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PURPOSE: Socioeconomic status (SES) influences health care outcomes, but the influence of primary payer on cancer-associated wasting is unknown. We hypothesized that primary payer as an indicator of SES would influence pretreatment cancer-associated weight loss and treatment outcomes. MATERIALS AND METHODS: Retrospective review of medical records identified 1,366 patients with non-small-cell lung cancer (NSCLC) consecutively treated at a tertiary care health system between January 1, 2006 and December 31, 2013. Insurance status was obtained from an institutional tumor registry. Cancer-associated weight loss was based on the validated international consensus definition of cachexia. Multivariable regression analyses were used to identify prognostic factors of pretreatment cancer-associated weight loss and survival. RESULTS: The cohort included a representative group of patients with a median age at diagnosis of 64 years, 47% females, and 33% patients of nonwhite race. Pretreatment cancer-associated weight loss was present at the time of NSCLC diagnosis in 17%, 14%, 32%, and 38% of patients with stage I, II, III, and IV disease, respectively. Pretreatment cancer-associated weight loss was associated with increasing age at diagnosis, black race, single marital status, tobacco use, and disease stage. Compared with private insurance, Medicaid insurance (odds ratio, 2.17; 95% CI, 1.42 to 3.30) and lack of insurance (odds ratio, 2.32; 95% CI, 1.50 to 3.58) were associated with pretreatment cancer-associated weight loss. Among cachectic patients, comorbidity, histology, tumor grade, and disease stage were prognostic of survival on multivariable analysis; however, primary payer was not. CONCLUSION: Pretreatment cancer-associated weight loss is common in patients with NSCLC, and its presence is significantly associated with lower SES. However, among patients with pretreatment cancer-associated weight loss, SES was not predictive of survival. Early use of cancer cachexia-directed therapies may improve outcomes, and further study on the biologic mechanisms of cancer cachexia will provide novel therapeutic avenues.
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Carcinoma de Pulmón de Células no Pequeñas/epidemiología , Neoplasias Pulmonares/epidemiología , Clase Social , Pérdida de Peso , Adulto , Anciano , Anciano de 80 o más Años , Caquexia/etiología , Carcinoma de Pulmón de Células no Pequeñas/complicaciones , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Humanos , Cobertura del Seguro , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Pronóstico , Modelos de Riesgos Proporcionales , Vigilancia en Salud Pública , Estudios Retrospectivos , Factores de Riesgo , Factores Socioeconómicos , Tasa de Supervivencia , Resultado del Tratamiento , Adulto JovenRESUMEN
PURPOSE: Cancer-associated weight loss is associated with poor prognosis in advanced malignancy; however, its pretreatment prevalence and survival impact are inadequately described in large cohorts. Such data, stratified by tumor type and stage, may facilitate the optimal and timely allocation of complementary care, leading to improvements in patient survival and quality of life. METHODS: We performed a retrospective cohort study of 3,180 consecutively treated adult patients with lung or GI (including colorectal, liver, and pancreatic) cancer. Pretreatment cancer-associated weight loss was based on the international consensus definition of cachexia. Prevalence and survival impact of pretreatment cancer-associated weight loss were evaluated using the Kaplan-Meier method and compared using log-rank test. RESULTS: Cancer-associated weight loss was observed at the time of cancer diagnosis in 34.1% of patients. Pretreatment weight loss was documented in 17.6%, 25.8%, 36.6%, and 43.3% of stage I, II, III, and IV cancers, respectively. Wasting was common regardless of tumor type, with prevalence at diagnosis ranging from 27.3% in patients with colorectal cancer to 53.4% in patients with gastroesophageal cancer. Pretreatment weight loss was associated with reduced overall survival after adjusting for stage, size, grade, comorbidity, age, sex, and tobacco history (hazard ratio, 1.26; 95% CI, 1.13 to 1.39). CONCLUSION: Pretreatment cancer-associated weight loss is common, even in early-stage disease, and is independently associated with reduced survival. Minimal weight loss represents a clinically distinct entity with an associated overall survival intermediate to that of no weight loss and overt wasting. Early diagnosis and treatment of cancer-associated wasting offers a novel therapeutic avenue for reducing cancer mortality.
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Neoplasias/complicaciones , Neoplasias/mortalidad , Pérdida de Peso , Anciano , Caquexia/epidemiología , Caquexia/etiología , Caquexia/mortalidad , Comorbilidad , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Neoplasias/diagnóstico , Neoplasias/epidemiología , Cuidados Paliativos , Prevalencia , Pronóstico , Sistema de RegistrosRESUMEN
Frameless, surface imaging guided radiosurgery (SIG-RS) is a novel platform for stereotactic radiosurgery (SRS) wherein patient positioning is monitored in real-time through infra-red camera tracking of facial topography. Here we describe our initial clinical experience with SIG-RS for the treatment of benign neoplasms of the skull base. We identified 48 patients with benign skull base tumors consecutively treated with SIG-RS at a single institution between 2009 and 2011. Patients were diagnosed with meningioma (n = 22), vestibular schwannoma (n = 20), or nonfunctional pituitary adenoma (n = 6). Local control and treatment-related toxicity were retrospectively assessed. Median follow-up was 65 months (range 61-72 months). Prescription doses were 12-13 Gy in a single fraction (n = 18), 8 Gy × 3 fractions (n = 6), and 5 Gy × 5 fractions (n = 24). Actuarial tumor control rate at 5 years was 98%. No grade ≥3 treatment-related toxicity was observed. Grade ≤2 toxicity was associated with symptomatic lesions (p = 0.049) and single fraction treatment (p = 0.005). SIG-RS for benign skull base tumors produces clinical outcomes comparable to conventional frame-based SRS techniques while enhancing patient comfort.
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Imagen por Resonancia Magnética/métodos , Radiocirugia/métodos , Neoplasias de la Base del Cráneo/diagnóstico por imagen , Neoplasias de la Base del Cráneo/radioterapia , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasias de la Base del Cráneo/clasificaciónRESUMEN
OBJECTIVES: To report a case of primary rhabdomyosarcoma (RMS) of the pineal gland in an adult, as well as review the literature on this rare entity. METHODS: The case is compared with previous reports of similar entities, with emphasis on this patient's characteristics and clinical presentation, investigations, and management. RESULTS: Diagnosis of primary RMS of the pineal gland was based on the presence of strap cells and multinucleated myotube-like structures, as well as tumor cell expression of skeletal muscle markers consistent with myogenic differentiation. Multimodality treatment was initiated based on pediatric protocols. Unfortunately, the disease progressed on treatment, and the patient survived only 5 months from diagnosis. CONCLUSIONS: Pineal RMS is a rare disease with poor prognosis. Optimal management is unknown but likely to involve aggressive multimodality therapy.
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Biomarcadores de Tumor/metabolismo , Neoplasias Encefálicas/diagnóstico , Glándula Pineal/patología , Rabdomiosarcoma/diagnóstico , Adulto , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/cirugía , Diagnóstico Diferencial , Resultado Fatal , Femenino , Humanos , Glándula Pineal/metabolismo , Rabdomiosarcoma/metabolismo , Rabdomiosarcoma/cirugía , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: Stereotactic radiosurgery (SRS) is a well-accepted treatment for patients with intracranial metastases, but outcomes with volumetric modulated arc radiosurgery (VMAR) are poorly described. OBJECTIVE: To report our initial clinical experience applying a novel single-isocenter technique to frameless VMAR for simultaneous treatment of multiple intracranial metastases. METHODS: We performed a retrospective analysis of 15 patients undergoing frameless VMAR for multiple intracranial metastases using a single, centrally located isocenter in the period 2009 and 2011. Of these, 3 patients were treated for progressive or recurrent intracranial disease. A total of 62 metastases (median, 3 per patient; range, 2-13) were treated to a median dose of 20 Gy (range, 15-30 Gy). Three patients were treated with fractionated SRS. Follow-up including clinical examination and magnetic resonance imaging (MRI) occurred every 3 months. RESULTS: The median follow-up for all patients was 7.1 months (range, 1.1-24.3), with 11 patients (73.3%) followed until death. For the remaining 4 patients alive at the time of analysis, the median follow-up was 19.6 months (range, 9.2-24.3). Local control at 6 and 12 months was 91.7% (95% confidence interval [CI], 84.6%-100.0%) and 81.5% (95% CI, 67.9%-100.0%), respectively. Regional failure was observed in 9 patients (60.0%), and 7 patients (46.7%) received salvage therapy. Overall survival at 6 months was 60.0% (95% CI, 40.3%-88.2%). Grade 3 or higher treatment-related toxicity was not observed. The median total treatment time was 7.2 minutes (range, 2.8-13.2 minutes). CONCLUSION: Single-isocenter, frameless VMAR for multiple intracranial metastases is a promising technique that may provide similar clinical outcomes compared with conventional radiosurgery.
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Neoplasias Encefálicas/secundario , Neoplasias Encefálicas/cirugía , Radiocirugia/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Radiometría , Radiocirugia/efectos adversos , Estudios Retrospectivos , Terapia Recuperativa , Análisis de Supervivencia , Insuficiencia del Tratamiento , Resultado del TratamientoRESUMEN
BACKGROUND: The purpose of this study was to describe our clinical experience using stereotactic body radiation therapy (SBRT) to treat medically inoperable stage I non-small-cell lung cancer (NSCLC) in very elderly patients. PATIENTS AND METHODS: Twenty-four consecutive octogenarians with stage I NSCLC were treated with SBRT between 2007 and 2011 at a single center. Median prescription dose was 48 Gy (range, 48-56). Follow-up clinical examination and computed tomography (CT) were performed every 2 to 3 months. RESULTS: Median age was 85 years (range, 80-89). Twenty-three (96%) patients had peripheral tumors, and median tumor size was 22 mm (range, 11-49). Tissue diagnosis was obtained in 16 (67%) patients. Median follow-up for all patients was 27.6 months (range, 4.3-61.2). The 24-month disease-free survival was 77% (95% confidence interval [CI], 61%-97%). The 24-month overall survival (OS) was 74% (95% CI, 57%-94%). No local failure (LF) was observed during the period of observation. Nodal failure (NF) and distant failure (DF) occurred in 2 and 4 patients, respectively. The cumulative incidence of competing mortality at 24 months was estimated at 13% (95% CI, 3%-30%). No difference in outcomes with or without tissue diagnosis was observed. No grade ≥ 3 early or late treatment-related toxicities were observed. CONCLUSION: Octogenarians tolerate SBRT well, which makes it an attractive treatment option.
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Carcinoma de Pulmón de Células no Pequeñas/cirugía , Neoplasias Pulmonares/cirugía , Radiocirugia , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Masculino , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
PURPOSE: Stereotactic radiosurgery (SRS) is well accepted treatment for patients with intracranial metastases, but the role of frameless radiosurgery is not well defined. Here, we describe our clinical experience applying a novel single-isocenter technique to frameless intensity modulated stereotactic radiosurgery (IMRS) for simultaneous treatment of multiple intracranial metastases. METHODS AND MATERIALS: Between 2006 and 2012, 100 consecutive patients received frameless IMRS for multiple intracranial metastases using a single, centrally-located isocenter. Among these, 29 patients were treated for progressive or recurrent intracranial disease. A total of 465 metastases (median, 4 per patient, range, 2-18) were treated to a median dose of 20 Gy (range, 15-50 Gy). Follow-up including clinical examination and magnetic resonance imaging (MRI) occurred every 3 months. RESULTS: Median follow-up for all patients was 4.3 months (range, 0.2-58.3 months), with 83 patients (83.0%) followed until their death. For the remaining 17 patients alive at the time of analysis, median follow-up was 9.2 months (range, 2.2-58.3 months). Overall survival at 6 months was 49.5% [95% confidence interval (CI), 35.3-63.6%]. Local control at 6 and 12 months was 88.9% (95% CI, 79.1-98.6%) and 81.5% (95% CI, 65.2-97.7%), respectively. Regional failure was observed in 39 patients (39%), and 25 patients (25%) received salvage therapy. Grade 3 or greater treatment-related toxicity was observed in 4 patients (4%) and included intracranial hemorrhage, seizure, and radionecrosis. Median total treatment time was 17.2 minutes (range, 2.8-55.3 minutes). CONCLUSIONS: Single-isocenter IMRS for multiple intracranial metastases can produce clinical outcomes comparable to those of conventional radiosurgery techniques.
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Receptor tyrosine kinases and integrins play an essential role in tumor cell invasion and metastasis. We previously showed that EGF and other growth factors induce human carcinoma cell invasion and metastasis mediated by integrin αvß5 that is prevented by Src blockade. MUC1, a transmembrane glycoprotein, is expressed in most epithelial tumors as a heterodimer consisting of an extracellular and a transmembrane subunit. The MUC1 cytoplasmic domain of the transmembrane subunit (MUC1.CD) translocates to the nucleus where it promotes the transcription of a metastatic gene signature associated with epithelial to mesenchymal transition. Here, we demonstrate a requirement for MUC1 in carcinoma cell metastasis dependent on EGFR and Src without affecting primary tumor growth. EGF stimulates Src-dependent MUC1 cleavage and nuclear localization leading to the expression of genes linked to metastasis. Moreover, expression of MUC1.CD results in its nuclear localization and is sufficient for transcription of the metastatic gene signature and tumor cell metastasis. These results demonstrate that EGFR and Src activity contribute to carcinoma cell invasion and metastasis mediated by integrin αvß5 in part by promoting proteolytic cleavage of MUC1 and highlight the ability of MUC1.CD to promote metastasis in a context-dependent manner. Our findings may have implications for the use and future design of targeted therapies in cancers known to express EGFR, Src, or MUC1.
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Factor de Crecimiento Epidérmico , Receptores ErbB , Mucina-1 , Invasividad Neoplásica/genética , Proteínas Tirosina Quinasas , Receptores de Vitronectina , Animales , Proteína Tirosina Quinasa CSK , Carcinoma/genética , Carcinoma/metabolismo , Carcinoma/patología , Línea Celular Tumoral , Embrión de Pollo , Factor de Crecimiento Epidérmico/metabolismo , Factor de Crecimiento Epidérmico/farmacología , Transición Epitelial-Mesenquimal , Receptores ErbB/genética , Receptores ErbB/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Mucina-1/genética , Mucina-1/metabolismo , Metástasis de la Neoplasia , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/metabolismo , Receptores de Vitronectina/genética , Receptores de Vitronectina/metabolismo , Transducción de Señal , Familia-src QuinasasRESUMEN
Pancreatic cancer is one of the most lethal malignancies. To discover functionally relevant modulators of pancreatic neoplasia, we performed activity-based proteomic profiling on primary human ductal adenocarcinomas. Here, we identify retinoblastoma-binding protein 9 (RBBP9) as a tumor-associated serine hydrolase that displays elevated activity in pancreatic carcinomas. Whereas RBBP9 is expressed in normal and malignant tissues at similar levels, its elevated activity in tumor cells promotes anchorage-independent growth in vitro as well as pancreatic carcinogenesis in vivo. At the molecular level, RBBP9 activity overcomes TGF-beta-mediated antiproliferative signaling by reducing Smad2/3 phosphorylation, a previously unknown role for a serine hydrolase in cancer biology. Conversely, loss of endogenous RBBP9 or expression of mutationally inactive RBBP9 leads to elevated Smad2/3 phosphorylation, implicating this serine hydrolase as an essential suppressor of TGF-beta signaling. Finally, RBBP9-mediated suppression of TGF-beta signaling is required for E-cadherin expression as loss of the serine hydrolase activity leads to a reduction in E-cadherin levels and a concomitant decrease in the integrity of tumor cell-cell junctions. These data not only define a previously uncharacterized serine hydrolase activity associated with epithelial neoplasia, but also demonstrate the potential benefit of functional proteomics in the identification of new therapeutic targets.
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Carcinoma Ductal Pancreático/enzimología , Proteínas de Ciclo Celular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias Pancreáticas/enzimología , Secuencia de Aminoácidos , Animales , Cadherinas/metabolismo , Carcinoma Ductal Pancreático/etiología , Carcinoma Ductal Pancreático/patología , Proteínas de Ciclo Celular/genética , Línea Celular Tumoral , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Ratones , Ratones Desnudos , Datos de Secuencia Molecular , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/etiología , Neoplasias Pancreáticas/patología , Fosforilación , Proteómica , Homología de Secuencia de Aminoácido , Serina Endopeptidasas/genética , Serina Endopeptidasas/metabolismo , Transducción de Señal , Proteína Smad2/metabolismo , Proteína smad3/metabolismo , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
PURPOSE: We tested the significance of associations among students' demographics, communication styles, and feedback received during clerkships. METHODS: US medical students who completed at least one required clinical clerkship were invited between April and July 2006 to complete an anonymous, online survey inquiring about demographics, communication styles (assertiveness and reticence), feedback (positive and negative), and clerkship grades. The effects of self-identified race/ethnicity, gender, and generation (immigrant, first- or second-generation American) and their 2-way interactions on assertiveness, reticence, total positive and total negative feedback comments were tested using factorial analysis of covariance, controlling for age, clerkship grades, and mother's and father's education; pairwise comparisons used simple contrasts. Two-sided P values < .05 were considered significant. RESULTS: Medical students from 105 schools responded (N = 2395: 55% women; 57% white). Men reported more assertiveness than women (P = .001). Reticence (P < .001) and total positive comments (P = .006) differed by race/ethnicity; in pairwise contrasts, black, East Asian, and Native American/ Alaskan students reported greater reticence than white students (P < .001), and white students reported receiving more positive comments than black, and South and East Asian students. Race/ethnicity-by-generation (P = .022) and gender-by-generation (P = .025) interaction effects were observed for total negative comments; white first-generation Americans reported receiving the fewest and male immigrants reported receiving the most negative comments. CONCLUSIONS: Demographic differences in students' communication styles and feedback they received highlight a need for cultural competency training to improve medical student-teacher interactions, analogous to training currently advocated to improve physician-patient interactions.
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Prácticas Clínicas , Competencia Cultural , Diversidad Cultural , Estudiantes de Medicina/estadística & datos numéricos , Asertividad , Comunicación , Evaluación Educacional , Etnicidad/estadística & datos numéricos , Retroalimentación Psicológica , Femenino , Humanos , Masculino , Grupos Minoritarios/estadística & datos numéricos , Factores Sexuales , Encuestas y Cuestionarios , Estados UnidosRESUMEN
OBJECTIVES: Because clinical clerkship grades are associated with resident selection and performance and are largely based on residents'/attendings' subjective ratings, it is important to identify variables associated with clinical clerkship grades. METHODS: U.S. medical students who completed > or =1 of the following required clinical clerkships--internal medicine, surgery, obstetrics/gynecology, pediatrics, neurology and psychiatry--were invited to participate in an anonymous online survey, which inquired about demographics, degree program, perceived quality of clerkship experiences, assertiveness, reticence and clerkship grades. RESULTS: A total of 2395 medical students (55% women; 57% whites) from 105 schools responded. Multivariable logistic regression models identified factors independently associated with receiving lower clerkship grades (high pass/pass or B/C) compared with the highest grade (honors or A). Students reporting higher quality of clerkship experiences were less likely to report lower grades in all clerkships. Older students more likely reported lower grades in internal medicine (P = 0.02) and neurology (P < 0.001). Underrepresented minorities more likely reported lower grades in all clerkships (P < 0.001); Asians more likely reported lower grades in obstetrics/gynecology (P = 0.007), pediatrics (P = 0.01) and neurology (P = 0.01). Men more likely reported lower grades in obstetrics/gynecology (P < 0.001) and psychiatry (P = 0.004). Students reporting greater reticence more likely reported lower grades in internal medicine (P = 0.02), pediatrics (P = 0.02) and psychiatry (P < 0.05). Students reporting greater assertiveness less likely reported lower grades in all clerkships (P < 0.03) except IM. CONCLUSIONS: The independent associations between lower clerkship grades and nonwhite race, male gender, older age, lower quality of clerkship experiences, and being less assertive and more reticent are concerning and merit further investigation.
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Prácticas Clínicas/métodos , Competencia Clínica/normas , Evaluación Educacional/métodos , Estudiantes de Medicina/psicología , Adulto , Femenino , Humanos , Masculino , Estados UnidosRESUMEN
PU.1 is a member of the ETS family of transcription factors that is known to be important for hematopoietic development. Recently, haploinsufficiency for PU.1 has been shown to cause a shift in myelomonocytic progenitor fate toward the myeloid lineage. We have previously shown that transgenic mice expressing PML-RARalpha (PR) and RARalpha-PML frequently develop acute promyelocytic leukemia (APL) in association with a large (>20 Mb) interstitial deletion of chromosome 2 that includes PU.1. To directly assess the relevance of levels of expression of PU.1 for leukemia progression, we bred hCG-PR mice with PU.1+/- mice and assessed their phenotype. Young, nonleukemic hCG-PR x PU.1+/- mice developed splenomegaly because of the abnormal expansion of myeloid cells in their spleens. hCG-PR x PU.1+/- mice developed a typical APL syndrome after a long latent period, but the penetrance of disease was 84%, compared with 7% in hCG-PR x PU.1+/+ mice (P < 0.0001). The residual PU.1 allele in hCG-PR x PU.1+/- APL cells was expressed, and complete exonic resequencing revealed no detectable mutations in nine of nine samples. However, PR expression in U937 myelomonocytic cells and primary murine myeloid bone marrow cells caused a reduction in PU.1 mRNA levels. Therefore, the loss of one copy of PU.1 through a deletional mechanism, plus down-regulation of the residual allele caused by PR expression, may synergize to expand the pool of myeloid progenitors that are susceptible to transformation, increasing the penetrance of APL.
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Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/patología , Células Progenitoras Mieloides/patología , Proteínas de Neoplasias/genética , Proteínas de Fusión Oncogénica/genética , Proteínas Proto-Oncogénicas/genética , Transactivadores/genética , Animales , Deleción Cromosómica , Regulación hacia Abajo , Expresión Génica , Humanos , Leucemia Promielocítica Aguda/etiología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Fenotipo , Proteínas Proto-Oncogénicas/deficiencia , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Neoplásico/genética , ARN Neoplásico/metabolismo , Esplenomegalia/etiología , Esplenomegalia/genética , Esplenomegalia/patología , Transactivadores/deficiencia , Células U937RESUMEN
Leukemia results from the expansion of self-renewing hematopoietic cells that are thought to contain mutations that contribute to disease initiation and progression. Studies of the gene expression profiles of human acute myeloid leukemia samples has allowed their classification based on the presence of translocations and French-American-British subtypes, but it is not yet clear whether their molecular signatures reflect the initiating mutations or mutations acquired during progression. To begin to address this question, we examined the expression profiles of normal murine promyelocyte-enriched samples, nontransformed murine promyelocytes expressing human promyelocytic leukemia-retinoic acid receptor alpha (PML-RARalpha) fusion gene, and primary acute promyelocytic leukemia cells. The expression profile of nontransformed cells expressing PML-RARalpha was remarkably similar to that of wild-type promyelocytes. In contrast, the expression profiles of fully transformed cells from three acute promyelocytic leukemia model systems were all different, suggesting that the expression signature of acute promyelocytic leukemia cells reflects the genetic changes that contributed to progression. To further evaluate these progression events, we compared two high-penetrance acute promyelocytic leukemia models that both commonly acquire an interstitial deletion of chromosome 2 during progression. The two models exhibited distinct gene expression profiles, suggesting that the dominant molecular signatures of murine acute promyelocytic leukemia can be influenced by several independent progression events.