Project description:Melanoma patients with high mRNA levels of the HDL receptor SR-BI (SCARB1) reveal poor survival outcome. The aim of the study was to evaluate the role of SR-BI in cancer progression. Therefore, SR-BI was targeted either by siRNA or by using the SR-BI specific lipid transfer inhibitor BLT-1. The SR-BI knockdown specifically revealed reduced protein glycosylation, STAT5 target gene expression and EMT pathway activation. Thus, SR-BI target genes reflect the metastatic phenotype in melanoma cells. We used the transcriptome analysis to compare SR-BI depletion to BLT-1 treatment (which specifically blocks SR-BI mediated lipid transfer) in human melanoma cells.
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. RNA was isolated from two different metastatic melanoma cell lines 30 hours after one of four different treaments: (i) transfection with siRNA targeting PAX3; or (ii) transfection with siRNA targeting MITF; or (iii) or transfection with siRNA targeting luciferase (non-targeting negative control); or (iv) treatment with media only (control). Therefore, eight samples were used for gene expression profiling by using GeneChip arrays, with one replicate per cell line per treatment.
Project description:We analyzed the transcriptional response of the human melanoma cell line Ma-Mel-15 either transfected with control siRNA (siNT = non-targeting siRNA) or transfected with siRNAs (pool of 4 active and independent siRNAs) directed against the melanocytic transcription factor and lineage oncogene MITF (Microphthalmia-associated transcription factor). The experiment was performed as biological duplicates and RNA was isolated 48 hours after siRNA transfection. We aimed to determine novel markers and pathways of melanoma cell plasticity. Total RNA was obtained from siRNA-treated Ma-Mel-15 melanoma cell lines and global gene expression profiling was done using the Illumina Human HT12 v4 platform.
Project description:We analyzed the transcriptional response of the human melanoma cell line MZ7 to TNF-alpha (24 hours) in a dose-dependent manner (TNF-alpha 10U/ml, 100U/ml, 1000U/ml) either transfected with control siRNA (siNT = non-targeting siRNA) or transfected with siRNAs (pool of 4 active and independent siRNAs) against the melanocytic transcription factor and lineage oncogene MITF. (Microphthalmia-associated transcription factor). The experiment was performed as biological duplicate. As MITF is critical for melanoma cell state control, we aimed to explore how MITF expression intersects with inflammation-induced plasticity pathways in melanoma. Total RNA was obtained from siRNA/TNF-treated MZ7 melanoma cell lines at various conditions and global gene expression profiling was done using the Illumina Human HT12 v4 platform.
Project description:Mice with homozygous null mutations in the HDL receptor (SR-BI) and apoE genes (SR-BI KO/apoE double KO (dKO) mice) spontaneously develop occlusive, atherosclerotic coronary artery disease (CAD) and die prematurely (50% mortality at 42 days of age) on standard chow diet feeding. Microarray analysis was performed to investigate the changes in gene expression profiles during the development of spontaneous severe CAD, which includes myocardial infarction and heart failure. These data will provide new insights in understanding the pathophysiology of CAD. The whole Hearts from dKO or SR-BI+/- apoE-/- (HET) mice (n=9-12) were harvested at 21, 31 and 43 days of age, and analyzed using Affymetrix microarrays. dKO mice do not show detectable signs of CAD at 21 days of age, small myocardial infarction (MI) and heart failure at 31 days of age, and extensive MI and severe heart failure at 43 days of age (50% mortality at 42 days of age). Each mouse was assigned to one array. SR-BI+/- apoE-/- mice (HET) which do not develop detectable signs of CAD on chow diet were used as controls.The data also include those from probucol treated dKO and HET mice (n=2-8).
Project description:Melanoma metastasis is a devastating outcome in need of novel preventive therapies. We provide pharmacologic, nolecuar, and genetic evidence establishing the liver-X nuclear hormone receptor (LXR) as a therapeutic target in melanoma. Molecular and genetic experiments revealed these effects to be mediated by LXRb, which elicits these outcomes through transcriptional induction of tumoral and systemic apolipoprotein-E (ApoE). LXRb agonism robustly suppressed tumor growth and metastasis across a wide spectrum of melanoma lines of diverse mutational subtypes established in xenograft, immunocompetent, and genetically-initiated model. We propose a path for the clinical testing of LXRb targeting-a therapeutic approach that uniquely acts by transcriptionally acivating a metastasis suppressor gene. In this experiment we analyzed the effect of GW3965 treatment on gene expression in the MeWo human melanoma cell line. The cells were treated either with DMSO or GW3965 at 1 micromolar for 48 hours, after which the RNA was extracted and gene expression was analyzed by transcriptomic profiling
Project description:LPAR1 (lysophosphatidic acid receptor 1) is identified in targeted siRNA screens which is required for the survival and maintenance of nueral crest stem cells (NCSC) as well as the growth and invasion of melanoma cells. To gain mechanistic insights into how LPAR signaling modulates melanoma cell growth, We conducted an Illumina genome-wide gene expression microarray experiment to profile melanoma cells treated with the autotaxin inhibitor, HA130. Melanoma cells treated with vehicle control,DMSO is included as a control.
Project description:To investigate the function of CITED1 in melanoma, its expression was transiently down regulated using CITED1-targeting siRNA. The HT144 melanoma cell line was chosen as it had a relatively high level of detectable CITED1 mRNA and protein expression. HT144 melanoma cells were transfected with 2 siRNAs targeting CITED1 (4 replicates each) and a negative control non-targeting siRNA (4 replicates). RNA was harvested at 48 h post-transfection.