RESUMEN
>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
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.
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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.
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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
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.
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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
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.
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Antineoplásicos/administración & dosificación , Interferón-alfa/administración & dosificación , Escisión del Ganglio Linfático , Melanoma/tratamiento farmacológico , Melanoma/patología , Biopsia del Ganglio Linfático Centinela , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología , Adulto , Anciano , Quimioterapia Adyuvante , Esquema de Medicación , Femenino , Estudios de Seguimiento , Humanos , Inmunohistoquímica , Interferón alfa-2 , Estimación de Kaplan-Meier , Masculino , Melanoma/cirugía , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Prospectivos , Proteínas Recombinantes/administración & dosificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias Cutáneas/cirugía , Resultado del Tratamiento , Espera Vigilante , Melanoma Cutáneo MalignoAsunto(s)
Internet , Melanoma/prevención & control , Autoexamen/métodos , Neoplasias Cutáneas/prevención & control , Anciano , Femenino , Humanos , Masculino , Melanoma/etiología , Melanoma/patología , Persona de Mediana Edad , Neoplasias Cutáneas/etiología , Neoplasias Cutáneas/patología , Luz Solar/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
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
BACKGROUND: Occupational ultraviolet radiation (UVR) exposure is a risk factor for skin cancer, and Hispanic individuals are over-represented in a number of outdoor occupations (e.g., farming, landscaping). This study examined predictors of occupational sunscreen use in a group of US Hispanic adults who work outdoors. RESULTS: A population-based sample of outdoor workers (n = 149, 85 % male) completed survey measures regarding their demographics, melanoma risk, perceived skin cancer risk, skin cancer knowledge, and their occupational sunscreen use. Sixty-nine percent of the sample reported never or rarely wearing sunscreen while working outdoors. Being female (p = .02), having a higher level of education (p = .03), and residing at a higher latitude (p = .04) were associated with more frequent sunscreen use. CONCLUSIONS: This study highlights the importance of interventions to promote sun protection behaviors among US Hispanic outdoor workers, and identifies potential intervention targets.
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Hispánicos o Latinos , Exposición Profesional/prevención & control , Protectores Solares/uso terapéutico , Adulto , Femenino , Humanos , Modelos Logísticos , Masculino , Estados UnidosRESUMEN
Our group has previously reported that the majority of human melanomas (>60%) express the metabotropic glutamate receptor 1 (GRM1) and that the glutamate release inhibitor riluzole, a drug currently used to treat amyotrophic lateral sclerosis, can induce apoptosis in GRM1-expressing melanoma cells. Our group previously reported that in vitro riluzole treatment reduces cell growth in three-dimensional (3D) soft agar colony assays by 80% in cells with wildtype phosphoinositide 3-kinase (PI3K) pathway activation. However, melanoma cell lines harboring constitutive activating mutations of the PI3K pathway (PTEN and NRAS mutations) showed only a 35% to 40% decrease in colony formation in soft agar in the presence of riluzole. In this study, we have continued our preclinical studies of riluzole and its effect on melanoma cells alone and in combination with inhibitors of the PI3 kinase pathway: the AKT inhibitor, API-2, and the mammalian target of rapamycin (mTOR) inhibitor, rapamycin. We modeled these combinatorial therapies on various melanoma cell lines in 3D and 2D systems and in vivo. Riluzole combined with mTOR inhibition is more effective at halting melanoma anchorage-independent growth and xenograft tumor progression than either agent alone. PI3K signaling changes associated with this combinatorial treatment shows that 3D (nanoculture) modeling of cell signaling more closely resembles in vivo signaling than monolayer models. Riluzole combined with mTOR inhibition is effective at halting tumor cell progression independent of BRAF mutational status. This makes this combinatorial therapy a potentially viable alternative for metastatic melanoma patients who are BRAF WT and are therefore ineligible for vemurafenib therapy.
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Approximately 50% of patients having metastatic melanoma develop brain metastases during the course of their illness. Evidence exists that melanoma cells have increased aptitude for the repair of sublethal DNA damage caused by ionizing radiation therapy. To address the radio-resistance of melanoma, many groups adopted radiotherapy schedules that deliver larger daily fractions of radiation, but due to the risk of neurotoxicity, these large fractions cannot be delivered to the whole brain for patients with brain metastases. Here, we used orthotopic implanted GRM1 expressing human melanoma cell xenografts in mice, to demonstrate that animals receiving concurrent glutamate signaling blockade (riluzole) and radiation led to a decrease in intracranial tumor growth compared to either modality alone. These preclinical results suggest riluzole may cause radio-sensitization that offers enhanced efficacy for a subset of human melanoma patients undergoing radiotherapy for brain metastasis.
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Neoplasias Encefálicas/secundario , Melanoma/tratamiento farmacológico , Melanoma/patología , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Receptores de Glutamato Metabotrópico/metabolismo , Riluzol/uso terapéutico , Animales , Neoplasias Encefálicas/tratamiento farmacológico , Línea Celular Tumoral , Células Clonales , Modelos Animales de Enfermedad , Humanos , Luciferasas/metabolismo , Luminiscencia , Ratones , Fármacos Sensibilizantes a Radiaciones/farmacología , Riluzol/farmacología , Carga Tumoral , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Fibroblast growth factor (FGF2) regulates endothelial and melanoma cell migration. The binding of FGF2 to its receptor requires N-sulfated heparan sulfate (HS) glycosamine. We have previously reported that Epac1, an exchange protein activated by cAMP, increases N-sulfation of HS in melanoma. Therefore, we examined whether Epac1 regulates FGF2-mediated cell-cell communication. Conditioned medium (CM) of melanoma cells with abundant expression of Epac1 increased migration of human umbilical endothelial cells (HUVEC) and melanoma cells with poor expression of Epac1. CM-induced increase in migration was inhibited by antagonizing FGF2, by the removal of HS and by the knockdown of Epac1. In addition, knockdown of Epac1 suppressed the binding of FGF2 to FGF receptor in HUVEC, and in vivo angiogenesis in melanoma. Furthermore, knockdown of Epac1 reduced N-sulfation of HS chains attached to perlecan, a major secreted type of HS proteoglycan that mediates the binding of FGF2 to FGF receptor. These data suggested that Epac1 in melanoma cells regulates melanoma progression via the HS-FGF2-mediated cell-cell communication.
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Movimiento Celular , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Factores de Intercambio de Guanina Nucleótido/biosíntesis , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Melanoma/metabolismo , Proteínas de Neoplasias/metabolismo , Neovascularización Patológica/metabolismo , Comunicación Paracrina , Línea Celular Tumoral , Factor 2 de Crecimiento de Fibroblastos/genética , Regulación Neoplásica de la Expresión Génica/genética , Técnicas de Silenciamiento del Gen , Factores de Intercambio de Guanina Nucleótido/genética , Células Endoteliales de la Vena Umbilical Humana/patología , Humanos , Melanoma/irrigación sanguínea , Melanoma/genética , Melanoma/patología , Proteínas de Neoplasias/genética , Neovascularización Patológica/genética , Neovascularización Patológica/patologíaRESUMEN
Store-operated Ca(2+) entry (SOCE) is a major mechanism of Ca(2) (+) import from extracellular to intracellular space, involving detection of Ca(2+) store depletion in endoplasmic reticulum (ER) by stromal interaction molecule (STIM) proteins, which then translocate to plasma membrane and activate Orai Ca(2+) channels there. We found that STIM1 and Orai1 isoforms were abundantly expressed in human melanoma tissues and multiple melanoma/melanocyte cell lines. We confirmed that these cell lines exhibited SOCE, which was inhibited by knockdown of STIM1 or Orai1, or by a pharmacological SOCE inhibitor. Inhibition of SOCE suppressed melanoma cell proliferation and migration/metastasis. Induction of SOCE was associated with activation of extracellular-signal-regulated kinase (ERK), and was inhibited by inhibitors of calmodulin kinase II (CaMKII) or Raf-1, suggesting that SOCE-mediated cellular functions are controlled via the CaMKII/Raf-1/ERK signaling pathway. Our findings indicate that SOCE contributes to melanoma progression, and therefore may be a new potential target for treatment of melanoma, irrespective of whether or not Braf mutation is present.
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Señalización del Calcio/fisiología , Calcio/metabolismo , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Melanocitos/metabolismo , Melanoma/metabolismo , Neoplasias Cutáneas/metabolismo , Animales , Canales de Calcio/metabolismo , Línea Celular Tumoral , Retículo Endoplásmico/metabolismo , Humanos , Melanoma/patología , Ratones , Neoplasias Cutáneas/patologíaRESUMEN
In the present study, we investigated the role of the transcription factor RUNX2 in melanomagenesis. We demonstrated that the expression of transcriptionally active RUNX2 was increased in melanoma cell lines as compared with human melanocytes. Using a melanoma tissue microarray, we showed that RUNX2 levels were higher in melanoma cells as compared with nevic melanocytes. RUNX2 knockdown in melanoma cell lines significantly decreased Focal Adhesion Kinase expression, and inhibited their cell growth, migration and invasion ability. Finally, the pro-hormone cholecalciferol reduced RUNX2 transcriptional activity and decreased migration of melanoma cells, further suggesting a role of RUNX2 in melanoma cell migration.
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Movimiento Celular , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Melanoma/metabolismo , Neoplasias Cutáneas/metabolismo , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular , Colecalciferol/farmacología , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Quinasa 1 de Adhesión Focal/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Metaloproteinasa 13 de la Matriz/genética , Melanoma/genética , Melanoma/patología , Invasividad Neoplásica , Regiones Promotoras Genéticas , Interferencia de ARN , Transducción de Señal , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patología , Análisis de Matrices Tisulares , Transcripción Genética , Transfección , Regulación hacia ArribaRESUMEN
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
Glutamate-triggered signal transduction is thought to contribute widely to cancer pathogenesis. In melanoma, overexpression of the metabotropic glutamate receptor (GRM)-1 occurs frequently and its ectopic expression in melanocytes is sufficient for neoplastic transformation. Clinical evaluation of the GRM1 signaling inhibitor riluzole in patients with advanced melanoma has demonstrated tumor regressions that are associated with a suppression of the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathways. Together, these results prompted us to investigate the downstream consequences of GRM1 signaling and its disruption in more detail. We found that melanoma cells with enhanced GRM1 expression generated larger tumors in vivo marked by more abundant blood vessels. Media conditioned by these cells in vitro contained relatively higher concentrations of interleukin-8 and VEGF due to GRM1-mediated activation of the AKT-mTOR-HIF1 pathway. In clinical specimens from patients receiving riluzole, we confirmed an inhibition of MAPK and PI3K/AKT activation in posttreatment as compared with pretreatment tumor specimens, which exhibited a decreased density of blood vessels. Together, our results demonstrate that GRM1 activation triggers proangiogenic signaling in melanoma, offering a mechanistic rationale to design treatment strategies for the most suitable combinatorial use of GRM1 inhibitors in patients.
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Melanoma/metabolismo , Neovascularización Patológica/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Neoplasias Cutáneas/metabolismo , Inhibidores de la Angiogénesis/farmacología , Animales , Movimiento Celular , Compuestos Heterocíclicos con 3 Anillos/farmacología , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Indazoles/farmacología , Proteínas Inhibidoras de la Apoptosis/metabolismo , Interleucina-8/metabolismo , Melanoma/irrigación sanguínea , Melanoma/patología , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Riluzol/farmacología , Transducción de Señal , Sirolimus/farmacología , Neoplasias Cutáneas/irrigación sanguínea , Neoplasias Cutáneas/patología , Survivin , Carga Tumoral , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
TNBC is an aggressive breast cancer subtype that does not express hormone receptors (estrogen and progesterone receptors, ER and PR) or amplified human epidermal growth factor receptor type 2 (HER2), and there currently exist no targeted therapies effective against it. Consequently, finding new molecular targets in triple negative breast cancer (TNBC) is critical to improving patient outcomes. Previously, we have detected the expression of metabotropic glutamate receptor-1 (gene: GRM1; protein: mGluR1) in TNBC and observed that targeting glutamatergic signaling inhibits TNBC growth both in vitro and in vivo. In this study, we explored how mGluR1 contributes to TNBC progression, using the isogenic MCF10 progression series, which models breast carcinogenesis from nontransformed epithelium to malignant basal-like breast cancer. We observed that mGluR1 is expressed in human breast cancer and that in MCF10A cells, which model nontransformed mammary epithelium, but not in MCF10AT1 cells, which model atypical ductal hyperplasia, mGluR1 overexpression results in increased proliferation, anchorage-independent growth, and invasiveness. In contrast, mGluR1 knockdown results in a decrease in these activities in malignant MCF10CA1d cells. Similarly, pharmacologic inhibition of glutamatergic signaling in MCF10CA1d cells results in a decrease in proliferation and anchorage-independent growth. Finally, transduction of MCF10AT1 cells, which express c-Ha-ras, using a lentiviral construct expressing GRM1 results in transformation to carcinoma in 90% of resultant xenografts. We conclude that mGluR1 cooperates with other factors in hyperplastic mammary epithelium to contribute to TNBC progression and therefore propose that glutamatergic signaling represents a promising new molecular target for TNBC therapy.
Asunto(s)
Receptores de Glutamato Metabotrópico/metabolismo , Neoplasias de la Mama Triple Negativas/metabolismo , Neoplasias de la Mama Triple Negativas/patología , Animales , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/metabolismo , Transformación Celular Neoplásica/patología , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Expresión Génica , Silenciador del Gen , Xenoinjertos , Humanos , Ratones , Receptores de Glutamato Metabotrópico/genética , Transducción de Señal , Neoplasias de la Mama Triple Negativas/genéticaRESUMEN
Gain of function of the neuronal receptor, metabotropic glutamate receptor 1 (Grm1), was sufficient to induce melanocytic transformation in vitro and spontaneous melanoma development in vivo when ectopically expressed in melanocytes. The human form of this receptor, GRM1, has been shown to be ectopically expressed in a subset of human melanomas but not benign nevi or normal melanocytes, suggesting that misregulation of GRM1 is involved in the pathogenesis of certain human melanomas. Sustained stimulation of Grm1 by the ligand, glutamate, is required for the maintenance of transformed phenotypes in vitro and tumorigenicity in vivo. In this study, we investigate the mechanism of an inhibitor of glutamate release, riluzole, on human melanoma cells that express metabotropic glutamate receptor 1 (GRM1). Various in vitro assays conducted show that inhibition of glutamate release in several human melanoma cell lines resulted in an increase of oxidative stress and DNA damage response markers.