Melanoma tumour vasculature heterogeneity: from mice models to human

Tumour angiogenesis is defined by an anarchic vasculature and irregularities in alignment of endothelial cells. These structural abnormalities could explain the variability in distribution of nanomedicines in various tumour models. Then, the main goal of this study was to compare and to characterize the tumour vascular structure in different mouse models of melanoma tumours (B16F10 and SK-Mel-28) and in human melanomas from different patients. Tumours were obtained by subcutaneous injection of 106 B16F10 and 3.106 SK-Mel-28 melanoma cells in C57BL/6 and nude mice, respectively. Tumour growth was evaluated weekly, while vasculature was analysed through fluorescent labelling via CD31 and desmin. Significant differences in tumour growth and mice survival were evidenced between the two melanoma models. A fast evolution of tumours was observed for B16F10 melanoma, reaching a tumour size of 100 mm3 in 7 days compared to SK-Mel-28 which needed 21 days to reach the same volumes. Important differences in vascularization were exposed between the melanoma models, characterized by a significant enhancement of vascular density and a significant lumen size for mice melanoma models compared to human. Immunostaining revealed irregularities in endothelium structure for both melanoma models, but structural differences of vasculature were observed, characterized by a stronger expression of desmin in SK-Mel-28 tumours. While human melanoma mainly develops capillaries, structural irregularities are also observed on the samples of this tumour model. Our study revealed an impact of cell type and tumour progression on the structural vasculature of melanoma, which could impact the distribution of drugs in the tumour environment

Electrochemical methods for speciation of trace elements in marine waters. Dynamic aspects

The contribution of electrochemical methods to the knowledge of dynamic speciation of toxic trace elements in marine waters is critically reviewed. Due to the importance of dynamic considerations in the interpretation of the electrochemical signal, the principles and recent developments of kinetic features in the interconversion of metal complex species will be presented. As dynamic electrochemical methods, only stripping techniques (anodic stripping voltammetry and stripping chronopotentiometry) will be used because they are the most important for the determination of trace elements. Competitive ligand ex- change-adsorptive cathodic stripping voltammetry, which should be considered an equilibrium technique rather than a dynamic method, will be also discussed because the complexing parameters may be affected by some kinetic limitations if equilibrium before analysis is not attained and/or the flux of the adsorbed complex is in fluenced by the lability of the natural complexes in the water sample. For a correct data interpretation and system characterization the comparison of results obtained from different techniques seems essential in the articulation of a serious discussion of their meaning

Characterization of an endothelial-mesenchymal transition cell model application to melanoma

International audienc

Phase II study of vinflunine in malignant pleural mesothelioma.

PURPOSE: Malignant pleural mesothelioma (MPM) is a disease of increasing incidence for which treatment options are limited. This study reports the clinical efficacy data for vinflunine, a novel microtubule inhibitor, in MPM. PATIENTS AND METHODS: Patients with a histologically confirmed diagnosis of MPM were eligible for enrollment onto this multicenter phase II trial if they had not received prior chemotherapy or radiotherapy and had measurable lesions by Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Vinflunine 320 mg/m2 by 10-minute intravenous infusion was administered on day 1 of 21-day cycles. Modifications of dose and schedule were made according to National Cancer Institute Common Toxicity Criteria version 2.0. Efficacy was assessed by an external, independent radiologist. The one-sample multiple testing procedure of Fleming was applied at the predetermined recruitment stages of 20 and 40 assessable patients. RESULTS: Sixty-seven patients were enrolled. Five patients were not assessable for tumor response. The response rate was 13.8% (95% CI, 6.5% to 24.7%). The median survival was 10.8 months (95% CI, 7.8 to 12.0 months). The most common adverse events were anemia, neutropenia, fatigue, constipation, and nausea. Of grade 3 and 4 toxicities, neutropenia and constipation were the most common (45% and 9% of patients, respectively). CONCLUSION: Vinflunine can be delivered with high-dose intensity in patients with MPM. The response rate and median survival are encouraging for a single agent. These data suggest that vinflunine should be further evaluated in the management of MPM