RESUMEN
Importance: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignant tumor, and durable disease control is rare with the current standard of care, even for patients who undergo surgical resection. Objective: To assess whether neoadjuvant modified 5-fluorouracil, leucovorin, oxaliplatin, and irinotecan (mFOLFIRINOX) leads to early control of micrometastasis and improves survival. Design, Setting, and Participants: This open-label, single-arm, phase 2 nonrandomized controlled trial for resectable PDAC was conducted at the Yale Smilow Cancer Hospital from April 3, 2014, to August 16, 2021. Pancreatic protocol computed tomography was performed at diagnosis to assess surgical candidacy. Data were analyzed from January to July 2023. Interventions: Patients received 6 cycles of neoadjuvant mFOLFIRINOX before surgery and 6 cycles of adjuvant mFOLFIRINOX. Whole blood was collected and processed to stored plasma for analysis of circulating tumor DNA (ctDNA) levels. Tumors were evaluated for treatment response and keratin 17 (K17) expression. Main Outcomes and Measures: The primary end point was 12-month progression-free survival (PFS) rate. Additional end points included overall survival (OS), ctDNA level, tumor molecular features, and K17 tumor levels. Survival curves were summarized using Kaplan-Meier estimator. Results: Of 46 patients who received mFOLFIRINOX, 31 (67%) were male, and the median (range) age was 65 (46-80) years. A total of 37 (80%) completed 6 preoperative cycles and 33 (72%) underwent surgery. A total of 27 patients (59%) underwent resection per protocol (25 with R0 disease and 2 with R1 disease); metastatic or unresectable disease was identified in 6 patients during exploration. Ten patients underwent surgery off protocol. The 12-month PFS was 67% (90% CI, 56.9-100); the median PFS and OS were 16.6 months (95% CI, 13.3-40.6) and 37.2 months (95% CI, 17.5-not reached), respectively. Baseline ctDNA levels were detected in 16 of 22 patients (73%) and in 3 of 17 (18%) after 6 cycles of mFOLFIRINOX. Those with detectable ctDNA levels 4 weeks postresection had worse PFS (hazard ratio [HR], 34.0; 95% CI, 2.6-4758.6; P = .006) and OS (HR, 11.7; 95% CI, 1.5-129.9; P = .02) compared with those with undetectable levels. Patients with high K17 expression had nonsignificantly worse PFS (HR, 2.7; 95% CI, 0.7-10.9; P = .09) and OS (HR, 3.2; 95% CI, 0.8-13.6; P = .07). Conclusions and Relevance: This nonrandomized controlled trial met its primary end point, and perioperative mFOLFIRINOX warrants further evaluation in randomized clinical trials. Postoperative ctDNA positivity was strongly associated with recurrence. K17 and ctDNA are promising biomarkers that require additional validation in future prospective studies. Trial Registration: ClinicalTrials.gov Identifier: NCT02047474.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Fluorouracilo , Irinotecán , Leucovorina , Oxaliplatino , Neoplasias Pancreáticas , Humanos , Masculino , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/cirugía , Fluorouracilo/uso terapéutico , Fluorouracilo/administración & dosificación , Leucovorina/uso terapéutico , Leucovorina/administración & dosificación , Femenino , Irinotecán/uso terapéutico , Irinotecán/administración & dosificación , Persona de Mediana Edad , Oxaliplatino/uso terapéutico , Oxaliplatino/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Anciano , Terapia Neoadyuvante , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/cirugía , Carcinoma Ductal Pancreático/mortalidad , Anciano de 80 o más Años , Supervivencia sin ProgresiónRESUMEN
BACKGROUND: Retesting for Human epidermal growth factor receptor-2 (HER2) in post-neoadjuvant therapy resection is variable, and data is conflicting regarding the prognostic significance of changes in HER2 expression pre and post therapy. METHODS: We identified 104 patients with localized HER2 IHC 3+ breast cancer who received neoadjuvant trastuzumab(T)/pertuzumab(P) containing chemotherapy at Yale Cancer Center between 2012 and 2022. Patients were divided into 3 cohorts by response and HER2 IHC in the residual disease: Cohort 1 pathologic complete response (pCR), Cohort 2 pre-treatment IHC 3+/post treatment IHC 1+/2+, and Cohort 3 pre-treatment IHC 3+/post-treatment IHC 3+. Kaplan-Meier survival analysis was performed to assess recurrence free survival at 36 months. RESULTS: The overall pCR rate was 62.5% (65/104), while 37.5% (39/104) of patients had residual disease (RD). Among patients with RD, 58.9% (23/39) remained IHC 3+ and 41.1% (16/39) had reduced HER2 expression IHC1+ or 2+. In patients with HER2 IHC 3+ RD, 26% (6/23) developed local recurrence or distant metastasis while none of patients with post NAT HER2 IHC 1+ or 2+ RD had relapse (p = 0.0309). In patients with pCR, 6.15% (4/65) had recurrence. Kaplan-Meier survival analysis revealed superior disease-free survival in patients with reduced HER2 IHC expression compared to those with remained IHC 3+ (log rank p = 0.004). CONCLUSION: We conclude that reduced HER2 expression by IHC following neoadjuvant treatment was associated with lower recurrence rates in HER2 IHC 3+ breast cancer. If confirmed, RD HER2 IHC expression could be used as a prognostic biomarker to stratify patients in adjuvant trials and identify patients who may benefit from more intensive adjuvant therapy and post therapy surveillance.
Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/cirugía , Pronóstico , Terapia Neoadyuvante , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Recurrencia Local de Neoplasia/etiología , Receptor ErbB-2/metabolismo , Trastuzumab/uso terapéuticoRESUMEN
PURPOSE: The incidence of triple-negative breast cancer (TNBC) is higher among Black or African American (AA) women, yet they are underrepresented in clinical trials. To evaluate safety and efficacy of durvalumab concurrent with neoadjuvant chemotherapy for stage I-III TNBC by race, we enrolled additional AA patients to a Phase I/II clinical trial. PATIENTS AND METHODS: Our study population included 67 patients. The primary efficacy endpoint was pathologic complete response (pCR; ypT0/is, N0) rate. χ2 tests were used to evaluate associations between race and baseline characteristics. Cox proportional hazards models were used to assess association between race and overall survival (OS) and event-free survival (EFS). Multivariate logistic regression analyses were used to evaluate associations between race and pCR, immune-related adverse events (irAE) and recurrence. RESULTS: Twenty-one patients (31%) self-identified as AA. No significant associations between race and baseline tumor stage (P = 0.40), PD-L1 status (0.92), and stromal tumor-infiltrating lymphocyte (sTIL) count (P = 0.57) were observed. pCR rates were similar between AA (43%) and non-AA patients (48%; P = 0.71). Three-year EFS rates were 78.3% and 71.4% in non-AA and AA patients, respectively [HR, 1.451; 95% confidence interval (CI), 0.524-4.017; P = 0.474]; 3-year OS was 87% and 81%, respectively (HR, 1.72; 95% CI, 0.481-6.136; P = 0.405). The incidence of irAEs was similar between AA and non-AA patients and no significant associations were found between irAEs and pathologic response. CONCLUSIONS: pCR rates, 3-year OS and EFS after neoadjuvant immunotherapy and chemotherapy were similar in AA and non-AA patients. Toxicities, including the frequency of irAEs, were also similar.
Asunto(s)
Neoplasias de la Mama , Neoplasias de la Mama Triple Negativas , Anticuerpos Monoclonales , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Biomarcadores , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Humanos , Terapia Neoadyuvante , Neoplasias de la Mama Triple Negativas/patologíaRESUMEN
The goal of this Phase I/II trial is to assess the safety and efficacy of administering durvalumab concurrent with weekly nab-paclitaxel and dose-dense doxorubicin/cyclophosphamide (ddAC) neoadjuvant therapy for stages I-III triple-negative breast cancer. The primary endpoint is pathologic complete response (pCR:ypT0/is, ypN0). The response was correlated with PDL1 expression and stromal tumor-infiltrating lymphocytes (sTILs). Two dose levels of durvalumab (3 and 10 mg/kg) were assessed. PD-L1 was assessed using the SP263 antibody; ≥1% immune and tumor cell staining was considered positive; sTILs were calculated as the area occupied by mononuclear inflammatory cells over the total intratumoral stromal area. 59 patients were evaluable for toxicity and 55 for efficacy in the Phase II study (10 mg/kg dose). No dose-limiting toxicities were observed in Phase I. In Phase II, pCR rate was 44% (95% CI: 30-57%); 18 patients (31%) experienced grade 3/4 treatment-related adverse events (AE), most frequently neutropenia (n = 4) and anemia (n = 4). Immune-related grade 3/4 AEs included Guillain-Barre syndrome (n = 1), colitis (n = 2), and hyperglycemia (n = 2). Of the 50 evaluable patients for PD-L1, 31 (62%) were PD-L1 positive. pCR rates were 55% (95% CI: 0.38-0.71) and 32% (95% CI: 0.12-0.56) in the PD-L1 positive and negative groups (p = 0.15), respectively. sTIL counts were available on 52 patients and were significantly higher in the pCR group (p = 0.0167). Concomitant administration of durvalumab with sequential weekly nab-paclitaxel and ddAC neoadjuvant chemotherapy resulted in a pCR rate of 44%; pCR rates were higher in sTIL-high cancers.
RESUMEN
BACKGROUND: TAS-102, a novel antimetabolite, is approved for treatment of refractory metastatic colorectal cancer (CRC). This study sought to determine whether the addition of TAS-102 to oxaliplatin (TAS-OX) was safe and effective in metastatic CRC previously treated with oxaliplatin. METHODS: This investigator-initiated, open-label, single-arm phase 1b study enrolled patients with metastatic CRC previously treated with 5-fluorouracil, irinotecan, and oxaliplatin. In dose escalation, TAS-102 was given at 3 dose levels: 25, 30, and 35 mg/m2 twice daily on day 1 to day 5 with 85 mg/m2 oxaliplatin on day 1 in 14-day cycles. The primary endpoint of dose escalation was the recommended dose for expansion, and in dose expansion, the primary endpoint was overall response rate (ORR) according to the Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1). RESULTS: Forty-one patients were treated with TAS-OX. No dose-limiting toxicities were observed in the 11 patients treated in escalation. The recommended dose for expansion was 35 mg/m2 TAS-102 twice daily on day 1 to day 5 in combination with 85 mg/m2 oxaliplatin on day 1 in 14-day cycles. In the intention-to-treat population, the ORR was 2.4% (95% CI, 0%-12.9%) with 1 of 41 patients having a partial response, although 12 (29%) had tumor shrinkage. The median progression-free survival was 2.7 months (95% CI, 2.4-4.8 months) and median overall survival was 6.8 months (95% CI, 5.7-10 months). CONCLUSIONS: TAS-OX is safe with no unexpected toxicities at standard doses of each agent. The combination did not result in a clinically meaningful ORR, although progression-free survival and overall survival were encouraging in this heavily pretreated population. LAY SUMMARY: For metastatic colorectal cancer, the treatment combination of TAS-102 and oxaliplatin was found to be well-tolerated and revealed no unexpected side effects. Twelve of 41 patients had reductions in the size of their tumor, and the study treatment delayed the time to tumor growth as opposed to what would be expected.
Asunto(s)
Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias Colorrectales/tratamiento farmacológico , Oxaliplatino/administración & dosificación , Pirrolidinas/administración & dosificación , Timina/administración & dosificación , Trifluridina/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias Colorrectales/mortalidad , Esquema de Medicación , Combinación de Medicamentos , Resistencia a Antineoplásicos , Femenino , Fluorouracilo/administración & dosificación , Humanos , Irinotecán/administración & dosificación , Leucovorina/administración & dosificación , Masculino , Persona de Mediana Edad , Compuestos Organoplatinos/administración & dosificación , Oxaliplatino/efectos adversos , Supervivencia sin Progresión , Pirrolidinas/efectos adversos , Criterios de Evaluación de Respuesta en Tumores Sólidos , Timina/efectos adversos , Trifluridina/efectos adversosRESUMEN
BACKGROUND: Bullous disorders associated with anti-programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) therapy are increasingly reported and may pose distinct therapeutic challenges. Their frequency and impact on cancer therapy are not well established. OBJECTIVE: To evaluate the clinical and histopathologic findings, frequency, and impact on cancer therapy of bullous eruptions due to anti-PD-1/PD-L1 therapy. METHODS: We retrospectively reviewed the medical records of patients evaluated by the oncodermatology clinic and consultative service of Yale New Haven Hospital from 2016 to 2018. RESULTS: We identified 9 of 853 patients who developed bullous eruptions (â¼1%) that were treated with an-PD-1/PD-L1 therapy at our institution during the study period: 7 presented with bullous pemphigoid, 1 presented with bullous lichenoid dermatitis, and 1 presented with linear IgA bullous dermatosis in the context of vancomycin therapy. In all, 8 patients required systemic steroids, 5 required maintenance therapy, and 8 required interruption of immunotherapy. All 9 patients had an initial positive tumor response or stable disease, but 4 went on to develop disease progression. LIMITATIONS: This was a retrospective study from a single tertiary care center. CONCLUSIONS: Bullous disorders developed in approximately 1% of patients treated with anti-PD-1/PD-L1 therapy at our institution and frequently resulted in interruption of immune therapy and management with systemic corticosteroids and occasionally steroid-sparing agents.
Asunto(s)
Antineoplásicos Inmunológicos/efectos adversos , Antígeno B7-H1/antagonistas & inhibidores , Erupciones por Medicamentos/etiología , Proteínas de Neoplasias/antagonistas & inhibidores , Neoplasias/complicaciones , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Enfermedades Cutáneas Vesiculoampollosas/inducido químicamente , Corticoesteroides/uso terapéutico , Anciano , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados/efectos adversos , Erupciones por Medicamentos/tratamiento farmacológico , Femenino , Humanos , Erupciones Liquenoides/inducido químicamente , Masculino , Persona de Mediana Edad , Neoplasias/tratamiento farmacológico , Nivolumab/efectos adversos , Penfigoide Ampolloso/inducido químicamente , Estudios Retrospectivos , Enfermedades Cutáneas Vesiculoampollosas/tratamiento farmacológico , Centros de Atención Terciaria , Resultado del TratamientoRESUMEN
BACKGROUND: The median survival for patients with metastatic gastroesophageal adenocarcinoma is <12 months. Bevacizumab has demonstrated promising activity in metastatic gastroesophageal adenocarcinoma when used in combination with cisplatin-based regimens for patients from the Americas. We conducted a prospective phase II trial to investigate the efficacy of bevacizumab in combination with the oxaliplatin-based regimen, modified FOLFOX6, in patients with metastatic gastroesophageal adenocarcinoma. METHODS: Patients with untreated metastatic adenocarcinoma of the stomach, gastroesophageal junction, or distal esophagus received mFOLFOX6 (leucovorin 400 mg/m, fluorouracil 400 mg/m bolus and 2400 mg/m continuous infusion over 46 h, oxaliplatin 85 mg/m) and bevacizumab (10 mg/kg) every 2 weeks until disease progression or intolerance. Response by RECIST was evaluated by CT scan every 8 weeks. The primary objective was progression-free survival (PFS); secondary objectives were safety, response rate, and overall survival (OS). RESULTS: A total of 39 patients with untreated metastastic gastroesophageal adenocarcinoma were enrolled between September 2008 and June 2012. Median number of cycles administered was 12 (range, 4 to 86). The confirmed response rate was 56.4% (3 complete response and 19 partial response). The median PFS was 7.8 months and median OS was 14.7 months. Three patients remain on treatment, and 11 patients are alive, of whom 6 have survived >24 months. Treatment-related grade 3/4 toxicities included neutropenia (33.3%), neuropathy (20.5%), thromboembolism (VTE) (7.7%), thrombocytopenia (7.7%), anemia (2.6%), hypertension (2.6%), and proteinuria (2.6%). We observed no GI perforations or grade 3/4 GI hemorrhagic events. CONCLUSIONS: First-line mFOLFOX6 with bevacizumab for metastatic gastroesophageal adenocarcinoma was well tolerated and associated with longer PFS and OS compared with historical data from similar populations treated without bevacizumab. Our results suggest that the addition of bevacizumab to mFOLFOX6 may provide clinical benefit in American patients with metastatic gastroesophageal adenocarcinoma, a finding consistent with previous studies of first-line bevacizumab in combination with chemotherapy for this disease.
Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/secundario , Inhibidores de la Angiogénesis/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Bevacizumab/administración & dosificación , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/secundario , Unión Esofagogástrica , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/secundario , Adulto , Anciano , Quimioterapia Combinada , Femenino , Fluorouracilo/administración & dosificación , Humanos , Leucovorina/administración & dosificación , Masculino , Persona de Mediana Edad , Compuestos Organoplatinos/administración & dosificación , Estudios ProspectivosRESUMEN
INTRODUCTION: Bevacizumab, a recombinant humanized monoclonal antibody against vascular endothelial growth factor, was approved by the US Food and Drug Administration for the treatment of advanced non-small-cell lung cancer (NSCLC) in combination with carboplatin and paclitaxel. ARIES (Avastin Regimens: Investigation of Effectiveness and Safety), a prospective observational cohort study, evaluated outcomes in a large, community-based population of patients with first-line NSCLC. METHODS: From 2006 to 2009, ARIES enrolled patients with locally advanced or metastatic NSCLC who were eligible for bevacizumab, excluding those with predominantly squamous histology. Patients were required to provide informed consent and to have initiated bevacizumab with chemotherapy within 4 months before enrollment. There were no protocol-defined treatments or assessments. The dosing of bevacizumab and chemotherapy, and the choice of chemotherapy regimen, was at the discretion of the treating physician. RESULTS: ARIES enrolled 1967 patients with first-line NSCLC. At study closure, median follow-up was 12.5 months (range, 0.2-65.5). Median age was 65 years (range, 31-93), and 252 patients (12.8%) identified as never smokers. Median progression-free survival was 6.6 months (95% confidence interval, 6.3-6.9), and median overall survival was 13.0 months (95% confidence interval, 12.2-13.8) with first-line bevacizumab plus chemotherapy. Incidences of bevacizumab-associated adverse events (19.7% overall) were consistent with those in randomized controlled trials of bevacizumab in NSCLC. CONCLUSION: Results from ARIES demonstrate similar outcomes to randomized controlled trials of bevacizumab when added to standard chemotherapy in a real-world patient population with advanced NSCLC.
Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Inhibidores de la Angiogénesis/uso terapéutico , Bevacizumab , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Supervivencia sin Enfermedad , Quimioterapia Combinada , Europa (Continente)/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Tasa de Supervivencia/tendencias , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos/epidemiología , Factor A de Crecimiento Endotelial VascularRESUMEN
OBJECTIVES: Amended reports (AmRs) need to follow patients to treating physicians, to avoid erroneous management based on the original diagnosis. This study was undertaken to determine if AmRs followed the patient appropriately. METHODS: AmRs with diagnostic changes and discrepancies between ordering and treating physicians were tracked. Chart reviews, electronic medical report (EMR) reviews, and interviews were conducted to establish receipt of the AmR by the correct physician. RESULTS: Seven of 60 AmRs had discrepancies between the ordering and treating physicians, all with malignant diagnoses. The AmR was present in the treating physician's chart in only one case. Ordering physicians indicated that AmRs were not forwarded to treating physicians when corrected results arrived after patient referral, under the assumption that the new physician was automatically forwarded pathology updates. No harm was documented in any of our cases. In one case with a significant amendment, the correct information was entered in the patient chart based on a tumor board discussion. A review of two electronic health record systems uncovered significant shortcomings in each delivery system. CONCLUSIONS: AmRs fail to follow the patient's chain of referrals to the correct care provider, and EMR systems lack the functionality to address this failure and alert clinical teams of amendments.
Asunto(s)
Registros Médicos , Patología Quirúrgica , Pautas de la Práctica en Medicina , Derivación y Consulta , Registros Electrónicos de Salud , HumanosRESUMEN
Triple negative breast cancer (TNBC) is characterized by high proliferation, poor differentiation and a poor prognosis due to high rates of recurrence. Despite lower overall incidence African American (AA) patients suffer from higher breast cancer mortality in part due to the higher proportion of TNBC cases among AA patients compared to European Americans (EA). It was recently shown that the clinical heterogeneity of TNBC is reflected by distinct transcriptional programs with distinct drug response profiles in preclinical models. In this study, gene expression profiling and immunohistochemistry were used to elucidate potential differences between TNBC tumors of EA and AA patients on a molecular level. In a retrospective cohort of 136 TNBC patients, a major transcriptional signature of proliferation was found to be significantly upregulated in samples of AA ethnicity. Furthermore, transcriptional profiles of AA tumors showed differential activation of insulin-like growth factor 1 (IGF1) and a signature of BRCA1 deficiency in this cohort. Using signatures derived from the meta-analysis of TNBC gene expression carried out by Lehmann et al., tumors from AA patients were more likely of basal-like subtypes whereas transcriptional features of many EA samples corresponded to mesenchymal-like or luminal androgen receptor driven subtypes. These results were validated in The Cancer Genome Atlas mRNA and protein expression data, again showing enrichment of a basal-like phenotype in AA tumors and mesenchymal subtypes in EA tumors. In addition, increased expression of VEGF-activated genes together with elevated microvessel area determined by the AQUA method suggest that AA patients exhibit higher tumor vascularization. This study confirms the existence of distinct transcriptional programs in triple negative breast cancer in two separate cohorts and that these programs differ by racial group. Differences in TNBC subtypes and levels of tumor angiogenesis in AA versus EA patients suggest that targeted therapy choices should be considered in the context of race.
Asunto(s)
Neoplasias de la Mama , Bases de Datos Genéticas , Regulación Neoplásica de la Expresión Génica , Proteínas de Neoplasias , Neovascularización Patológica , ARN Mensajero , ARN Neoplásico , Adulto , Negro o Afroamericano , Anciano , Neoplasias de la Mama/etnología , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Femenino , Humanos , Persona de Mediana Edad , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , Neovascularización Patológica/etnología , Neovascularización Patológica/genética , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patología , ARN Mensajero/biosíntesis , ARN Mensajero/genética , ARN Neoplásico/biosíntesis , ARN Neoplásico/genética , Estudios RetrospectivosRESUMEN
The HOX family of homeobox genes plays an important role in normal and malignant hematopoiesis. Dysregulated HOX gene expression profoundly effects the proliferation and differentiation of hematopoietic stem cells (HSCs) and committed progenitors, and aberrant activation of HOX genes is a common event in human myeloid leukemia. HOXB6 is frequently overexpressed in human acute myeloid leukemia (AML). To gain further insight into the role of HOXB6 in hematopoiesis, we overexpressed HOXB6 in murine bone marrow using retrovirus-mediated gene transfer. We also explored structure-function relationships using mutant HOXB6 proteins unable to bind to DNA or a key HOX-binding partner, pre-B-cell leukemia transcription factor-1 (PBX1). Additionally, we investigated the potential cooperative interaction with myeloid ecotropic viral integration site 1 homolog (MEIS1). In vivo, HOXB6 expanded HSCs and myeloid precursors while inhibiting erythropoiesis and lymphopoiesis. Overexpression of HOXB6 resulted in AML with a median latency of 223 days. Coexpression of MEIS1 dramatically shortened the onset of AML. Cytogenetic analysis of a subset of HOXB6-induced AMLs revealed recurrent deletions of chromosome bands 2D-E4, a region frequently deleted in HOXA9-induced AMLs. In vitro, HOXB6 immortalized a factor-dependent myelomonocytic precursor capable of granulocytic and monocytic differentiation. These biologic effects of HOXB6 were largely dependent on DNA binding but independent of direct interaction with PBX1.
Asunto(s)
Células de la Médula Ósea/metabolismo , Células de la Médula Ósea/patología , Transformación Celular Neoplásica/patología , Proteínas de Homeodominio/biosíntesis , Proteínas de Homeodominio/genética , Leucemia Mieloide/sangre , Células Progenitoras Mieloides/metabolismo , Células Progenitoras Mieloides/patología , Enfermedad Aguda , Animales , Diferenciación Celular/genética , Línea Celular Transformada , Proliferación Celular , Eritropoyesis/genética , Femenino , Proteínas de Homeodominio/fisiología , Cariotipificación , Leucemia Mieloide/genética , Leucemia Mieloide/patología , Linfopoyesis/genética , Ratones , Ratones Congénicos , Ratones Endogámicos C57BL , Proteína 1 del Sitio de Integración Viral Ecotrópica Mieloide , Proteínas de Neoplasias/fisiología , Fenotipo , Factores de TiempoRESUMEN
HOXA9 expression is a common feature of acute myeloid leukemia, and high-level expression is correlated with poor prognosis. Moreover, HOXA9 overexpression immortalizes murine marrow progenitors that are arrested at a promyelocytic stage of differentiation when cultured and causes leukemia in recipient mice following transplantation of HOXA9 expressing bone marrow. The molecular mechanisms underlying the physiologic functions and transforming properties of HOXA9 are poorly understood. This study demonstrates that HOXA9 is phosphorylated by protein kinase C (PKC) and casein kinase II and that PKC mediates phosphorylation of purified HOXA9 on S204 as well as on T205, within a highly conserved consensus sequence, in the N-terminal region of the homeodomain. S204 in the endogenous HOXA9 protein was phosphorylated in PLB985 myeloid cells, as well as in HOXA9-immortalized murine marrow cells. This phosphorylation was enhanced by phorbol ester, a known inducer of PKC, and was inhibited by a specific PKC inhibitor. PKC-mediated phosphorylation of S204 decreased HOXA9 DNA binding affinity in vitro and the ability of the endogenous HOXA9 to form cooperative DNA binding complexes with PBX. PKC inhibition significantly reduced the phorbol-ester induced differentiation of the PLB985 hematopoietic cell line as well as HOXA9-immortalized murine bone marrow cells. These data suggest that phorbol ester-induced myeloid differentiation is in part due to PKC-mediated phosphorylation of HOXA9, which decreases the DNA binding of the homeoprotein.