Sox10 controls migration of melanoma cells through multiple regulatory target genes
Ontology highlight
ABSTRACT: It is believed that the inherent differentiation program of melanocytes during embryogenesis predisposes melanoma cells to high frequency of metastasis. Sox10, a transcription factor expressed in neural crest stem cells and a subset of progeny lineages, plays a key role in the development of melanocytes. We show that B16F10 melanoma cells transfected with siRNA specific for Sox10 display reduced migratory activity which in turn indicated that a subset of transcriptional regulatory target genes of Sox10 are likely to be involved in migration and metastasis of melanoma cells. We carried out microarray-based gene expression profiling using Sox10-specific siRNA to identify regulatory targets and found that multiple genes including melanocortin-1 receptor (Mc1R) partake in the regulation of migration. We provide evidences that a significant portion of the effect of Sox10 on migration is mediated by Mitf, a transcription factor downstream to Sox10. The involvement of Mc1R in migration was studied in detail in vivo using a murine metastasis model. Specifically, B16F10 melanoma cells treated with a specific siRNA showed reduced tendency in metastasizing to and colonizing the lung after being injected in the tail vein. These data reveal a cadre of novel regulators and mediators involved in migration and metastasis of melanoma cells that represent potential targets of therapeutic intervention.
Project description:It is believed that the inherent differentiation program of melanocytes during embryogenesis predisposes melanoma cells to high frequency of metastasis. Sox10, a transcription factor expressed in neural crest stem cells and a subset of progeny lineages, plays a key role in the development of melanocytes. We show that B16F10 melanoma cells transfected with siRNA specific for Sox10 display reduced migratory activity which in turn indicated that a subset of transcriptional regulatory target genes of Sox10 are likely to be involved in migration and metastasis of melanoma cells. We carried out microarray-based gene expression profiling using Sox10-specific siRNA to identify regulatory targets and found that multiple genes including melanocortin-1 receptor (Mc1R) partake in the regulation of migration. We provide evidences that a significant portion of the effect of Sox10 on migration is mediated by Mitf, a transcription factor downstream to Sox10. The involvement of Mc1R in migration was studied in detail in vivo using a murine metastasis model. Specifically, B16F10 melanoma cells treated with a specific siRNA showed reduced tendency in metastasizing to and colonizing the lung after being injected in the tail vein. These data reveal a cadre of novel regulators and mediators involved in migration and metastasis of melanoma cells that represent potential targets of therapeutic intervention. Chemically synthesized siRNA duplex (WT1-Sox10) was used to knock-down the transcription factor Sox10 in murine melanoma cell line B16F10. For the control, siRNA containing 5 nucleotide alterations (MT1-Sox10) were used. Total RNA was subsequently prepared to synthesize probes for microarray screening. A total of three pairs of replicate samples were generated each from separate transfection followed by RNA preparation. Expression values were determined and compared within each pair of WT1-Sox10 and MT1-Sox10 transfections. Genes showing over 2 fold changes in all three replicate pairs were subjected to subsequent analyses.
Project description:To investigate the function of MC1R in antitumor immunity, we compared the gene expression between B16F10 WT and B16F10 Mc1r knockdown cells at different conditions. We then performed gene expression profiling analysis using data obtained from RNA-seq of 2 different cells at three treatments.
Project description:The transcription factor SRY(sex related protein-Y)-box10 (SOX10) plays a key role in the development of melanocytes and peripheral glial cells from neural crest precursors. Recently, we and other groups found SOX10 to be involved in melanoma initiation, proliferation, invasion, and survival. However, specific mediators which impart the oncogenic role of SOX10 in melanoma remain widely unknown. To identify potential target genes of SOX10, we performed RNA sequencing to analyze genome-wide expression alterations after ectopic expression of SOX10. Among nine genes differentially regulated by SOX10, only peripheral myelin protein 2 (PMP2) was found upregulated in several other melanoma cell lines. PMP2 is one of the most abundant myelin proteins in glial cells and is necessary for the formation and maintenance of the myelin sheath. We detected PMP2 expression in a subset of human melanoma cell lines while it was absent in human melanocytes and fibroblasts. Direct binding of SOX10 to the PMP2 promoter was shown by chromatin immunoprecipitation and electrophoretic shift assay. In three-dimensional spheroid assays, we found that PMP2 overexpression increased melanoma cell invasion. In conclusion, we identified PMP2 as target gene of SOX10 and propose a novel role for PMP2 in melanoma cell invasion.
Project description:Melanoblastoma-bearing Libechov minipigs (MeLiM) provide an animal model for the study of spontaneous cutaneous melanoma. We compared the serial analysis of gene expression (SAGE) profile between normal skin melanocytes and melanoma cells from a pulmonary metastasis of MeLiM. Keywords: disease state study To minimise the contribution of cells other than melanocytes, we constructed SAGE libraries from a primary culture of melanoma cells derived from a pulmonary melanoma metastasis of a young MeLiM and from a pigmented melanocyte cell line, PigMel, derived from the skin of a healthy Meishan pig.
Project description:SOX10 is a lineage-specific transcription factor critical for melanoma tumor growth, while SOX10 loss-of-function drives the emergence of therapy-resistant, invasive melanoma phenotypes. A major challenge has been developing therapeutic strategies targeting SOX10’s role in melanoma proliferation, while preventing a concomitant increase in tumor cell invasion. We found that the lysine acetyltransferase (KAT) EP300 and SOX10 gene loci on Chromosome 22 are frequently co-amplified in melanomas, including UV-associated and acral tumors. We further show that p300 KAT activity mediates SOX10 protein stability and that the p300 inhibitor, A-485, downregulates SOX10 protein levels in melanoma cells via proteasome-mediated degradation. Additionally, A-485 potently inhibits proliferation of SOX10+ melanoma cells while decreasing invasion in AXLhigh/MITFlow melanoma cells through downregulation of metastasis-related genes. We conclude that the SOX10/p300 axis is critical to melanoma growth and invasion, and that inhibition of p300 KAT activity through A-485 may be a worthwhile therapeutic approach for SOX10-reliant tumors.
Project description:Melanoma is one of the most aggressive and treatment-resistant cancers. It represents the most life-threatening neoplasm of the skin, and its incidence has been increasing for the last three decades. Melanoma evolves from the local transformation of melanocytes to primary tumors, which can metastasize to multiple organs. Brain metastases represent one of the most significant causes of death in cutaneous melanoma patients. Despite aggressive multi-modality threapy, patients with melanoma brain metastasis have a median survival of less than a year, with a majority of these patients dying as a result of their intracranial disease. To identify alterations in gene expression related to brain metastasis, we used Affymetrix expression arrays to assess differentially expressed genes in melanocytes, lymph node metastases, and brain metastases. Total RNA from twenty-two specimens representing normal melanocytes (n=3), melanoma lymph node metastasis (n=12), and melanoma brain metastasis (n=7) was extracted and analyzed by Affymetrix expression arrays. Melanocytes specimens were used as control samples. Melanocytes were acquired from Invitrogen (LifeTechnologies). Metastatic melanoma specimens were taken from different patients, established as cell lines in the John Wayne Cancer Institute. Early passages (less than 6) were used to perform expression analysis.
Project description:The “cancerized field” concept posits that cells of a given tissue share a potentially oncogenic mutation or insult and are thus cancer-prone, yet only discreet clones within the field initiate tumor formation. In melanoma, tumors frequently (~50%) carry the oncogenic BRAFV600E mutation that is also nearly always present in benign nevi that rarely become melanoma. The zebrafish crestin gene is expressed embryonically in neural crest progenitors and is then specifically re-expressed in melanoma tumors. Here, we show by live imaging transgenic zebrafish crestin reporters that single melanocytes in a cancerized field with oncogenic BRAFV600E and p53 tumor suppressor loss undergo a change that recapitulates the neural crest progenitor (NCP) state, and patches of these cells initiate early melanoma. The crestin element is regulated by the NCP transcription factor sox10. Forced sox10 overexpression in melanocytes accelerated melanoma formation, consistent with reprogramming to the NCP state and activation of super-enhancers that lead to melanoma. Our work highlights the importance of the reemergence of the NCP state as a barrier to melanoma initiation.
Project description:The “cancerized field” concept posits that cells of a given tissue share a potentially oncogenic mutation or insult and are thus cancer-prone, yet only discreet clones within the field initiate tumor formation. In melanoma, tumors frequently (~50%) carry the oncogenic BRAFV600E mutation that is also nearly always present in benign nevi that rarely become melanoma. The zebrafish crestin gene is expressed embryonically in neural crest progenitors and is then specifically re-expressed in melanoma tumors. Here, we show by live imaging transgenic zebrafish crestin reporters that single melanocytes in a cancerized field with oncogenic BRAFV600E and p53 tumor suppressor loss undergo a change that recapitulates the neural crest progenitor (NCP) state, and patches of these cells initiate early melanoma. The crestin element is regulated by the NCP transcription factor sox10. Forced sox10 overexpression in melanocytes accelerated melanoma formation, consistent with reprogramming to the NCP state and activation of super-enhancers that lead to melanoma. Our work highlights the importance of the reemergence of the NCP state as a barrier to melanoma initiation.
Project description:Affymetrix oligonucleotide microarrays were used to assess global differential gene expression comparing normal human melanocytes with six independent melanoma cell strains from advanced lesions. The data, validated at the protein level for selected genes, confirmed the overexpression in melanoma cells relative to normal melanocytes of several genes in the growth factor/receptor family that confer growth advantage and metastasis. In addition, novel pathways and patterns of associated expression in melanoma cells not reported before emerged.
Project description:SOX10 is a lineage-restricted transcription factor important for melanoma proliferation and survival. Our data demonstrate that SOX10 genetic depletion by CRISPR/Cas9 significantly impaired melanoma proliferation. We chose 7 different melanoma, all of which exhibited growth dependency on SOX10 with different levels. To define the SOX10 transcriptional signature shared with different SOX10-dependent melanoma, we performed bulk RNA-seq on 7 melanoma transfected with siSOX10 or siControl. Each melanoma cell line was plated and transfected with each siRNA to deplete SOX10 protein expression. After 72 hrs, cells were lysed with Buffer TCL(QIAGEN) supplemented with 2-ME and stored at -80C until use. Libraries from each cell line were made with the modified Smart-seq2 protocol. Each replicate was uniquely barcoded and all the samples were pooled for sequencing. (2) We developed a chemical probe (SH-0029) that covalently engages SOX10. To examine the effect of SH-0029 on SOX10 target genes, SOX10-dependent SKMEL5 melanoma were plated and treated with SH-0029, SH-0105 (a control probe), or DMSO(vehicle) for 48h. Total RNA was extracted with NucleoSpin RNA extraction kit (MACHEREY-NAGEL) and mRNA was subsequently purified with poly dT-attached magnetic beads. We found that downregulated genes induced by SH-0029 treatment strongly overlapped with those by SOX10 genetic depletion, suggesting that SOX10 covalent ligand controls SOX10 transcriptional network.