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:Transcriptional profiling of comparing control and GAPLINC stable knocking-down human gastric cancer cell lines. Goal was to determine the different gene expression between control and GAPLINC stable knocking-down human gastric cancer cell lines. Control and GAPLINC stable knocking-down human gastric cancer cell lines were prepared for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Breast cancer cell lines containing stable dox inducible shRNAs targeting SF3B1 were profiled by RNA sequencing. We determined the effect of gene expression and splicing changes before and after knocking down SF3B1 in cell lines with normal copy number (SF3B1neutral) or partial copy loss (SF3B1loss) cell lines
Project description:Transcriptional profiling of comparing control and GAPLINC knocking-down human gastric cancer cell lines. Goal was to determine the different gene expression between control and GAPLINC knocking-down human gastric cancer cell lines.
Project description:Brain metastasis is one of the most feared complications of cancer and the most common intracranial malignancy in adults. Its underlying mechanisms remain unknown. From breast cancer patients with metastatic disease we isolated cell populations that aggressively colonize the brain. Transcriptomic analysis of these cells yielded overlapping gene sets whose expression is selectively associated with brain metastasis. The expression of seventeen of these genes in primary breast tumors is associated with brain relapse in breast cancer patients. Some of these genes are also associated with metastasis to lung but not to liver, bone or lymph nodes, providing a molecular basis for the long-observed clinical link between brain and lung metastasis. Among the functionally validated brain metastasis genes, the cyclooxygenase COX-2, the EGFR ligand HB-EGF, and the brain-specific α2-6 sialyltransferase ST6GALNAC5 mediate cancer cell passage through the blood-brain barrier. Other brain metastasis genes encode inflammatory factors and brain-specific proteolytic regulators, suggesting a multifaceted program for breast cancer colonization of the brain. Experiment Overall Design: Two different breast cancer cell lines, MDA-MB-231 and freshly isolated pleural effusion CN34 were used in this study. The MDA-MB-231 group contains three biological replicates of the parental, unselected population, and 4 brain metastatic isolates. CN34 contains 2 biological replicates of the parental, unselected population, and 4 brain metastatic isolates. In each case, the parental population was compared to the brain metastatic isolates to identify gene expression changes associated with the brain metastatic phenotype.
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.
Project description:Introduction: The prognosis for patients with breast tumor metastases to brain is extremely poor. Identification of prognostic molecular markers of the metastatic process is critical for designing therapeutic modalities for reducing the occurrence of metastasis. Although ubiquitously present in most human organs, calcium-activated potassium (BK) channel is significantly upregulated in breast cancer cells. In this study we investigated the role of KCNMA1 gene, which encodes α subunit of KCa channels (BK channels) in breast cancer metastasis and invasion. Methods: We performed Global exon array to study the expression of KCNMA1 in metastatic breast cancer in brain, compared its expression in primary breast cancer and breast cancers metastatic to other organs, and validated the findings by RT-PCR. Immunohistochemistry was performed to study the expression and localization of α subunit of KCa channel protein in primary and metastatic breast cancer tissues and breast cancer cell lines. We performed matrigel invasion, transendothelial migration and membrane potential assays in established lines of normal breast cells (MCF-10A), non-metastatic breast cancer (MCF-7), non-brain metastatic breast cancer cells (MDA-MB-231), and brain-specific metastatic breast cancer cells (MDA-MB-361) to study whether KCa channel inhibition attenuates breast tumor invasion and metastasis using KCNMA1 knockdown with siRNA and biochemical inhibition with IBTX (Iberiotoxin). Results: The Global exon array and RT-PCR showed higher KCNMA1 expression in metastatic breast cancer in brain compared to metastatic breast cancers in other organs. Our results clearly show that metastatic breast cancer cells exhibit increased BK channel activity, leading to greater invasiveness and transendothelial migration, both of which could be attenuated by blocking KCNMA1. Conclusion: Determining the relative abundance of BK channel over expression in breast cancer metastatic to brain and the mechanism of its action in brain metastasis will provide a unique opportunity to identify and differentiate between low grade breast tumors that are at high risk for metastasis from those at low risk for metastasis. This distinction would in turn allow for the appropriate and efficient application of effective treatments while sparing patients with low risk for metastasis from the toxic side effects of chemotherapy.