Browse
Submit Data
Databases
API
Help

Dataset Information

18 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Androgen receptor degradation by the E3 ligase CHIP modulates mitotic arrest in prostate cancer cells.

ABSTRACT: The androgen receptor (AR) has a vital role in the onset and progression of prostate cancer by promoting G1-S progression, possibly by functioning as a licensing factor for DNA replication. We here report that low dose 2-methoxyestradiol (2-ME), an endogenous estrogen metabolite, induces mitotic arrest in prostate cancer cells involving activation of the E3 ligase CHIP (C-terminus of Hsp70-interacting protein) and degradation of the AR. Depletion of the AR by small interfering RNA (siRNA) eliminates 2-ME-induced arrest and introducing AR into PC3-M cells confers 2-ME-induced mitotic arrest. Knockdown of CHIP or MDM2 (mouse homolog of double minute 2 protein) individually or in combination reduced AR degradation and abrogated M phase arrest induced by 2-ME. Our data link AR degradation via ubiquitination to mitotic arrest. Targeting the AR by activating E3 ligases such as CHIP represents a novel strategy for the treatment of prostate cancer.

SUBMITTER: Sarkar S

PROVIDER: S-EPMC3899837 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Androgen receptor degradation by the E3 ligase CHIP modulates mitotic arrest in prostate cancer cells.

Sarkar S S Brautigan D L DL Parsons S J SJ Larner J M JM

Oncogene 20121217 1

The androgen receptor (AR) has a vital role in the onset and progression of prostate cancer by promoting G1-S progression, possibly by functioning as a licensing factor for DNA replication. We here report that low dose 2-methoxyestradiol (2-ME), an endogenous estrogen metabolite, induces mitotic arrest in prostate cancer cells involving activation of the E3 ligase CHIP (C-terminus of Hsp70-interacting protein) and degradation of the AR. Depletion of the AR by small interfering RNA (siRNA) elimin ...[more]

PMID: 23246967

Similar Datasets

The E3 Ligase CHIP Mediates p21 Degradation to Maintain Radioresistance.

Project description:Lung cancer resists radiotherapy, making it one of the deadliest forms of cancer. Here, we show that human lung cancer cell lines can be rendered sensitive to ionizing radiation (IR) by RNAi knockdown of C-terminus of Hsc70-interacting protein (CHIP/STUB1), a U-box-type E3 ubiquitin ligase that targets a number of stress-induced proteins. Mechanistically, ubiquitin-dependent degradation of the cyclin-dependent kinase (CDK) inhibitor, p21 protein, is reduced by CHIP knockdown, leading to enhanced senescence of cells in response to exposure to IR. Cellular senescence and sensitivity to IR is prevented by CRISPR/Cas9-mediated deletion of the p21 gene (CDKN1A) in CHIP knockdown cells. Conversely, overexpression of CHIP potentiates p21 degradation and promotes greater radioresistance of lung cancer cells. In vitro and cell-based assays demonstrate that p21 is a novel and direct ubiquitylation substrate of CHIP that also requires the CHIP-associated chaperone HSP70. These data reveal that the inhibition of the E3 ubiquitin ligase CHIP promotes radiosensitivity, thus suggesting a novel strategy for the treatment of lung cancer.Implications: The CHIP-HSP70-p21 ubiquitylation/degradation axis identified here could be exploited to enhance the efficacy of radiotherapy in patients with non-small cell lung cancer. Mol Cancer Res; 15(6); 651-9. ©2017 AACR.

| S-EPMC5687089 | biostudies-literature

Aurora Kinase A Promotes AR Degradation via the E3 Ligase CHIP.

Project description:Reducing the levels of the androgen receptor (AR) is one of the most viable approaches to combat castration-resistant prostate cancer. Previously, we observed that proteasomal-dependent degradation of AR in response to 2-methoxyestradiol (2-ME) depends primarily on the E3 ligase C-terminus of HSP70-interacting protein (STUB1/CHIP). Here, 2-ME stimulation activates CHIP by phosphorylation via Aurora kinase A (AURKA). Aurora A kinase inhibitors and RNAi knockdown of Aurora A transcript selectively blocked CHIP phosphorylation and AR degradation. Aurora A kinase is activated by 2-ME in the S-phase as well as during mitosis, and phosphorylates CHIP at S273. Prostate cancer cells expressing an S273A mutant of CHIP have attenuated AR degradation upon 2-ME treatment compared with cells expressing wild-type CHIP, supporting the idea that CHIP phosphorylation by Aurora A activates its E3 ligase activity for the AR. These results reveal a novel 2-ME?Aurora A?CHIP?AR pathway that promotes AR degradation via the proteasome that may offer novel therapeutic opportunities for prostate cancer. Mol Cancer Res; 15(8); 1063-72. ©2017 AACR.

| S-EPMC5697428 | biostudies-literature

The E3 ubiquitin ligase CHIP mediates ubiquitination and proteasomal degradation of PRMT5.

Project description:Protein arginine methyltransferase 5 (PRMT5) is an important member of the protein arginine methyltransferase family that regulates many cellular processes through epigenetic control of target gene expression. Because of its overexpression in a number of human cancers and its essential role in cell proliferation, transformation, and cell cycle progression, PRMT5 has been recently proposed to function as an oncoprotein in cancer cells. However, how its expression is regulated in cancer cells remains largely unknown. We have previously demonstrated that the transcription of PRMT5 can be negatively regulated by the PKC/c-Fos signaling pathway through modulating the transcription factor NF-Y in prostate cancer cells. In the present study, we demonstrated that PRMT5 undergoes polyubiquitination, possibly through multiple lysine residues. We also identified carboxyl terminus of heat shock cognate 70-interacting protein (CHIP), an important chaperone-dependent E3 ubiquitin ligase that couples protein folding/refolding to protein degradation, as an interacting protein of PRMT5 via mass spectrometry. Their interaction was further verified by co-immuoprecipitation, GST pull-down, and bimolecular fluorescence complementation (BiFC) assay. In addition, we provided evidence that the CHIP/chaperone system is essential for the negative regulation of PRMT5 expression via K48-linked ubiquitin-dependent proteasomal degradation. Given that down-regulation of CHIP and overexpression of PRMT5 have been observed in several human cancers, our finding suggests that down-regulation of CHIP may be one of the mechanisms underlying PRMT5 overexpression in these cancers.

| S-EPMC5397900 | biostudies-literature

The E3 ligase CHIP mediates ubiquitination and degradation of mixed-lineage kinase 3.

Project description:Mixed-lineage kinase 3 (MLK3) activates mitogen-activated protein kinase (MAPK) signaling pathways and has important functions in migration, invasion, proliferation, tumorigenesis, and apoptosis. We investigated the role of the E3 ligase carboxyl terminus of Hsc70-interacting protein (CHIP) in the regulation of MLK3 protein levels. We show that CHIP interacts with MLK3 and, together with the E2 ubiquitin-conjugating enzyme UbcH5 (UbcH5a, -b, -c, or -d), ubiquitinates MLK3 in vitro. CHIP or Hsp70 overexpression promoted endogenous MLK3 ubiquitination and induced a decline in MLK3 protein levels in cells with Hsp90 inhibition. Furthermore, CHIP overexpression caused a proteasome-dependent reduction in exogenous MLK3 protein. Geldanamycin (GA), heat shock, and osmotic shock treatments also reduced the level of MLK3 protein via a CHIP-dependent mechanism. In addition, CHIP depletion in ovarian cancer SKOV3 cells increased cell invasion, and the enhancement of invasiveness was abrogated by small interfering RNA (siRNA)-mediated knockdown of MLK3. Thus, CHIP modulates MLK3 protein levels in response to GA and stress stimuli, and CHIP-dependent regulation of MLK3 is required for suppression of SKOV3 ovarian cancer cell invasion.

| S-EPMC4135596 | biostudies-literature

The E3 ubiquitin ligase Siah2 contributes to castration-resistant prostate cancer by regulation of androgen receptor transcriptional activity.

Project description:Understanding the mechanism underlying the regulation of the androgen receptor (AR), a central player in the development of castration-resistant prostate cancer (CRPC), holds promise for overcoming the challenge of treating CRPC. We demonstrate that the ubiquitin ligase Siah2 targets a select pool of NCOR1-bound, transcriptionally-inactive AR for ubiquitin-dependent degradation, thereby promoting expression of select AR target genes implicated in lipid metabolism, cell motility, and proliferation. Siah2 is required for prostate cancer cell growth under androgen-deprivation conditions in vitro and in vivo, and Siah2 inhibition promotes prostate cancer regression upon castration. Notably, Siah2 expression is markedly increased in human CRPCs. Collectively, we find that selective regulation of AR transcriptional activity by the ubiquitin ligase Siah2 is important for CRPC development.

| S-EPMC3750989 | biostudies-literature

The E3 ubiquitin ligase Siah2 contributes to castration-resistant prostate cancer by regulation of androgen receptor transcriptional activity

Project description:Analysis of gene expression altered upon knockdown of Siah2 in prosate cancer cells. The objective is to elucidate which signaling pathways or transcription factors are regulated by the E3 ubiquitin ligase Siah2 in human prostate cancer cells. CWR22Rv1 cells were in fected with pLKO.1 control or Siah2 shRNA, and selected with 1ug/ml of puromycin to get stable transfectants. Total RNA was extracted for micorarray analysis to compare the diffentially expressed genes between pLKO.1 control and Siah2 knockdown cells.

2013-03-19 | E-GEOD-38851 | biostudies-arrayexpress

The E3 ubiquitin ligase Siah2 contributes to castration-resistant prostate cancer by regulation of androgen receptor transcriptional activity cancer.

Project description:The androgen receptor (AR) plays a central role in the development of castration resistant prostate cancer (CRPC). Here, we demonstrate that the ubiquitin ligase Siah2 targets a select pool of NCOR1-bound, transcriptionally inactive AR for ubiquitination dependent degradation, thereby promoting the expression of ~13% of AR target genes. The Siah2 binding sites located within the AR ligand-binding domain are mutated in PCa, resulting in attenuation of Siah2-mediated regulation. Siah2 is required for growth of PCa cells under androgen-deprivation conditions in vitro and in vivo. Significantly, inhibition of Siah2 promotes PCa regression upon castration and Siah2 expression is markedly increased in human CRPCs. Collectively our findings identify a key role for Siah2 in CRPC through the selective regulation of AR transcriptional activity. Tumor Harvest. When tumor size reached approximately 1.5 cm in diameter (6-8 weeks after injection), and the serum PSA was greater than 50 ng/ml, animals were surgically castrated under methoxyfluorane anesthesia and monitored for PSA levels for several weeks. Animals were sacrificed by carbon dioxide asphyxiation when tumors were harvested at several points along the PSA curve (pre-castrate (11), regressing (6), nadir (10), recurring (6) and castration resistant (12). Tumor segments were placed in RNALater (Qiagen) and frozen immediately at -80M-BM-0C.weeks. Tumors were harvested at several points along the PSA curve. The epithelial:stromal ratio is consistent within this tumor model and varies 10% between tumors, as assessed by immunohistochemistry of cytokeratin 14 (epithelium) and vimentin (stroma).

2013-02-15 | E-GEOD-44319 | biostudies-arrayexpress

NRIP/DCAF6 stabilizes the androgen receptor protein by displacing DDB2 from the CUL4A-DDB1 E3 ligase complex in prostate cancer.

Project description:Both nuclear receptor interaction protein (NRIP) and DNA damage binding protein 2 (DDB2) belong to the Cullin 4 (CUL4)-DDB1 binding protein family and are androgen receptor (AR)-interacting proteins. Here, we investigated the expression patterns of the NRIP, DDB2 and AR proteins in human prostate cancer tissues and found that the expression levels of NRIP and AR were higher, but the DDB2 level was lower, in prostate cancer tissues than in non-neoplastic controls, suggesting NRIP as a candidate tumor promoter and DDB2 as a tumor suppressor in prostate cancer. Furthermore, both NRIP and DDB2 shared the same AR binding domain; they were competitors for the AR, but not for DDB1 binding, in the AR-DDB2-DDB1-CUL4A complex. Conclusively, NRIP stabilizes the AR protein by displacing DDB2 from the AR-DDB2 complex. Consistent with our hypothesis, a specific expression pattern with high levels of NRIP and AR, together with a low level of DDB2, was found more frequently in the human prostate cancer tissues with a cribriform pattern than in non-cribriform tumors, suggesting that disruption of the balance between NRIP and DDB2 may change AR protein homeostasis and contribute to pathogenesis in certain aggressive types of prostate cancer.

| S-EPMC5400601 | biostudies-literature

The E3 ubiquitin ligase Siah2 contributes to castration-resistant prostate cancer by regulation of androgen receptor transcriptional activity

2013-03-19 | GSE38851 | GEO

The chaperone-assisted E3 ligase C terminus of Hsc70-interacting protein (CHIP) targets PTEN for proteasomal degradation.

Project description:The tumor suppressor, PTEN is key to the regulation of diverse cellular processes, making it a prime candidate to be tightly regulated. The PTEN level is controlled in a major way by E3 ligase-mediated degradation through the Ubiquitin-Proteasome System (UPS). Nedd 4-1, XIAP, and WWP2 have been shown to maintain PTEN turnover. Here, we report that CHIP, the chaperone-associated E3 ligase, induces ubiquitination and regulates the proteasomal turnover of PTEN. It was apparent from our findings that PTEN transiently associates with the molecular chaperones and thereby gets diverted to the degradation pathway through its interaction with CHIP. The TPR domain of CHIP and parts of the N-terminal domain of PTEN are required for their interaction. Overexpression of CHIP leads to elevated ubiquitination and a shortened half-life of endogenous PTEN. On the other hand, depletion of endogenous CHIP stabilizes PTEN. CHIP is also shown to regulate PTEN-dependent transcription presumably through its down-regulation. PTEN shared an inverse correlation with CHIP in human prostate cancer patient samples, thereby triggering the prospects of a more complex mode of PTEN regulation in cancer.

| S-EPMC3346122 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data