Transcription profiling of human breast tumors to identify a signature to predict survival
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Warmoes M
PROVIDER: S-ECPF-UCON-1 | biostudies-other | 2012 Jul
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Expression profiling of breast cancer patients to identify a signature
2006-08-23 | E-UCON-1 | biostudies-arrayexpress
Project description:Breast cancer arising in young women has a poorer prognosis, is less likely to be hormone sensitive, and represents a particularly challenging clinical entity. The biology driving the aggressive nature of breast cancer arising in young women has yet to be defined. Among 784 patients with early stage breast cancer, using prospectively-defined, age-specific cohorts (young <= 45 years; older >= 65 years), 411 eligible patients (n = 200 < 45 years; n = 211 >= 65 years) with clinically-annotated Affymetrix microarray data were identified. Gene set enrichment analyses, signatures of oncogenic pathway deregulation and predictors of chemotherapy sensitivity were evaluated within the two age-defined cohorts. In comparing deregulation of oncogenic pathways between age groups, a statistically higher probability of PI3K (p = 0.006) and Myc (p = 0.03) pathway deregulation was observed in the tumors of younger women. When evaluating unique patterns of pathway deregulation, a low probability of Src and E2F deregulation in tumors of younger women, concurrent with activation of PI3K, Myc, and beta-catenin, conferred a worse prognosis (HR = 4.15; p = 0.008). In contrast, a higher probability of Src and E2F pathway activation in tumors of older women, concurrent low probability of PI3K, Myc and beta-catenin deregulation, was associated with a poorer outcome (HR = 2.7; p = 0.006). Similar pathway differences were identified using gene set enrichment analysis. Importantly, in multivariate analyses including clinico-pathologic variables, genomic clusters of pathway deregulation were identified to be independent predictors of disease-free survival. Finally, a significant relationship (p = 0.02) between anthracycline sensitivity and genomic clusters was observed among women aged >= 65 years. Submitters do not have approval to publish the .CEL files Experiment Overall Design: n=78
| S-ECPF-GEOD-7849 | biostudies-other
Project description:BackgroundThe expression pattern of transcription factors (TFs) can be used to develop potential prognostic biomarkers for cancer. In this study, we aimed to identify and validate a TF signature for predicting disease-free survival (DFS) of breast cancer (BRCA) patients.MethodsLasso and the Cox regression analyses were applied to construct a TF signature based on a gene expression dataset from TCGA. The prognosis value of the TF signature was investigated in the TCGA database, and its reliability was further validated in 3 independent datasets from Gene Expression Omnibus (GEO). The prognosis performance of the TF signature was compared with 4 previously published gene signatures. To investigate the association between the TF signature and hallmarks of cancer, Gene Set Enrichment Analysis (GSEA) was carried out. The correlations of the TF signature and the levels of immune infiltration were also investigated.ResultsAn 11-TF prognostic signature was constructed with good survival prediction performance for BRCA patients. By using the risk score model based on the 11-TF signature, BRCA patients were stratified into low- and high-risk groups and showed good and poor disease-free survival (DFS), respectively. The risk score was an independent prediction indicator when adjusting for other clinicopathological factors. Furthermore, the 11-TF signature had a better survival prediction performance compared to 4 previously published gene signatures. Moreover, the risk score was a cancer hallmark. Finally, a high-risk score was associated with higher infiltration of M0 and M2 macrophages and was associated with a lower infiltration of resting memory CD4+ T cells and CD8+ T cells.ConclusionThe findings in this study identified and validated a novel prognostic TF signature, which is an independent biomarker for the prediction of DFS in BRCA patients.
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Project description:To investigate the biological basis between aging and sporadic breast cancer incidence and prognosis, RNA samples from matched ER+ invasive breast cancers diagnosed in either young (≤45) or old (≥70) women were analyzed by expression microarrays Experiment Overall Design: ER+ breast cancers collected from either young or old women, well matched for other clinical parameters were analyzed using expression microarrays. Age associated tumor subtypes and enrichment of pre-defined gene signatures were identified. Age associated differential expression and an age signature (gene-based classifier) was assessed
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Project description:bulk breast tumor RNA from patient; Abstract: Sporadic basal-like cancers (BLC) are a distinct class of human breast cancers that are phenotypically similar to BRCA1-associated cancers. Like BRCA1-deficient tumors, most BLC lack markers of a normal inactive X chromosome (Xi). Duplication of the active X chromosome and loss of Xi characterized almost half of BLC cases tested. Others contained biparental but nonheterochromatinized X chromosomes or gains of X chromosomal DNA. These abnormalities did not lead to a global increase in X chromosome transcription but were associated with overexpression of a small subset of X chromosomal genes. Other, equally aneuploid, but non-BLC rarely displayed these X chromosome abnormalities. These results suggest that X chromosome abnormalities contribute to the pathogenesis of BLC, both inherited and sporadic. total 62 sample incudes 43 tumor, 7 normal breast and 12 normal organelle Experiment Overall Design: compare expression of tumor to normal breast tissue
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Project description:Tumorigenic breast cancer cells characterized by CD44 expression and low or undetectable CD24 levels (CD44+/CD24-/low) may be resistant to chemotherapy and therefore responsible for cancer relapse. Paired breast cancer core biopsies before and after neoadjuvant chemotherapy or lapatinib were obtained and as single cell suspensions stained using antibodies against CD24, CD44, and lineage markers, and then analyzed by flow cytometry. Mammosphere (MS) formation in culture was compared before and after treatment. Global gene expression differences between cancer cells bearing CD44+/CD24-/low cells and all other sorted cells, and between cancer MS and the primary bulk invasive cancers were analyzed. We report that CD44+/CD24-/low tumorigenic breast cancer cells were intrinsically chemoresistant - chemotherapy led to increased CD44+/CD24-/low cells, increased self-renewal capacity on MS assays, and enhanced tumorigeneicity in immunocompromised SCID/Beige mice. Conversely, in patients with HER2 overexpressing tumors, the EGFR/HER2 tyrosine kinase inhibitor, lapatinib decreased CD44+/CD24-/low cells, with the majority of these patients after conventional therapy achieving pathologic complete response, a validated surrogate marker for long-term survival. Gene transcription pathways that underlie chemoresistant, MS-forming CD44+/CD24-/low cells involve genes belonging to stem cell self-renewal, Wnt signaling, and early development pathways. Experiment Overall Design: Cells from human breast tumors were grown as mammospheres (MS). Experiment Overall Design: Isolated single cell suspensions from primary breast cancers were plated onto non-adherent (polyhema-coated) plastic, counted with a hematocytometer, and 20,000 cells were then seeded into a 6-well ultra-low attachment plate supplemented with 2mL MEGM, with the addition of 2 mL of freshly unfrozen MEGM every 3-4 days. Gene expression profiles were taken of both MS and primary bulk tumors and compared with each other.
| S-ECPF-GEOD-7515 | biostudies-other
Project description:Background: Recently a 76-gene prognostic signature able to predict distant metastases in lymph node-negative (N-) breast cancer patients was reported. The aims of this study conducted by TRANSBIG were to independently validate these results and to compare the outcome with clinical risk assessment. Materials and Methods: Gene expression profiling of frozen samples from 198 N- systemically untreated patients was performed at the Bordet Institute, blinded to clinical data and independent of Veridex. Genomic risk was defined by Veridex, blinded to clinical data. Survival analyses, done by an independent statistician, were performed with the genomic risk and adjusted for the clinical risk, defined by Adjuvant!Online. Results: The actual 5- and 10-year time to distant metastasis (TDM) were 98% (88%-100%) and 94% (83%-98%) respectively for the good profile group and 76% (68%- 82%) and 73% (65%-79%) for the poor profile group. The actual 5- and 10-year overall survival (OS) were 98% (88%-100%) and 87% (73%-94%) respectively for the good profile group and 84% (77%-89%) and 72% (63%-78%) for the poor profile group. We observed a strong time-dependency of this signature, leading to an adjusted HR of 13.58 (1.85-99.63) and 8.20 (1.10-60.90) at 5 years, and 5.11 (1.57-16.67) and 2.55 (1.07-6.10) at 10 years for TDM and OS respectively. Conclusion: This independent validation confirmed the performance of the 76-gene signature and adds to the growing evidence that gene expression signatures are of clinical relevance, especially for identifying patients at high risk of early distant metastases. Experiment Overall Design: dataset of microarray experiments from primary breast tumors used to validate the 76-gene signature (VERIDEX). No replicate, no reference sample.
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Project description:The aim of our work was the comparison of human and mouse gene expression data and to identify a conserved breast tumor gene set. The results encourage the usefulness of transgenic mice as a model for human breast cancer formation and therapy. Experiment Overall Design: The aim of our work was to establish a database for breast cancer gene expression data in order to compare human and mouse breast cancer. We identified human and mouse homologues genes and compared the expression profile of 24 human breast tumors with six WAP-SVT/t breast tumors (WAP-SVT/t animals, line 8). Our studies confirmed the heterogeneity in gene expression of human as well as mouse breast cancer cells. However, 63 genes were found to be differentially expressed (upregulated: 40; downregulated: 23 genes) in at least 75% of the breast tumors of both species.
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