Promising pre-clinical validation of targeted radionuclide therapy using a [131I] labelled iodoquinoxaline derivative for an effective melanoma treatment

Targeted internal radionuclide therapy (TRT) would be an effective alternative to current therapies for dissemi- nated melanoma treatment. At our institution, a class of iodobenzamides has been developed as potent melanoma- seeking agents. This review described the preclinical vali- dations of a quinoxaline derivative molecule (ICF01012) as tracer for TRT application. It was selected for its high, specific and long-lasting uptake in tumour with rapid clear- ance from non-target organs providing suitable dosimetry parameters for TRT. Extended in vivo study of metabolic profiles confirmed durable tumoural concentration of the unchanged molecule form. Moreover melanin specificity of ICF01012 was determined by binding assay with syn- thetic melanin and in vivo by SIMS imaging. Then, we showed in vivo that [131I] ICF01012 treatment drastically inhibited growth of B16F0, B16Bl6 and M4Beu tumours whereas [131I] NaI or unlabelled ICF01012 treatment was without significant effect. Histological analysis showed that residual tumour cells exhibit a significant loss of aggres- siveness after treatment. This anti-tumoural effect was associated with a lengthening of the treated-mice survival time and an inhibition of lung dissemination for B16Bl6 model. Results presented here support the concept of TRT using a [131I] labelled iodoquinoxaline derivative for an effective melanoma treatment.<br /

Comparative proteomics: assessment of biological variability and dataset comparability

BACKGROUND: Comparative proteomics in bacteria are often hampered by the differential nature of dataset quality and/or inherent biological deviations. Although common practice compensates by reproducing and normalizing datasets from a single sample, the degree of certainty is limited in comparison of multiple dataset. To surmount these limitations, we introduce a two-step assessment criterion using: (1) the relative number of total spectra (R (TS)) to determine if two LC-MS/MS datasets are comparable and (2) nine glycolytic enzymes as internal standards for a more accurate calculation of relative amount of proteins. Lactococcus lactis HR279 and JHK24 strains expressing high or low levels (respectively) of green fluorescent protein (GFP) were used for the model system. GFP abundance was determined by spectral counting and direct fluorescence measurements. Statistical analysis determined relative GFP quantity obtained from our approach matched values obtained from fluorescence measurements. RESULTS: L. lactis HR279 and JHK24 demonstrates two datasets with an R (TS) value less than 1.4 accurately reflects relative differences in GFP levels between high and low expression strains. Without prior consideration of R (TS) and the use of internal standards, the relative increase in GFP calculated by spectral counting method was 3.92 ± 1.14 fold, which is not correlated with the value determined by the direct fluorescence measurement (2.86 ± 0.42 fold) with the p = 0.024. In contrast, 2.88 ± 0.92 fold was obtained by our approach showing a statistically insignificant difference (p = 0.95). CONCLUSIONS: Our two-step assessment demonstrates a useful approach to: (1) validate the comparability of two mass spectrometric datasets and (2) accurately calculate the relative amount of proteins between proteomic datasets. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12859-015-0561-9) contains supplementary material, which is available to authorized users

Expression and function of neurotrophins and their receptors in human melanocytes.

Melanocytes and cells of the nervous system are of common ectodermal origin and neurotrophins (NT) have been shown to be released by human keratinocytes. We investigated the expression and function of NT [nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), NT-3, NT-4/-5] and their receptors in human melanocytes. Human melanocytes produce all NT in different amounts, whereas they only release NT-4. NT-4 release is downregulated, whereas NT-3 is upregulated by ultraviolet (UVB) irradiation. Melanocytes treated with phorbol 12-myristate 13-acetate (PMA) express TrkA and TrkB, but not TrkC. NT fail to stimulate melanocyte proliferation, whereas they stimulate the synthesis of tyrosinase and tyrosinase-related protein-1 (TRP-1). Finally, NT-3, NT-4 and NGF increase melanin production. Taken together, these results demonstrate an intriguing interaction between melanocytes and the nervous system. We speculate that NT could be considered the target of therapy for disorders of skin pigmentation

Nouveaux traceurs TEMP : exemple des traceurs des protéoglycanes et de la mélanine

International audienceThe majority of research program on new radiopharmaceutics turn to tracers used for positron emission tomography (PET). Only a few teamswork on new non fluorine labeled tracers. However, the coming of SPECT/CT gamma cameras, the arrival of semi-conductors gamma camerasshould boost the development of non-PET tracers.We exhibit in this article the experience acquired by our laboratory in the conception and designof two new non fluorine labelled compounds. The 99mTc-NTP 15-5 which binds to proteoglycans could be used for the diagnosis and staging ofosteoarthritis and chondrosarcoma. The iodobenzamides, specific to the melanin, are nowadays compared to 18F-fluorodeoxyglucose in a phase IIIclinical trial for the diagnosis and detection of melanoma metastasis. Our last development focus on BZA heteroaromatic analogues usable formelanoma treatment.La plupart des programmes de recherche sur les nouveaux radiopharmaceutiques portent actuellement sur les traceurs utilisés en tomographie par émission de positons (TEP). Seules quelques équipes continuent à travailler sur des nouveaux traceurs non fluorés. Toutefois, l'arrivée des gammas caméras TEMP/TDM et le frémissement des caméras à semi-conducteur, pourraient donner un nouvel élan au développement des traceurs non TEP. Nous exposons dans cet article l'expérience acquise par notre laboratoire dans la conception et l'étude de deux nouvelles familles de molécules non fluorées. Le 99m Tc-NTP 15-5 se lie sur les protéoglycanes et pourrait ainsi être utilisé pour le diagnostic ou suivi de l'arthrose et du chondrosarcome. Les iodobenzamides, traceurs de la mélanine, sont actuellement comparés au 18 F-fluorodéoxyglucose dans un essai de phase III pour le suivi et le diagnostic de métastases de mélanome. Nos derniers travaux portent sur de nouveaux analogues hétérocycliques utilisables pour le traitement du mélanome

Comprehensive Transcriptional Profiling of Human Epidermis, Reconstituted Epidermal Equivalents, and Cultured Keratinocytes Using DNA Microarray Chips

Because of its accessibility, skin has been among the first organs analyzed using DNA microarrays; psoriasis, melanomas, carcinomas, chronic wound biopsies, and epidermal keratinocytes in culture have been intensely investigated. Skin has everything: stem cells, differentiation, signaling, inflammation, diseases, cancer, etc. Here we provide step-by-step instructions for bioinformatics analysis of transcriptional profiling of skin. Specifically, we describe the use of GCOS and RMA programs for initial normalization and selection of differentially expressed genes, DAVID and LOLA programs for annotation of genes, and statistically relevant identification of over- and under-represented functional and biological categories in identified gene sets, L2L and Venn diagrams for comparing multiple lists of genes, and oPOSSUM for identification of statistically over-represented transcription factor binding sites in the promoter regions of gene sets. The work can be a primer for researchers embarking on skinomics, the comprehensive analysis of transcriptional changes in the skin