3-7) are the less known active peptides of RAS. This study examines the influence of these two peptide hormones on the metabolic activity, proliferation and migration of prostate cancer cells. Significant changes in MTT dye reduction were observed depending on the type of angiotensin and its concentration as well as time of incubation. Ang-(1-9) did not regulate the 2D cell division of either prostate cancer lines however, it reduced the size of LNCaP colonies formed in soft agar, maybe through down-regulation of the HIF1a gene. Ang-(3-7) increased the number of PC3 cells in the S phase and improved anchorage-independent growth as well as mobility. In this case, a significant increase in MKI67, BIRC5, and CDH-1 gene expression was also observed as well as all members of the NF-kB family. Furthermore, we speculate that this peptide can repress the proliferation of LNCaP cells by NOS3-mediated G2/M cell cycle arrest. No changes in expression of BIRC5 and BCL2/BAX ratio were observed but a decrease mRNA proapoptotic BAD gene was seen. In the both lines, Ang-(3-7) improved ROCK1 gene expression however, increased VEGF and NOS3 mRNA was only seen in the PC3 or LNCaP cells, respectively. Interestingly, it appears that Ang-(1-9) and Ang-(3-7) can modulate the level of steroidogenic enzymes responsible for converting cholesterol to testosterone in both prostate cancer lines. Furthermore, in PC3 cells, Ang-(1-9) upregulated AR expression while Ang-(3-7) upregulated the expression of both estrogen receptor genes. Ang-(1-9) and Ang-(3-7) can impact on biological properties of prostate cancer cells by modulating inflammatory and steroidogenesis pathway genes, among others.

scholarly journals Nuclear localization of parathyroid hormone-related peptide confers resistance to anoikis in prostate cancer cells

2012 ◽  
Vol 19 (3) ◽  
pp. 243-254 ◽  
Author(s):  
Serk In Park ◽  
Laurie K McCauley
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Parathyroid Hormone ◽  
Cancer Cells ◽  
Nuclear Localization ◽  
Molecular Mechanisms ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
Related Peptide ◽  
Parathyroid Hormone Related Peptide

Prostate cancer remains a leading cause of cancer-related death in men, largely attributable to distant metastases, most frequently to bones. Despite intensive investigations, molecular mechanisms underlying metastasis are not completely understood. Among prostate cancer-derived factors, parathyroid hormone-related peptide (PTHrP), first discovered as an etiologic factor for malignancy-induced hypercalcemia, regulates many cellular functions critical to tumor growth, angiogenesis, and metastasis. In this study, the role of PTHrP in tumor cell survival from detachment-induced apoptosis (i.e. anoikis) was investigated. Reduction ofPTHLH(encoding PTHrP) gene expression in human prostate cancer cells (PC-3) increased the percentage of apoptotic cells when cultured in suspension. Conversely, overexpression of PTHrP protected prostate cancer cells (Ace-1 and LNCaP, both typically expressing low or undetectable basal PTHrP) from anoikis. Overexpression of nuclear localization signal (NLS)-defective PTHrP failed to protect cells from anoikis, suggesting that PTHrP-dependent protection from anoikis is an intracrine event. A PCR-based apoptosis-related gene array showed that detachment increased expression of theTNFgene (encoding the proapoptotic protein tumor necrosis factor-α) fourfold greater in PTHrP-knockdown PC-3 cells than in control PC-3 cells. In parallel,TNFgene expression was significantly reduced in PTHrP-overexpressing LNCaP cells, but not in NLS-defective PTHrP overexpressing LNCaP cells, when compared with control LNCaP cells. Subsequently, in a prostate cancer skeletal metastasis mouse model, PTHrP-knockdown PC-3 cells resulted in significantly fewer metastatic lesions compared to control PC-3 cells, suggesting that PTHrP mediated antianoikis events in the bloodstream. In conclusion, nuclear localization of PTHrP confers prostate cancer cell resistance to anoikis, potentially contributing to prostate cancer metastasis.

Longitudinal analysis of androgen deprivation of prostate cancer cells identifies pathways to androgen independence

The Prostate ◽  
2008 ◽  
Vol 68 (7) ◽  
pp. 698-714 ◽  
Author(s):  
Jason M. D'Antonio ◽  
Changqing Ma ◽  
Federico A. Monzon ◽  
Beth R. Pflug
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Longitudinal Analysis ◽  
Androgen Deprivation ◽  
Prostate Cancer Cells ◽  
Androgen Independence

T-LAK cell-originated protein kinase (TOPK) enhances androgen receptor splice variant (ARv7) and drives androgen-independent growth in prostate cancer

2020 ◽  
Author(s):  
Lama Alhawas ◽  
Karishma S Amin ◽  
Bharath Salla ◽  
Partha P Banerjee
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Prostate Cancer Cells ◽  
Androgen Independence ◽  
Androgen Synthesis ◽  
Lak Cell ◽  
Androgen Independent ◽  
Constitutively Active

Abstract Despite impressive advances in the treatment of prostate cancer with various efficacious inhibitors along the androgen/androgen receptor axis, eventual development of incurable metastatic Castration-Resistant Prostate Cancer (mCRPC) is inevitable and remains a major clinical challenge. Constitutively active androgen receptor (AR) spliced variants have emerged as primary means of resistance to anti-androgens and androgen synthesis inhibitors. The alternatively spliced AR variant, ARv7, has attracted significant interest due to its constitutively active status in CRPC that drives androgen-independence. Factors that are involved in regulating ARv7 levels in CRPC are not clearly known. We recently demonstrated that a protein kinase, T-LAK cell-originated protein kinase (TOPK) level correlates with the aggressiveness of prostate cancer and its invasive behavior. In this study we investigated whether TOPK plays a role in driving androgen-independence in prostate cancer cells. Our data demonstrate that TOPK overexpression in androgen-dependent LNCaP and VCaP induces ARv7 and drives androgen-independent growth. On the other hand, pharmacological inhibition of TOPK in androgen-independent LNCaP95 and 22Rv1 represses AR transactivation, and AR stability. In summary, this study illustrates a direct role of TOPK in regulating ARv7 and driving androgen-independence in prostate cancer cells.

scholarly journals Expression of a hyperactive androgen receptor leads to androgen-independent growth of prostate cancer cells

2008 ◽  
Vol 41 (1) ◽  
pp. 13-23 ◽  
Author(s):  
Chen-Lin Hsieh ◽  
Changmeng Cai ◽  
Ahmed Giwa ◽  
Aaronica Bivins ◽  
Shao-Yong Chen ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Cancer Cells ◽  
Transcriptional Activation ◽  
Soluble Guanylyl Cyclase ◽  
Growth Conditions ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
Transcriptional Activation Domain ◽  
Androgen Independent

Cellular changes that affect the androgen receptor (AR) can cause prostate cancer to transition from androgen dependent to androgen independent, which is usually lethal. One common change in prostate tumors is overexpression of the AR, which has been shown to lead to androgen-independent growth of prostate cancer cells. This led us to hypothesize that expression of a hyperactive AR would be sufficient for androgen-independent growth of prostate cancer cells. To test this hypothesis, stable lune cancer prostate (LNCaP) cell lines were generated, which express a virion phosphoprotein (VP)16-AR hybrid protein that contains full-length AR fused to the strong viral transcriptional activation domain VP16. This fusion protein elicited as much as a 20-fold stronger transcriptional activity than the natural AR. Stable expression of VP16-AR in LNCaP cells yielded androgen-independent cell proliferation, while under the same growth conditions the parental LNCaP cells exhibited only androgen-dependent growth. These results show that expression of a hyperactive AR is sufficient for androgen-independent growth of prostate cancer cells. To study the molecular basis of this enhanced growth, we measured the expression of soluble guanylyl cyclase-α1 (sGCα1), a subunit of the sGC, an androgen-regulated gene that has been shown to be involved in prostate cancer cell growth. Interestingly, the expression of sGCα1 is androgen independent in VP16-AR-expressing cells, in contrast to its androgen-induced expression in control LNCaP cells. RNAI-dependent inhibition of sGCα1 expression resulted in significantly reduced proliferation of VP16-AR cells, implicating an important role for sGCα1 in the androgen-independent growth of these cells.

The significance of Her2 on androgen receptor protein stability in the transition of androgen requirement in prostate cancer cells

2011 ◽  
Vol 300 (5) ◽  
pp. E902-E908 ◽  
Author(s):  
Fu-Ning Hsu ◽  
Min-Shiou Yang ◽  
Eugene Lin ◽  
Chun-Fu Tseng ◽  
Ho Lin
Keyword(s):  
Prostate Cancer ◽  
Cell Cycle ◽  
Androgen Receptor ◽  
Protein Stability ◽  
Cancer Cells ◽  
Cell Lines ◽  
Lncap Cells ◽  
Prostate Cancer Cells ◽  
Androgen Ablation ◽  
Androgen Independent

Androgen ablation therapy is the most common strategy for suppressing prostate cancer progression; however, tumor cells eventually escape androgen dependence and progress to an androgen-independent phase. The androgen receptor (AR) plays a pivotal role in this transition. To address this transition mystery in prostate cancer, we established an androgen-independent prostate cancer cell line (LNCaPdcc), by long-term screening of LNCaP cells in androgen-deprived conditions, to investigate changes of molecular mechanisms before and after androgen withdrawal. We found that LNCaPdcc cells displayed a neuroendocrine morphology, less aggressive growth, and lower expression levels of cell cycle-related factors, although the cell cycle distribution was similar to parental LNCaP cells. Notably, higher protein expression of AR, phospho-Ser81-AR, and PSA in LNCaPdcc cells were observed. The nuclear distribution and protein stability of AR increased in LNCaPdcc cells. In addition, cell proliferation results exhibited the biphasic nature of the androgen (R1881) effect in two cell lines. On the other hand, LNCaPdcc cells expressed higher levels of Her2, phospho-Tyr1221/1222-Her2, ErbB3, and ErbB4 proteins than parental LNCaP cells. These two cell lines exhibited distinct responses to Her2 activation (by heregulin treatment) on Her2 phosphorylation and Her2 inhibition (by AG825 or Herceptin treatments) on proliferation. In addition, the Her2 inhibitor more effectively caused AR degradation and diminished AR Ser81 phosphorylation in LNCaPdcc cells. Taken together, our data demonstrate that Her2 plays an important role in the support of AR protein stability in the transition of androgen requirement in prostate cancer cells. We hope these findings will provide novel insight into the treatment of hormone-refractory prostate cancer.

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