Project description:Comparison of gene expression profiles between a primary melanoma and an early metastatic specimen from the same patient will provide essential biological insight into early metastatic processes. The DASL (cDNA mediated annealing, selection, extension and ligation) assay has been used to generate gene expression data for 502 cancer-related genes from very small formalin-fixed sentinel node biopsy (SNB) melanoma samples, this data has been further compared with gene expression of the matched formalin-fixed primary melanoma. Tissue was sampled from twenty-five SNB deposits using laser capture microdissection. The mean number of genes detected using DASL with SNB samples was lower than when using a core of primary melanoma tumor (242 versus 434 genes). A large proportion of SNB samples failed (<240 genes detected) the assay (57.7%). Area of tissue microdissected, RNA concentration and qRT-PCR quality control did not predict performance of samples on the array but age of sampled tissue negatively correlated with number of genes detected (p=0.01). For samples that performed successfully, matched primary samples were available for 10 samples. Gene expression profiles correlated between all matched tumor pairs (Spearman’s rho 0.15-0.80, p<0.01), although a number of genes were differentially expressed between nodal and primary tumors in all tumor pairs. This study demonstrates that the DASL assay can be used to generate gene expression data from small formalin-fixed samples, but not consistently. Differentially expressed genes were identified across 10 matched primary and nodal tumor pairs suggesting that the DASL assay could be used to derive essential biological information about early metastasis.
Project description:Comparison of gene expression profiles between a primary melanoma and an early metastatic specimen from the same patient will provide essential biological insight into early metastatic processes. The DASL (cDNA mediated annealing, selection, extension and ligation) assay has been used to generate gene expression data for 502 cancer-related genes from very small formalin-fixed sentinel node biopsy (SNB) melanoma samples, this data has been further compared with gene expression of the matched formalin-fixed primary melanoma. Tissue was sampled from twenty-five SNB deposits using laser capture microdissection. The mean number of genes detected using DASL with SNB samples was lower than when using a core of primary melanoma tumor (242 versus 434 genes). A large proportion of SNB samples failed (<240 genes detected) the assay (57.7%). Area of tissue microdissected, RNA concentration and qRT-PCR quality control did not predict performance of samples on the array but age of sampled tissue negatively correlated with number of genes detected (p=0.01). For samples that performed successfully, matched primary samples were available for 10 samples. Gene expression profiles correlated between all matched tumor pairs (Spearman’s rho 0.15-0.80, p<0.01), although a number of genes were differentially expressed between nodal and primary tumors in all tumor pairs. This study demonstrates that the DASL assay can be used to generate gene expression data from small formalin-fixed samples, but not consistently. Differentially expressed genes were identified across 10 matched primary and nodal tumor pairs suggesting that the DASL assay could be used to derive essential biological information about early metastasis. Formalin-fixed paraffin-embedded SNB samples and primary tumors were identified from two study sets. In Study 1, population ascertained melanoma patients were recruited to a cohort in the period from 2000 till the present day. Eight positive SNB samples were identified, from patients whose primary tumors had already been sampled for DASL studies. In Study 2, seventeen positive SNB samples were identified in a study designed to identify predictors of sentinel node positivity and relapse (SNB study). One nodal RNA sample, microdissected from a diagnostic H&E slide, was not sent for DASL analysis because of low RNA concentration (0.37 ng/μl), therefore a total of 26 nodal samples (including 2 replicate samples) were supplied to the Illumina DASL service provider. Of the 11 samples successfully yielding gene expression data, 10 had matched primary samples (e.g., Node_1 and Primary_1) for which gene expression data were available and is presented in this data set.
Project description:Tumor-derived exosomes are emerging as mediators of tumorigenesis with a tissue-specific address and message. We explored the function of melanoma-derived exosomes in formation of primary tumors and metastatic progression in both murine models and patients. Whereas exosomes from highly metastatic melanoma cells increased the metastatic behavior of primary tumor cells by educating bone marrow (BM) progenitor cells via the MET receptor, exosomes from low metastatic melanoma cells did not alter the incidence of metastases. Melanoma-derived exosomes induced vascular leakiness at pre-metastatic sites, and reprogrammed BM progenitor cells towards a pro-vasculogenic phenotype (c-Kit+Tie2+MET+). Reducing MET expression in tumor-derived exosomes diminished the pro-metastatic behavior of BM cells. Importantly, MET expression was upregulated in circulating BM progenitor cells (CD45-CD117low and CD45-CD117lowTIE2+) isolated from stage III and stage IV melanoma patients. Rab1a, Rab5b, Rab7, and Rab27a were highly expressed in melanoma and Rab27a RNA interference decreased exosome production and/or soluble angiogenic factors in melanoma cells, thereby preventing mobilization of BM progenitor cells, tumor growth and metastasis. Finally, we identified a melanoma signature in exosomes isolated from metastatic melanoma patients, comprised of TYRP2, VLA-4, Hsp70, an Hsp90 isoform and MET oncoprotein, which together with Rab proteins, appear to represent exosome-specific proteins with prognostic potential, and may provide new therapeutic targets. Identification of molecular finger associated to exosome effects in metastatic organs Microarray analysis of genes differentially expressed in the lungs 24 and 48 hours after B16-F10 exosome tail vein injection compared to control.
Project description:The identification of novel tumor-specific markers may improve understanding of melanoma progression and prognostic accuracy. Whole genome expression profiling of 46 primary melanomas, 12 metastases, and 16 normal skin samples using Affymetrix U133 PLUS 2.0 array generated gene lists including both known and new melanoma genes. The molecular genetic alterations contributing to the pathogenesis of melanoma are incompletely defined and few independent prognostic features have been identified beyond the pathologic characteristics of the primary tumor. Early stage melanoma is frequently curable, in contrast to the inferior prognosis of melanomas with regional lymph nodes involvement and the incurability of distant metastatic disease. The identification of novel tumor-specific markers may improve our understanding of melanoma progression and prognostic accuracy. To find differentially expressed genes that can distinguish melanoma from normal tissue, we performed a whole genome expression profiling of 46 primary melanoma samples, 12 regional or distant metastases, and 16 normal skin samples using Affymetrix U133 2.0 Plus array. Our study generated lists of differentially expressed genes in melanoma and identified novel prognostic marker HMGA2. It is a novel, highly overexpressed melanoma gene associated with poor prognosis. The overexpression of HMGA2 is strongly associated with regional and distant metastases and serves as an independent predictor of disease-free survival and overall survival in melanoma.
Project description:Formalin fixed paraffin embedded (FFPE) primary-recurrent Glioblastoma (pGBM-rGBM) matched patient samples and normal tissue adjacent to tumor (NAT) were analyzed by shotgun DDA proteomics. The proteomic profiles of pGBM-rGBM pairs revealed differentially expressed proteins in rGBM samples, which in future could be used for potential therapeutic interventions.
Project description:The identification of novel tumor-specific markers may improve understanding of melanoma progression and prognostic accuracy. Whole genome expression profiling of 46 primary melanomas, 12 metastases, and 16 normal skin samples using Affymetrix U133 PLUS 2.0 array generated gene lists including both known and new melanoma genes. The molecular genetic alterations contributing to the pathogenesis of melanoma are incompletely defined and few independent prognostic features have been identified beyond the pathologic characteristics of the primary tumor. Early stage melanoma is frequently curable, in contrast to the inferior prognosis of melanomas with regional lymph nodes involvement and the incurability of distant metastatic disease. The identification of novel tumor-specific markers may improve our understanding of melanoma progression and prognostic accuracy. To find differentially expressed genes that can distinguish melanoma from normal tissue, we performed a whole genome expression profiling of 46 primary melanoma samples, 12 regional or distant metastases, and 16 normal skin samples using Affymetrix U133 2.0 Plus array. Our study generated lists of differentially expressed genes in melanoma and identified novel prognostic marker HMGA2. It is a novel, highly overexpressed melanoma gene associated with poor prognosis. The overexpression of HMGA2 is strongly associated with regional and distant metastases and serves as an independent predictor of disease-free survival and overall survival in melanoma. Melanoma samples were obtained through an IRB-approved protocol using informed consent at the University of Michigan Multidisciplinary Melanoma Clinic. A portion of pigmented lesions clinically suspicious for melanoma and known melanoma were sampled by punch biopsy at the time of excision. The punch biopsy was bisected; half was sent to for clinical diagnosis and the other half along with adjacent normal skin when available immediately snap-frozen in liquid nitrogen. Snap-frozen tissue was embedded in OCT (TissueTek) followed by frozen sectioning and H&E slide preparation. The slides were evaluated by dermatopathologist who identified areas with greater than 70% tumor cellularity, which were sampled for RNA extraction. Primary melanomas and melanoma metastases were derived from different patients. Metastatic samples included lymph nodes (n=8), subcutaneous soft tissue (n=2), spleen (n=1), and small intestine (n=1).
Project description:Genotyping of a matched normal, primary and metastatic acral melanoma DNA from blood and one matched Primary and one metastatic acral melanoma was genotyped on Affmetrix SNP6
Project description:To look at genes/pathways differentially expressed in metastatic and primary tumor cells we performed global gene expression profiling of the 3 sets of HNSCC lines derived from primary tumors and matched metastatic sites. Illumina HT-12 v4 BeadChip arrays were used. The data suggest that HNSCC lines derived from metastatic sites exhibit phenotypes distinct from those found in cells derived from the corresponding primary tumors. Metastatic cell lines upregulated several pathways involved in stem cell self-renewal, invasion and migration, which are well known characteristics of metastatic progression. We conclude that the cell lines derived from primary patient tumors and matched metastatic sites represent a reliable model to study HNSCC metastasis.
Project description:Assessment of mutation on expression levels Transcriptomic profile of a matched primary and metastatic acral melanoma One Primary and one metastatic acral melanoma transcript expression were assayed (no matched normal)