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The impact of point mutations in the human androgen receptor: classification of mutations on the basis of transcriptional activity.

Hay CW, McEwan IJ - PLoS ONE (2012)

Bottom Line: In order to remedy this omission, we have combined an expansive study of forty five mutations which are predominantly associated with high Gleason scores and metastatic tumors, and span the entire length of the receptor, with a literature review of the mutations under investigation.Importantly, mutations introducing constitutive gain of function are uncommon, with the majority of mutations leading to either loss of function or no significant change from wild-type activity.In addition, the transcriptional outcome of some mutations is dependent upon the androgen receptor responsive element.

View Article: PubMed Central - PubMed

Affiliation: School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom.

ABSTRACT
Androgen receptor mediated signaling drives prostate cancer cell growth and survival. Mutations within the receptor occur infrequently in prostate cancer prior to hormonal therapy but become prevalent in incurable androgen independent and metastatic tumors. Despite the determining role played by the androgen receptor in all stages of prostate cancer progression, there is a conspicuous dearth of comparable data on the consequences of mutations. In order to remedy this omission, we have combined an expansive study of forty five mutations which are predominantly associated with high Gleason scores and metastatic tumors, and span the entire length of the receptor, with a literature review of the mutations under investigation. We report the discovery of a novel prevalent class of androgen receptor mutation that possesses loss of function at low levels of androgen yet transforms to a gain of function at physiological levels. Importantly, mutations introducing constitutive gain of function are uncommon, with the majority of mutations leading to either loss of function or no significant change from wild-type activity. Therefore, the widely accepted supposition that androgen receptor mutations in prostate cancer result in gain of function is appealing, but mistaken. In addition, the transcriptional outcome of some mutations is dependent upon the androgen receptor responsive element. We discuss the consequences of these findings and the role of androgen receptor mutations for prostate cancer progression and current treatment options.

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Related in: MedlinePlus

A. Comparison of firefly luciferase reporter plasmids. COS-7 cells were cotransfected with the indicated luciferase reporter plasmid and pSVARo expressing WT hAR. The cells were treated with DHT and firefly luciferase activity was determined. The results were calculated as the fold stimulation of a given reporter plasmid compared to untreated cells transfected with the same plasmid. Values are means of a minimum of three independent experiments performed in quadruplicate ± SEM. B. Western blotting analysis of hAR expressed by mutated pSVARo plasmids. COS-7 cells were transiently transfected with plasmid encoding the indicated mutation, and cell lysates were analyzed for hAR by western blotting. Lysate from untransfected cells (UT) was used as the control.
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pone-0032514-g002: A. Comparison of firefly luciferase reporter plasmids. COS-7 cells were cotransfected with the indicated luciferase reporter plasmid and pSVARo expressing WT hAR. The cells were treated with DHT and firefly luciferase activity was determined. The results were calculated as the fold stimulation of a given reporter plasmid compared to untreated cells transfected with the same plasmid. Values are means of a minimum of three independent experiments performed in quadruplicate ± SEM. B. Western blotting analysis of hAR expressed by mutated pSVARo plasmids. COS-7 cells were transiently transfected with plasmid encoding the indicated mutation, and cell lysates were analyzed for hAR by western blotting. Lysate from untransfected cells (UT) was used as the control.

Mentions: Initial experiments were performed to determine the most informative firefly luciferase reporter plasmid with which to investigate the functional effects of AR mutations on transactivation activity in the presence of the natural androgen DHT. Comparison of AR transactivation activity on simple or complex promoters present in the plasmids GRE2-TATA-Luc, PSA61Luc and MMTV-Luc, co-transfected into COS-7 cells along with a full length human AR expression, revealed that all responded to 10 nM DHT; generating 63.6, 24.3 and 2.6 fold stimulation respectively (Fig. 2A).


The impact of point mutations in the human androgen receptor: classification of mutations on the basis of transcriptional activity.

Hay CW, McEwan IJ - PLoS ONE (2012)

A. Comparison of firefly luciferase reporter plasmids. COS-7 cells were cotransfected with the indicated luciferase reporter plasmid and pSVARo expressing WT hAR. The cells were treated with DHT and firefly luciferase activity was determined. The results were calculated as the fold stimulation of a given reporter plasmid compared to untreated cells transfected with the same plasmid. Values are means of a minimum of three independent experiments performed in quadruplicate ± SEM. B. Western blotting analysis of hAR expressed by mutated pSVARo plasmids. COS-7 cells were transiently transfected with plasmid encoding the indicated mutation, and cell lysates were analyzed for hAR by western blotting. Lysate from untransfected cells (UT) was used as the control.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3293822&req=5

pone-0032514-g002: A. Comparison of firefly luciferase reporter plasmids. COS-7 cells were cotransfected with the indicated luciferase reporter plasmid and pSVARo expressing WT hAR. The cells were treated with DHT and firefly luciferase activity was determined. The results were calculated as the fold stimulation of a given reporter plasmid compared to untreated cells transfected with the same plasmid. Values are means of a minimum of three independent experiments performed in quadruplicate ± SEM. B. Western blotting analysis of hAR expressed by mutated pSVARo plasmids. COS-7 cells were transiently transfected with plasmid encoding the indicated mutation, and cell lysates were analyzed for hAR by western blotting. Lysate from untransfected cells (UT) was used as the control.
Mentions: Initial experiments were performed to determine the most informative firefly luciferase reporter plasmid with which to investigate the functional effects of AR mutations on transactivation activity in the presence of the natural androgen DHT. Comparison of AR transactivation activity on simple or complex promoters present in the plasmids GRE2-TATA-Luc, PSA61Luc and MMTV-Luc, co-transfected into COS-7 cells along with a full length human AR expression, revealed that all responded to 10 nM DHT; generating 63.6, 24.3 and 2.6 fold stimulation respectively (Fig. 2A).

Bottom Line: In order to remedy this omission, we have combined an expansive study of forty five mutations which are predominantly associated with high Gleason scores and metastatic tumors, and span the entire length of the receptor, with a literature review of the mutations under investigation.Importantly, mutations introducing constitutive gain of function are uncommon, with the majority of mutations leading to either loss of function or no significant change from wild-type activity.In addition, the transcriptional outcome of some mutations is dependent upon the androgen receptor responsive element.

View Article: PubMed Central - PubMed

Affiliation: School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom.

ABSTRACT
Androgen receptor mediated signaling drives prostate cancer cell growth and survival. Mutations within the receptor occur infrequently in prostate cancer prior to hormonal therapy but become prevalent in incurable androgen independent and metastatic tumors. Despite the determining role played by the androgen receptor in all stages of prostate cancer progression, there is a conspicuous dearth of comparable data on the consequences of mutations. In order to remedy this omission, we have combined an expansive study of forty five mutations which are predominantly associated with high Gleason scores and metastatic tumors, and span the entire length of the receptor, with a literature review of the mutations under investigation. We report the discovery of a novel prevalent class of androgen receptor mutation that possesses loss of function at low levels of androgen yet transforms to a gain of function at physiological levels. Importantly, mutations introducing constitutive gain of function are uncommon, with the majority of mutations leading to either loss of function or no significant change from wild-type activity. Therefore, the widely accepted supposition that androgen receptor mutations in prostate cancer result in gain of function is appealing, but mistaken. In addition, the transcriptional outcome of some mutations is dependent upon the androgen receptor responsive element. We discuss the consequences of these findings and the role of androgen receptor mutations for prostate cancer progression and current treatment options.

Show MeSH
Related in: MedlinePlus