Project description:Epigenetic alterations play significant roles in the melanoma tumorigenesis and malignant progression. We profiled genome-wide promoter DNA methylation patterns of melanoma cells deribed from primary lesions of Radial Growrth phase (RGP) and Vertical Growth Phase (VGP), metastatic lesions, and primary normal melanocytes by interrogating 14,495 genes using Illumina bead chip technology. By comparative analysis of the promoter methylation profiles, we identified epigenetically silenced gene signatures that potentially associated with malignant melanoma progression. Bisulphite converted genomic DNA from a group of melanoma cells representing pathologic stages of melanoma progression (3 cell lines derived from RGP melanoma lesions, 4 cell lines derived from VGP lesions, and 3 melastatic melanomas) and normal human primary melanocytes isolated from lightly pigmented adult skin were hybridized to Illumina's Infinium HumanMethylation27 BeadChips
Project description:Epigenetic alterations play significant roles in the melanoma tumorigenesis and malignant progression. We profiled genome-wide promoter DNA methylation patterns of melanoma cells deribed from primary lesions of Radial Growrth phase (RGP) and Vertical Growth Phase (VGP), metastatic lesions, and primary normal melanocytes by interrogating 14,495 genes using Illumina bead chip technology. By comparative analysis of the promoter methylation profiles, we identified epigenetically silenced gene signatures that potentially associated with malignant melanoma progression.
Project description:The imbalance of cellular homeostasis during oncogenesis together with the high heterogeneity of tumor-associated stromal cells have a marked effect on the repertoire of the proteins secreted by malignant cells (the secretome). Hence, the study of tumoral secretomes provides insights for understanding the cross-talk between cells within the tumor microenvironment as well as the key effectors for the establishment of the pre-metastatic niche in distant tumor sites. In this context, we performed a proteomic analysis of the secretomes derived from four cell lines: (i) a paired set of fibroblasts - Hs 895. T, a cell line obtained from a lung node metastatic site from a patient who had melanoma and Hs 895.Sk, a skin fibroblast cell line (derived from the same patient); (ii) two malignant metastatic melanoma cell lines - A375, a malignant melanoma cell line from primary source and SH-4, a cell line derived from pleural effusion of a patient with metastatic melanoma. Clustering of expression profiles together with functional enrichment revealed patterns that mirrored each cell type (skin fibroblasts, cancer-associated fibroblasts and metastatic cells). These patterns might be the result of cell-specific protein expression programs and may serve as basis for further proteomic analysis of melanoma cell lines secretomes.
Project description:<p>BRCA1 mutations are a hallmark of hereditary ovarian cancer, strongly linked to deficiencies in homologous recombination (HR) DNA repair and impaired DNA replication fork protection. However, its roles in cancer progression beyond maintaining genomic integrity remain poorly understood. Through metabolomics approaches, we found BRCA1-deficiency strikingly increased choline metabolism. Loss of BRCA1 promotes choline uptake through upregulating choline transporter-like protein 4 (CTL4). BRCA1 directly binds and recruits EZH2-mediated H3K27Me3 deposition to CTL4 promoter. CTL4 was therefore overexpressed in ovarian cancer tissues with BRCA1 mutations. Furthermore, BRCA1-deficiency significantly promotes ovarian cancer invasion, while inhibition of CTL4 reverses the high metastatic potential of BRCA1-deficient ovarian cancer cells, suggesting the functionality and specificity of CTL4 as a therapeutic target. Additionally, we discovered that phosphocholine, the choline metabolite increased by CTL4 overexpression, interacted with and stabilized the epithelial-to-mesenchymal transition inducer FAM3C in BRCA1-deficient ovarian cancer cells. Importantly, we identified a potent CTL4 inhibitor, DT-13, which significantly reduces choline metabolism and effectively suppresses metastasis in BRCA1-deficient ovarian cancers. Therefore, our study uncovers a mechanism underlying metastasis in BRCA1-deficient cancers and identifies CTL4 as a therapeutic target for metastatic ovarian cancer patients with BRCA1 mutations.</p>