Prostate cancer cells demonstrate a remarkable ＂addiction＂ to androgen receptor （AR） signaling in all stages of disease progression. As such, suppression of AR signaling remains the therapeutic goal in systemic tr...Prostate cancer cells demonstrate a remarkable ＂addiction＂ to androgen receptor （AR） signaling in all stages of disease progression. As such, suppression of AR signaling remains the therapeutic goal in systemic treatment of prostate cancer. A number of molecular alterations arise in patients treated with AR-directed therapies. These molecular alterations may indicate the emergence of treatment resistance and may be targeted for the development of novel agents for prostate cancer. The presence of functional androgen receptor splice variants may represent a potential explanation for resistance to abiraterone and enzalutamide, newer AR-directed agents developed to treat metastatic castration-resistant prostate cancer （mCRPC）. In the last 8 years, many androgen receptor splice variants have been identified and characterized. Among these, androgen receptor splice variant-7 （AR-V7） has been investigated extensively. In AR-V7, the entire COOH-terminal ligand-binding domain of the canonical AR is truncated and replaced with a variant-specific peptide of 16 amino acids. Functionally, AR-V7 is capable of mediating constitutive nuclear localization and androgen receptor signaling in the absence of androgens, or in the presence of enzalutamide. In this review, we will focus on clinical translational studies involving detection/measurement of AR-V7. Methods have been developed to detect AR-V7 in clinical mCRPC specimens. AR-V7 can be reliably measured in both tissue and circulating tumor cells derived from mCRPC patients, making it possible to conduct both cross-sectional and longitudinal clinical correlative studies. Current evidence derived from studies focusing on detection of AR-V7 in mCRPC support its potential clinical utility as a treatment selection marker.展开更多
Circulating tumor cells (CTC)have become an important biomarker in patients with advanced prostate cancer.CTC count has been demonstrated to be a prognostic factor for overall survival in patients with metastatic cast...Circulating tumor cells (CTC)have become an important biomarker in patients with advanced prostate cancer.CTC count has been demonstrated to be a prognostic factor for overall survival in patients with metastatic castration-resistant prostate cancer (mCRPC). In localized prostate cancer,a clear correlation between CTC counts and clinicopathological risk parameters and outcome has not been observed.Currently,the focus of research is shifting from CTC enumeration towards molecular characterization of CTC leading to the discovery of markers predicting treatment response.The role of androgen receptor splice variants expressed by CTC as markers of resistance to abiraterone and enzalutamide has been assessed by various studies.The identification of CTC markers predicting treatment response represents a key step to guide the selection of treatment (e.g.,abiraterone/enzalutamide vs taxanes), particularly in patients with mCRPC.As an alternative to CTC,the analysis of circulating tumor DNA has been shown to enable a noninvasive disease characterization having high potential to promote precision oncology.展开更多
In the current clinical setting,many disease management options are available for men diagnosed with prostate cancer.For metastatic prostate cancer,first-line therapies almost always involve agents designed to inhibit...In the current clinical setting,many disease management options are available for men diagnosed with prostate cancer.For metastatic prostate cancer,first-line therapies almost always involve agents designed to inhibit androgen receptor(AR)signaling.Castration-resistant prostate cancers(CRPCs)that arise following first-line androgen deprivation therapies(ADT)may continue to respond to additional lines of AR-targeting therapies(abiraterone and enzalutamide),chemotherapies(docetaxel and cabazitaxel),bonetargeting Radium-223 therapy,and immunotherapy sipuleucel-T.The rapidly expanding therapies for CRPC is expected to transform this lethal disease into one that can be managed for prolonged period of time.In the past 3 years,a number of promising biomarkers that may help to guide treatment decisions have been proposed and evaluated,including androgen receptor splice variant-7(AR-V7),a truncated AR lacking the ligand-binding domain(LBD)and mediate constitutively-active AR signaling.Putative treatment selection markers such as ARV7 may further improve survival benefit of existing therapies and help to accelerate development of new agents for metastatic prostate cancer.In the metastatic setting,it is important to consider compatibility between the putative biomarker with non-invasive sampling.In this review,biomarkers relevant to the setting of metastatic prostate cancer are discussed with respect to a number of key attributes critical for clinical development of non-invasive,actionable markers.It is envisioned that biomarkers for metastatic prostate cancer will continue to be discovered,developed,and refined to meet the unmet needs in both standard-of-care and clinical trial settings.展开更多
The Y-located testis-specific protein Y-encoded (TSPY) and its X-homologue TSPX originated from the same ancestral gene, but act as a proto-oncogene and a tumor suppressor gene, respectively. TSPY has specialized in m...The Y-located testis-specific protein Y-encoded (TSPY) and its X-homologue TSPX originated from the same ancestral gene, but act as a proto-oncogene and a tumor suppressor gene, respectively. TSPY has specialized in male-specific functions, while TSPX has assumed the functions of the ancestral gene. Both TSPY and TSPX harbor a conserved SET/NAP domain, but are divergent at flanking structures. Specifically, TSPX contains a C-terminal acidic domain, absent in TSPY. They possess contrasting properties, in which TSPY and TSPX, respectively, accelerate and arrest cell proliferation, stimulate and inhibit cyclin B-CDK1 phosphorylation activities, have no effect and promote proteosomal degradation of the viral HBx oncoprotein, and exacerbate and repress androgen receptor (AR) and constitutively active AR variant, such as AR-V7, gene transactivation. The inhibitory domain has been mapped to the carboxyl acidic domain in TSPX, truncation of which results in an abbreviated TSPX exerting positive actions as TSPY. Transposition of the acidic domain to the C-terminus of TSPY results in an inhibitory protein as intact TSPX. Hence, genomic mutations/aberrant splicing events could generate TSPX proteins with truncated acidic domain and oncogenic properties as those for TSPY. Further, TSPY is upregulated by AR and AR-V7 in ligand-dependent and ligand-independent manners, respectively, suggesting the existence of a positive feedback loop between a Y-located proto-oncogene and male sex hormone/receptors, thereby amplifying the respective male oncogenic actions in human cancers and diseases. TSPX counteracts such positive feedback loop. Hence, TSPY and TSPX are homologues on the sex chromosomes that function at the two extremes of the human oncogenic spectrum.展开更多
文摘Prostate cancer cells demonstrate a remarkable ＂addiction＂ to androgen receptor （AR） signaling in all stages of disease progression. As such, suppression of AR signaling remains the therapeutic goal in systemic treatment of prostate cancer. A number of molecular alterations arise in patients treated with AR-directed therapies. These molecular alterations may indicate the emergence of treatment resistance and may be targeted for the development of novel agents for prostate cancer. The presence of functional androgen receptor splice variants may represent a potential explanation for resistance to abiraterone and enzalutamide, newer AR-directed agents developed to treat metastatic castration-resistant prostate cancer （mCRPC）. In the last 8 years, many androgen receptor splice variants have been identified and characterized. Among these, androgen receptor splice variant-7 （AR-V7） has been investigated extensively. In AR-V7, the entire COOH-terminal ligand-binding domain of the canonical AR is truncated and replaced with a variant-specific peptide of 16 amino acids. Functionally, AR-V7 is capable of mediating constitutive nuclear localization and androgen receptor signaling in the absence of androgens, or in the presence of enzalutamide. In this review, we will focus on clinical translational studies involving detection/measurement of AR-V7. Methods have been developed to detect AR-V7 in clinical mCRPC specimens. AR-V7 can be reliably measured in both tissue and circulating tumor cells derived from mCRPC patients, making it possible to conduct both cross-sectional and longitudinal clinical correlative studies. Current evidence derived from studies focusing on detection of AR-V7 in mCRPC support its potential clinical utility as a treatment selection marker.
文摘Circulating tumor cells (CTC)have become an important biomarker in patients with advanced prostate cancer.CTC count has been demonstrated to be a prognostic factor for overall survival in patients with metastatic castration-resistant prostate cancer (mCRPC). In localized prostate cancer,a clear correlation between CTC counts and clinicopathological risk parameters and outcome has not been observed.Currently,the focus of research is shifting from CTC enumeration towards molecular characterization of CTC leading to the discovery of markers predicting treatment response.The role of androgen receptor splice variants expressed by CTC as markers of resistance to abiraterone and enzalutamide has been assessed by various studies.The identification of CTC markers predicting treatment response represents a key step to guide the selection of treatment (e.g.,abiraterone/enzalutamide vs taxanes), particularly in patients with mCRPC.As an alternative to CTC,the analysis of circulating tumor DNA has been shown to enable a noninvasive disease characterization having high potential to promote precision oncology.
基金Due to limited scope of the review,many published studies that formed the basis for viewpoints expressed in this review were not citedThe author wishes to thank all investigators who contributed to the knowledge and insight in the topic covered in this review.The author’s laboratory is currently funded by a Prostate Cancer Foundation grant,an NIH grant R01 CA185297US Department of Defense Prostate Cancer Research Program grants W81XWH-13-2-0093 and W81XWH-15-2-0050.
文摘In the current clinical setting,many disease management options are available for men diagnosed with prostate cancer.For metastatic prostate cancer,first-line therapies almost always involve agents designed to inhibit androgen receptor(AR)signaling.Castration-resistant prostate cancers(CRPCs)that arise following first-line androgen deprivation therapies(ADT)may continue to respond to additional lines of AR-targeting therapies(abiraterone and enzalutamide),chemotherapies(docetaxel and cabazitaxel),bonetargeting Radium-223 therapy,and immunotherapy sipuleucel-T.The rapidly expanding therapies for CRPC is expected to transform this lethal disease into one that can be managed for prolonged period of time.In the past 3 years,a number of promising biomarkers that may help to guide treatment decisions have been proposed and evaluated,including androgen receptor splice variant-7(AR-V7),a truncated AR lacking the ligand-binding domain(LBD)and mediate constitutively-active AR signaling.Putative treatment selection markers such as ARV7 may further improve survival benefit of existing therapies and help to accelerate development of new agents for metastatic prostate cancer.In the metastatic setting,it is important to consider compatibility between the putative biomarker with non-invasive sampling.In this review,biomarkers relevant to the setting of metastatic prostate cancer are discussed with respect to a number of key attributes critical for clinical development of non-invasive,actionable markers.It is envisioned that biomarkers for metastatic prostate cancer will continue to be discovered,developed,and refined to meet the unmet needs in both standard-of-care and clinical trial settings.
文摘The Y-located testis-specific protein Y-encoded (TSPY) and its X-homologue TSPX originated from the same ancestral gene, but act as a proto-oncogene and a tumor suppressor gene, respectively. TSPY has specialized in male-specific functions, while TSPX has assumed the functions of the ancestral gene. Both TSPY and TSPX harbor a conserved SET/NAP domain, but are divergent at flanking structures. Specifically, TSPX contains a C-terminal acidic domain, absent in TSPY. They possess contrasting properties, in which TSPY and TSPX, respectively, accelerate and arrest cell proliferation, stimulate and inhibit cyclin B-CDK1 phosphorylation activities, have no effect and promote proteosomal degradation of the viral HBx oncoprotein, and exacerbate and repress androgen receptor (AR) and constitutively active AR variant, such as AR-V7, gene transactivation. The inhibitory domain has been mapped to the carboxyl acidic domain in TSPX, truncation of which results in an abbreviated TSPX exerting positive actions as TSPY. Transposition of the acidic domain to the C-terminus of TSPY results in an inhibitory protein as intact TSPX. Hence, genomic mutations/aberrant splicing events could generate TSPX proteins with truncated acidic domain and oncogenic properties as those for TSPY. Further, TSPY is upregulated by AR and AR-V7 in ligand-dependent and ligand-independent manners, respectively, suggesting the existence of a positive feedback loop between a Y-located proto-oncogene and male sex hormone/receptors, thereby amplifying the respective male oncogenic actions in human cancers and diseases. TSPX counteracts such positive feedback loop. Hence, TSPY and TSPX are homologues on the sex chromosomes that function at the two extremes of the human oncogenic spectrum.
