Identification of novel metastases-suppressor genes involved in breast cancer brain metastases (BCBM) formation
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Kemming Dirk
PROVIDER: S-ECPF-GEOD-44354 | biostudies-other |
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Initial screening for potential metastases suppressors down regulated by methylation was performed using breast cancer cell line models specific for site-specific metastasation. Gene expression profiling and qRT-PCR validations were conducted on tumor tissues from primary breast cancer (BC) and BCBM. CADM1 and RECK were further characterized for their methylation patterns and finally the protein expression of CADM1 was validated in a large number of BC and BCBM samples and correlated with clinico-pathologic parameters. A subclone of MDA-MB-231, which has a high metastatic potential for the brain (MDA-MB-231 BR), was compared to the parental MDA-MB-231 WT and to a bone-seeking subclone (MDA-MB-231 SA) in order to find genes, which might be specifically involved in brain metastasis formation. The cell lines were treated with 5-Aza-2'-deoxycytidine in order to find genes potentially down regulated by methylation. The non-tumorigenic epithelial cell line MCF 10A was used to control for stress response after the treatment with 5-Aza-2'-deoxycytidine.
2014-03-04 | E-GEOD-44354 | biostudies-arrayexpress
Project description:Initial screening for potential metastases suppressors down regulated by methylation was performed using breast cancer cell line models specific for site-specific metastasation. Gene expression profiling and qRT-PCR validations were conducted on tumor tissues from primary breast cancer (BC) and BCBM. CADM1 and RECK were further characterized for their methylation patterns and finally the protein expression of CADM1 was validated in a large number of BC and BCBM samples and correlated with clinico-pathologic parameters.
2014-03-04 | GSE44354 | GEO
Project description:Initial screening for potential metastases suppressors down regulated by methylation was performed using lung cancer cell line models specific for site-specific metastasation. Gene expression profiling and qRT-PCR validations were conducted on tumor tissues from primary lung cancer (LC) and brain metastasis. HERC5 was further characterized for the methylation pattern. Three human lung cancer cell lines H1993, H1395 and were compared to the (SV40)-transformed human bronchial epithelial cell line BEAS-2B in order to find genes, which might be specifically involved in brain metastasis formation. The cell lines were treated with 5-Aza-2'-deoxycytidine in order to find genes potentially down regulated by methylation. The non-tumorigenic cell line BEAS-2B was used to control for stress response after the treatment with 5-Aza-2'-deoxycytidine.
| S-ECPF-GEOD-57492 | biostudies-other
Project description:Initial screening for potential metastases suppressors down regulated by methylation was performed using lung cancer cell line models specific for site-specific metastasation. Gene expression profiling and qRT-PCR validations were conducted on tumor tissues from primary lung cancer (LC) and brain metastasis. HERC5 was further characterized for the methylation pattern. Three human lung cancer cell lines H1993, H1395 and were compared to the (SV40)-transformed human bronchial epithelial cell line BEAS-2B in order to find genes, which might be specifically involved in brain metastasis formation. The cell lines were treated with 5-Aza-2'-deoxycytidine in order to find genes potentially down regulated by methylation. The non-tumorigenic cell line BEAS-2B was used to control for stress response after the treatment with 5-Aza-2'-deoxycytidine.
2014-11-18 | E-GEOD-57492 | biostudies-arrayexpress
Project description:Initial screening for potential metastases suppressors down regulated by methylation was performed using lung cancer cell line models specific for site-specific metastasation. Gene expression profiling and qRT-PCR validations were conducted on tumor tissues from primary lung cancer (LC) and brain metastasis. HERC5 was further characterized for the methylation pattern.
2014-11-18 | GSE57492 | GEO
Project description:Brain metastases represent a major cause of mortality among patients with breast cancer, and few effective targeted treatment options are currently available. Development of new biomarkers and therapeutic targets for breast cancer brain metastases (BCBM) is therefore urgently needed. In this study, we compared the gene expression profiles of the brain metastatic cell line MDA-MB-231-BR (231-BR) and its parental MDA-MB-231, and identified a total of 84 genes in the primary screening through a series of bioinformatic analyses, including construction of protein-protein interaction (PPI) networks by STRING database, identification of hub genes by applying of MCODE and Cytohubba algorithms, identification of leading-edge subsets of Gene Set Enrichment Analysis (GSEA), and identification of most up-regulated genes. Eight genes were identified as candidate genes due to their elevated expression in brain metastatic 231-BR cells and prognostic values in patients with BCBM. Then we knocked down the eight individual candidate genes in 231-BR cells and evaluated their impact on cell migration through a wound-healing assay, and four of them (KRT19, FKBP10, GSK3B and SPANXB1) were finally identified as key genes. Furthermore, the expression of individual key genes showed a correlation with the infiltration of major immune cells in the brain tumor microenvironment (TME) as analyzed by Tumor Immune Estimation Resource (TIMER) and Gene Expression Profiling Interactive Analysis (GEPIA), suggesting possible roles of them in regulation of the tumor immune response in TME. Therefore, the present work may provide new potential biomarkers for BCBM. Additionally, using GSEA, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Enrichment Analysis, we determined the top enriched cellular functions or pathways in 231-BR cells, which may help better understand the biology governing the development and progression of BCBM.
| S-EPMC8792448 | biostudies-literature
Project description:BACKGROUND:Breast cancer brain metastases (BCBM) develop in about 20-30% of breast cancer (BC) patients. BCBM are associated with dismal prognosis not at least due to lack of valuable molecular therapeutic targets. The aim of the study was to identify new molecular biomarkers and targets in BCBM by using complementary state-of-the-art techniques. METHODS:We compared array expression profiles of three BCBM with 16 non-brain metastatic BC and 16 primary brain tumors (prBT) using a false discovery rate (FDR) p < 0.05 and fold change (FC) > 2. Biofunctional analysis was conducted on the differentially expressed probe sets. High-density arrays were employed to detect copy number variations (CNVs) and whole exome sequencing (WES) with paired-end reads of 150 bp was utilized to detect gene mutations in the three BCBM. RESULTS:The top 370 probe sets that were differentially expressed between BCBM and both BC and prBT were in the majority comparably overexpressed in BCBM and included, e.g. the coding genes BCL3, BNIP3, BNIP3P1, BRIP1, CASP14, CDC25A, DMBT1, IDH2, E2F1, MYCN, RAD51, RAD54L, and VDR. A number of small nucleolar RNAs (snoRNAs) were comparably overexpressed in BCBM and included SNORA1, SNORA2A, SNORA9, SNORA10, SNORA22, SNORA24, SNORA30, SNORA37, SNORA38, SNORA52, SNORA71A, SNORA71B, SNORA71C, SNORD13P2, SNORD15A, SNORD34, SNORD35A, SNORD41, SNORD53, and SCARNA22. The top canonical pathway was entitled, role of BRCA1 in DNA damage response. Network analysis revealed key nodes as Akt, ERK1/2, NFkB, and Ras in a predicted activation stage. Downregulated genes in a data set that was shared between BCBM and prBT comprised, e.g. BC cell line invasion markers JUN, MMP3, TFF1, and HAS2. Important cancer genes affected by CNVs included TP53, BRCA1, BRCA2, ERBB2, IDH1, and IDH2. WES detected numerous mutations, some of which affecting BC associated genes as CDH1, HEPACAM, and LOXHD1. CONCLUSIONS:Using complementary molecular genetic techniques, this study identified shared and unshared molecular events in three highly aberrant BCBM emphasizing the challenge to detect new molecular biomarkers and targets with translational implications. Among new findings with the capacity to gain clinical relevance is the detection of overexpressed snoRNAs known to regulate some critical cellular functions as ribosome biogenesis.
| S-EPMC5747948 | biostudies-literature
Project description:BackgroundBreast cancer (BC) is the most frequent malignant tumor in females and the 2nd most common cause of brain metastasis (BM), that are associated with a fatal prognosis. The increasing incidence from 10% up to 40% is due to more effective treatments of extracerebral sites with improved prognosis and increasing use of MRI in diagnostics. A frequently administered, potent chemotherapeutic group of drugs for BC treatment are taxanes usually used in the adjuvant and metastatic setting, which, however, have been suspected to be associated with a higher incidence of BM. The aim of our study was to experimentally analyze the impact of the taxane docetaxel (DTX) on brain metastasis formation, and to elucidate the underlying molecular mechanism.MethodsA monocentric patient cohort was analyzed to determine the association of taxane treatment and BM formation. To identify the specific impact of DTX, a murine brain metastatic model upon intracardial injection of breast cancer cells was conducted. To approach the functional mechanism, dynamic contrast-enhanced MRI and electron microscopy of mice as well as in-vitro transendothelial electrical resistance (TEER) and tracer permeability assays using brain endothelial cells (EC) were carried out. PCR-based, immunohistochemical and immunoblotting analyses with additional RNA sequencing of murine and human ECs were performed to explore the molecular mechanisms by DTX treatment.ResultsTaxane treatment was associated with an increased rate of BM formation in the patient cohort and the murine metastatic model. Functional studies did not show unequivocal alterations of blood-brain barrier properties upon DTX treatment in-vivo, but in-vitro assays revealed a temporary DTX-related barrier disruption. We found disturbance of tubulin structure and upregulation of tight junction marker claudin-5 in ECs. Furthermore, upregulation of several members of the tubulin family and downregulation of tetraspanin-2 in both, murine and human ECs, was induced.ConclusionIn summary, a higher incidence of BM was associated with prior taxane treatment in both a patient cohort and a murine mouse model. We could identify tubulin family members and tetraspanin-2 as potential contributors for the destabilization of the blood-brain barrier. Further analyses are needed to decipher the exact role of those alterations on tumor metastatic processes in the brain.
| S-EPMC6819416 | biostudies-literature
Project description:Brain metastases are an increasing burden among breast cancer patients, particularly for those with HER2+ and triple negative (TN) subtypes. Mechanistic insight into the pathophysiology of brain metastases and preclinical validation of therapies has relied almost exclusively on intracardiac injection of brain-homing cells derived from highly aggressive TN MDA-MB-231 and HER2+ BT474 breast cancer cell lines. Yet, these well characterized models are far from representing the tumor heterogeneity observed clinically and, due to their fast progression in vivo, their suitability to validate therapies for established brain metastasis remains limited. The goal of this study was to develop and characterize novel human brain metastasis breast cancer patient-derived xenografts (BM-PDXs) to study the biology of brain metastasis and to serve as tools for testing novel therapeutic approaches. We obtained freshly resected brain metastases from consenting donors with breast cancer. Tissue was immediately implanted in the mammary fat pad of female immunocompromised mice and expanded as BM-PDXs. Brain metastases from 3/4 (75%) TN, 1/1 (100%) estrogen receptor positive (ER+), and 5/9 (55.5%) HER2+ clinical subtypes were established as transplantable BM-PDXs. To facilitate tracking of metastatic dissemination using BM-PDXs, we labeled PDX-dissociated cells with EGFP-luciferase followed by reimplantation in mice, and generated a BM-derived cell line (F2-7). Immunohistologic analyses demonstrated that parental and labeled BM-PDXs retained expression of critical clinical markers such as ER, progesterone receptor, epidermal growth factor receptor, HER2, and the basal cell marker cytokeratin 5. Similarly, RNA sequencing analysis showed clustering of parental, labeled BM-PDXs and their corresponding cell line derivative. Intracardiac injection of dissociated cells from BM-E22-1, resulted in magnetic resonance imaging-detectable macrometastases in 4/8 (50%) and micrometastases (8/8) (100%) mice, suggesting that BM-PDXs remain capable of colonizing the brain at high frequencies. Brain metastases developed 8-12?weeks after ic injection, located to the brain parenchyma, grew around blood vessels, and elicited astroglia activation characteristic of breast cancer brain metastasis. These novel BM-PDXs represent heterogeneous and clinically relevant models to study mechanisms of brain metastatic colonization, with the added benefit of a slower progression rate that makes them suitable for preclinical testing of drugs in therapeutic settings.
| S-EPMC5673842 | biostudies-literature
Project description:INTRODUCTION: Metastases to the brain from breast cancer have a high mortality, and basal-like breast cancers have a propensity for brain metastases. However, the mechanisms that allow cells to colonize the brain are unclear. METHODS: We used morphology, immunohistochemistry, gene expression and somatic mutation profiling to analyze 39 matched pairs of primary breast cancers and brain metastases, 22 unmatched brain metastases of breast cancer, 11 non-breast brain metastases and 6 autopsy cases of patients with breast cancer metastases to multiple sites, including the brain. RESULTS: Most brain metastases were triple negative and basal-like. The brain metastases over-expressed one or more members of the HER family and in particular HER3 was significantly over-expressed relative to matched primary tumors. Brain metastases from breast and other primary sites, and metastases to multiple organs in the autopsied cases, also contained somatic mutations in EGFR, HRAS, KRAS, NRAS or PIK3CA. This paralleled the frequent activation of AKT and MAPK pathways. In particular, activation of the MAPK pathway was increased in the brain metastases compared to the primary tumors. CONCLUSIONS: Deregulated HER family receptors, particularly HER3, and their downstream pathways are implicated in colonization of brain metastasis. The need for HER family receptors to dimerize for activation suggests that tumors may be susceptible to combinations of anti-HER family inhibitors, and may even be effective in the absence of HER2 amplification (that is, in triple negative/basal cancers). However, the presence of activating mutations in PIK3CA, HRAS, KRAS and NRAS suggests the necessity for also specifically targeting downstream molecules.
| S-EPMC2949633 | biostudies-literature