RESUMO
The androgen receptor (AR) signaling inhibitor enzalutamide (enza) is one of the principal treatments for metastatic castration-resistant prostate cancer (CRPC). Several emergent enza clinical resistance mechanisms have been described, including lineage plasticity in which the tumors manifest reduced dependency on the AR. To improve our understanding of enza resistance, herein we analyze the transcriptomes of matched biopsies from men with metastatic CRPC obtained prior to treatment and at progression (n = 21). RNA-sequencing analysis demonstrates that enza does not induce marked, sustained changes in the tumor transcriptome in most patients. However, three patients' progression biopsies show evidence of lineage plasticity. The transcription factor E2F1 and pathways linked to tumor stemness are highly activated in baseline biopsies from patients whose tumors undergo lineage plasticity. We find a gene signature enriched in these baseline biopsies that is strongly associated with poor survival in independent patient cohorts and with risk of castration-induced lineage plasticity in patient-derived xenograft models, suggesting that tumors harboring this gene expression program may be at particular risk for resistance mediated by lineage plasticity and poor outcomes.
Assuntos
Fator de Transcrição E2F1 , Neoplasias de Próstata Resistentes à Castração , Antagonistas de Receptores de Andrógenos/farmacologia , Benzamidas , Biópsia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Fator de Transcrição E2F1/metabolismo , Humanos , Masculino , Nitrilas , Feniltioidantoína , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , RNA , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismoRESUMO
PURPOSE: The purpose of this study was to measure genomic changes that emerge with enzalutamide treatment using analyses of whole-genome sequencing and RNA sequencing. EXPERIMENTAL DESIGN: One hundred and one tumors from men with metastatic castration-resistant prostate cancer (mCRPC) who had not been treated with enzalutamide (n = 64) or who had enzalutamide-resistant mCRPC (n = 37) underwent whole genome sequencing. Ninety-nine of these tumors also underwent RNA sequencing. We analyzed the genomes and transcriptomes of these mCRPC tumors. RESULTS: Copy number loss was more common than gain in enzalutamide-resistant tumors. Specially, we identified 124 protein-coding genes that were more commonly lost in enzalutamide-resistant samples. These 124 genes included eight putative tumor suppressors located at nine distinct genomic regions. We demonstrated that focal deletion of the 17q22 locus that includes RNF43 and SRSF1 was not present in any patient with enzalutamide-naïve mCRPC but was present in 16% (6/37) of patients with enzalutamide-resistant mCRPC. 17q22 loss was associated with lower RNF43 and SRSF1 expression and poor overall survival from time of biopsy [median overall survival of 19.3 months in 17q22 intact vs. 8.9 months in 17q22 loss, HR, 3.44 95% confidence interval (CI), 1.338-8.867, log-rank P = 0.006]. Finally, 17q22 loss was linked with activation of several targetable factors, including CDK1/2, Akt, and PLK1, demonstrating the potential therapeutic relevance of 17q22 loss in mCRPC. CONCLUSIONS: Copy number loss is common in enzalutamide-resistant tumors. Focal deletion of chromosome 17q22 defines a previously unappreciated molecular subset of enzalutamide-resistant mCRPC associated with poor clinical outcome.
Assuntos
Benzamidas/farmacologia , Biomarcadores Tumorais/genética , Cromossomos Humanos Par 17/genética , Resistencia a Medicamentos Antineoplásicos/genética , Nitrilas/farmacologia , Feniltioidantoína/farmacologia , Neoplasias de Próstata Resistentes à Castração/genética , Benzamidas/uso terapêutico , Biópsia , Variações do Número de Cópias de DNA , Intervalo Livre de Doença , Humanos , Masculino , Nitrilas/uso terapêutico , Feniltioidantoína/uso terapêutico , Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/mortalidade , Neoplasias de Próstata Resistentes à Castração/patologia , RNA-Seq , Análise de SobrevidaRESUMO
The androgen receptor (AR) antagonist enzalutamide is one of the principal treatments for men with castration-resistant prostate cancer (CRPC). However, not all patients respond, and resistance mechanisms are largely unknown. We hypothesized that genomic and transcriptional features from metastatic CRPC biopsies prior to treatment would be predictive of de novo treatment resistance. To this end, we conducted a phase II trial of enzalutamide treatment (160 mg/d) in 36 men with metastatic CRPC. Thirty-four patients were evaluable for the primary end point of a prostate-specific antigen (PSA)50 response (PSA decline ≥50% at 12 wk vs. baseline). Nine patients were classified as nonresponders (PSA decline <50%), and 25 patients were classified as responders (PSA decline ≥50%). Failure to achieve a PSA50 was associated with shorter progression-free survival, time on treatment, and overall survival, demonstrating PSA50's utility. Targeted DNA-sequencing was performed on 26 of 36 biopsies, and RNA-sequencing was performed on 25 of 36 biopsies that contained sufficient material. Using computational methods, we measured AR transcriptional function and performed gene set enrichment analysis (GSEA) to identify pathways whose activity state correlated with de novo resistance. TP53 gene alterations were more common in nonresponders, although this did not reach statistical significance (P = 0.055). AR gene alterations and AR expression were similar between groups. Importantly, however, transcriptional measurements demonstrated that specific gene sets-including those linked to low AR transcriptional activity and a stemness program-were activated in nonresponders. Our results suggest that patients whose tumors harbor this program should be considered for clinical trials testing rational agents to overcome de novo enzalutamide resistance.
Assuntos
Antineoplásicos/administração & dosagem , Resistencia a Medicamentos Antineoplásicos , Feniltioidantoína/análogos & derivados , Neoplasias de Próstata Resistentes à Castração/genética , Receptores Androgênicos/administração & dosagem , Receptores Androgênicos/genética , Idoso , Idoso de 80 Anos ou mais , Benzamidas , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Nitrilas , Feniltioidantoína/administração & dosagem , Antígeno Prostático Específico/metabolismo , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/metabolismoRESUMO
BACKGROUND: Metastatic castration-resistant prostate cancer (mCRPC) is the lethal form of the disease. Several recent studies have identified genomic alterations in mCRPC, but the clinical implications of these genomic alterations have not been fully elucidated. OBJECTIVE: To use whole-genome sequencing (WGS) to assess the association between key driver gene alterations and overall survival (OS), and to use whole-transcriptome RNA sequencing to identify genomic drivers of enzalutamide resistance. DESIGN, SETTING, AND PARTICIPANTS: We performed survival analyses and gene set enrichment analysis (GSEA) on WGS and RNA sequencing results for a cohort of 101 mCRPC patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: OS was the clinical endpoint for all univariate and multivariable survival analyses. Candidate drivers of enzalutamide resistance were identified in an unbiased manner, and mutations of the top candidate were further assessed for enrichment among enzalutamide-resistant patients using Fisher's exact test. RESULTS AND LIMITATIONS: Harboring two DNA alterations in RB1 was independently predictive of poor OS (median 14.1 vs 42.0mo; p=0.007) for men with mCRPC. GSEA identified the Wnt/ß-catenin pathway as the top differentially modulated pathway among enzalutamide-resistant patients. Furthermore, ß-catenin mutations were exclusive to enzalutamide-resistant patients (p=0.01) and independently predictive of poor OS (median 13.6 vs 41.7mo; p=0.025). CONCLUSIONS: The presence of two RB1 DNA alterations identified in our WGS analysis was independently associated with poor OS among men with mCRPC. The Wnt/ß-catenin pathway plays an important role in enzalutamide resistance, with differential pathway expression and enrichment of ß-catenin mutations in enzalutamide-resistant patients. Moreover, ß-catenin mutations were predictive of poor OS in our cohort. PATIENT SUMMARY: We observed a correlation between genomic findings for biopsy samples from metastases from men with metastatic castration-resistant prostate cancer (mCRPC) and clinical outcomes. This work sheds new light on clinically relevant genomic alterations in mCRPC and provides a roadmap for the development of new personalized treatment regimens in mCRPC.
Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Metástase Neoplásica , Feniltioidantoína/análogos & derivados , Próstata/patologia , Neoplasias de Próstata Resistentes à Castração , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Benzamidas , Biomarcadores Tumorais/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica/tratamento farmacológico , Estadiamento de Neoplasias , Nitrilas , Avaliação de Resultados em Cuidados de Saúde , Feniltioidantoína/administração & dosagem , Feniltioidantoína/efeitos adversos , Valor Preditivo dos Testes , Prognóstico , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/patologia , Sequenciamento Completo do Genoma/métodosRESUMO
Background: PARP inhibition is a promising therapeutic strategy for the treatment of men with metastatic castration-resistant prostate cancer whose tumors harbor homologous recombination DNA repair gene alterations. However, questions remain for many practicing clinicians about which patients are ideally suited for PARP inhibitor treatment. This report details our institutional experience using PARP inhibitor therapy in patients whose tumors harbored specific DNA repair gene alterations. Patients and Methods: We performed a retrospective chart review to identify patients at Oregon Health & Science University who were treated with PARP inhibition. We identified 8 patients and determined the impact of the specific DNA repair gene alterations on tumor response and time on treatment with PARP inhibition. Results: A number of DNA repair gene alterations were identified. Three patients had pathogenic BRCA2 mutations and one had a BRCA2 mutation of uncertain significance. Conversely, the 4 other patients' tumors harbored alterations in other DNA repair genes, none of which were clearly pathogenic. A statistically significant difference in benefit was seen between patients whose tumors harbored BRCA2 gene alterations and those whose tumors did not, as measured by >50% decline in prostate-specific antigen levels (100% vs 0%; P=.03) and duration on therapy (31.4 vs 6.4 weeks; P=.03). Conclusions: Our results demonstrate that not all DNA repair alterations are equally predictive of PARP inhibitor response. Importantly, all responding patients had tumors harboring BRCA2 DNA repair alterations, including one without a known pathogenic mutation. Conversely, among the 4 nonresponders, several DNA repair alterations in genes other than BRCA2 were identified that were not clearly pathogenic. This demonstrates the need to carefully examine the functional relevance of the DNA repair alterations identified, especially in genes other than BRCA2, when considering patients for PARP inhibitor treatment.
Assuntos
Biomarcadores Tumorais/genética , Reparo do DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Idoso , Proteína BRCA2/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Prognóstico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Purpose The prevalence and features of treatment-emergent small-cell neuroendocrine prostate cancer (t-SCNC) are not well characterized in the era of modern androgen receptor (AR)-targeting therapy. We sought to characterize the clinical and genomic features of t-SCNC in a multi-institutional prospective study. Methods Patients with progressive, metastatic castration-resistant prostate cancer (mCRPC) underwent metastatic tumor biopsy and were followed for survival. Metastatic biopsy specimens underwent independent, blinded pathology review along with RNA/DNA sequencing. Results A total of 202 consecutive patients were enrolled. One hundred forty-eight (73%) had prior disease progression on abiraterone and/or enzalutamide. The biopsy evaluable rate was 79%. The overall incidence of t-SCNC detection was 17%. AR amplification and protein expression were present in 67% and 75%, respectively, of t-SCNC biopsy specimens. t-SCNC was detected at similar proportions in bone, node, and visceral organ biopsy specimens. Genomic alterations in the DNA repair pathway were nearly mutually exclusive with t-SCNC differentiation ( P = .035). Detection of t-SCNC was associated with shortened overall survival among patients with prior AR-targeting therapy for mCRPC (hazard ratio, 2.02; 95% CI, 1.07 to 3.82). Unsupervised hierarchical clustering of the transcriptome identified a small-cell-like cluster that further enriched for adverse survival outcomes (hazard ratio, 3.00; 95% CI, 1.25 to 7.19). A t-SCNC transcriptional signature was developed and validated in multiple external data sets with > 90% accuracy. Multiple transcriptional regulators of t-SCNC were identified, including the pancreatic neuroendocrine marker PDX1. Conclusion t-SCNC is present in nearly one fifth of patients with mCRPC and is associated with shortened survival. The near-mutual exclusivity with DNA repair alterations suggests t-SCNC may be a distinct subset of mCRPC. Transcriptional profiling facilitates the identification of t-SCNC and novel therapeutic targets.
Assuntos
Carcinoma Neuroendócrino/genética , Carcinoma Neuroendócrino/patologia , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Idoso , Idoso de 80 Anos ou mais , Carcinoma Neuroendócrino/epidemiologia , Reparo do DNA/genética , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias de Próstata Resistentes à Castração/epidemiologiaRESUMO
While mutations affecting protein-coding regions have been examined across many cancers, structural variants at the genome-wide level are still poorly defined. Through integrative deep whole-genome and -transcriptome analysis of 101 castration-resistant prostate cancer metastases (109X tumor/38X normal coverage), we identified structural variants altering critical regulators of tumorigenesis and progression not detectable by exome approaches. Notably, we observed amplification of an intergenic enhancer region 624 kb upstream of the androgen receptor (AR) in 81% of patients, correlating with increased AR expression. Tandem duplication hotspots also occur near MYC, in lncRNAs associated with post-translational MYC regulation. Classes of structural variations were linked to distinct DNA repair deficiencies, suggesting their etiology, including associations of CDK12 mutation with tandem duplications, TP53 inactivation with inverted rearrangements and chromothripsis, and BRCA2 inactivation with deletions. Together, these observations provide a comprehensive view of how structural variations affect critical regulators in metastatic prostate cancer.
Assuntos
Variação Estrutural do Genoma/genética , Neoplasias da Próstata/genética , Idoso , Idoso de 80 Anos ou mais , Proteína BRCA2/metabolismo , Quinases Ciclina-Dependentes/metabolismo , Variações do Número de Cópias de DNA , Exoma , Perfilação da Expressão Gênica/métodos , Genômica/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Metástase Neoplásica/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Sequências de Repetição em Tandem/genética , Proteína Supressora de Tumor p53/metabolismo , Sequenciamento Completo do Genoma/métodosRESUMO
BACKGROUND: Real-time knowledge of the somatic genome can influence management of patients with metastatic castration-resistant prostate cancer (mCRPC). While routine metastatic tissue biopsy is challenging in mCRPC, plasma circulating tumor DNA (ctDNA) has emerged as a minimally invasive tool to sample the tumor genome. However, no systematic comparisons of matched "liquid" and "solid" biopsies have been performed that would enable ctDNA profiling to replace the need for direct tissue sampling. METHODS: We performed targeted sequencing across 72 clinically relevant genes in 45 plasma cell-free DNA (cfDNA) samples collected at time of metastatic tissue biopsy. We compared ctDNA alterations with exome sequencing data generated from matched tissue and quantified the concordance of mutations and copy number alterations using the Fisher exact test and Pearson correlations. RESULTS: Seventy-five point six percent of cfDNA samples had a ctDNA proportion greater than 2% of total cfDNA. In these patients, all somatic mutations identified in matched metastatic tissue biopsies were concurrently present in ctDNA. Furthermore, the hierarchy of variant allele fractions for shared mutations was remarkably similar between ctDNA and tissue. Copy number profiles between matched liquid and solid biopsy were highly correlated, and individual copy number calls in clinically actionable genes were 88.9% concordant. Detected alterations included AR amplifications in 22 (64.7%) samples, SPOP mutations in three (8.8%) samples, and inactivating alterations in tumor suppressors TP53 , PTEN , RB1 , APC , CDKN1B , BRCA2 , and PIK3R1 . In several patients, ctDNA sequencing revealed robust changes not present in paired solid biopsy, including clinically relevant alterations in the AR, WNT, and PI3K pathways. CONCLUSIONS: Our study shows that, in the majority of patients, a ctDNA assay is sufficient to identify all driver DNA alterations present in matched metastatic tissue and supports development of DNA biomarkers to guide mCRPC patient management based on ctDNA alone.
Assuntos
DNA Tumoral Circulante/sangue , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Proteína da Polipose Adenomatosa do Colo/genética , Proteína BRCA2/genética , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Classe Ia de Fosfatidilinositol 3-Quinase , Inibidor de Quinase Dependente de Ciclina p27/genética , Variações do Número de Cópias de DNA , Humanos , Biópsia Líquida , Masculino , Mutação , Metástase Neoplásica , Proteínas Nucleares/genética , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/genética , Receptores Androgênicos/genética , Proteínas Repressoras/genética , Proteínas de Ligação a Retinoblastoma/genética , Proteína Supressora de Tumor p53/genética , Ubiquitina-Proteína Ligases/genética , Via de Sinalização Wnt/genéticaRESUMO
Increased AR activity has been shown to be preserved in spatially distinct metastatic tumors from the same patient suggesting the requirement for lineage-specific dependencies for metastatic castration resistant prostate cancer (mCRPC). Amplification of the AR gene is a common mechanism by which mCRPC increase AR activity. To determine whether AR amplification in circulating tumor cells (CTC) could complement metastatic tissue biopsies in men undergoing treatment for mCRPC, we developed a novel two-step assay to isolate CTCs and subsequently analyzed AR amplification status in CTCs and matched biopsy tissue from the same patient by fluorescence in situ hybridization (FISH). AR gene status in CTCs showed strong concordance with AR gene status in matched tissue samples in 24 of 25 patients (Correlation: 96%; Kappa: 0.83; Sensitivity: 100%, Specificity: 83%). Our work demonstrates that AR amplification is conserved between CTCs and biopsies and that CTCs can serve as non-invasive surrogate to document AR amplification in mCRPC.
RESUMO
Noninvasive biomarkers that detect the activity of important oncogenic drivers could significantly improve cancer diagnosis and management of treatment. The goal of this study was to determine whether 68Ga-citrate (which avidly binds to circulating transferrin) can detect MYC-positive prostate cancer tumors, as the transferrin receptor is a direct MYC target gene. PET imaging paired with 68Ga-citrate and molecular analysis of preclinical models, human cell-free DNA (cfDNA), and clinical biopsies were conducted to determine whether 68Ga-citrate can detect MYC-positive prostate cancer. Importantly, 68Ga-citrate detected human prostate cancer models in a MYC-dependent fashion. In patients with castration-resistant prostate cancer, analysis of cfDNA revealed that all patients with 68Ga-citrate avid tumors had a gain of at least one MYC copy number. Moreover, biopsy of two PET avid metastases showed molecular or histologic features characteristic of MYC hyperactivity. These data demonstrate that 68Ga-citrate targets prostate cancer tumors with MYC hyperactivity. A larger prospective study is ongoing to demonstrate the specificity of 68Ga-citrate for tumors with hyperactive MYC.Implications: Noninvasive measurement of MYC activity with quantitative imaging modalities could substantially increase our understanding of the role of MYC signaling in clinical settings for which invasive techniques are challenging to implement or do not characterize the biology of all tumors in a patient. Moreover, measuring MYC activity noninvasively opens the opportunity to study changes in MYC signaling in patients under targeted therapeutic conditions thought to indirectly inhibit MYC. Mol Cancer Res; 15(9); 1221-9. ©2017 AACR.
Assuntos
Genes myc/genética , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Próstata/genética , Transferrina/metabolismo , Humanos , MasculinoRESUMO
PURPOSE: To evaluate the success rate of CT-guided bone biopsies in metastatic castration-resistant prostate cancer (mCRPC) and to investigate associated technical, imaging, and clinical parameters affecting diagnostic yields. MATERIALS AND METHODS: Eighty CT-guided bone biopsy specimens were obtained from 72 men (median age, 68 y; range, 49-89 y) enrolled in a multicenter trial to identify mechanisms of resistance in mCRPC. Successful biopsy was determined by histologic confirmation of tumor cells and successful isolation of RNA for molecular analysis. RESULTS: The overall success rate of CT-guided bone biopsies was 69% (55/80) based on histology and 64% (35/55) based on isolation of molecular material for RNA sequencing. Biopsies performed in lesions with areas of radiolucency had significantly higher diagnostic yields compared with lesions of predominantly dense sclerosis (95% vs 33%; P = .002) and lesions of predominantly subtle sclerosis (95% vs 65%; P = .04). Success rates increased in lesions with density ≤ 475 HU (79% for ≤ 475 HU vs 33% for > 475 HU; P = .001) and in lesions with ill-defined margins (76% for ill-defined margins vs 36% for well-circumscribed margins; P = .005). Alkaline phosphatase was the only clinical parameter to correlate significantly with diagnostic yield (83% for > 110 U/L vs 50% for ≤ 110 U/L; P = .001). CONCLUSIONS: Image-guided bone tumor biopsies can be successfully used to acquire cellular and molecular material for analyses in patients with osteoblastic prostate cancer metastases. Diagnostic yields are significantly increased in lesions with areas of radiolucency, density ≤ 475 HU, ill-defined margins, and interval growth and in patients with alkaline phosphatase > 110 U/L.
Assuntos
Neoplasias Ósseas/secundário , Biópsia Guiada por Imagem/métodos , Neoplasias de Próstata Resistentes à Castração/patologia , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Approximately 20% of metastatic prostate cancers harbor mutations in genes required for DNA repair by homologous recombination repair (HRR) such as BRCA2 HRR defects confer synthetic lethality to PARP inhibitors (PARPi) such as olaparib and talazoparib. In ovarian or breast cancers, olaparib resistance has been associated with HRR restoration, including by BRCA2 mutation reversion. Whether similar mechanisms operate in prostate cancer, and could be detected in liquid biopsies, is unclear. Here, we identify BRCA2 reversion mutations associated with olaparib and talazoparib resistance in patients with prostate cancer. Analysis of circulating cell-free DNA (cfDNA) reveals reversion mutation heterogeneity not discernable from a single solid-tumor biopsy and potentially allows monitoring for the emergence of PARPi resistance.Significance: The mechanisms of clinical resistance to PARPi in DNA repair-deficient prostate cancer have not been described. Here, we show BRCA2 reversion mutations in patients with prostate cancer with metastatic disease who developed resistance to talazoparib and olaparib. Furthermore, we show that PARPi resistance is highly multiclonal and that cfDNA allows monitoring for PARPi resistance. Cancer Discov; 7(9); 999-1005. ©2017 AACR.See related commentary by Domchek, p. 937See related article by Kondrashova et al., p. 984See related article by Goodall et al., p. 1006This article is highlighted in the In This Issue feature, p. 920.
Assuntos
Antineoplásicos/uso terapêutico , Proteína BRCA2/genética , Ácidos Nucleicos Livres/genética , Resistencia a Medicamentos Antineoplásicos/genética , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Neoplasias da Próstata/genética , Variações do Número de Cópias de DNA , Mutação em Linhagem Germinativa , Humanos , Masculino , Ftalazinas/uso terapêutico , Piperazinas/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/patologia , Sequenciamento do ExomaRESUMO
The Stand Up 2 Cancer/Prostate Cancer Foundation-funded West Coast Dream Team project is a prospective multi-institutional study focused on acquiring metastatic castration-resistant prostate cancer (mCRPC) biopsy tissue at the time of resistance to abiraterone or enzalutamide. It is the first large-scale study designed to analyze mCRPC tissue specifically in this patient population. Study accrual is on target, with 261 out of a planned 300 metastatic tumor biopsies performed by August 2016. Paired biopsies have been completed in 42 patients, with paired genomic data before and after therapy obtained in 26 cases. Accrual is expected to be complete by December 2016.
RESUMO
PURPOSE: Although novel agents targeting the androgen-androgen receptor (AR) axis have altered the treatment paradigm of metastatic castration-resistant prostate cancer (mCRPC), development of therapeutic resistance is inevitable. In this study, we examined whether AR gene aberrations detectable in circulating cell-free DNA (cfDNA) are associated with resistance to abiraterone acetate and enzalutamide in mCRPC patients. EXPERIMENTAL DESIGN: Plasma was collected from 62 mCRPC patients ceasing abiraterone acetate (n = 29), enzalutamide (n = 19), or other agents (n = 14) due to disease progression. DNA was extracted and subjected to array comparative genomic hybridization (aCGH) for chromosome copy number analysis, and Roche 454 targeted next-generation sequencing of exon 8 in the AR. RESULTS: On aCGH, AR amplification was significantly more common in patients progressing on enzalutamide than on abiraterone or other agents (53% vs. 17% vs. 21%, P = 0.02, χ(2)). Missense AR exon 8 mutations were detected in 11 of 62 patients (18%), including the first reported case of an F876L mutation in an enzalutamide-resistant patient and H874Y and T877A mutations in 7 abiraterone-resistant patients. In patients switched onto enzalutamide after cfDNA collection (n = 39), an AR gene aberration (copy number increase and/or an exon 8 mutation) in pretreatment cfDNA was associated with adverse outcomes, including lower rates of PSA decline ≥ 30% (P = 0.013, χ(2)) and shorter time to radiographic/clinical progression (P = 0.010, Cox proportional hazards regression). CONCLUSIONS: AR gene aberrations in cfDNA are associated with resistance to enzalutamide and abiraterone in mCRPC. Our data illustrate that genomic analysis of cfDNA is a minimally invasive method for interrogating mechanisms of therapeutic resistance in mCRPC.
Assuntos
Androstenos/farmacologia , Biomarcadores Tumorais/sangue , DNA de Neoplasias/sangue , Neoplasias de Próstata Resistentes à Castração/genética , Receptores Androgênicos/genética , Taxoides/farmacologia , Idoso , Idoso de 80 Anos ou mais , Androstenos/uso terapêutico , Variações do Número de Cópias de DNA , Análise Mutacional de DNA , Intervalo Livre de Doença , Docetaxel , Resistencia a Medicamentos Antineoplásicos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Metástase Neoplásica , Células Neoplásicas Circulantes , Modelos de Riscos Proporcionais , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/mortalidade , Taxoides/uso terapêuticoRESUMO
Insulin resistance, the diminished response of target tissues to insulin, is associated with the metabolic syndrome and a predisposition towards diabetes in a growing proportion of the worldwide population. Under insulin resistant states, the cellular response of the insulin signaling pathway is diminished and the body typically responds by increasing serum insulin concentrations to maintain insulin signaling. Some evidence indicates that the increased insulin concentration may itself further dampen insulin response. If so, insulin resistance would worsen as the level of circulating insulin increases during compensation, which could contribute to the transition of insulin resistance to more severe disease. Here, we investigated the consequences of excess insulin exposure to insulin receptor (IR) activity. Cells chronically exposed to insulin show a diminished the level of IR tyrosine and serine autophosphorylation below that observed after short-term insulin exposure. The diminished IR response did not originate with IR internalization since IR amounts at the cell membrane were similar after short- and long-term insulin incubation. Förster resonance energy transfer between fluorophores attached to the IR tyrosine kinase (TK) domain showed that a change in the TK domain occurred upon prolonged, but not short-term, insulin exposure. Even though the altered 'insulin refractory' IR TK FRET and IR autophosphorylation levels returned to baseline (non-stimulated) levels after wash-out of the original insulin stimulus, subsequent short-term exposure to insulin caused immediate re-establishment of the insulin-refractory levels. This suggests that some cell-based 'memory' of chronic hyperinsulinemic exposure acts directly at the IR. An improved understanding of that memory may help define interventions to reset the IR to full insulin responsiveness and impede the progression of insulin resistance to more severe disease states.
Assuntos
Hiperinsulinismo/metabolismo , Resistência à Insulina/fisiologia , Receptor de Insulina/metabolismo , Transdução de Sinais/fisiologia , Animais , Células CHO , Linhagem Celular Tumoral , Cricetulus , Insulina/metabolismo , Insulina/farmacologia , Fosforilação/efeitos dos fármacos , Estrutura Terciária de Proteína/fisiologia , Ratos , Transdução de Sinais/efeitos dos fármacosRESUMO
The insulin-like growth factor receptor (IGF-1R) is a receptor tyrosine kinase (RTK) involved in all stages of the development and propagation of breast and other cancers. The inhibition of IGF-1R by small molecules remains a promising strategy to treat cancer. Herein, we explore SAR around previously characterized lead compound (1), which is an aryl-heteroaryl urea (AHU) consisting of 4-aminoquinaldine and a substituted aromatic ring system. A library of novel AHU compounds was prepared based on derivatives of the 4-aminoquinoline heterocycle (including various 2-substituted derivatives, and naphthyridines). The compounds were screened for in vitro inhibitory activity against IGF-1R, and several compounds with improved activity (3-5 microM) were identified. Furthermore, a computational docking study was performed, which identifies a fairly consistent lowest energy mode of binding for the more-active set of inhibitors in this series, while the less-active inhibitors do not adopt a consistent mode of binding.
Assuntos
Aminoquinolinas/química , Aminoquinolinas/farmacologia , Receptores de Somatomedina/antagonistas & inibidores , Receptores de Somatomedina/metabolismo , Ureia/química , Ureia/farmacologia , Aminoquinolinas/síntese química , Humanos , Modelos Moleculares , Ligação Proteica , Receptores de Somatomedina/química , Ureia/síntese químicaRESUMO
BACKGROUND: The purpose of this study was to determine whether a preparation of controlled-release alpha lipoic acid (CRLA) influences features of the polycystic ovary syndrome (PCOS). METHODS: We administered CRLA 600 mg twice daily for 16 weeks to six lean, nondiabetic patients with PCOS. Insulin sensitivity was measured by the euglycemic, hyperinsulinemic clamp. Plasma lipids were measured by vertical ultracentrifugation. Oxidative stress markers were measured in serum. RESULTS: At the end of 16 weeks of CRLA treatment, there was a 13.5% improvement in insulin sensitivity as determined by the euglycemic, hyperinsulinemic clamp (p < .03). There was also a lowering of triglyceride levels (p < .04) and a shift in the distribution of low-density lipoprotein (LDL) particles toward the larger, more buoyant LDL subclass fraction. Two of the subjects who were not on oral contraception had an increased number of menstrual cycles. Controlled-release alpha lipoic acid treatment, however, was neither associated with an increase in plasma antioxidant capacity nor with a reduction in plasma lipid oxidation products. CONCLUSIONS: These data suggest that the CRLA has positive effects on the PCOS phenotype. The effects of CRLA, however, may have been exerted through a mechanism not involving changes in oxidative stress.
Assuntos
Síndrome do Ovário Policístico/tratamento farmacológico , Ácido Tióctico/uso terapêutico , Adulto , Glicemia/metabolismo , Índice de Massa Corporal , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Preparações de Ação Retardada/administração & dosagem , Exercício Físico , Feminino , Técnica Clamp de Glucose/métodos , Humanos , Hiperinsulinismo/sangue , Insulina/farmacologia , Lipoproteínas LDL/sangue , Lipoproteínas LDL/classificação , Ciclo Menstrual/efeitos dos fármacos , Estresse Oxidativo , Síndrome do Ovário Policístico/sangue , Magreza/sangue , Ácido Tióctico/administração & dosagem , Triglicerídeos/sangueRESUMO
It has been well documented that nordihydroguaiaretic acid (NDGA), a phenolic lignan isolated from the creosote bush, Larrea tridentate, has anti-cancer activity in vitro and in vivo. Several mechanisms have been identified that could contribute to these actions, as NDGA directly inhibits metabolic enzymes and receptor tyrosine kinases that are established anti-cancer targets. In the present study, we show that NDGA inhibits the transforming growth factor beta (TGF-beta) type I receptor, a serine threonine kinase receptor. In cultured cells, NDGA treatment repressed Smad2 phosphorylation induced by TGF-beta treatment and by a constitutively active mutant of TGF-beta type I receptor (T202D). NDGA also inhibited downstream transcriptional activation mediated by both TGF-beta treatment and the constitutively active mutant receptor. In vitro, NDGA inhibited TGF-beta type I receptor mediated Smad2 phosphorylation in crude cell lysates and in a purified preparation. Importantly, screening select analogs demonstrated that modification of NDGA's structure resulted in altered potency against the receptor. These results indicated that the structure of NDGA can be modified to achieve increased potency. Together our data provide a novel mechanism for NDGA activity which could help explain its anti-cancer activity, and suggest that NDGA could serve as a structural motif for developing serine/threonine kinase inhibitors with selectivity for TGF-beta type I receptor.
Assuntos
Masoprocol/farmacologia , Receptores de Fatores de Crescimento Transformadores beta/antagonistas & inibidores , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Humanos , Masoprocol/análogos & derivados , Fosforilação/efeitos dos fármacos , Proteína Smad2/metabolismo , Transcrição Gênica/efeitos dos fármacos , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
BACKGROUND: Nordihydroguaiaretic acid (NDGA) is an inhibitor of the IGF-1 receptor (IGF-1R) in breast and other cancers, and concomitantly inhibits tumor growth both in cultured cells and animals. The current study evaluates the effect of NDGA on the androgen-stimulated growth of human prostate cancer cells. METHODS: LAPC-4 prostate cancer cells in tissue culture were androgen starved for 3 days, 1 nM dihydrotestosterone (DHT) and other androgens were then added for up to 7 days, and cell proliferation measured. IGF-1R protein expression was measured by Western blot, and IGF-1R mRNA expression by quantitative PCR. IGF-1R receptor kinase activation was measured by ELISA. RESULTS: After 7 days, LAPC-4 growth was doubled by 1 nM DHT. NDGA had a rapid effect to inhibit IGF-1R autophosphorylation induced by IGF-1. DHT increased the expression of IGF-1R protein and mRNA levels. Maximal IGF-1R protein levels were observed 3 days after the addition of androgen. In addition, NDGA, at 10 microM or less, inhibited DHT-induced proliferation in both cells grown in plates and cells grown in soft agar. Androgen receptor (AR) studies by FRET revealed that NDGA had no conformational effects on the AR in response to ligand. CONCLUSIONS: NDGA blocks the DHT-induced growth of LAPC-4 prostate cancer cells by several mechanisms including rapid inhibition of the IGF-1R kinase, and a dose-dependent inhibition of androgen stimulation of IGF-1R expression. Clinical studies of this agent will determine its efficacy in the setting of androgen-dependent prostate cancer.