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BACKGROUND: Cutaneous melanoma is the most lethal skin cancer and its incidence in developed countries has dramatically increased over the past decades. Localized tumors are easily treated by surgery, but advanced melanomas lack efficient treatment and are associated with very poor outcomes. Thus, understanding the processes underlying melanoma development and progression is critical. The Transforming Growth Factor beta (TGFß) acts as a potent tumor suppressor in human melanoma, by inhibiting cell growth and preventing cellular migration and invasion. METHODS: In this study, we aimed at elucidating the molecular mechanisms underlying TGFß-mediated tumor suppression. Human cutaneous melanoma cell lines, derived from different patients, were used to assess for cell cycle analysis, apoptosis/caspase activity and cell migration. Techniques involved immunoblotting, immunohistochemistry, real time PCR and luciferase reporter assays. RESULTS: We found the leukemia inhibitory factor (LIF) to be strongly up-regulated by TGFß in melanoma cells, defining LIF as a novel TGFß downstream target gene in cutaneous melanoma. Interestingly, we also showed that TGFß-mediated LIF expression is required for TGFß-induced cell cycle arrest and caspase-mediated apoptosis, as well as for TGFß-mediated inhibition of cell migration. Moreover, we found that TGFß-mediated LIF expression leads to activation of transcription of the cell cycle inhibitor p21 in a STAT3-dependent manner, and further showed that p21 is required for TGFß/LIF-mediated cell cycle arrest and TGFß-induced gene activation of several pro-apoptotic genes. CONCLUSIONS: Together, our results define the LIF/p21 signaling cascade as a novel tumor suppressive-like pathway in melanoma, acting downstream of TGFß to regulate cell cycle arrest and cell death, further highlight new potential therapeutic strategies for the treatment of cutaneous melanoma.
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Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Factor Inhibidor de Leucemia/biosíntesis , Melanoma/genética , Neoplasias Cutáneas/genética , Factor de Crecimiento Transformador beta1/genética , Adulto , Apoptosis/genética , Puntos de Control del Ciclo Celular/genética , Movimiento Celular/genética , Proliferación Celular/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Factor Inhibidor de Leucemia/genética , Masculino , Melanoma/metabolismo , Melanoma/patología , Persona de Mediana Edad , Cultivo Primario de Células , Unión Proteica , Factor de Transcripción STAT3/genética , Transducción de Señal/genética , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Factor de Crecimiento Transformador beta1/metabolismo , Melanoma Cutáneo MalignoRESUMEN
Western blot is an extensively used method for protein detection in cell biology. To optimize this procedure, here we examined a panel of buffers for their ability to efficiently transfer proteins from SDS-polyacrylamide gels onto nitrocellulose membranes in a short 12-min period, designated here as fast semidry transfer. Our results show for the first time that HEPES- and HEPPS/EPPS-based buffers represent the most efficient buffers for fast semidry transfer.
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Colodión/química , Electroforesis en Gel de Poliacrilamida/métodos , Membranas Artificiales , Proteínas/aislamiento & purificación , Tampones (Química) , Electroforesis en Gel de Poliacrilamida/economía , HEPES/química , Factores de TiempoRESUMEN
During the Second World War, the Hadfield Spears ambulance took care of around 22,000 wounded and/or sick patients across three continents. This article analyses how military attacks and instances of violence impacted on the psychological, emotional and physical health of those attending the wounded within this mobile unit. While historiography of allied medicine develops apace, analysis of the Free French health service remains rare. Yet the history of the Hadfield Spears ambulance provides a fascinating window into the neglected issue of attacks on healthcare in wartime, as well as a fresh scope for combining macro and micro perspectives. The deployment of both approaches suggests potent ways to connect intimate responses to attacks to broader histories of allied frictions and cooperation. Crucially, it offers rich insights into the development of a transnational 'ethos of stoicism', which helped to sustain the hospital's community, in a fraught allied diplomatic context.
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Robust preclinical testing is essential to predict clinical safety and efficacy and provide data to determine safe dose for first-in-man studies. There are a growing number of examples where the preclinical development of drugs failed to adequately predict clinical adverse events in part due to their assessment with inappropriate preclinical models. Preclinical investigations of T cell receptor (TCR)-based immunotherapies prove particularly challenging as these biologics are human-specific and thus the conventional testing in animal models is inadequate. As these molecules harness the full force of the immune system, and demonstrate tremendous potency, we set out to design a preclinical package that would ensure adequate evaluation of these therapeutics. Immune Mobilising Monoclonal TCR Against Cancer (ImmTAC) molecules are bi-specific biologics formed of an affinity-enhanced TCR fused to an anti-CD3 effector function. ImmTAC molecules are designed to activate human T lymphocytes and target peptides within the context of a human leukocyte antigen (HLA), thus require an intact human immune system and peptidome for suitable preclinical screening. Here we draw upon the preclinical testing of four ImmTAC molecules, including IMCgp100, the first ImmTAC molecule to reach the clinic, to present our comprehensive, informative and robust approach to in vitro preclinical efficacy and safety screening. This package comprises a broad range of cellular and molecular assays using human tissues and cultured cells to test efficacy, safety and specificity, and hence predict human responses in clinical trials. We propose that this entirely in vitro package offers a potential model to be applied to screening other TCR-based biologics.
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Anticuerpos Biespecíficos/farmacología , Ensayos de Selección de Medicamentos Antitumorales/métodos , Proteínas/farmacología , Anticuerpos de Cadena Única/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Humanos , Técnicas In Vitro , Flujo de TrabajoRESUMEN
Over the past decades, the incidence of cutaneous melanoma in developed countries has increased faster than any other cancer. Although most patients have localized disease at the time of diagnosis and are cured by surgical excision of the primary tumor, melanoma can be highly malignant and the survival dramatically decreases for advanced stage melanomas. It is thus necessary to understand the progression of this disease. Cell migration and invasion promote tumor metastasis, the major cause of melanoma cancer morbidity and death. In this study, we investigated the role of the TGFß/Smad signaling pathway in melanoma tumor progression and found TGFß to potently inhibit both cell migration and invasion in human melanoma cell lines, established from different patients. Furthermore, we elucidated the molecular mechanisms by which TGFß exerts its effects and found the plasminogen activation system (PAS) to play a central role in the regulation of these effects. We found TGFß to strongly up-regulate the Plasminogen Activator Inhibitor-1 (PAI-1) in melanoma cells, leading to reduced plasmin generation and activity and, in turn to inhibition of cell migration and invasion. Together, our results define TGFß as a potent suppressor of tumor progression in cutaneous melanoma, inhibiting both cell migration and invasion.
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Movimiento Celular/efectos de los fármacos , Inhibidor 1 de Activador Plasminogénico/metabolismo , Activadores Plasminogénicos/metabolismo , Factor de Crecimiento Transformador beta/farmacología , Adulto , Anciano , Supervivencia Celular/efectos de los fármacos , Femenino , Fibrinolisina/metabolismo , Humanos , Masculino , Melanoma/metabolismo , Melanoma/patología , Persona de Mediana Edad , Inhibidor 1 de Activador Plasminogénico/química , Inhibidor 1 de Activador Plasminogénico/genética , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Transducción de Señal , Neoplasias Cutáneas/metabolismo , Neoplasias Cutáneas/patología , Proteínas Smad/antagonistas & inhibidores , Proteínas Smad/genética , Proteínas Smad/metabolismo , Células Tumorales Cultivadas , Regulación hacia ArribaRESUMEN
A femtosecond laser based transfection method using off-resonance plasmonic gold nanoparticles is described. For human cancer melanoma cells, the treatment leads to a very high perforation rate of 70%, transfection efficiency three times higher than for conventional lipofection, and very low toxicity (<1%). Off-resonance laser excitation inhibited the fracture of the nanoparticles into possibly toxic DNA intercalating particles. This efficient and low toxicity method is a promising alternative to viral transfection for skin cancer treatment.