RESUMO
BACKGROUND AND OBJECTIVE: Androgen deprivation therapy (ADT) with salvage radiation therapy (RT) improves survival for patients with prostate-specific antigen (PSA) recurrence after radical prostatectomy (RP) for prostate cancer (PC), but many patients suffer further relapse. This study aims to determine the benefit of the combination of ADT, apalutamide, salvage RT, and docetaxel for high-risk PSA recurrent PC. METHODS: STARTAR is a multicenter, investigator-initiated phase 2 trial of men with PSA recurrent PC after RP. The key inclusion criteria included M0 by computed tomography/bone scan, Gleason 7 with either T3/positive margin/N1 disease or Gleason 8-10 prostate adenocarcinoma, PSA relapse (0.2-4 ng/ml) <4 yr after RP, and fewer than four positive resected lymph nodes. Patients received ADT with apalutamide for 9 mo, RT starting week 8, and then six cycles of docetaxel. The primary endpoint was 36-mo progression-free survival (PFS) with testosterone recovery and compared against the prior STREAM trial. KEY FINDINGS AND LIMITATIONS: We enrolled 39 men, including those with Gleason 8-10 (46%), pN1 (23%); the median PSA was 0.58 ng/ml. The median follow-up was 37 mo. All patients achieved undetectable PSA nadir. At 24 and 36 mo, PFS rates were 84% and 71%, respectively, which improved significantly over 3-yr 47% historic PFS and 54% enzalutamide/ADT/RT (STREAM) PFS rates (p = 0.004 and p = 0.039, respectively). Common any-grade adverse events included 98% hot flashes, 88% fatigue, 77% alopecia, 53% rash (10% G3), and 5% febrile neutropenia. CONCLUSIONS AND CLINICAL IMPLICATIONS: In this phase 2 trial of ADT, apalutamide, salvage RT, and six cycles of docetaxel for high-risk PSA recurrence, the 3-yr PFS rate improved to 71%, indicating feasible and efficacious treatment intensification, with durable remissions beyond historic data. PATIENT SUMMARY: Prostate cancer recurrence after surgical removal of the tumor occurs often, and current treatment options to limit recurrence after surgery are only partially effective. In this study, we found that the addition of an androgen receptor inhibitor and docetaxel chemotherapy to standard postsurgery radiation therapy and androgen deprivation therapy significantly improved progression-free survival at 3 yr after treatment. These results suggest that intensification of treatment after surgery can provide long-term benefit to a subset of patients with high-risk prostate cancer.
RESUMO
The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for diagnostic workup, staging, and treatment of patients with renal cell carcinoma (RCC). These NCCN Guidelines Insights focus on the systemic therapy options for patients with advanced RCC and summarize the new clinical data evaluated by the NCCN panel for the recommended therapies in Version 2.2024 of the NCCN Guidelines for Kidney Cancer.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/terapia , Neoplasias Renais/diagnóstico , Neoplasias Renais/terapiaRESUMO
The majority of kidney cancers are detected incidentally and typically diagnosed at a localized stage, however, the development of regional or distant disease occurs in one-third of patients. Over 90% of kidney tumors are renal cell carcinomas, of which, clear cell is the most predominate histologic subtype. Von Hippel Lindau (VHL) gene alterations result in the overexpression of growth factors that are central to the pathogenesis of clear cell carcinoma. The therapeutic strategies have revolved around this tumor suppressor gene and have led to the approval of tyrosine kinase inhibitors (TKI) targeting the vascular endothelial growth factor (VEGF) axis. The treatment paradigm shifted with the introduction of immune checkpoint inhibitors (ICI) and programed death-1 (PD-1) inhibition, leading to durable response rates and improved survival. Combinations of TKI and/or ICIs have become the standard of care for advanced clear cell renal cell carcinoma (ccRCC), changing the outlook for patients, with several new and promising therapeutic targets under development.
RESUMO
Introduction: Most patients with advanced NSCLC will experience disease progression and death within 2 years. Novel approaches are needed to improve outcomes. Methods: We conducted an open-label, nonrandomized, phase 2 trial in patients with treatment-naive, advanced NSCLC to assess the safety and efficacy of nivolumab 360 mg every 3 weeks, ipilimumab 1 mg/kg every 6 weeks, and four to six cycles of paclitaxel 80 mg/m2 on days 1 and 8 of every 21-day treatment. The primary end point of the study was median progression-free survival (PFS), with secondary end points of safety, objective response rate, and median overall survival (OS). Results: A total of 46 patients underwent consent and received treatment. The median age was 66 (range: 48-82) years, most had adenocarcinoma (63%), and 50% (23) had programmed death-ligand 1 greater than or equal to 1%. The median follow-up on the study as of October 2021 was 19 months. The primary end point of median PFS was 9.4 months (95% confidence interval [CI]: 5.9-16.6) in all patients regardless of programmed death-ligand 1 expression. The objective response rate for patients in the study was 47.8% (95% CI: 33.4-62.3). The 12-month OS rate was 69.5% (95% CI: 53%-81%), and median OS was not yet reached. Treatment-related grade greater than or equal to 3 adverse events was found in 54.3% of the patients. Conclusions: The toxicity observed was consistent with other reported chemo-immunotherapeutic combinations and was manageable. The primary end point of exceeding median PFS of 9 months was achieved with nivolumab, ipilimumab, and weekly paclitaxel and should be evaluated further in a randomized trial.
RESUMO
The NCCN Guidelines for Kidney Cancer focus on the screening, diagnosis, staging, treatment, and management of renal cell carcinoma (RCC). Patients with relapsed or stage IV RCC typically undergo surgery and/or receive systemic therapy. Tumor histology and risk stratification of patients is important in therapy selection. The NCCN Guidelines for Kidney Cancer stratify treatment recommendations by histology; recommendations for first-line treatment of ccRCC are also stratified by risk group. To further guide management of advanced RCC, the NCCN Kidney Cancer Panel has categorized all systemic kidney cancer therapy regimens as "Preferred," "Other Recommended Regimens," or "Useful in Certain Circumstances." This categorization provides guidance on treatment selection by considering the efficacy, safety, evidence, and other factors that play a role in treatment selection. These factors include pre-existing comorbidities, nature of the disease, and in some cases consideration of access to agents. This article summarizes surgical and systemic therapy recommendations for patients with relapsed or stage IV RCC.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/terapia , Humanos , Neoplasias Renais/diagnóstico , Neoplasias Renais/terapia , OncologiaRESUMO
PURPOSE: To evaluate the safety and efficacy of gemcitabine and cisplatin in combination with the immune checkpoint inhibitor pembrolizumab as neoadjuvant therapy before radical cystectomy (RC) in muscle-invasive bladder cancer. METHODS: Patients with clinical T2-4aN0/XM0 muscle-invasive bladder cancer eligible for RC were enrolled. The initial six patients received lead-in pembrolizumab 200 mg once 2 weeks prior to pembrolizumab 200 mg once on day 1, cisplatin 70 mg/m2 once on day 1, and gemcitabine 1,000 mg/m2 once on days 1 and 8 every 21 days for four cycles. This schedule was discontinued for toxicity and subsequent patients received cisplatin 35 mg/m2 once on days 1 and 8 without lead-in pembrolizumab. The primary end point was pathologic downstaging (< pT2N0) with null and alternative hypothesis rates of 35% and 55%, respectively. Secondary end points were toxicity including patient-reported outcomes, complete pathologic response (pT0N0), event-free survival, and overall survival. Association of pathologic downstaging with programmed cell death ligand 1 staining was explored. RESULTS: Thirty-nine patients were enrolled between June 2016 and March 2020 (72% cT2, 23% cT3, and 5% cT4a). Patients received a median of four cycles of therapy. All patients underwent RC except one who declined. Twenty-two of 39 patients (56% [95% CI, 40 to 72]) achieved < pT2N0 and 14 of 39 (36% [95% CI, 21 to 53]) achieved pT0N0. Most common adverse events (AEs) of any grade were thrombocytopenia (74%), anemia (69%), neutropenia (67%), and hypomagnesemia (67%). One patient had new-onset type 1 diabetes mellitus with ketoacidosis related to pembrolizumab and no patients required steroids for immune-related AEs. Clinicians consistently under-reported AEs when compared with patients. CONCLUSION: Neoadjuvant gemcitabine and cisplatin plus pembrolizumab met its primary end point for improved pathologic downstaging and was generally safe. A global study of perioperative chemotherapy plus pembrolizumab or placebo is ongoing.
Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Cisplatino/administração & dosagem , Cistectomia , Desoxicitidina/análogos & derivados , Inibidores de Checkpoint Imunológico/administração & dosagem , Terapia Neoadjuvante , Neoplasias da Bexiga Urinária/terapia , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Quimioterapia Adjuvante , Cisplatino/efeitos adversos , Cistectomia/efeitos adversos , Cistectomia/mortalidade , Desoxicitidina/administração & dosagem , Desoxicitidina/efeitos adversos , Progressão da Doença , Feminino , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante/efeitos adversos , Invasividade Neoplásica , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Fatores de Tempo , Neoplasias da Bexiga Urinária/mortalidade , Neoplasias da Bexiga Urinária/patologia , GencitabinaRESUMO
The NCCN Guidelines for Kidney Cancer provide multidisciplinary recommendations for diagnostic workup, staging, and treatment of patients with renal cell carcinoma (RCC). These NCCN Guidelines Insights focus on recent updates to the guidelines, including changes to certain systemic therapy recommendations for patients with relapsed or stage IV RCC. They also discuss the addition of a new section to the guidelines that identifies and describes the most common hereditary RCC syndromes and provides recommendations for genetic testing, surveillance, and/or treatment options for patients who are suspected or confirmed to have one of these syndromes.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/terapia , Testes Genéticos , Humanos , Neoplasias Renais/diagnóstico , Neoplasias Renais/genética , Neoplasias Renais/terapiaRESUMO
BACKGROUND: Pembrolizumab is approved for patients with metastatic, microsatellite instability (MSI)-high or mismatch repair-deficient (dMMR) solid tumors. However, very few men with prostate cancer were included in these initial studies. METHODS: We performed a single institution retrospective review of men with metastatic castrate-resistant prostate cancer (mCRPC) who were treated with pembrolizumab. The primary objective was to describe the clinical efficacy of pembrolizumab associated with patient and genomic characteristics. RESULTS: We identified 48 men who received ≥1 cycle of pembrolizumab for mCRPC. Of these, 94% (45/48) had ≥3 prior lines of therapy for mCRPC. Somatic tumor sequencing was available in 18/48 men (38%). We found that 17% (8/48) had a ≥50% confirmed PSA decline with pembrolizumab, and 8% (4/48) had a ≥90% PSA decline with durations of response ranging from 3.1 to 16.3 months. Two of these four men had mutations in LRP1b, one of whom also had MSH2 loss and was MSI-H and TMB-high. Despite prior progression on enzalutamide, 48% (23/48) of men were treated with concurrent enzalutamide. The median PSA progression-free-survival was 1.8 months (range 0.4-13.7 months), with 31% of patients remaining on pembrolizumab therapy and 54% of men remain alive with a median follow-up of 7.1 months. CONCLUSIONS: In a heavily pretreated population of men with mCRPC, pembrolizumab was associated with a ≥50% PSA decline in 17% (8/48) of men, including a dramatic ≥90% PSA response in 8% (4/48), two of whom harbored pathogenic LRP1b mutations suggesting that LRP1b mutations may enrich for PD-1 inhibitor responsiveness in prostate cancer.
Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos Imunológicos/administração & dosagem , Calicreínas/efeitos dos fármacos , Antígeno Prostático Específico/efeitos dos fármacos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Análise de Sequência de DNA/métodos , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais Humanizados/farmacologia , Antineoplásicos Imunológicos/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 2 Homóloga a MutS/genética , Mutação , Metástase Neoplásica , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores de LDL/genética , Estudos Retrospectivos , Análise de Sobrevida , Resultado do TratamentoAssuntos
Neoplasias Encefálicas/secundário , Neoplasias Encefálicas/terapia , Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Neoplasias Encefálicas/diagnóstico , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Gerenciamento Clínico , Humanos , Resultado do TratamentoRESUMO
BACKGROUND: Platinum-based chemotherapy is effective in men with neuroendocrine prostate cancer (NEPC), but it is unclear whether histology (adenocarcinoma vs. non-adenocarcinoma NEPC variants) is predictive of platinum sensitivity. Given that NEPC exists as a spectrum, there may be men with adenocarcinoma who might benefit from platinum chemotherapy, particularly those men with DNA repair defects. METHODS: This was a retrospective study of all of the men seen at Duke University since 2005 who had metastatic castration-resistant prostate cancer (mCRPC) and were treated with a platinum agent. Data surrounding clinical features, histology, imaging, safety, and neuroendocrine transformation were collected. Scans were re-reviewed using RECIST v1.1 criteria to estimate responses as well as calculate radiographic progression-free survival (rPFS). RESULTS: A database search identified 73 men with mCRPC treated with cisplatin, carboplatin, or oxaliplatin. There were three men with primary NEPC and small cell prostate cancer, and 14 with a NEPC transformation. In the first-line setting, 10 (63%) men with NEPC had a partial response (PR) compared with 14 (29%) of the men with adenocarcinoma (p = 0.017), with a median rPFS of 5.1 mo (3.1-7.8) and 4.3 mo (3.0-5.2 mo), respectively. The median overall survival was 8.5 mo (6.4-20.1 mo) for men with NEPC compared to 10.0 mo (8.0-14.4) in men with adenocarcinoma. Prostate-specific antigen (PSA) declines meeting >30%, >50%, and >90% criteria from baseline were observed in 64/57/29% of NEPC patients (n = 14) treated with platinum chemotherapy vs. 48/30/14% of men with prostate adenocarcinoma (n = 50), respectively. CONCLUSIONS: This study suggests that NEPC histology enriches for platinum sensitivity, but that an important minority group (20-30%) of men with adenocarcinoma have a clinical benefit with platinum-based chemotherapy. Molecular predictors, such as germline or somatic mutations in DNA repair enzymes, should be evaluated for platinum responsiveness.
Assuntos
Adenocarcinoma/tratamento farmacológico , Tumores Neuroendócrinos/tratamento farmacológico , Platina/efeitos adversos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Adenocarcinoma/sangue , Adenocarcinoma/patologia , Idoso , Progressão da Doença , Intervalo Livre de Doença , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/sangue , Tumores Neuroendócrinos/patologia , Platina/administração & dosagem , Próstata/efeitos dos fármacos , Próstata/patologia , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/patologia , Resultado do TratamentoRESUMO
PURPOSE: Evidence suggests differences in androgen receptor AR signaling between black (B) and white (W) patients with prostate cancer, but pivotal trials of abiraterone acetate (AA) for patients with metastatic castration-resistant prostate cancer (mCRPC) enrolled few black patients, a population with a higher mortality from prostate cancer. Our primary objective was to determine differences in response to AA between B and W patients. METHODS: We performed a retrospective case-control study of B vs. W patients treated with AA between May 1, 2008 and June 16, 2015 at Duke University Medical Center. Patients were identified (W control patients were matched 2:1 to B patients stratified based on previous docetaxel exposure) through pharmacy records and were eligible if treated with AA for metastatic castration-resistant prostate cancer. Patients with previous enzalutamide use were excluded. The primary objective was to compare the rate of≥90% prostate-specific antigen (PSA) decline from baseline between B vs. W patients. Secondary outcomes included comparing time on therapy, time to PSA progression, and overall survival among groups. RESULTS: Baseline characteristics among patients (n = 45 B, n = 90 W) were identified; these included Karnofsky performance status, PSA, Gleason score, alkaline phosphatase, albumin, hemoglobin, lactate dehydrogenase, opiate use for pain, and metastatic sites. Baseline characteristics among groups were similar except for median hemoglobin (B = 11.4g/dl, W = 12.3g/dl). The proportion of B patients achieving a≥90% PSA level decline was 37.8% vs. 28.9% for W patients (P = 0.296). Statistically significant differences were found in the proportion of patients achieving a≥50% PSA level decline (B = 68.9%, W = 48.9% [P = 0.028]) and≥30% PSA level decline (B = 77.8%, W = 54.4% [P = 0.008]). Rates of primary abiraterone-refractory disease (PSA increase as best response) trended higher in W (31.1%) than in B (15.6%) patients (P = 0.052). Median treatment duration (B = 9.4 mo, W = 8.3 mo) did not differ (Wilcoxon P = 0.444). Median overall survival (B = 27.3 mo [95% CI: 13.9, not estimable], W = 24.8 mo [95% CI: 19, 31.6] [P = 0.669]) and median time to PSA progression (B = 11.0 mo [95% CI: 4.3, 18.0], W = 9.4 mo [95% CI: 6.2, 13.0] [P = 0.917]) did not differ. CONCLUSIONS: Black patients may have a higher PSA response to AA than white patients. An ongoing prospective clinical study (NCT01940276) is evaluating outcomes between black and white patients treated with AA.
Assuntos
Acetato de Abiraterona/uso terapêutico , Calicreínas/sangue , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , População Negra , Estudos de Casos e Controles , Progressão da Doença , Humanos , Masculino , Metástase Neoplásica , Estudos Prospectivos , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/etnologia , Neoplasias de Próstata Resistentes à Castração/patologia , Estudos Retrospectivos , População BrancaRESUMO
Atezolizumab (Tecentriq, MPDL3280A; Genentech/Roche) is an FcγR binding-deficient, fully humanized IgG1 mAb designed to interfere with the binding of PD-L1 ligand to its two receptors, PD-1 and B7.1. By blocking the PD-L1/PD-1 immune checkpoint, atezolizumab reduces immunosuppressive signals found within the tumor microenvironment and, consequently, increases T-cell-mediated immunity against the tumor. Atezolizumab has been FDA approved as second-line therapy for advanced bladder cancer. This accelerated approval was based on phase II trial data in patients with metastatic bladder cancer that showed unexpected and durable tumor responses. In subjects whose tumors progressed on first-line platinum-based chemotherapy, the objective response rate was 15%, the complete response rate was 5%, and 1-year overall survival was 36%. In subjects that were chemotherapy naïve and cisplatin ineligible, the objective response rate was 24%, the complete response rate was 7%, and 1-year overall survival was 57%. Better responses were associated with higher PD-L1 expression on the tumor-infiltrating leukocytes. These data suggest that patients with advanced bladder cancer treated with atezolizumab have significantly better response rates and survival than historical controls treated with other second-line regimens. The toxicity profile of atezolizumab is also favorable. Trials are currently assessing whether atezolizumab is effective in earlier bladder cancer stages and in the first-line metastatic setting. Clin Cancer Res; 23(8); 1886-90. ©2016 AACR.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Carcinoma de Células de Transição/tratamento farmacológico , Neoplasias da Bexiga Urinária/tratamento farmacológico , Anticorpos Monoclonais Humanizados , HumanosRESUMO
Here we present, to the best of our knowledge, the first case of a paraneoplastic Cushing's syndrome (hypercortisolism) resulting from treatment-related neuroendocrine prostate cancer - a highly aggressive and difficult disease to treat. A 51-year-old man was started on androgen deprivation therapy after presenting with metastatic prostate cancer, characterized by diffuse osseous metastasis. Shortly thereafter, he developed progressive disease with biopsy proven neuroendocrine prostate cancer as well as symptoms of increased skin pigmentation, hypokalemia, hypertension, hyperglycemia and profound weakness, consistent with ectopic Cushing's syndrome. Molecular analysis of the patient's tumor through RNA sequencing showed high expression of several genes including CHGA, ASCL1, CALCA, HES6, PCSK1, CALCB and INSM1 confirming his neuroendocrine phenotype; elevated POMC expression was found, supporting the diagnosis of ectopic Cushing's syndrome.
Assuntos
Síndrome de Cushing/etiologia , Síndromes Paraneoplásicas , Neoplasias da Próstata/tratamento farmacológico , Expressão Gênica , Humanos , Hiperglicemia , Masculino , Pessoa de Meia-Idade , Segunda Neoplasia PrimáriaRESUMO
The use of targeted therapies in patients with genitourinary malignancies has significantly improved outcomes. For example, androgen receptor (AR) pathway inhibitors have improved outcomes for patients with prostate cancer, and antiangiogenic agents have improved outcomes for those with kidney cancer. However, these advances have been accompanied by musculoskeletal side effects that manifest as physical dysfunction. Although the effects of androgen deprivation therapy on skeletal muscle are well-known, an additional concern is that the muscle loss associated with these newer drugs-especially AR pathway inhibitors-may result in insulin resistance and metabolic syndrome, thus increasing the risk for cardiovascular events and diabetes. Antiangiogenic agents also may cause muscle loss, although this has been poorly described in the literature. As these targeted therapies begin to be used in the earlier stages of treatment, there will be a critical need to prevent treatment-related toxicities with nonpharmacologic interventions. Over the past decade, exercise training has emerged as a novel nonpharmacologic adjunctive method to address toxicities resulting from these targeted therapies. Despite numerous studies in patients with prostate cancer, there remains a large gap in our knowledge of the true efficacy of exercise therapy, as well as the best way to prescribe exercise programs. Here, we suggest that the central role of skeletal muscle in the development of side effects of AR pathway inhibitors and antiangiogenic agents may unlock a number of unique opportunities to study how exercise prescriptions can be used more effectively. Resistance training may be a particularly important modality.
Assuntos
Transtornos Musculares Atróficos/etiologia , Transtornos Musculares Atróficos/terapia , Treinamento Resistido , Neoplasias Urogenitais/complicações , Antagonistas de Androgênios/efeitos adversos , Antagonistas de Androgênios/uso terapêutico , Antineoplásicos Hormonais/efeitos adversos , Antineoplásicos Hormonais/uso terapêutico , Humanos , Terapia de Alvo Molecular , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Estadiamento de Neoplasias , Inibidores de Proteínas Quinases/uso terapêutico , Resultado do Tratamento , Neoplasias Urogenitais/diagnóstico , Neoplasias Urogenitais/tratamento farmacológico , Neoplasias Urogenitais/mortalidadeRESUMO
A number of observational studies and clinical trials have shown that physical activity after a diagnosis of prostate cancer is associated with a decrease in disease progression and an increase in survival, and that specific exercises reduce morbidity from prostate cancer treatments. However, providers need more guidance on what types of physical activity to recommend to patients across different disease states and treatments in prostate cancer, and when and how to initiate the discussion. In addition to evaluating important studies showing benefits of physical activity in patients with prostate cancer, this review suggests some evidence-based methods for incorporating physical activity interventions into clinical practice.
Assuntos
Antineoplásicos/uso terapêutico , Atividade Motora , Prostatectomia , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/terapia , Antineoplásicos/efeitos adversos , Progressão da Doença , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Medicina Baseada em Evidências , Humanos , Masculino , Complicações Pós-Operatórias/prevenção & controle , Prostatectomia/efeitos adversos , Prostatectomia/mortalidade , Neoplasias da Próstata/mortalidade , Lesões por Radiação/prevenção & controle , Radioterapia/efeitos adversos , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
The p53 transcription factor and tumor suppressor is regulated primarily by the E3 ubiquitin ligase Mdm2, which ubiquitinates p53 to target it for proteasomal degradation. Aside from its ubiquitin ligase function, Mdm2 has been believed to be capable of suppressing p53's transcriptional activity by binding with and masking the transactivation domain of p53. The ability of Mdm2 to restrain p53 activity by binding alone, without ubiquitination, was challenged by a 2007 study using a knockin mouse harboring a single cysteine-to-alanine point mutation (C462A) in Mdm2's RING domain. Mouse embryonic fibroblasts with this mutation, which abrogates Mdm2's E3 ubiquitin ligase activity without affecting its ability to bind with p53, were unable to suppress p53 activity. In this study, we utilized the Mdm2(C462A) mouse model to characterize in further detail the role of Mdm2's RING domain in the control of p53. Here, we show in vivo that the Mdm2(C462A) protein not only fails to suppress p53, but compared to the complete absence of Mdm2, Mdm2(C462A) actually enhances p53 transcriptional activity toward p53 target genes p21/CDKN1A, MDM2, BAX, NOXA, and 14-3-3σ. In addition, we found that Mdm2(C462A) facilitates the interaction between p53 and the acetyltransferase CBP/p300, and it fails to heterodimerize with its homolog and sister regulator of p53, Mdmx, suggesting that a fully intact RING domain is required for Mdm2's inhibition of the p300-p53 interaction and for its interaction with Mdmx. These findings help us to better understand the complex regulation of the Mdm2-p53 pathway and have important implications for chemotherapeutic agents targeting Mdm2, as they suggest that inhibition of Mdm2's E3 ubiquitin ligase activity may be sufficient for increasing p53 activity in vivo, without the need to block Mdm2-p53 binding.
Assuntos
Proteína p300 Associada a E1A/metabolismo , Mutação , Proteínas Proto-Oncogênicas c-mdm2/química , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Domínios RING Finger/genética , Transcrição Gênica , Proteína Supressora de Tumor p53/metabolismo , Animais , Linhagem Celular , Inibidor de Quinase Dependente de Ciclina p21/genética , Camundongos , Regiões Promotoras Genéticas/genética , Ligação Proteica , Proteínas Proto-Oncogênicas c-mdm2/genéticaRESUMO
Conventional molecular biology techniques have identified a large number of cell signaling pathways; however, the importance of these pathways often varies, depending on factors such as treatment type, dose, time after treatment, and cell type. Here, we describe a technique using "reverse-phase" protein lysate microarrays (RPAs) to acquire multiple dimensions of information on protein dynamics in response to DNA damage. Whole-cell lysates from three cellular stress treatments (IR, UV, and ADR) were collected at four doses per treatment, and each, in turn, at 10 time points, resulting in a single-slide RPA consisting of 10,240 features, including replicates. The dynamic molecular profile of 18 unique protein species was compared to phenotypic fate by FACS analysis for corresponding stress conditions. Our initial quantitative results in this new platform confirmed that (1) there is clear stress dose-response effect in p53 protein and (2) a comparison of the rates of increase of p21 and Cyclin D3/p53-Ser15 in response to DNA damage may be associated with the pattern of DNA content. This method, offering a quantitative time-course monitoring of protein expression levels, can provide an experimental reference for developing mathematical models of cell signaling dynamics. Although the present study focuses on the DNA damage-repair pathway, the technique is generally useful to the study of protein signaling.
Assuntos
Dano ao DNA/fisiologia , Proteínas/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , DNA/metabolismo , Reparo do DNA/fisiologia , Células HCT116 , Humanos , Análise Serial de Proteínas , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/metabolismoRESUMO
Mathematical simulations of the p53-Mdm2 feedback loop suggest that both proteins will exhibit impulsive expression characteristics in response to high cellular stress levels. However, little quantitative experimental evaluation has been done, particularly of the phosphorylated forms. To evaluate the mathematical models experimentally, we used lysate microarrays from an isogenic pair of gamma-ray-irradiated cell lysates from HCT116 (p53(+/+) and p53(-/-)). Both p53 and Mdm2 proteins showed expected pulses in the wild type, whereas no pulses were seen in the knockout. Based on experimental observations, we determined model parameters and generated an in silico "knockout," reflecting the experimental data, including phosphorylated proteins.