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1.
Oncologist ; 27(12): e938-e948, 2022 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-36190331

RESUMO

BACKGROUND: Ramucirumab is indicated for patients with advanced hepatocellular carcinoma (HCC) and α-fetoprotein (AFP) ≥400 ng/mL following sorafenib. Here, we prospectively studied ramucirumab following non-sorafenib systemic therapies. MATERIALS AND METHODS: This open-label, non-comparative cohort of REACH-2 enrolled patients with advanced HCC, Child-Pugh class-A liver disease, and AFP ≥400 ng/mL who had received 1-2 lines of therapy, excluding sorafenib or chemotherapy. Ramucirumab was administered 8 mg/kg intravenously Q2W. The primary endpoint was safety. Secondary endpoints were overall survival, progression-free survival, objective response rate (RECIST v1.1), time to progression, pharmacokinetics, and patient-reported outcomes. Final analysis occurred after all enrolled patients completed ≥3 treatment cycles or discontinued treatment. RESULTS: Between April 27, 2018, and March 29, 2021, 47 patients were treated at 21 investigative sites in Asia, Europe, and USA. The most frequently reported grade ≥3 adverse events, regardless of causality, were hypertension (11%), proteinuria (6%), hyponatremia (6%), and AST increased (6%). Two patients died from adverse events (myocardial infarction and upper gastrointestinal hemorrhage), deemed related to treatment. Median progression-free survival, time to progression, and overall survival were 1.7 months, 2.8 months, and 8.7 months, respectively. The objective response rate was 10.6% with a median duration response of 8.3 months. Median time to deterioration in FHSI-8 total score was 4.4 months. CONCLUSION: Ramucirumab demonstrated consistent and meaningful clinical activity with no new safety signals following non-sorafenib therapies in patients with advanced HCC and AFP ≥400 ng/mL. This represents one of the first sequencing studies for patients with advanced HCC not treated with sorafenib.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Sorafenibe/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , alfa-Fetoproteínas , Neoplasias Hepáticas/tratamento farmacológico , Europa (Continente)
2.
EClinicalMedicine ; 54: 101679, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36247923

RESUMO

Background: In the global REACH-2 study, ramucirumab significantly improved overall survival (OS) compared with placebo in patients with advanced hepatocellular carcinoma (HCC) and elevated alpha-fetoprotein (AFP). REACH-2 China study aimed to evaluate the efficacy and safety of ramucirumab in Chinese patients with advanced HCC (NCT02435433). Methods: REACH-2 China was a randomised, double-blind, placebo-controlled, phase 3 study done at 31 centres in China between Sep 16, 2015, and March 15, 2021. Patients with advanced HCC and AFP ≥400 ng/mL after first-line sorafenib were randomly assigned (2:1) to receive ramucirumab 8 mg/kg intravenously or placebo Q2W, until disease progression or unacceptable toxicity. The primary endpoint was OS. Efficacy was assessed per intention-to-treat, and safety in patients who received any treatment. Findings: Of 104 Chinese patients enrolled (44 in the global study and 60 in the China extension study), 70 received ramucirumab and 34 received placebo. Median OS was 9·1 months in the ramucirumab group and 6·2 months in the placebo group (HR = 0·854 [95% CI: 0·536, 1·359]). The most common grade 3 or worse treatment-emergent adverse event were hypertension (5 [7·1%] of 70 patients in the ramucirumab group vs 1 [2.9%] of 34 in the placebo group), pneumonia (5 [7·1%] vs 1 [2·9%]), and hyponatraemia (4 [5·7%] vs 0 [0%]). Interpretation: Ramucirumab demonstrated clinically meaningful improvement in OS compared to placebo for Chinese patients with advanced HCC and elevated AFP, although lacking statistical superiority. Ramucirumab was well tolerated, with a manageable safety profile. The results are consistent with those of the global REACH-2 study, supporting a favourable risk-benefit profile for ramucirumab in this population. Funding: Eli Lilly and Company, USA.

3.
Immunotherapy ; 14(16): 1341-1351, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36285590

RESUMO

Aim: The authors investigated surrogacy of radiology-based end points for clinical trials investigating immune checkpoint inhibitors in advanced hepatocellular carcinoma. Methods: Data were collected from electronic databases reporting median overall survival (OS), median progression-free survival (PFS) and objective response rate (ORR). Weighted Pearson correlation coefficients and 95% confidence intervals (CIs) were calculated. Results: 26 clinical trials (41 treatment arms, 5144 patients) were included. ORR (coefficient: 0.71; 95% CI: 0.52-0.84) and PFS (coefficient: 0.63; 95% CI: 0.21-0.92) were positively correlated with OS. Sensitivity analyses suggested liver function, line of therapy and study phase did not greatly impact results. The COSMIC-312 study negatively impacted the overall weighted correlation. Conclusion: ORR and PFS are positively correlated with OS in patients with advanced hepatocellular carcinoma.


This study was conducted to determine how effective measurements of tumor size are at predicting how long patients with liver cancer survive when they receive a drug that blocks proteins involved in immune system regulation, which are made by some types of immune system cells in the body. The authors calculated how closely measurements of a patient's tumor were related to survival by examining data from 26 separate clinical trials that included more than 5000 patients. This study showed measurements of tumor size and the response (shrinkage, growth or no change in size) to checkpoint inhibitor drugs were likely to be related to the length of survival. This information is important for designing future clinical trials and may help speed the delivery of effective medicines to patients with liver cancer.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Intervalo Livre de Progressão , Biomarcadores
4.
Clin Cancer Res ; 28(11): 2297-2305, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35247922

RESUMO

PURPOSE: Ramucirumab is an effective treatment for patients with advanced hepatocellular carcinoma (aHCC) and baseline alpha-fetoprotein (AFP) ≥400 ng/mL. We aimed to identify prognostic and predictive factors of response to ramucirumab in patients with aHCC with AFP ≥400 ng/mL from the phase III REACH and REACH-2 randomized trials. PATIENTS AND METHODS: Patients with aHCC, Child-Pugh class A with prior sorafenib treatment were randomized in REACH and REACH-2 (ramucirumab 8 mg/kg or placebo, biweekly). Meta-analysis of individual patient-level data (pooled population) from REACH (AFP ≥400 ng/mL) and REACH-2 was performed. A drug exposure analysis was conducted for those with evaluable pharmacokinetic data. To identify potential prognostic factors for overall survival (OS), multivariate analyses were performed using a Cox proportional hazards regression model. To define predictors of ramucirumab benefit, subgroup-by-treatment interaction terms were evaluated. RESULTS: Of 542 patients (316 ramucirumab, 226 placebo) analyzed, eight variables had independent prognostic value associated with poor outcome (geographical region, Eastern Cooperative Oncology Group performance score ≥1, AFP >1,000 ng/mL, Child-Pugh >A5, extrahepatic spread, high neutrophil-to-lymphocyte ratio, high alkaline phosphatase and aspartate aminotransferase). Ramucirumab survival benefit was present across all subgroups, including patients with very aggressive HCC [above median AFP; HR: 0.64; 95% confidence interval (CI): 0.49-0.84] and nonviral aHCC (HR: 0.56; 95% CI: 0.40-0.79). While no baseline factor was predictive of a differential OS benefit with ramucirumab, analyses demonstrated an association between high drug exposure, treatment-emergent hypertension (grade ≥3), and increased ramucirumab benefit. CONCLUSIONS: Ramucirumab provided a survival benefit irrespective of baseline prognostic covariates, and this benefit was greatest in patients with high ramucirumab drug exposure and/or those with treatment-related hypertension.


Assuntos
Carcinoma Hepatocelular , Hipertensão , Neoplasias Hepáticas , Anticorpos Monoclonais Humanizados , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/patologia , Ensaios Clínicos Fase III como Assunto , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , alfa-Fetoproteínas , Ramucirumab
5.
Liver Cancer ; 10(5): 451-460, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34721507

RESUMO

BACKGROUND: Intermediate-stage hepatocellular carcinoma (HCC), as defined by Barcelona Clinic Liver Cancer (BCLC) stage B, is heterogeneous in terms of liver function and tumor burden. REACH and REACH-2 investigated ramucirumab in patients with HCC after prior sorafenib, with REACH-2 enrolling only patients with baseline α-fetoprotein (AFP) ≥400 ng/mL. An exploratory analysis of outcomes by BCLC stage was performed. METHODS: A pooled meta-analysis of independent patient data (stratified by study) from REACH (AFP ≥ 400 ng/mL) and REACH-2 was performed. All patients had Child-Pugh A, Eastern Cooperative Oncology Group performance status 0-1, prior sorafenib treatment, and either HCC BCLC stage B (refractory/not amenable to locoregional therapy) or BCLC stage C. Patients were randomized to ramucirumab 8 mg/kg or placebo every 2 weeks. Median overall survival (OS) and progression-free survival were estimated by the Kaplan-Meier method. Treatment effects in BCLC stage B and C were evaluated by Cox proportional-hazards model; prognosis of BCLC staging for OS was evaluated by multivariate Cox proportional-hazards model. Tumor responses were evaluated according to Response Evaluation in Solid Tumors v1.1. Liver function was assessed with albumin-bilirubin score. RESULTS: Baseline characteristics were generally balanced between treatment arms in each BCLC stage. BCLC staging trended as an independent prognostic factor for OS (B vs. C; hazard ratio [HR] 0.756 [95% CI 0.546-1.046]). Consistent treatment benefit was observed for ramucirumab versus placebo across BCLC stages. Median OS for ramucirumab versus placebo was 13.7 versus 8.2 months; HR (95%): 0.43 (0.23-0.83) and 7.7 versus 4.8 months; HR (95%): 0.72 (0.59-0.89) for BCLC stage B and C, respectively. Adverse events (AEs) were consistent with observations from both studies; hypertension was the most frequent grade ≥3 AE. Liver function was preserved throughout the study and similar between treatment arms in both BCLC stages. CONCLUSIONS: Ramucirumab provided a better survival benefit irrespective of BCLC stage and was well tolerated without compromising liver function during treatment.

6.
Liver Int ; 41(11): 2759-2767, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34173317

RESUMO

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) is a common complication of chronic liver disease with diverse underlying aetiologies. REACH/REACH-2 were global phase III studies investigating ramucirumab in advanced HCC (aHCC) following sorafenib treatment. We performed an exploratory analysis of outcomes by liver disease aetiology and baseline serum viral load. METHODS: Meta-analysis was conducted in patients with aHCC and alpha-fetoprotein (AFP) ≥400 ng/mL (N = 542) from REACH/REACH-2 trials. Individual patient-level data were pooled with results reported by aetiology subgroup (hepatitis B [HBV] or C [HCV] and Other). Pre-treatment serum HBV DNA and HCV RNA were quantified using Roche COBAS AmpliPrep/COBAS TaqMan. Overall survival (OS) and progression-free survival (PFS) were evaluated using the Kaplan-Meier method and Cox proportional hazard model (stratified by study). RESULTS: Baseline characteristics were generally balanced between arms in each subgroup (HBV: N = 225, HCV: N = 127, Other: N = 190). No significant difference in treatment effect by aetiology subgroup was detected (OS interaction P-value = .23). Median OS (ramucirumab vs placebo) in months was 7.7 versus 4.5 (HR 0.74, 95% CI 0.55-0.99) for HBV, 8.2 versus 5.5 (HR 0.82, 95% CI 0.55-1.23) for HCV and 8.5 versus 5.4 (HR 0.56, 95% CI 0.40-0.79) for Other. Ramucirumab showed similar overall safety profiles across subgroups. Worst outcomes were noted in patients with a detectable HBV load. Use of HBV antiviral therapy, irrespective of viral load, was beneficial for survival, liver function and liver-specific adverse events. CONCLUSIONS: Ramucirumab improved survival across aetiology subgroups with a tolerable safety profile, supporting its use in patients with aHCC and elevated AFP.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Anticorpos Monoclonais Humanizados/efeitos adversos , Carcinoma Hepatocelular/tratamento farmacológico , Ensaios Clínicos Fase III como Assunto , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Ramucirumab
7.
Hepatol Res ; 51(6): 715-721, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33743189

RESUMO

AIM: The REACH and REACH-2 trials investigated ramucirumab versus placebo in patients with advanced hepatocellular carcinoma (HCC). Ascites is common in HCC and is associated with poorer outcomes. This exploratory, pooled meta-analysis of patients with baseline α-fetoprotein (AFP) ≥400 ng/ml investigated outcomes by treatment-emergent (TE) ascites in REACH and REACH-2. METHODS: A pooled meta-analysis of independent patient data for participants (N = 542) with baseline AFP ≥400 ng/ml (stratified by study) from REACH and REACH-2 was carried out. Overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan-Meier estimator, and OS further assessed by Cox models. The effect of TE ascites on OS was evaluated by multivariate Cox models. RESULTS: Treatment-emergent ascites developed in 66 patients (20.9%) in the ramucirumab group and 33 patients (14.8%) in the placebo group. When adjusted for treatment duration, the incidence rates per 100 patient-years of any grade TE ascites were 59.1 and 71.9 for the ramucirumab and placebo groups, respectively, and the incidence of grade ≥3 TE ascites were 13.4 and 19.6, respectively. Treatment-emergent ascites was associated with TE hypoalbuminemia (odds ratio 4.9; 95% confidence interval 2.5-9.3), but not TE proteinuria or hypertension. One patient discontinued ramucirumab treatment due to TE ascites. Ramucirumab treatment improved OS and PFS compared with placebo, irrespective of TE ascites. CONCLUSIONS: When adjusted for treatment duration, the incidence of TE ascites was no higher in patients who received ramucirumab than in those who received placebo. Ramucirumab was well tolerated and provided a survival benefit irrespective of the development of TE ascites.

8.
Br J Cancer ; 124(8): 1388-1397, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33531690

RESUMO

BACKGROUND: Post hoc analyses assessed the prognostic and predictive value of baseline alpha-fetoprotein (AFP), as well as clinical outcomes by AFP response or progression, during treatment in two placebo-controlled trials (REACH, REACH-2). METHODS: Serum AFP was measured at baseline and every three cycles. The prognostic and predictive value of baseline AFP was assessed by Cox regression models and Subpopulation Treatment Effect Pattern Plot method. Associations between AFP (≥ 20% increase) and radiographic progression and efficacy were assessed. RESULTS: Baseline AFP was confirmed as a continuous (REACH, REACH-2; p < 0.0001) and dichotomous (≥400 vs. <400 ng/ml; REACH, p < 0.01) prognostic factor, and was predictive for ramucirumab survival benefit in REACH (p = 0.0042 continuous; p < 0.0001 dichotomous). Time to AFP (hazard ratio [HR] 0.513; p < 0.0001) and radiographic (HR 0.549; p < 0.0001) progression favoured ramucirumab. Association between AFP and radiographic progression was shown for up to 6 (odds ratio [OR] 5.1; p < 0.0001) and 6-12 weeks (OR 1.8; p = 0.0065). AFP response was higher with ramucirumab vs. placebo (p < 0.0001). Survival was longer in patients with an AFP response than patients without (13.6 vs. 5.6 months, HR 0.451; 95% confidence interval, 0.354-0.574; p < 0.0001). CONCLUSIONS: AFP is an important prognostic factor and a predictive biomarker for ramucirumab survival benefit. AFP ≥ 400 ng/ml is an appropriate selection criterion for ramucirumab. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, REACH (NCT01140347) and REACH-2 (NCT02435433).


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos/administração & dosagem , Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , alfa-Fetoproteínas/metabolismo , Anticorpos Monoclonais Humanizados/farmacologia , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/metabolismo , Prognóstico , Análise de Sobrevida , Resultado do Tratamento , Regulação para Cima , Ramucirumab
9.
JHEP Rep ; 3(2): 100215, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33392490

RESUMO

BACKGROUND & AIMS: The albumin-bilirubin (ALBI) grade/score is derived from a validated nomogram to objectively assess prognosis and liver function in patients with hepatocellular carcinoma (HCC). In this post hoc analysis, we assessed prognosis in terms of survival by baseline ALBI grade and monitored liver function during treatment with ramucirumab or placebo using the ALBI score in patients with advanced HCC. METHODS: Patients with advanced HCC, Child-Pugh class A with prior sorafenib treatment were randomised in REACH trials to receive ramucirumab 8 mg/kg or placebo every 2 weeks. Data were analysed by trial and as a meta-analysis of individual patient-level data (pooled population) from REACH (alpha-fetoprotein ≥400 ng/ml) and REACH-2. Patients from REACH with Child-Pugh class B were analysed as a separate cohort. The ALBI grades and scores were calculated at baseline and before each treatment cycle. RESULTS: Baseline characteristics by ALBI grade were balanced between treatment arms among patients in the pooled population (ALBI-1, n = 231; ALBI-2, n = 296; ALBI-3, n = 7). Baseline ALBI grade was prognostic for overall survival (OS; ALBI grade 2 vs. 1; hazard ratio [HR]: 1.38 [1.13-1.69]), after adjusting for other significant prognostic factors. Mean ALBI scores remained stable in both treatment arms compared with baseline and were unaffected by baseline ALBI grade, macrovascular invasion, tumour response, geographical region, or prior locoregional therapy. Baseline ALBI grades 2 and 3 were associated with increased incidence of liver-specific adverse events and discontinuation rates in both treatments. Ramucirumab improved OS in patients with baseline ALBI grade 1 (HR 0.605 [0.445-0.824]) and ALBI grade 2 (HR 0.814 [0.630-1.051]). CONCLUSIONS: Compared with placebo, ramucirumab did not negatively impact liver function and improved survival irrespective of baseline ALBI grade. LAY SUMMARY: Hepatocellular carcinoma is the third leading cause of cancer-related death worldwide. Prognosis is affected by many clinical factors including liver function both before and during anticancer treatment. Here we have used a validated approach to assess liver function using 2 laboratory parameters, serum albumin and bilirubin (ALBI), both before and during treatment with ramucirumab in 2 phase III placebo-controlled studies. We confirm the practicality of using this more simplistic approach in assessing liver function prior to and during anticancer therapy, and demonstrate ramucirumab did not impair liver function when compared with placebo.

10.
Liver Int ; 41(3): 598-607, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33188713

RESUMO

BACKGROUND & AIMS: Radiological progression patterns to first-line sorafenib have been associated with post-progression and overall survival in advanced hepatocellular carcinoma, but these associations remain unknown for therapies in second- and later-line settings. This post hoc analysis of REACH and REACH-2 examined outcomes by radiological progression patterns in the second-line setting of patients with advanced hepatocellular carcinoma treated with ramucirumab or placebo. METHODS: Patients with advanced hepatocellular carcinoma, Child-Pugh A and Eastern Cooperative Oncology Group Performance Status 0 or 1 with prior sorafenib were randomized to receive ramucirumab 8mg/kg or placebo every 2 weeks. Among 625 patients with ≥1 progression pattern (new extrahepatic lesion [including new macrovascular invasion], new intrahepatic lesion, extrahepatic growth or intrahepatic growth), data were analysed by trial and for pooled individual patient data for REACH-2 and REACH (alpha-fetoprotein ≥400 ng/mL). Cox models evaluated prognostic implications of progression patterns on overall and post-progression survival. RESULTS: Post-progression survival was worse among those with new extrahepatic lesions in REACH (HR 2.33, 95% CI 1.51-3.60), REACH-2 (HR 1.49, 95% CI 0.72-3.08) and the pooled population (HR 1.75, 95% CI 1.12-2.74) compared to other progression patterns. Overall survival was also significantly reduced in those with new extrahepatic lesions across studies. Ramucirumab provided an overall survival benefit across progression patterns, including patients with new extrahepatic lesions (HR 0.56, 95% CI 0.39-0.80) in the pooled population. CONCLUSIONS: The emergence of new extrahepatic lesions in the second-line setting is a poor prognostic factor for post-progression survival. The benefit of ramucirumab for overall survival was consistent across progression patterns.


Assuntos
Anticorpos Monoclonais Humanizados , Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/tratamento farmacológico , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Sorafenibe/uso terapêutico , Resultado do Tratamento , Ramucirumab
11.
Liver Int ; 40(8): 2008-2020, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32279446

RESUMO

BACKGROUND & AIMS: Limited data on treatment of elderly patients with hepatocellular carcinoma (HCC) increase the unmet need. REACH and REACH-2 were global phase III studies of ramucirumab in patients with HCC after prior sorafenib, where patients with alpha-fetoprotein (AFP) ≥400 ng/mL showed an overall ssurvival (OS) benefit for ramucirumab. These post-hoc analyses examined efficacy and safety of ramucirumab in patients with HCC and baseline AFP ≥ 400 ng/mL by three prespecified age subgroups (<65, ≥65 to <75 and ≥75 years). METHODS: Individual patient data were pooled from REACH (baseline AFP ≥400 ng/mL) and REACH-2. Kaplan-Meier and Cox proportional hazards regression methods (stratified by study) assessed OS, progression-free survival (PFS), time to progression (TTP) and patient-reported outcomes (Functional Hepatobiliary System Index-8 [FHSI-8] score). RESULTS: A total of 542 patients (<65 years: n = 302; ≥65 to <75 years: n = 160; ≥75 years: n = 80) showed similar baseline characteristics between ramucirumab and placebo. Older subgroups had higher hepatitis C and steatohepatitis incidences, and lower AFP levels, than the <65 years subgroup. Ramucirumab prolonged OS in patients <65 years (hazard ratio [HR], 0.753; 95% CI 0.581-0.975), ≥65 to <75 years (0.602; 0.419-0.866) and ≥75 years (0.709; 0.420-1.199), PFS and TTP irrespective of age. Ramucirumab showed similar overall safety profiles across subgroups, with a consistent median relative dose intensity ≥97.8%. A trend towards a delay in symptom deterioration in FHSI-8 with ramucirumab was observed in all subgroups. CONCLUSIONS: In this post-hoc analysis, ramucirumab showed a survival benefit across age subgroups with a tolerable safety profile, supporting its use in advanced HCC with elevated AFP, irrespective of age, including ≥75 years.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Idoso , Anticorpos Monoclonais Humanizados , Carcinoma Hepatocelular/tratamento farmacológico , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Sorafenibe , Resultado do Tratamento , alfa-Fetoproteínas , Ramucirumab
12.
Lancet Oncol ; 20(8): 1109-1123, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31301962

RESUMO

BACKGROUND: Pre-clinical and clinical evidence suggests that simultaneous blockade of VEGF receptor-2 (VEGFR-2) and PD-1 or PD-L1 enhances antigen-specific T-cell migration, antitumour activity, and has favourable toxicity. In this study, we aimed to assess the safety and preliminary antitumour activity of ramucirumab (an IgG1 VEGFR-2 antagonist) combined with pembrolizumab (an IgG4 PD-1 antagonist) in patients with previously treated advanced gastric or gastro-oesophageal junction adenocarcinoma, non-small-cell lung cancer, or urothelial carcinoma. METHODS: We did a multicohort, non-randomised, open-label, phase 1a/b trial at 16 academic medical centres, hospitals, and clinics in the USA, France, Germany, Spain, and the UK. We enrolled adult patients aged 18 years or older with histologically confirmed gastric or gastro-oesophageal junction adenocarcinoma (cohorts A and B), non-small-cell lung cancer (cohort C), or urothelial carcinoma (cohort D), whose disease had progressed on one or two lines of previous therapy (for those with gastric or gastro-oesophageal junction adenocarcinoma) or one to three lines of previous therapy (for those with non-small-cell lung cancer and urothelial carcinoma) that included platinum (for all tumour types) or fluoropyrimidine or both (for gastric or gastro-oesophageal junction adenocarcinoma). Eligibility criteria included presence of measurable disease and an Eastern Cooperative Oncology Group performance status of 0-1. Patients with previously untreated gastric or gastro-oesophageal junction adenocarcinoma and non-small-cell lung cancer were also enrolled (in two additional separate cohorts); the results for these cohorts will be reported separately. The first 21-day treatment cycle was a dose-limiting toxicity observation period (phase 1a; safety run-in), followed by a phase 1b cohort expansion stage. Pembrolizumab 200 mg was administered intravenously on day 1, and intravenous ramucirumab was administered at 8 mg/kg on days 1 and 8 for cohort A or at 10 mg/kg on day 1 for cohorts B, C, and D, every 3 weeks, until disease progression or other discontinuation criteria were met. The primary endpoint was the safety and tolerability of ramucirumab in combination with pembrolizumab assessed by the incidence of adverse events in both phase 1a and 1b and as dose-limiting toxicities during phase 1a. The safety and activity analysis set included all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, number NCT02443324, and is no longer enrolling patients. FINDINGS: Between July 30, 2015 and June 24, 2016, we enrolled and treated 92 patients (41 with gastric or gastro-oesophageal junction adenocarcinoma, 27 with non-small-cell lung cancer, and 24 with urothelial carcinoma). Median follow-up was 32·8 months (IQR 28·1-33·6). During the first cycle of treatment (phase 1a safety run-in; n=11), one patient with gastro-oesophageal junction adenocarcinoma who received the 8 mg/kg dose of ramucirumab had grade 3 abdominal pain, colitis, hepatitis, interstitial lung disease, and jaundice, and grade 4 cholestasis, and died on treatment on day 40; the death was deemed related to progressive disease. No additional dose-limiting toxicities occurred and the decision was made to maintain the full planned doses of ramucirumab and pembrolizumab in phase 1b (n=81). Treatment-related adverse events occurred in 75 (82%) of 92 patients, the most common of which was fatigue (in 33 patients [36%]), predominantly of grade 1 or 2 severity. 22 patients (24%) had one or more treatment-related adverse events of grade 3 or worse, most commonly hypertension (six patients; 7%) and colitis (five patients; 5%). Serious adverse events occurred in 53 (58%) of 92 patients, and were deemed related to treatment in 22 (24%) patients. The most common treatment-related serious adverse events were abdominal pain in patients with gastric or gastro-oesophageal junction adenocarcinoma (in three [7%] of 41 patients); asthenia and myocardial infarction in patients with non-small-cell lung cancer (two [7%] of 27 patients), and colitis in patients with urothelial carcinoma (two [8%] of 24 patients). Six (7%) of 92 patients discontinued treatment because of treatment-related adverse events, and one death (from pulmonary sepsis in a patient with gastric or gastro-oesophageal junction adenocarcinoma) was deemed related to treatment. The number of patients achieving an objective response was three (7%; 95% CI 1·5-19·9) of 41 in the gastric or gastro-oesophageal junction adenocarcinoma cohort, eight (30%; 13·8-50·2) of 27 in the non-small-cell lung cancer cohort, and three (13%, 2·7-32·4) in the urothelial carcinoma cohort. INTERPRETATION: Ramucirumab in combination with pembrolizumab showed a manageable safety profile with favourable antitumour activity in patients with previously treated advanced gastric or gastro-oesophageal junction adenocarcinoma, non-small-cell lung cancer, and urothelial carcinoma. Our results contribute to the growing evidence that supports dual inhibition of the VEGF-VEGFR2 and PD-1-PD-L1 pathways. This combination could be further explored with or without chemotherapy, especially for patients with tumours for which single-agent checkpoint inhibitors have shown no additional benefit over chemotherapy. FUNDING: Eli Lilly and Company, and Merck and Co.


Assuntos
Adenocarcinoma/tratamento farmacológico , Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos Imunológicos/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma de Células de Transição/tratamento farmacológico , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Antineoplásicos Imunológicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Relação Dose-Resposta a Droga , Neoplasias Esofágicas/tratamento farmacológico , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/tratamento farmacológico , Ramucirumab
13.
Cancer Res ; 79(7): 1465-1479, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30482772

RESUMO

Given the integral role of stimulator of interferon genes (STING, TMEM173) in the innate immune response, its loss or impairment in cancer is thought to primarily affect antitumor immunity. Here we demonstrate a role for STING in the maintenance of cellular homeostasis through regulation of the cell cycle. Depletion of STING in human and murine cancer cells and tumors resulted in increased proliferation compared with wild-type controls. Microarray analysis revealed genes involved in cell-cycle regulation are differentially expressed in STINGko compared with WT MEFs. STING-mediated regulation of the cell cycle converged on NFκB- and p53-driven activation of p21. The absence of STING led to premature activation of cyclin-dependent kinase 1 (CDK1), early onset to S-phase and mitosis, and increased chromosome instability, which was enhanced by ionizing radiation. These results suggest a pivotal role for STING in maintaining cellular homeostasis and response to genotoxic stress. SIGNIFICANCE: These findings provide clear mechanistic understanding of the role of STING in cell-cycle regulation, which may be exploited in cancer therapy because most normal cells express STING, while many tumor cells do not.See related commentary by Gius and Zhu, p. 1295.


Assuntos
Imunidade Inata , Proteínas de Membrana/genética , Animais , Proliferação de Células , Instabilidade Cromossômica , Homeostase , Humanos , Camundongos
14.
Oncologist ; 23(12): 1407-e136, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29853658

RESUMO

LESSONS LEARNED: Ramucirumab plus pembrolizumab revealed no unexpected safety findings in patients with advanced or metastatic biliary tract cancer, which is consistent with reports of other tumor cohorts within this phase Ia/b trial.Ramucirumab plus pembrolizumab did not demonstrate an improvement in overall survival when compared with historical controls in biomarker unselected, heavily pretreated patients with advanced or metastatic biliary tract cancer.Patients with programmed death-ligand 1 (PD-L1)-positive tumors had improved overall survival compared with patients with PD-L1-negative disease. BACKGROUND: Few treatment options exist for patients with advanced biliary tract cancer (BTC) following progression on gemcitabine-cisplatin. Preclinical evidence suggests that simultaneous blockade of vascular endothelial growth factor receptor 2 (VEGFR-2) and programmed death 1 (PD-1) or programmed death-ligand 1 (PD-L1) enhances antitumor effects. We assessed the safety and efficacy of ramucirumab, an IgG1 VEGFR-2 antagonist, with pembrolizumab, an IgG4 PD-1 antagonist, in biomarker-unselected patients with previously treated advanced or metastatic BTC. METHODS: Patients had previously treated advanced or metastatic adenocarcinoma of the gallbladder, intrahepatic and extrahepatic bile ducts, or ampulla of Vater. Ramucirumab 8 mg/kg was administered intravenously on days 1 and 8 with intravenous pembrolizumab 200 mg on day 1 every 3 weeks. The primary endpoint was safety and tolerability of the combination. Secondary endpoints included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). RESULTS: Twenty-six patients were treated at 12 centers in five countries. Hypertension was the most common grade 3 treatment-related adverse event (TRAE), occurring in five patients. One patient experienced a grade 4 TRAE (neutropenia), and no treatment-related deaths occurred. Objective response rate was 4%. Median progression-free survival and overall survival were 1.6 months and 6.4 months, respectively. CONCLUSION: Ramucirumab-pembrolizumab showed limited clinical activity with infrequent grade 3-4 TRAEs in patients with biomarker-unselected progressive BTC.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias dos Ductos Biliares/tratamento farmacológico , Adulto , Idoso , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais Humanizados/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias dos Ductos Biliares/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ramucirumab
15.
Clin Lung Cancer ; 19(3): 213-220.e4, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29317191

RESUMO

BACKGROUND: Despite the likelihood of an initial response to an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), EGFR-mutant non-small-cell lung cancer (NSCLC) patients develop disease progression. Antiangiogenic agents in combination with an EGFR TKI might provide additional benefit in patients with EGFR-mutant NSCLC. In this article we report safety, exposure, and progression-free survival (PFS) results for part A (phase Ib) of RELAY, a randomized, double-blind, phase Ib/III study investigating safety and efficacy of erlotinib (EGFR TKI) with ramucirumab (anti-vascular endothelial growth factor receptor-2 antibody) or placebo in first-line EGFR-mutant stage IV NSCLC. PATIENTS AND METHODS: Eligible patients had untreated stage IV NSCLC, Eastern Cooperative Oncology Group performance status of 0 to 1, and activating EGFR mutation (exon 19 deletion or exon 21 L858R substitution). Patients received ramucirumab 10 mg/kg on day 1 of a repeating 14-day cycle and erlotinib 150 mg/d. Treatment continued until disease progression or unacceptable toxicity. The primary objective was to assess safety and tolerability, in terms of dose-limiting toxicities (DLTs), during the first 2 cycles. RESULTS: Fourteen patients were treated and 12 were evaluable for DLTs. One patient experienced a DLT of Grade 3 elevated alanine aminotransferase during the DLT assessment period. Adverse events were reported in all patients, but were generally mild and manageable. The most common Grade 3 adverse events were hypertension, rash, and diarrhea. No serious or Grade 4 to 5 events occurred. Median PFS was 17.1 months (95% confidence interval, 8.8-not reached). Five patients continue receiving study treatment. CONCLUSION: Ramucirumab with erlotinib showed no unexpected toxicities and encouraging clinical activity in part A. Phase III enrollment has been initiated, maintaining ramucirumab 10 mg/kg every 2 weeks with erlotinib 150 mg/d.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Anticorpos Monoclonais/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Inibidores da Angiogênese/efeitos adversos , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Método Duplo-Cego , Receptores ErbB/genética , Cloridrato de Erlotinib/administração & dosagem , Feminino , Humanos , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Mutação , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Ramucirumab
16.
Lancet ; 390(10109): 2266-2277, 2017 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-28916371

RESUMO

BACKGROUND: Few treatments with a distinct mechanism of action are available for patients with platinum-refractory advanced or metastatic urothelial carcinoma. We assessed the efficacy and safety of treatment with docetaxel plus either ramucirumab-a human IgG1 VEGFR-2 antagonist-or placebo in this patient population. METHODS: We did a randomised, double-blind, phase 3 trial in patients with advanced or metastatic urothelial carcinoma who progressed during or after platinum-based chemotherapy. Patients were enrolled from 124 sites in 23 countries. Previous treatment with one immune-checkpoint inhibitor was permitted. Patients were randomised (1:1) using an interactive web response system to receive intravenous docetaxel 75 mg/m2 plus either intravenous ramucirumab 10 mg/kg or matching placebo on day 1 of repeating 21-day cycles, until disease progression or other discontinuation criteria were met. The primary endpoint was investigator-assessed progression-free survival, analysed by intention-to-treat in the first 437 randomised patients. This study is registered with ClinicalTrials.gov, number NCT02426125. FINDINGS: Between July, 2015, and April, 2017, 530 patients were randomly allocated either ramucirumab plus docetaxel (n=263) or placebo plus docetaxel (n=267). Progression-free survival was prolonged significantly in patients allocated ramucirumab plus docetaxel versus placebo plus docetaxel (median 4·07 months [95% CI 2·96-4·47] vs 2·76 months [2·60-2·96]; hazard ratio [HR] 0·757, 95% CI 0·607-0·943; p=0·0118). A blinded independent central analysis was consistent with these results. An objective response was achieved by 53 (24·5%, 95% CI 18·8-30·3) of 216 patients allocated ramucirumab and 31 (14·0%, 9·4-18·6) of 221 assigned placebo. The most frequently reported treatment-emergent adverse events, regardless of causality, in either treatment group (any grade) were fatigue, alopecia, diarrhoea, decreased appetite, and nausea. These events occurred predominantly at grade 1-2 severity. The frequency of grade 3 or worse adverse events was similar for patients allocated ramucirumab and placebo (156 [60%] of 258 vs 163 [62%] of 265 had an adverse event), with no unexpected toxic effects. 63 (24%) of 258 patients allocated ramucirumab and 54 (20%) of 265 assigned placebo had a serious adverse event that was judged by the investigator to be related to treatment. 38 (15%) of 258 patients allocated ramucirumab and 43 (16%) of 265 assigned placebo died on treatment or within 30 days of discontinuation, of which eight (3%) and five (2%) deaths were deemed related to treatment by the investigator. Sepsis was the most common adverse event leading to death on treatment (four [2%] vs none [0%]). One fatal event of neutropenic sepsis was reported in a patient allocated ramucirumab. INTERPRETATION: To the best of our knowledge, ramucirumab plus docetaxel is the first regimen in a phase 3 study to show superior progression-free survival over chemotherapy in patients with platinum-refractory advanced urothelial carcinoma. These data validate inhibition of VEGFR-2 signalling as a potential new therapeutic treatment option for patients with urothelial carcinoma. FUNDING: Eli Lilly and Company.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Carcinoma de Células de Transição/tratamento farmacológico , Carcinoma de Células de Transição/patologia , Taxoides/administração & dosagem , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Adulto , Idoso , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células de Transição/mortalidade , Intervalo Livre de Doença , Docetaxel , Método Duplo-Cego , Feminino , Humanos , Internacionalidade , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante/métodos , Invasividade Neoplásica/patologia , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Medição de Risco , Análise de Sobrevida , Resultado do Tratamento , Neoplasias da Bexiga Urinária/mortalidade , Ramucirumab
17.
Proc Natl Acad Sci U S A ; 111(4): E484-91, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24434553

RESUMO

An siRNA screen targeting 89 IFN stimulated genes in 14 different cancer cell lines pointed to the RIG-I (retinoic acid inducible gene I)-like receptor Laboratory of Genetics and Physiology 2 (LGP2) as playing a key role in conferring tumor cell survival following cytotoxic stress induced by ionizing radiation (IR). Studies on the role of LGP2 revealed the following: (i) Depletion of LGP2 in three cancer cell lines resulted in a significant increase in cell death following IR, (ii) ectopic expression of LGP2 in cells increased resistance to IR, and (iii) IR enhanced LGP2 expression in three cell lines tested. Studies designed to define the mechanism by which LGP2 acts point to its role in regulation of IFNß. Specifically (i) suppression of LGP2 leads to enhanced IFNß, (ii) cytotoxic effects following IR correlated with expression of IFNß inasmuch as inhibition of IFNß by neutralizing antibody conferred resistance to cell death, and (iii) mouse embryonic fibroblasts from IFN receptor 1 knockout mice are radioresistant compared with wild-type mouse embryonic fibroblasts. The role of LGP2 in cancer may be inferred from cumulative data showing elevated levels of LGP2 in cancer cells are associated with more adverse clinical outcomes. Our results indicate that cytotoxic stress exemplified by IR induces IFNß and enhances the expression of LGP2. Enhanced expression of LGP2 suppresses the IFN stimulated genes associated with cytotoxic stress by turning off the expression of IFNß.


Assuntos
Sobrevivência Celular/fisiologia , RNA Helicases DEAD-box/fisiologia , Neoplasias Experimentais/patologia , RNA Helicases/fisiologia , Radiação Ionizante , Animais , Apoptose , Neoplasias Encefálicas/patologia , Proteína DEAD-box 58 , RNA Helicases DEAD-box/metabolismo , Glioblastoma/patologia , Humanos , Interferon Tipo I/biossíntese , Camundongos , Camundongos Knockout , Neoplasias Experimentais/metabolismo , RNA Helicases/metabolismo , Células Tumorais Cultivadas
18.
Mol Cell Biol ; 32(21): 4270-82, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22907756

RESUMO

In addition to cancer surveillance, p19(Arf) plays an essential role in blocking signals stemming from platelet-derived growth factor receptor ß (Pdgfrß) during eye development, but the underlying mechanisms have not been clear. We now show that without Arf, pericyte hyperplasia in the eye results from enhanced Pdgfrß-dependent proliferation from embryonic day 13.5 (E13.5) of mouse development. Loss of Arf in the eye increases Pdgfrß expression. In cultured fibroblasts and pericyte-like cells, ectopic p19(Arf) represses and Arf knockdown enhances the expression of Pdgfrß mRNA and protein. Ectopic Arf also represses primary Pdgfrß transcripts and a plasmid driven by a minimal promoter, including one missing the CCAAT element required for high-level expression. p19(Arf) uses both p53-dependent and -independent mechanisms to control Pdgfrß. In vivo, without p53, Pdgfrß mRNA is elevated and eye development abnormalities resemble the Arf (-/-) phenotype. However, effects of p53 on Pdgfrß mRNA do not appear to be due to direct p53 or RNA polymerase II recruitment to the promoter. Although p19(Arf) controls Pdgfrß mRNA in a p53-dependent manner, it also blunts Pdgfrß protein expression by blocking new protein synthesis in the absence of p53. Thus, our findings demonstrate a novel capacity for p19(Arf) to control Pdgfrß expression by p53-dependent and -independent mechanisms involving RNA transcription and protein synthesis, respectively, to promote the vascular remodeling needed for normal vision.


Assuntos
Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Olho/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Fatores de Ribosilação do ADP/genética , Animais , Linhagem Celular , Inibidor p16 de Quinase Dependente de Ciclina/deficiência , Inibidor p16 de Quinase Dependente de Ciclina/genética , Olho/irrigação sanguínea , Olho/embriologia , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pericitos/citologia , Pericitos/fisiologia , Biossíntese de Proteínas , Proteínas Proto-Oncogênicas c-mdm2/genética , RNA Polimerase II/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Transdução de Sinais , Transcrição Gênica , Proteína Supressora de Tumor p53/deficiência , Proteína Supressora de Tumor p53/genética
19.
Biochim Biophys Acta ; 1813(12): 2036-43, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21985982

RESUMO

Delta ligands are important for regulating Notch signaling through transcellular stimulation of Notch receptors. The cytoplasmic tails of Delta ligands have multiple potential regulatory sites including several lysine residues that are putative targets for ubiquitination by the E3 ubiquitin ligases, Mind Bomb and Neuralized. To identify possible roles for specific lysine residues in the cytoplasmic tail of the Notch ligand Dll1 a mutational and functional analysis was performed. Examination of a panel of individual or clustered lysine mutants demonstrated that lysine 613 (K613) in the cytoplasmic tail of Dll1 is a key residue necessary for transcellular activation of Notch signaling. Multi-ubiquitination of the Dll1 mutant Dll1-K613R was altered compared to wild type Dll1, and the K613R mutation blocked the ability of Dll1 to interact with Notch1. Finally, mutation of K613 did not affect the stability of Dll1 or its ability to traffic to recycle to the plasma membrane, but did enhance the fraction associated with lipid rafts. Collectively these results suggest that the transcellular defect in Notch signaling attributed to residue K613 in cytoplasmic tail of Dll1 may result from altering its multi-ubiquitination and increasing its retention in lipid rafts.


Assuntos
Membrana Celular/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Lisina/metabolismo , Microdomínios da Membrana/metabolismo , Receptores Notch/metabolismo , Animais , Western Blotting , Proteínas de Ligação ao Cálcio , Células Cultivadas , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Endocitose , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Técnicas Imunoenzimáticas , Imunoprecipitação , Peptídeos e Proteínas de Sinalização Intercelular/genética , Rim/citologia , Rim/metabolismo , Lisina/genética , Camundongos , Mutação/genética , Ligação Proteica , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores Notch/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
20.
J Biol Chem ; 285(18): 13827-38, 2010 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-20220139

RESUMO

The tumor suppressor, death-associated protein kinase (DAPK), is a Ca(2+)/calmodulin-regulated Ser/Thr kinase with an important role in regulating cytoskeletal dynamics. Autophosphorylation within the calmodulin-binding domain at Ser-308 inhibits DAPK catalytic activity. Dephosphorylation of Ser-308 by a previously unknown phosphatase enhances kinase activity and proteasome-mediated degradation of DAPK. In these studies, we identified two holoenzyme forms of protein phosphatase 2A (PP2A), ABalphaC and ABdeltaC, as DAPK-interacting proteins. These phosphatase holoenzymes dephosphorylate DAPK at Ser-308 in vitro and in vivo resulting in enhanced kinase activity of DAPK. The enzymatic activity of PP2A also negatively regulates DAPK levels by enhancing proteasome-mediated degradation of the kinase. Overexpression of wild type DAPK induces cell rounding and detachment in HEK293 cells; however, this effect is not observed following expression of an inactive DAPK S308E mutant. Finally, activation of DAPK by PP2A was found to be required for ceramide-induced anoikis. Together, our results provide a mechanism by which PP2A and DAPK activities control cell adhesion and anoikis.


Assuntos
Anoikis/efeitos dos fármacos , Ceramidas/farmacologia , Proteína Fosfatase 2/metabolismo , Substituição de Aminoácidos , Anoikis/genética , Proteínas Reguladoras de Apoptose , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Adesão Celular/efeitos dos fármacos , Adesão Celular/genética , Citoesqueleto/genética , Citoesqueleto/metabolismo , Proteínas Quinases Associadas com Morte Celular , Células HeLa , Holoenzimas/genética , Holoenzimas/metabolismo , Humanos , Mutação de Sentido Incorreto , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Proteína Fosfatase 2/genética , Proteínas Supressoras de Tumor
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