Project description:Since bone metastatic breast cancer is an incurable disease, causing significant morbidity and mortality, understanding of the underlying molecular mechanisms would be highly valuable. Here, we describe in vitro and in vivo evidence for the importance of serine biosynthesis in the metastasis of breast cancer to bone. We first characterized the bone metastatic propensity of the MDA-MB-231(SA) cell line variant as compared to the parental MDA-MB-231 cells by radiographic and histological observations in the inoculated mice. Genome-wide gene expression profiling of this isogenic cell line pair revealed that all the three genes involved in the L-serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1), and phosphoserine phosphatase (PSPH) were upregulated in the highly metastatic variant. This pathway is the primary endogenous source for L-serine in mammalian tissues. Consistently, we observed that the proliferation of MDA-MB-231(SA) cells in serine-free conditions was dependent on PSAT1 expression. In addition, we observed that L-serine is essential for the formation of bone resorbing human osteoclasts and may thus contribute to the vicious cycle of osteolytic bone metastasis. High expression of PHGDH and PSAT1 in primary breast cancer was significantly associated with decreased relapse-free and overall survival of patients and malignant phenotypic features of breast cancer. In conclusion, high expression of serine biosynthesis genes in metastatic breast cancer cells and the stimulating effect of L-serine on osteoclastogenesis and cancer cell proliferation indicate a functionally critical role for serine biosynthesis in bone metastatic breast cancer and thereby an opportunity for targeted therapeutic interventions. Parental MDA-MB-231 cells and MDA-MB-231(SA) cells were cultured in cell culture flasks. RNA was isolated in order to compare the gene expression profiles of these cell variants. Total of two samples. No replicates.
Project description:To identify typical enhancers and super-enhancers in the MDA-MB-231 triple-negative breast cancer cell line, we performed ChIP-seq using DNA isolated from untreated MDA-MB-231 cells using an H3K27ac antibody.
Project description:Breast cancer invasive growth, metastasis and therapeutic resistance affects the clinical ourcome. We explored the epigenetic mechanisms that control these process in breast cancer cell line, MDA-MB-231 by knocking down a lysine specific demethylase KDM3A We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. Human breast cancer cell line MDA-MB-231 was infected with scramble or KDM3A shRNA. After selection, the cells were used for microarray analysis.
Project description:The project profiled the expression patterns in hypoxia induced secretomes between MDA-MB-231 parental and MDA-MB-231 Bone Tropic (BT) breast cancer cell lines which have been previously generated by Massague and colleagues (Kang et al. Cancer Cell 2003).
Project description:RRP1B is a breast cancer metastasis suppressor that interacts with various regulators of gene transcription We examined the changes in gene expression caused by the stable over-expression of RRP1B using lentiviral transduction in the human breast cancer cell line MDA-MB-231.
Project description:Since bone metastatic breast cancer is an incurable disease, causing significant morbidity and mortality, understanding of the underlying molecular mechanisms would be highly valuable. Here, we describe in vitro and in vivo evidence for the importance of serine biosynthesis in the metastasis of breast cancer to bone. We first characterized the bone metastatic propensity of the MDA-MB-231(SA) cell line variant as compared to the parental MDA-MB-231 cells by radiographic and histological observations in the inoculated mice. Genome-wide gene expression profiling of this isogenic cell line pair revealed that all the three genes involved in the L-serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1), and phosphoserine phosphatase (PSPH) were upregulated in the highly metastatic variant. This pathway is the primary endogenous source for L-serine in mammalian tissues. Consistently, we observed that the proliferation of MDA-MB-231(SA) cells in serine-free conditions was dependent on PSAT1 expression. In addition, we observed that L-serine is essential for the formation of bone resorbing human osteoclasts and may thus contribute to the vicious cycle of osteolytic bone metastasis. High expression of PHGDH and PSAT1 in primary breast cancer was significantly associated with decreased relapse-free and overall survival of patients and malignant phenotypic features of breast cancer. In conclusion, high expression of serine biosynthesis genes in metastatic breast cancer cells and the stimulating effect of L-serine on osteoclastogenesis and cancer cell proliferation indicate a functionally critical role for serine biosynthesis in bone metastatic breast cancer and thereby an opportunity for targeted therapeutic interventions.
Project description:Identification of changes in protein expression by label-free shotgun proteomics in breast cancer MDA-MB-231 cells with knockdown of ELOVL5 and IGFBP6 genes in comparison with control MDA-MB-231 cells.
Project description:The project profiled the expression patterns in hypoxia induced secretomes between MDA-MB-231 parental and MDA-MB-231 Bone Tropic (BT) breast cancer cell lines which have been previously generated by Massague and colleagues (Kang et al. Cancer Cell 2003).
Project description:RagC was immunoprecipitated from human breast cancer MDA-MB-231 cells treated or not with the Arp2/3 complex inhibitor, CK666, and the RagC interactome was analyzed by mass-spectrometry.
Project description:LRP-1 (low-density lipoprotein receptor-related protein-1) receptor is a multifunctional endocytosis receptor that is part of the LDL receptor family. Due to its capacity to control the pericellular level of various growth factors and proteases, LRP-1 plays a crucial role in controlling the dynamics of the membrane proteome. LRP-1 overexpression in breast cancer, prompted us to take an interest in its involvement in tumor progression. An RNA interference strategy in MDA-MB-231 line was used, based on shRNA stable expression. In addition to integrated experimental strategies (in vitro and in vivo) through combined approaches of biochemistry, molecular biology, cell biology, multimodal preclinical imaging, proteomics allowed us to compare shLRP-1 MDA-MB-231 tumor conditioned media to shCtrl MDA-MB-231 tumor conditioned media in order to identify secreted molecular targets modulate by LRP-1 repression and thus provide a better understanding of its regulatory action within the TNBC microenvironment.