RESUMEN
BACKGROUND/OBJECTIVES: Skin cancer incidence has been increasing in U.S. Hispanics over several decades and the postdiagnosis outcomes are worse for Hispanics than for non-Hispanic whites. Parents are influential in children's health preventive behaviors, but little is known about parental factors associated with children's skin cancer-related behaviors in the U.S. Hispanic population. The present study examined parental and child correlates of skin cancer-related behaviors (sunburns, sunbathing, sun-protective clothing use, and sunscreen use) of children of Hispanic parents. METHODS: This survey study included a population-based sample of 360 U.S. Hispanic parents (44.8% male) who had a child 14 years of age or younger. Measures included parental reports of parent and child demographic characteristics, parent skin cancer knowledge and linguistic acculturation, and parent and child skin cancer-related behaviors. RESULTS: Approximately 28% of children and 31.9% of parents experienced at least one sunburn in the past year and approximately 29% of children and 36.7% of parents were reported to sunbathe. Moderate use of sun-protective clothing and sunscreen was reported for parents and their children. Child sun-protective clothing use and sunscreen use, sunburns, and sunbathing were associated with the corresponding behaviors of their parents. CONCLUSIONS: Future research should consider the role of acculturation and perceived risk in the sun protection behaviors of U.S. Hispanic children, particularly in those who report a fair skin type. Hispanic parents should be included in interventions targeting their children's skin cancer-related behaviors, and it is suggested that such interventions could also encourage parents to improve their own behaviors.
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Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Neoplasias Cutáneas/prevención & control , Quemadura Solar/prevención & control , Protectores Solares/administración & dosificación , Aculturación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Encuestas Epidemiológicas , Hispánicos o Latinos , Humanos , Lactante , Masculino , Persona de Mediana Edad , Padres , Ropa de Protección/estadística & datos numéricos , Baño de Sol/estadística & datos numéricos , Adulto JovenRESUMEN
Acral lentiginous melanoma (ALM) is a rare subtype of melanoma mainly arising on the palms, soles, and nail beds. ALM is the most common subtype of melanoma found in patients of Asian or African descent and tends to more advanced at presentation due to delays in diagnosis. Surgical treatment is difficult owing to the complexity and functional importance of the hands and feet and reconstruction after resection is usually needed. The prognosis for patients with ALM depends on stage of disease and tends to be worse than with other subtypes of melanoma. Newer treatment modalities such as immunotherapies and targeted agents are being tested in patients with advanced ALM with some promising preliminary results.
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Melanoma/terapia , Neoplasias Cutáneas/terapia , Enfermedades del Pie/patología , Enfermedades del Pie/terapia , Mano , Humanos , Melanoma/patología , Enfermedades de la Uña/patología , Enfermedades de la Uña/terapia , Pronóstico , Neoplasias Cutáneas/patologíaRESUMEN
Constitutive activation of MEK-ERK signaling is often found in melanomas. Here, we identify a mechanism that links ERK with JNK signaling in human melanoma. Constitutively active ERK increases c-Jun transcription and stability, which are mediated by CREB and GSK3, respectively. Subsequently, c-Jun increases transcription of target genes, including RACK1, an adaptor protein that enables PKC to phosphorylate and enhance JNK activity, enforcing a feed-forward mechanism of the JNK-Jun pathway. Activated c-Jun is also responsible for elevated cyclin D1 expression, which is frequently overexpressed in human melanoma. Our data reveal that, in human melanoma, the rewired ERK signaling pathway upregulates JNK and activates the c-Jun oncogene and its downstream targets, including RACK1 and cyclin D1.
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Quinasas MAP Reguladas por Señal Extracelular/metabolismo , MAP Quinasa Quinasa 4/metabolismo , Sistema de Señalización de MAP Quinasas , Melanoma/enzimología , Secuencia de Bases , Humanos , Melanoma/patología , Proteínas Proto-Oncogénicas c-jun/metabolismo , ARN Interferente PequeñoRESUMEN
The incidence of skin cancer among U.S. Hispanics increased 1.3% annually from 1992 to 2008. However, little research has focused on skin cancer prevention among the rapidly growing Hispanic population. In this study, we examined theory-driven, psychosocial correlates of sun protection behaviors in a population-based sample of 787 Hispanic adults (49.6% female, mean age = 41.0 years) residing in five southern or western U.S. states. Participants completed an English- or Spanish-language online survey in September 2011. The outcomes of focus were sunscreen use, shade seeking, and use of sun protective clothing. The correlates included suntan benefits, sun protection benefits and barriers, skin color preference, perceived natural skin protection, photo-aging concerns, perceived skin cancer risk, skin cancer worry, skin cancer fatalism, and sun protection descriptive norms. Results of multiple linear regression analyses revealed the following: sun protection barriers were negatively associated with each outcome; descriptive norms were positively associated with each outcome; perceived natural skin protection was inversely associated with sunscreen use; skin cancer worry was positively associated with shade seeking and use of sun protective clothing; skin cancer fatalism was negatively associated with shade seeking; and skin color preference was negatively associated with use of sun protective clothing. A number of additional statistically significant associations were identified in bivariate correlation analyses. This study informs the potential content of interventions to promote engagement in sun protection behaviors among U.S. Hispanics.
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Conductas Relacionadas con la Salud , Conocimientos, Actitudes y Práctica en Salud , Hispánicos o Latinos/psicología , Ropa de Protección/estadística & datos numéricos , Neoplasias Cutáneas/prevención & control , Protectores Solares/administración & dosificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Cutáneas/psicología , Adulto JovenRESUMEN
BACKGROUND: Little skin cancer prevention research has focused on the US Hispanic population. OBJECTIVE: This study examined the prevalence and correlates of skin cancer surveillance behaviors among Hispanic adults. METHODS: A population-based sample of 788 Hispanic adults residing in 5 southern and western states completed an online survey in English or Spanish in September 2011. The outcomes were ever having conducted a skin self-examination (SSE) and having received a total cutaneous examination (TCE) from a health professional. The correlates included sociodemographic, skin cancer-related, and psychosocial factors. RESULTS: The rates of ever conducting a SSE or having a TCE were 17.6% and 9.2%, respectively. Based on the results of multivariable logistic regressions, factors associated with ever conducting a SSE included older age, English linguistic acculturation, a greater number of melanoma risk factors, more frequent sunscreen use, sunbathing, job-related sun exposure, higher perceived skin cancer risk, physician recommendation, more SSE benefits, and fewer SSE barriers. Factors associated with ever having a TCE were older age, English linguistic acculturation, a greater number of melanoma risk factors, ever having tanned indoors, greater skin cancer knowledge, higher perceived skin cancer severity, lower skin cancer worry, physician recommendation, more TCE benefits, and fewer SSE barriers. LIMITATIONS: The cross-sectional design limits conclusions regarding the causal nature of observed associations. CONCLUSIONS: Few Hispanic adults engage in skin cancer surveillance behaviors. The study highlights Hispanic subpopulations that are least likely to engage in skin cancer surveillance behaviors and informs the development of culturally appropriate interventions to promote these behaviors.
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Conductas Relacionadas con la Salud/etnología , Neoplasias Cutáneas/prevención & control , Adulto , Estudios Transversales , Femenino , Hispánicos o Latinos , Humanos , Masculino , Análisis Multivariante , Prevalencia , Neoplasias Cutáneas/epidemiología , Estados UnidosRESUMEN
BACKGROUND: Skin cancer prevention interventions that target the growing number of U.S. Hispanics are lacking. The current study examined the prevalence and correlates of sun protection and exposure behaviors (i.e., sunscreen use, shade seeking, use of sun protective clothing, and sunburns) among U.S. Hispanics with sun sensitive skin, with a focus on potential differences according to acculturation and Hispanic origin. METHODS: The sample consisted of 1676 Hispanic adults who reported having sun sensitive skin (i.e., they would experience a sunburn if they went out in the sun for one hour without protection after several months of not being in the sun). Participants completed survey questions as part of the nationally representative 2010 National Health Interview Survey. Analyses were conducted in August 2012. RESULTS: Greater acculturation was linked with both risky (i.e., not wearing sun protective clothing) and protective (i.e., using sunscreen) sun-related practices and with an increased risk of sunburns. Sun protection and exposure behaviors also varied according to individuals' Hispanic origin, with for example individuals of Mexican heritage having a higher rate of using sun protective clothing and experiencing sunburns than several other subgroups. CONCLUSIONS: Several Hispanic subpopulations (e.g., those who are more acculturated or from certain origins) represent important groups to target in skin cancer prevention interventions. Future research is needed to test culturally relevant, tailored interventions to promote sun protection behaviors among U.S. Hispanics. Such initiatives should focus on public health education and increasing healthcare provider awareness of the importance of skin cancer prevention among Hispanics.
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Aculturación , Exposición a Riesgos Ambientales/efectos adversos , Conductas Relacionadas con la Salud/etnología , Hispánicos o Latinos/psicología , Ropa de Protección/estadística & datos numéricos , Quemadura Solar/etnología , Protectores Solares/uso terapéutico , Adolescente , Adulto , Anciano , Estudios Transversales , Femenino , Encuestas Epidemiológicas , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Masculino , México/etnología , Persona de Mediana Edad , Medición de Riesgo , Factores de Riesgo , Asunción de Riesgos , Quemadura Solar/prevención & control , Estados Unidos , Adulto JovenRESUMEN
INTRODUCTION: Sentinel lymph nodes (SLNs) of melanoma patients show evidence of tumor-induced immune dysfunction. Our previous works have shown that IL-10 and IFNγ co-regulate indoleamine-2,3-dioxygenase (IDO)-expressing immunosuppressive dendritic cells (DCs) in melanoma SLNs. The goal of this study is to examine the relationship between melanoma SLN tumor burden and the degree of SLN immune dysfunction as a model to study tumor-induced immune dysfunction. We hypothesize that SLN tumor burden correlates with the degree of SLN immune dysfunction. METHODS: Patients undergoing SLN biopsy for clinical stages I and II melanomas were enrolled in the study under an IRB-approved protocol. During the SLN biopsy, non-hot and non-blue portion of the SLN was harvested, flash-frozen in liquid nitrogen, and mRNA was extracted. By using quantitative real-time PCR, gene expressions of cytokines (IL-4, IL-10, IFNγ, TGFß, GM-CSF) and the surrogates of immunosuppressive regulatory and effector cells (IDO-expressing DCs and Foxp3-expressing T-regs, respectively) were measured and correlated against the SLN tumor burden (MART1) and against each other. The data were log transformed for normalization. Statistical test used Student's t-test and stepwise multivariate regression analysis. Statistical significance was determined at P < 0.05. RESULTS: SLNs of 74 patients were analyzed in this analysis. Ten of seventy-four patients (13.5%) had tumor-positive SLNs. MART1 gene expression showed a significant difference between the SLN (+) and SLN (-) groups (P = 0.04). Among the various cytokines, multivariate analysis showed that only IFNγ gene expression correlated independently with MART1 gene expression (P < 0.0001, r = 0.91). Similar multivariate analyses show that IFNγ (P < 0.0001, r = 0.78), IL-10 (P = 0.0037, r = 0.60), and TGFß (P < 0.0001, r = 0.95) gene expressions correlated independently with IDO gene expression. IFNγ (P < 0.0001, r = 0.87) and GM-CSF (P = 0.042, r = 0.76) gene expressions correlated independently with Foxp3 gene expression. MART1 gene expression showed independent correlation with IDO (P = 0.0002, r = 0.75) and Foxp3 (P = 0.0002, r = 0.75) gene expressions. CONCLUSION: SLN tumor burden correlates with immunosuppressive IDO and Foxp3 expressions within the SLNs of melanoma patients. Our data are consistent with our theory that melanoma induces expressions of specific cytokines, which in turn, stimulate immune suppressors within the SLN. This study also supports our previous finding that IL-10 and IFNγ co-regulate IDO within the SLN. In our data, IFNγ is the sole cytokine that correlates with the SLN tumor burden and seems to play a central role in tumor-induced immunological changes in the SLN immune microenvironment.
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Factores de Transcripción Forkhead/genética , Ganglios Linfáticos/inmunología , Melanoma/inmunología , Melanoma/patología , Citocinas/genética , Citocinas/inmunología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Femenino , Factores de Transcripción Forkhead/inmunología , Expresión Génica , Humanos , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-10/genética , Interleucina-10/inmunología , Ganglios Linfáticos/patología , Metástasis Linfática , Antígeno MART-1/genética , Antígeno MART-1/inmunología , Masculino , Melanoma/genética , Persona de Mediana Edad , Análisis Multivariante , Reacción en Cadena de la Polimerasa , Análisis de Regresión , Biopsia del Ganglio Linfático Centinela , Linfocitos T Reguladores/inmunología , Carga TumoralRESUMEN
BACKGROUND: Recently we reported that activation of Epac1, an exchange protein activated by cAMP, increases melanoma cell migration via Ca 2+ release from the endoplasmic reticulum (ER). G-protein ßγ subunits (Gßγ) are known to act as an independent signaling molecule upon activation of G-protein coupled receptor. However, the role of Gßγ in cell migration and Ca 2+ signaling in melanoma has not been well studied. Here we report that there is crosstalk of Ca 2+ signaling between Gßγ and Epac in melanoma, which plays a role in regulation of cell migration. METHODS: SK-Mel-2 cells, a human metastatic melanoma cell line, were mainly used in this study. Intracellular Ca 2+ was measured with Fluo-4AM fluorescent dyes. Cell migration was examined using the Boyden chambers. RESULTS: The effect of Gßγ on Epac-induced cell migration was first examined. Epac-induced cell migration was inhibited by mSIRK, a Gßγ -activating peptide, but not its inactive analog, L9A, in SK-Mel-2 cells. Guanosine 5', α-ß-methylene triphosphate (Gp(CH2)pp), a constitutively active GTP analogue that activates Gßγ, also inhibited Epac-induced cell migration. In addition, co-overexpression of ß1 and γ2, which is the major combination of Gßγ, inhibited Epac1-induced cell migration. By contrast, when the C-terminus of ß adrenergic receptor kinase (ßARK-CT), an endogenous inhibitor for Gßγ, was overexpressed, mSIRK's inhibitory effect on Epac-induced cell migration was negated, suggesting the specificity of mSIRK for Gßγ. We next examined the effect of mSIRK on Epac-induced Ca 2+ response. When cells were pretreated with mSIRK, but not with L9A, 8-(4-Methoxyphenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (8-pMeOPT), an Epac-specific agonist, failed to increase Ca 2+ signal. Co-overexpression of ß1 and γ2 subunits inhibited 8-pMeOPT-induced Ca 2+ elevation. Inhibition of Gßγ with ßARK-CT or guanosine 5'-O-(2-thiodiphosphate) (GDPßS), a GDP analogue that inactivates Gßγ, restored 8-pMeOPT-induced Ca 2+ elevation even in the presence of mSIRK. These data suggested that Gßγ inhibits Epac-induced Ca 2+ elevation. Subsequently, the mechanism by which Gßγ inhibits Epac-induced Ca 2+ elevation was explored. mSIRK activates Ca 2+ influx from the extracellular space. In addition, W-5, an inhibitor of calmodulin, abolished mSIRK's inhibitory effects on Epac-induced Ca 2+ elevation, and cell migration. These data suggest that, the mSIRK-induced Ca 2+ from the extracellular space inhibits the Epac-induced Ca 2+ release from the ER, resulting suppression of cell migration. CONCLUSION: We found the cross talk of Ca 2+ signaling between Gßγ and Epac, which plays a major role in melanoma cell migration.
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Señalización del Calcio/fisiología , Subunidades beta de la Proteína de Unión al GTP/fisiología , Proteínas de Unión al GTP/fisiología , Factores de Intercambio de Guanina Nucleótido/antagonistas & inhibidores , Melanoma/patología , Proteínas de Neoplasias/fisiología , Secuencia de Aminoácidos , Bloqueadores de los Canales de Calcio/farmacología , Calmodulina/fisiología , Línea Celular Tumoral/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Subunidades beta de la Proteína de Unión al GTP/genética , Proteínas de Unión al GTP/genética , Factores de Intercambio de Guanina Nucleótido/fisiología , Guanosina Difosfato/análogos & derivados , Guanosina Difosfato/farmacología , Guanosina Trifosfato/análogos & derivados , Guanosina Trifosfato/farmacología , Humanos , Melanoma/secundario , Datos de Secuencia Molecular , Proteínas de Neoplasias/antagonistas & inhibidores , Fragmentos de Péptidos/farmacología , Péptidos/farmacología , Proteínas Recombinantes de Fusión/fisiología , Proteínas Recombinantes/farmacología , Tionucleótidos/farmacología , Quinasas de Receptores Adrenérgicos beta/antagonistas & inhibidoresRESUMEN
The ubiquitin ligase Siah2 has been shown to regulate prolyl hydroxylase 3 (PHD3) stability with concomitant effect on HIF-1alpha availability. Because HIF-1alpha is implicated in tumorigenesis and metastasis, we used SW1 mouse melanoma cells, which develop primary tumors with a propensity to metastasize, in a syngeneic mouse model to assess a possible role for Siah2 in these processes. Inhibiting Siah2 activity by expressing a peptide designed to outcompete association of Siah2-interacting proteins reduced metastasis through HIF-1alpha without affecting tumorigenesis. Conversely, inhibiting Siah2 activity by means of a dominant-negative Siah2 RING mutant primarily reduced tumorigenesis through the action of Sprouty 2, a negative regulator of Ras signaling. Consistent with our findings, reduced expression of PHD3 and Sprouty2 was observed in more advanced stages of melanoma tumors. Using complementary approaches, our data establish the role of Siah2 in tumorigenesis and metastasis by HIF-dependent and -independent mechanisms.
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Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Melanoma Experimental/etiología , Proteínas de la Membrana/metabolismo , Metástasis de la Neoplasia , Ubiquitina-Proteína Ligasas/fisiología , Proteínas Adaptadoras Transductoras de Señales , Animales , Péptidos y Proteínas de Señalización Intracelular , Melanoma Experimental/patología , Proteínas de la Membrana/análisis , Ratones , Procolágeno-Prolina Dioxigenasa/análisis , Procolágeno-Prolina Dioxigenasa/metabolismo , Proteínas Serina-Treonina Quinasas , Transducción de Señal , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas ras/metabolismoRESUMEN
INTRODUCTION: Some melanoma patients who undergo sentinel lymph node (SLN) biopsy will have false-negative (FN) results. We sought to determine the factors and outcomes associated with FN SLN biopsy. METHODS: Analysis was performed of a prospective multi-institutional study that included patients with melanoma of thickness > 1.0 mm who underwent SLN biopsy. FN results were defined as the proportion of node-positive patients who had a tumor-negative sentinel node biopsy. Kaplan-Meier survival analysis and univariate and multivariate analyses were performed. RESULTS: This analysis included 2,451 patients with median follow-up of 61 months. FN, true-positive (TP), and true-negative (TN) SLN results were found in 59 (10.8%), 486 (19.8%), and 1,906 (77.8%) patients, respectively. On univariate analysis comparing the FN with TP groups, respectively, the following factors were significantly different: age (52.6 vs. 47.6 years, p = 0.004), thickness (mean 2.1 vs. 3.1 mm, p = 0.003), lymphovascular invasion (LVI; 3.7 vs. 13.7%, p = 0.037), and local/in-transit recurrence (LITR; 32.2 vs. 12.4%, p < 0.0001); these factors remained significant on multivariate analysis. Overall 5-year survival was greater in the TN group (86.7%) compared with the TP (62.3%) and FN (51.3%) groups (p < 0.0001); however, there was no significant difference in overall survival comparing the TP and FN groups (p = 0.32). CONCLUSIONS: This is the largest study to evaluate FN SLN results in melanoma, with a FN rate of 10.8%. FN results are associated with greater patient age, lower mean thickness, less frequent LVI, and greater risk of LITR. However, survival of patients with FN SLN is not statistically worse than that of patients with TP SLN.
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Ganglios Linfáticos/patología , Melanoma/diagnóstico , Recurrencia Local de Neoplasia/diagnóstico , Biopsia del Ganglio Linfático Centinela , Neoplasias Cutáneas/diagnóstico , Adolescente , Adulto , Anciano , Reacciones Falso Negativas , Femenino , Estudios de Seguimiento , Humanos , Metástasis Linfática , Masculino , Melanoma/cirugía , Persona de Mediana Edad , Recurrencia Local de Neoplasia/cirugía , Estadificación de Neoplasias , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Neoplasias Cutáneas/cirugía , Tasa de Supervivencia , Adulto JovenRESUMEN
PURPOSE: Ectopic expression of GRM1 in murine melanocytes results in transformation into a form of melanoma, and more than 60% of human melanoma samples tested ectopically express GRM1. Stimulation of this receptor in vitro results in up-regulation of activated extracellular signal-regulated kinase (ERK). Furthermore, a xenograft model of melanoma treated with riluzole, an oral GRM1 blocking agent, showed decreased tumor growth compared with the untreated controls. We have now completed a phase 0 trial of riluzole in patients with melanoma. EXPERIMENTAL DESIGN: Patients enrolled on this trial underwent a pretreatment biopsy, took 200 mg of oral riluzole per day for 14 days, and then underwent resection of their remaining tumor. We compared the levels of pERK and pAKT in the pretreatment and post-treatment samples and assessed the metabolic activity of pretreatment and post-treatment tumors using fluorodeoxyglucose positron emission tomography (FDG-PET) scanning. RESULTS: We accrued 12 patients and all expressed GRM1. We found a significant decrease in pAKT and/or pERK in post-treatment tumor samples as compared with pretreatment samples in 4 (34%) patients. These four patients had a significant decrease in FDG-PET intensity post-treatment as well. Two other patients had a clinical response with no corresponding metabolic response; five patients had similar pretreatment and post-treatment FDG-PET scan findings; and one patient had progressive disease. CONCLUSIONS: Our data show that glutamate blockade with riluzole can inhibit signaling through the mitogen-activated protein kinase and phosphatidylinositol 3-kinase/AKT pathways and suppress the metabolic activity of melanoma. The ectopic expression of metabotropic glutamate receptors may be important in the pathogenesis of human melanoma, and targeting this pathway may be an effective therapy.
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Melanoma/tratamiento farmacológico , Riluzol/uso terapéutico , Western Blotting , Caspasa 3/metabolismo , Activación Enzimática/efectos de los fármacos , Antagonistas de Aminoácidos Excitadores/uso terapéutico , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Fluorodesoxiglucosa F18 , Humanos , Inmunohistoquímica , Antígeno Ki-67/metabolismo , Melanoma/genética , Melanoma/metabolismo , Mutación , Estadificación de Neoplasias , Proteína Oncogénica v-akt/metabolismo , Tomografía de Emisión de Positrones , Proteínas Proto-Oncogénicas B-raf/genética , Receptores de Glutamato Metabotrópico/metabolismo , Proteínas ras/genéticaRESUMEN
PURPOSE: Activation of the mitogen-activated protein kinase (MAPK) pathway and the phosphatidylinositol 3-kinase/AKT pathway seems to be critical for melanoma proliferation. Components of these pathways are client proteins of heat-shock protein 90 (hsp90), suggesting that inhibition of hsp90 could have significant antimelanoma effects. We conducted a phase II trial using the hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) in melanoma patients. The primary end points were clinical responses and whether treatment inhibited MAPK pathway activity. EXPERIMENTAL DESIGN: Melanoma patients with measurable disease were stratified on the basis of whether or not their tumor harbored a V600E BRAF mutation. The hsp90 inhibitor 17-AAG was administered i.v. once weekly x 6 weeks at 450 mg/m2. Tumor biopsies were obtained pretreatment and 18 to 50 hours after the first dose of 17-AAG, and were snap-frozen. RESULTS: Fifteen evaluable patients were treated; nine had BRAF mutations and six were wild-type. No objective responses were observed. Western blot analysis of tumor biopsies showed an increase in hsp70 and a decrease in cyclin D1 expression in the posttreatment biopsies but no significant effect on RAF kinases or phospho-extracellular signal-regulated kinase expression. Plasma analyzed by mutant-specific PCR for V600E BRAF showed 86% sensitivity and 67% specificity in predicting tumor DNA sequencing results. CONCLUSIONS: At this dose and schedule of 17-AAG, the effects of 17-AAG on RAF kinase expression were short-lived, and no objective antimelanoma responses were seen. Future trials in melanoma should focus on a more potent hsp90 inhibitor or a formulation that can be administered chronically for a more prolonged suppression of the MAPK pathway.
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Benzoquinonas/uso terapéutico , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Lactamas Macrocíclicas/uso terapéutico , Melanoma/tratamiento farmacológico , Adulto , Anciano , Femenino , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Melanoma/genética , Persona de Mediana Edad , Mutación , Proteínas Proto-Oncogénicas B-raf/genéticaRESUMEN
Recently, several laboratories have started to investigate the involvement of glutamate signaling in cancer. In previous studies, we reported on a transgenic mouse model that develops melanoma spontaneously. Subsequent studies in these mice identified that the aberrant expression of metabotropic glutamate receptor 1 (GRM1) in melanocytes played a critical role in the onset of melanoma. Confirmation of the etiologic role of GRM1 in melanoma development was shown in a second transgenic line with GRM1 expression under the regulation of a melanocyte-specific dopachrome tautomerase promoter. Ectopic expression of GRM1 was also detected in a subset of human melanoma cell lines and biopsies, suggesting that aberrant expression of GRM1 in melanocytes may contribute to the development of human melanoma. GRM1, a seven-transmembrane domain G protein-coupled receptor, is normally expressed and functional in neuronal cells, and its ligand, glutamate, is the major excitatory neurotransmitter. Human melanoma cells are shown here to release elevated levels of glutamate, implying a possible autocrine loop. Treatment of GRM1-expressing human melanoma cells with a GRM1 antagonist (LY367385 or BAY36-7620) or a glutamate release inhibitor (riluzole) leads to a suppression of cell proliferation as well as a decrease in levels of extracellular glutamate. Treatment of human melanoma cell xenografts with riluzole for 18 days via p.o. gavage or i.v. injection leads to inhibition of tumor growth by 50% in comparison with controls. These data suggest the importance of glutamate signaling in human melanoma and imply that the suppression of glutamate signaling may be a new target for melanoma therapy.
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Ácido Glutámico/metabolismo , Melanoma/etiología , Receptores de Glutamato Metabotrópico/fisiología , Neoplasias Cutáneas/etiología , Animales , Antineoplásicos/uso terapéutico , Apoptosis , Proliferación Celular/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Humanos , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Melanoma/patología , Ratones , Ratones Desnudos , Proteínas Mutantes/fisiología , Receptores de Glutamato Metabotrópico/antagonistas & inhibidores , Receptores de Glutamato Metabotrópico/genética , Riluzol/uso terapéutico , Transducción de Señal , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
>1.2 million people in the United States have a personal history of melanoma skin cancer and are at increased risk for disease recurrence and second primary melanomas. Many of these individuals do not follow recommendations to conduct regular, thorough skin self-examinations that facilitate early disease detection and do not sufficiently engage in sun protection behaviors. In this project, we are conducting a randomized controlled trial of an innovative, tailored, theory-driven Internet intervention-called mySmartSkin-to promote these behaviors among melanoma patients. This paper outlines the study design and characteristics of the study sample. A total of 441 patients were recruited (40.9% response rate) and randomized to the mySmartSkin or a Usual Care condition. Participants complete surveys at baseline and 8â¯weeks, 24â¯weeks, and 48â¯weeks later. The primary aim of the project is to examine the impact of mySmartSkin versus Usual Care on skin self-examination and sun protection behaviors. The secondary aim focuses on identifying mediators of the intervention's effects. In an exploratory aim, we will examine potential moderators of the impact of the intervention. At baseline, the recruited participants had a mean age of 61â¯years, 49% were female, 7.5% met criteria for having conducted a recent, thorough skin self-examination, and the mean score on the index of sun protection behaviors was 3.3 (on a scale from 1 to 5). The results of the project will determine whether the mySmartSkin intervention is efficacious in promoting skin self-examination and sun protection behaviors among individuals diagnosed with melanoma. Trial registration: ClinicalTrials.govNCT03028948.
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Conductas Relacionadas con la Salud , Melanoma/prevención & control , Educación del Paciente como Asunto/métodos , Autoexamen/métodos , Neoplasias Cutáneas/prevención & control , Protectores Solares/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Intervención basada en la Internet , Masculino , Melanoma/diagnóstico , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Proyectos de Investigación , Prevención Secundaria/educación , Prevención Secundaria/métodos , Neoplasias Cutáneas/diagnóstico , Melanoma Cutáneo MalignoRESUMEN
Exosomes are naturally occurring membrane-bound nanovesicles generated constitutively and released by various cell types, and often in higher quantities by tumor cells. Exosomes may facilitate communication between the primary tumor and its local microenvironment, supporting cell invasion and other early events in metastasis. A neuronal receptor, metabotropic glutamate receptor 1 (GRM1), when ectopically expressed in melanocytes, induces in vitro melanocytic transformation and spontaneous malignant melanoma development in vivo in a transgenic mouse model. Our earlier studies showed that genetic modulation in GRM1 expression by siRNA or disruption of GRM1-mediated glutamate signaling interfere with downstream effectors resulting in a decrease in both cell proliferation in vitro and tumor progression in vivo. In this study, we sought to determine whether exosome formation might play a role in GRM1 mediated melanoma development and progression. To test this, we utilized in vitro cultured cells in which GRM1 expression and function could be modulated by pharmacological and genetic means and determined effects on exosome production. We also tested the effects of exosomes from GRM1 expressing melanoma cells on growth, migration and invasion of GRM1 negative cells. Our results show that although GRM1 expression has no influence on exosome quantity, exosomes produced by GRM1-positive cells modulate the ability of the recipient cell to migrate, invade and exhibit anchorage-independent cell growth.
RESUMEN
Our research group demonstrated that riluzole, an inhibitor of glutamatergic signaling reduced melanoma cell proliferation in vitro and tumor progression in vivo. The underlying mechanisms of riluzole are largely unknown. Microarray analyses on two human melanoma cell lines revealed that riluzole stimulates expression of the cystine-glutamate amino acid antiporter, xCT (SLC7A11). Western immunoblot analysis from cultured human melanoma or normal melanocytic cells showed that xCT was significantly overexpressed in most melanomas, but not normal cells. Studies using human tumor biopsy samples demonstrated that overexpression of xCT was correlated with cancer stage and progression. To further investigate if xCT is involved in melanoma cell growth, we derived several stable clones through transfection of exogenous xCT to melanoma cells that originally showed very low expression of xCT. The elevated xCT expression promoted cell proliferation in vitro and inversely, these melanoma clones showed a dose-dependent decrease in cell proliferation in response to riluzole treatment. Xenograft studies showed that these clones formed very aggressive tumors at a higher rate compared to vector controls. Conversely, treatment of xenograft-bearing animals with riluzole down-regulated xCT expression suggesting that xCT is a molecular target of riluzole. Furthermore, protein lysates from tumor biopsies of patients that participated in a riluzole monotherapy phase II clinical trial showed a reduction in xCT levels in post-treatment specimens from patients with stable disease. Taken together, our results show that xCT may be utilized as a marker to monitor patients undergoing riluzole-based chemotherapies.
RESUMEN
Studies demonstrate that GRM, expressed by >60% of human melanomas, may be a therapeutic target. We performed a phase II trial of 100 mg PO bid of riluzole, an inhibitor of GRM1 signaling, in patients with advanced melanoma with the primary endpoint of response rate. Thirteen patients with GRM1-positive tumors were enrolled. No objective responses were observed, and accrual was stopped. Stable disease was noted in six (46%) patients, with one patient on study for 42 weeks. Riluzole was well tolerated, with fatigue (62%) as the most common adverse event. Downregulation of MAPK and PI3K/AKT was noted in 33% of paired tumor biopsies. Hypothesis-generating correlative studies suggested that downregulation of angiogenic markers and increased leukocytes at the active edge of tumor correlate with clinical benefit. Pharmacokinetic analysis showed interpatient variability consistent with prior riluzole studies. Future investigations should interrogate mechanisms of biologic activity and advance the development of agents with improved bioavailability.
Asunto(s)
Regulación hacia Abajo/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Melanoma , Receptores de Glutamato Metabotrópico/antagonistas & inhibidores , Riluzol/administración & dosificación , Adulto , Femenino , Humanos , Masculino , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Melanoma/patología , Persona de Mediana Edad , Receptores de Glutamato Metabotrópico/biosíntesis , Riluzol/efectos adversosRESUMEN
Many melanoma patients do not regularly perform thorough skin self-examinations. We examined the extent to which melanoma patients conduct thorough skin self-examination, how they perform skin self-examination, and their related knowledge and self-efficacy. A sample of 176 individuals (61.5% response rate) diagnosed with primary pathologic stage 0-III cutaneous malignant melanoma at a single cancer center completed a written or telephone survey regarding their skin self-examination behaviors and associated factors. Almost all participants (98.9%) reported their race as white. Almost three-quarters (71.6%) of participants reported doing an examination in the past 2 months. However, only 14.2% had examined all areas of the body in the past 2 months. Few participants reported always using a full-length mirror (13.4%), hand-held mirror (11.3%), or having someone help (9.2%) when doing an examination. Having a higher level of education, greater knowledge of the ABCDE rule for detecting potential melanoma, higher skin self-examination self-efficacy, being shown how to do skin self-examination, and being shown what a suspicious mole would look like were all significantly associated with conducting more thorough skin self-examination. Most melanoma patients do not engage in regular, thorough skin self-examination, and when they do examine their skin they typically do not sufficiently utilize tools and techniques to facilitate a thorough examination and tracking of potentially suspicious moles. Efforts to promote skin self-examination among melanoma patients should focus on increasing knowledge and self-efficacy and providing education about the why, when, and how of conducting self-examination and mole tracking.
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Conductas Relacionadas con la Salud , Melanoma/diagnóstico , Autoexamen/estadística & datos numéricos , Neoplasias Cutáneas/diagnóstico , Piel , Sobrevivientes/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Melanoma/epidemiología , Persona de Mediana Edad , Autoeficacia , Neoplasias Cutáneas/epidemiologíaRESUMEN
Receptor tyrosine kinases-based autocrine loops largely contribute to activate the MAPK and PI3K/AKT pathways in melanoma. However, the molecular mechanisms involved in generating these autocrine loops are still largely unknown. In the present study, we examine the role of the transcription factor RUNX2 in the regulation of receptor tyrosine kinase (RTK) expression in melanoma. We have demonstrated that RUNX2-deficient melanoma cells display a significant decrease in three receptor tyrosine kinases, EGFR, IGF-1R and PDGFRß. In addition, we found co-expression of RUNX2 and another RTK, AXL, in both melanoma cells and melanoma patient samples. We observed a decrease in phosphoAKT2 (S474) and phosphoAKT (T308) levels when RUNX2 knock down resulted in significant RTK down regulation. Finally, we showed a dramatic up regulation of RUNX2 expression with concomitant up-regulation of EGFR, IGF-1R and AXL in melanoma cells resistant to the BRAF V600E inhibitor PLX4720. Taken together, our results strongly suggest that RUNX2 might be a key player in RTK-based autocrine loops and a mediator of resistance to BRAF V600E inhibitors involving RTK up regulation in melanoma.
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Comunicación Autocrina/fisiología , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Regulación Neoplásica de la Expresión Génica/fisiología , Melanoma/metabolismo , Proteínas Tirosina Quinasas Receptoras/biosíntesis , Línea Celular Tumoral , Resistencia a Antineoplásicos/fisiología , HumanosRESUMEN
PURPOSE: The Sunbelt Melanoma Trial is a prospective randomized trial evaluating the role of high-dose interferon alfa-2b therapy (HDI) or completion lymph node dissection (CLND) for patients with melanoma staged by sentinel lymph node (SLN) biopsy. PATIENTS AND METHODS: Patients were eligible if they were age 18 to 70 years with primary cutaneous melanoma ≥ 1.0 mm Breslow thickness and underwent SLN biopsy. In Protocol A, patients with a single tumor-positive lymph node after SLN biopsy underwent CLND and were randomly assigned to observation versus HDI. In Protocol B, patients with tumor-negative SLN by standard histopathology and immunohistochemistry underwent molecular staging by reverse transcriptase polymerase chain reaction (RT-PCR). Patients positive by RT-PCR were randomly assigned to observation versus CLND versus CLND+HDI. Primary end points were disease-free survival (DFS) and overall survival (OS). RESULTS: In the Protocol A intention-to-treat analysis, there were no significant differences in DFS (hazard ratio, 0.82; P = .45) or OS (hazard ratio, 1.10; P = .68) for patients randomly assigned to HDI versus observation. In the Protocol B intention-to-treat analysis, there were no significant differences in overall DFS (P = .069) or OS (P = .77) across the three randomized treatment arms. Similarly, efficacy analysis (excluding patients who did not receive the assigned treatment) did not demonstrate significant differences in DFS or OS in Protocol A or Protocol B. Median follow-up time was 71 months. CONCLUSION: No survival benefit for adjuvant HDI in patients with a single positive SLN was found. Among patients with tumor-negative SLN by conventional pathology but with melanoma detected in the SLN by RT-PCR, there was no OS benefit for CLND or CLND+HDI.