Project description:This SuperSeries is composed of the following subset Series: GSE22301: Gene expression data from melanoma cell lines and melanocyte controls GSE22305: Affymetrix SNP6.0 Array data for melanoma cell lines Refer to individual Series
Project description:Melanoma cell lines were genotyped to evaluate copy number differences between nodular melanoma (NM) and superficial spreading melanoma (SSM). Cell lines were also evaluated for copy number alterations in the SKP2/p27 axis. Affymetrix SNP arrays were performed according to manufacturer's instructions using DNA extracted from 18 melanoma cell lines and 4 melanocyte controls. Affymetrix SNP6.0 Array data for melanoma cell lines Copy number analysis of Affymetrix SNP 6.0 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) that were used to construct the baseline for copy number analysis.
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:Melanoma cell lines were genotyped to evaluate copy number differences between nodular melanoma (NM) and superficial spreading melanoma (SSM). Cell lines were also evaluated for copy number alterations in the SKP2/p27 axis. Affymetrix SNP arrays were performed according to manufacturer's instructions using DNA extracted from 18 melanoma cell lines and 4 melanocyte controls.
Project description:The transcription factors PAX3 and MITF are required for the development of the neural crest and melanocyte lineage, and both proteins play important roles in melanoma cell growth and survival. PAX3 transcriptionally activates MITF expression during neural crest development, but the relationship between these transcription factors during melanocyte development and in melanoma cells is currently poorly understood. This study aimed to further our understanding of the interaction between transcriptional networks controlled by PAX3 and MITF by assessing the effect of siRNA-mediated knockdown of PAX3 and MITF in metastatic melanoma cell lines. The goals of this study were to determine (i) if PAX3 is required for maintaining expression of MITF in melanoma and melanocyte cell lines; (ii) whether PAX3 and MITF independently, or redundantly, influence growth and survival in melanoma cell lines; and (iii) to investigate the respective roles of PAX3 and MITF expression in melanoma cell differentiation. Microarrays were used to measure global changes in transcript expression in response to siRNA-mediated knockdown of PAX3 or MITF compared to non-targeting controls in two metastatic melanoma cells lines.