Project description:We compared the gene signatures of mouse melanocyte stem cells and the melanoma tumor derived from them upon Braf V600E mutation and loss of Pten, as well as the heterogeneity of the melanoma cells by single cell RNAseq
Project description:Dysregulated melanocyte state transitions are a pivotal driver of melanoma development, highlighting the need to identify key regulators of these processes. Understanding these factors is key to know how normal melanocyte functions and shift towards initiation of melanoma. Our study identifies Mgat4b, a glycosyl transferase involved in selective N-glycan branching enriched in pigment progenitors, as a key regulator of directional melanocyte migration and establishment of Melanocyte stem cell (McSC) pool during early development in zebrafish and mammalian melanocytes. Single cell RNA sequencing analysis in zebrafish upon targeted disruption of Mgat4b reveals that a subset of melanocytes marked by aberrant galectin expression are impaired in migration and are lost. Lectin binding proteomic analysis reveals the glycosylation of key melanocyte proteins Gpnmb, Kit, and Tyrp1 to be under the control of Mgat4b. Additionally, mislocalization of Gamma catenin (Jup) explains the observed defects in cell adhesion and migration to be regulated by mgat4b but not its isozyme mgat4a. Our meta-analysis further revealed that melanoma patients with both the BrafV600E mutation and elevated Mgat4b levels have significantly worse survival outcomes compared to those with only the BrafV600E mutation. By leveraging the MAZERATI platform to model BrafV600E driver mutation in vivo, we show that Mgat4b mutant cells fail to aggregate and initiate tumors. Our study underscores the importance of selective N-glycan branching in both melanocyte development and melanoma initiation, suggesting a Mitf controlled Mgat4b as a promising therapeutic target for melanoma treatment.
Project description:Dysregulated melanocyte state transitions are a pivotal driver of melanoma development, highlighting the need to identify key regulators of these processes. Understanding these factors is key to know how normal melanocyte functions and shift towards initiation of melanoma. Our study identifies Mgat4b, a glycosyl transferase involved in selective N-glycan branching enriched in pigment progenitors, as a key regulator of directional melanocyte migration and establishment of Melanocyte stem cell (McSC) pool during early development in zebrafish and mammalian melanocytes. Single cell RNA sequencing analysis in zebrafish upon targeted disruption of Mgat4b reveals that a subset of melanocytes marked by aberrant galectin expression are impaired in migration and are lost. Lectin binding proteomic analysis reveals the glycosylation of key melanocyte proteins Gpnmb, Kit, and Tyrp1 to be under the control of Mgat4b. Additionally, mislocalization of Gamma catenin (Jup) explains the observed defects in cell adhesion and migration to be regulated by mgat4b but not its isozyme mgat4a. Our meta-analysis further revealed that melanoma patients with both the BrafV600E mutation and elevated Mgat4b levels have significantly worse survival outcomes compared to those with only the BrafV600E mutation. By leveraging the MAZERATI platform to model BrafV600E driver mutation in vivo, we show that Mgat4b mutant cells fail to aggregate and initiate tumors. Our study underscores the importance of selective N-glycan branching in both melanocyte development and melanoma initiation, suggesting a Mitf controlled Mgat4b as a promising therapeutic target for melanoma treatment.
Project description:This SuperSeries is composed of the following subset Series: GSE35387: Expression data from normal melanocyte, melanoma cells and their exosomes (microRNA) GSE35388: Expression data from normal melanocyte, melanoma cells and their exosomes (mRNA) Refer to individual Series
Project description:The two most common melanoma histopathologic subtypes, superficial spreading (SSM) and nodular melanoma (NM), are believed to represent sequential phases of linear progression from radial to vertical growth. Studies suggest, however, that SSM and NM are biologically distinct. We utilized an integrative genomic approach to examine the possibility that SSM and NM are the result of independent pathways characterized by unique molecular alterations. Cell lines including SSM, NM, metastatic melanoma, and melanocyte controls were evaluated for copy number changes and differential mRNA expression using single nucleotide polymorphism array (SNP 6.0, Affymetrix) and gene array (U133A 2.0, Affymetrix). Data sets were integrated to identify copy number alterations that correlated with gene expression, and array results were validated using immunohistochemistry on human tissue microarrays (TMAs) and an external data set. The functional effect of genomic deletion was assessed by lentiviral overexpression. Integrative genomics revealed 8 genes in which NM/SSM-specific copy number alterations were correlated with NM/SSM differential gene expression (P<0.05, Spearman’s rank). Pathways analysis of differentially expressed genes (N=114) showed enrichment for metabolic-related processes. SSM-specific genomic deletions (DIS3, MTAP, G3BP2, SEC23IP, USO1) were verified in an expanded panel of cell lines, and forced overexpression of MTAP in SSM resulted in reduced cell growth. Metabolism-related gene ALDH7A1 was verified as overexpressed in NM using human TMAs.The identification of recurrent genomic deletions in SSM not present in NM challenges the linear model of melanoma progression and supports the unique molecular classification of SSM and NM. Gene expression profiling using Affymetrix U133A 2.0 arrays was performed on 18 melanoma cell lines including 2 primary superficial spreading melanoma, 2 primary nodular melanoma, 2 metastatic nodular melanoma, and 12 metastatic cell lines. Four melanocyte control lines were also evaluated including 2 immortalized melanocyte cell lines (Hermes 1 and 2B) and 2 normal melanocyte lines cultured from neonatal foreskin (HEM-N and HEM-LP).
Project description:We investigated the miRNAome in human melanocyte and melanoma cell lines using high-throughput RNA sequencing. We identified a group of dysregulated miRNAs by comparing the miRNA expression profiles among melanoma cell lines. Target genes of these miRNAs participate in functions associated with the cell cycle and apoptosis. Gene networks were built to investigate the interactions of genes during melanoma progression. We identified that the key genes that regulate melanoma cell proliferation were regulated by miRNAs. Our findings provide further knowledge regarding the mechanisms of melanoma development. miRNA profiles of melanocyte (HEMn-LP), low metastatic melanoma (A375) and high metastatic melanoma (A2058) cell line were generated using Illumina GA
Project description:This SuperSeries is composed of the following subset Series: GSE33092: Oncogenic BRAFV600E remodels the melanocyte transcriptome and induces BLNCR1 to regulate melanoma cell migration [HT-seq] GSE37132: Oncogenic BRAFV600E remodels the melanocyte transcriptome and induces BLNCR1 to regulate melanoma cell migration [Affymetrix] Refer to individual Series
Project description:We compared the transcriptomics of mouse melanocyte stem cells at the activation stage of the hair cycle (anagen onset) and mature melanocytes from the hair bulb by single cell RNAseq