The Hidden Story of Heterogeneous B-raf V600E Mutation Quantitative Protein Expression in Metastatic Melanoma-Association with Clinical Outcome and Tumor Phenotypes

In comparison to other human cancer types, malignant melanoma exhibits the greatest amount of heterogeneity. After DNA-based detection of the BRAF V600E mutation in melanoma patients, targeted inhibitor treatment is the current recommendation. This approach, however, does not take the abundance of the therapeutic target, i.e., the B-raf V600E protein, into consideration. As shown by immunohistochemistry, the protein expression profiles of metastatic melanomas clearly reveal the existence of inter-and intra-tumor variability. Nevertheless, the technique is only semi-quantitative. To quantitate the mutant protein there is a fundamental need for more precise techniques that are aimed at defining the currently non-existent link between the levels of the target protein and subsequent drug efficacy. Using cutting-edge mass spectrometry combined with DNA and mRNA sequencing, the mutated B-raf protein within metastatic tumors was quantitated for the first time. B-raf V600E protein analysis revealed a subjacent layer of heterogeneity for mutation-positive metastatic melanomas. These were characterized into two distinct groups with different tumor morphologies, protein profiles and patient clinical outcomes. This study provides evidence that a higher level of expression in the mutated protein is associated with a more aggressive tumor progression. Our study design, comprised of surgical isolation of tumors, histopathological characterization, tissue biobanking, and protein analysis, may enable the eventual delineation of patient responders/non-responders and subsequent therapy for malignant melanoma

CIGB-300, a synthetic peptide-based drug that targets the CK2 phosphoaceptor domain. Translational and clinical research

CK2 represents an oncology target scientifically validated. However, clinical research with inhibitors of the CK2-mediated phosphorylation event is still insufficient to recognize it as a clinically validated target. CIGB-300, an investigational peptide-based drug that targets the phosphoaceptor site, binds to a CK2 substrate array in vitro but mainly to B23/nucleophosmin in vivo. The CIGB-300 proapoptotic effect is preceded by its nucleolar localization, inhibition of the CK2-mediated phosphorylation on B23/nucleophosmin and nucleolar disassembly. Importantly, CIGB-300 shifted a protein array linked to apoptosis, ribosome biogenesis, cell proliferation, glycolisis, and cell motility in proteomic studies which helped to understand its mechanism of action. In the clinical ground, CIGB-300 has proved to be safe and well tolerated in a First-in-Human trial in women with cervical malignancies who also experienced signs of clinical benefit. In a second Phase 1 clinical trial in women with cervical cancer stage IB2/II, the MTD and DLT have been also identified in the clinical setting. Interestingly, in cervical tumors the B23/nucleophosmin protein levels were significantly reduced after CIGB-300 treatment at the nucleus compartment. In addition, expanded use of CIGB-300 in case studies has evidenced antitumor activity when administered as compassional option. Collectively, our data outline important clues on translational and clinical research from this novel peptide-based drug reinforcing its perspectives to treat cancer and paving the way to validate CK2 as a promising target in oncology.Fil: Perea, Silvio E.. Center for Genetic Engineering and Biotechnology; CubaFil: Baladron, Idania. Center for Genetic Engineering and Biotechnology; CubaFil: Garcia, Yanelda. Center for Genetic Engineering and Biotechnology; CubaFil: Perera, Yasser. Center for Genetic Engineering and Biotechnology; CubaFil: Lopez, Adlin. Center for Genetic Engineering and Biotechnology; CubaFil: Soriano, Jorge L.. Center for Genetic Engineering and Biotechnology; Cuba. General Hospital ‘‘Hermanos Ameijeiras’; CubaFil: Batista, Noyde. Center for Genetic Engineering and Biotechnology; Cuba. General Hospital ‘‘Hermanos Ameijeiras’; CubaFil: Palau, Aley. Center for Genetic Engineering and Biotechnology; Cuba. General Hospital ‘‘Hermanos Ameijeiras’; CubaFil: Hernández, Ignacio. Center for Genetic Engineering and Biotechnology; CubaFil: Farina, Hernán Gabriel. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garcia, Idrian. Center for Genetic Engineering and Biotechnology; CubaFil: Gonzalez, Lidia. Center for Genetic Engineering and Biotechnology; CubaFil: Gil, Jeovanis. Center for Genetic Engineering and Biotechnology; CubaFil: Rodriguez, Arielis. Center for Genetic Engineering and Biotechnology; CubaFil: Solares, Margarita. Center for Genetic Engineering and Biotechnology; CubaFil: Santana, Agueda. Center for Genetic Engineering and Biotechnology; CubaFil: Cruz, Marisol. Center for Genetic Engineering and Biotechnology; CubaFil: Lopez, Matilde. Center for Genetic Engineering and Biotechnology; CubaFil: Valenzuela, Carmen. Center for Genetic Engineering and Biotechnology; CubaFil: Reyes, Osvaldo. Center for Genetic Engineering and Biotechnology; CubaFil: López Saura, Pedro A.. Center for Genetic Engineering and Biotechnology; CubaFil: González, Carlos A.. Center for Genetic Engineering and Biotechnology; CubaFil: Diaz, Alina. Center for Genetic Engineering and Biotechnology; CubaFil: Castellanos, Lila. Center for Genetic Engineering and Biotechnology; CubaFil: Sanchez, Aniel. Center for Genetic Engineering and Biotechnology; CubaFil: Betancourt, Lazaro. Center for Genetic Engineering and Biotechnology; CubaFil: Besada, Vladimir. Center for Genetic Engineering and Biotechnology; CubaFil: González, Luis J.. Center for Genetic Engineering and Biotechnology; CubaFil: Garay, Hilda. Center for Genetic Engineering and Biotechnology; CubaFil: Gómez, Roberto. Center for Genetic Engineering and Biotechnology; CubaFil: Gomez, Daniel Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perrin, Phillipe. No especifíca;Fil: Renualt, Jean Yves. No especifíca;Fil: Sigman, Hugo. No especifíca;Fil: Herrera, Luis. Center for Genetic Engineering and Biotechnology; CubaFil: Acevedo, Boris. Center for Genetic Engineering and Biotechnology; Cub

The Human Melanoma Proteome Atlas—Complementing the melanoma transcriptome

The MM500 meta‐study aims to establish a knowledge basis of the tumor proteome to serve as a complement to genome and transcriptome studies. Somatic mutations and their effect on the transcriptome have been extensively characterized in melanoma. However, the effects of these genetic changes on the proteomic landscape and the impact on cellular processes in melanoma remain poorly understood. In this study, the quantitative mass‐spectrometry‐based proteomic analysis is interfaced with pathological tumor characterization, and associated with clinical data. The melanoma proteome landscape, obtained by the analysis of 505 well‐annotated melanoma tumor samples, is defined based on almost 16 000 proteins, including mutated proteoforms of driver genes. More than 50 million MS/MS spectra were analyzed, resulting in approximately 13,6 million peptide spectrum matches (PSMs). Altogether 13 176 protein‐coding genes, represented by 366 172 peptides, in addition to 52 000 phosphorylation sites, and 4 400 acetylation sites were successfully annotated. This data covers 65% and 74% of the predicted and identified human proteome, respectively. A high degree of correlation (Pearson, up to 0.54) with the melanoma transcriptome of the TCGA repository, with an overlap of 12 751 gene products, was found. Mapping of the expressed proteins with quantitation, spatiotemporal localization, mutations, splice isoforms, and PTM variants was proven not to be predicted by genome sequencing alone. The melanoma tumor molecular map was complemented by analysis of blood protein expression, including data on proteins regulated after immunotherapy. By adding these key proteomic pillars, the MM500 study expands the knowledge on melanoma disease

Lysine Acetylation Stoichiometry Analysis at the Proteome Level

Lysine acetylation is a widespread posttranslational modification (PTM) in all kingdoms of live. A large number of proteins involved in most of biological pathways are targets of this PTM. The lysine acetylation is a reversible modification controlled by two main groups of enzymes, lysine acetyltransferases responsible for transferring the acetyl group of acetylCoA to the side chain of lysine residues and lysine deacetylases which effectively remove the acetyl tag. Dysregulation of enzymes that control acetylation and/or target proteins have been associated with a growing number of human pathologies. Lysine acetylation is largely a modification that occurs at low stoichiometry at its target sites. Here we describe a method to identify lysine acetylation sites and estimate their site occupancy at the proteome scale. The method relies on a high-resolution mass spectrometry-based proteomics approach, which includes a specific chemical acetylation reaction on unmodified lysine residues that carry heavy isotopes. The procedures described here have been applied to cell line cultures and to clinically relevant samples stored as both snap-frozen and formalin-fixed paraffin-embedded (FFPE) tissues

Improved Melatonin Dissolution Properties : A Way Forward for Treating Children with Sleep Disorders

Sleep problems, in particular the difficulty in initiating and maintaining sleep are important comorbidities in children and adolescents with attention deficit hyperactivity disorder (ADHD), accompanied by a range of negative consequences for both patients and their caregivers. Melatonin, a naturally occurring hormone that is important for coordinating the body's sleep-wake cycle, has been used to treat insomnia in children with ADHD. This study compares the dissolution properties of two melatonin tablets (1 and 5 mg Mellozzan and Melatonin AGB). Results showed that Mellozzan dissolved rapidly (90% within 5 minutes) in all pH levels tested, whereas Melatonin AGB dissolved slower (60% within 30 minutes). The fast dissolution properties of melatonin observed in Mellozzan indicates that this formulation is preferable for the treatment of children where the dissolution step is critical to reach the desired clinical effect

Organ specific copy number variations in visceral metastases of human melanoma

Malignant melanoma is one of the most aggressive skin cancers with high potential of visceral dissemination. Since the information about melanoma genomics is mainly based on primary tumors and lymphatic or skin metastases, an autopsy-based visceral metastasis biobank was established. We used copy number variation arrays (N = 38 samples) to reveal organ specific alterations. Results were partly completed by proteomic analysis. A significant increase of high-copy number gains was found in an organ-specific manner, whereas copy number losses were predominant in brain metastases, including the loss of numerous DNA damage response genes. Amplification of many immune genes was also observed, several of them are novel in melanoma, suggesting that their ectopic expression is possibly underestimated. This “immunogenic mimicry” was exclusive for lung metastasis. We also provided evidence for the possible autocrine activation of c-MET, especially in brain and lung metastases. Furthermore, frequent loss of 9p21 locus in brain metastases may predict higher metastatic potential to this organ. Finally, a significant correlation was observed between BRAF gene copy number and mutant allele frequency, mainly in lung metastases. All of these events may influence therapy efficacy in an organ specific manner, which knowledge may help in alleviating difficulties caused by resistance

Peptide fractionation for the proteomics studies

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