Project description:Breast cancer is the leading type of cancer in women. Breast cancer brain metastasis is considered as an essential issue in breast cancer patients. Membrane proteins play important roles in breast cancer brain metastasis that contributes to the cell adhesion and penetration of blood-brain barrier. To achieve a deeper insight of the mechanism of breast cancer brain metastasis, liquid chromatography tandem mass spectrometry (LC-MS/MS) was performed to analyze the enriched membrane proteomes from six different breast cancer cell lines. Quantitative proteomic data of all cell lines were compared with MDA-MB-231BR which has the specific brain metastasis capacity. 1239 proteins were identified and 990 were quantified with more than 70% of membrane proteins in all cell lines. Each cell line can be separated apart from others in PCA. Ingenuity pathway analysis (IPA) supported the high brain metastatic ability of 231BR and suggested importance of the up-regulation of integrin proteins and down-regulation of EPHA in brain metastasis. 28 proteins were observed unique expression alteration in 231BR. The up-regulation of NPM1, hnRNP Q, hnRNP K and eIF3l and the down-regulation of TUBB4B and TUBB were observed to be associated with the brain metastasis cell line and may contributes to the breast cancer brain metastasis.
Project description:Hebert JD, Myers SA, Naba A, Abbruzzese G, Lamar J, Carr SA, Hynes RO.Metastasis causes most cancer-related deaths, and one poorly understood aspect of metastatic cancer is the adaptability of cells from a primary tumor to create new niches and survive in multiple, different secondary sites. We used quantitative mass spectrometry to analyze the extracellular matrix (ECM), a critical component of metastatic niches, in metastases to the brain, lungs, liver and bone marrow, all derived from parental MDA-MB-231 triple-negative breast cancer cells. We show that tumor and stromal cells cooperate in forming niches, with stromal cells producing predominantly core, structural ECM proteins and tumor cells producing a diverse array of ECM-associated proteins, including secreted factors and modulators of the matrix. Additionally, tumor and stromal cells together create distinct niches in each tissue, and we show that knocking down SERPINB1, a protein elevated in brain metastases, led to a reduction in brain metastasis, suggesting that some niche-specific ECM proteins may be involved in metastatic tropism.