Project description:PURPOSE: To estimate the effect of contamination with normal breast tissue for the development of gene signatures robust to pre-analytical conditions. METHODS: We evaluated the effect of contamination with normal breast tissue on gene signatures by comparing microarray profiles of breast cancer samples contaminated with increasing amounts of normal breast tissue.
Project description:Breast cancer and normal breast tissue samples to estimate the effect of contamination of breast cancer samples with normal breast tissue
Project description:Tumor associated miRNAs in hereditary breast cancer. In this study we investigated the role of miRNAs in hereditary breast tumors comparing with normal breast tissue. Global miRNA expression profiling was performed on 22 hereditary breast tumors and 15 non-tumoral breast tissues. We identified 19 miRNAs differentially expressed, most of them down-regulated in tumors. An important proportion of deregulated miRNAs in hereditary tumors were previously identified commonly deregulated in sporadic breast tumors. Our results identify miRNAs associated to hereditary breast cancer, as well as miRNAs commonly miss-expressed in hereditary and sporadic tumors, suggesting common underlying mechanisms of tumor progression. In addition, we provide evidence that KRAS is a target of miR-30c, and that this miRNA suppresses breast cancer cell growth potentially through inhibition of KRAS signaling.
Project description:Tumor associated miRNAs in hereditary breast cancer. In this study we investigated the role of miRNAs in hereditary breast tumors comparing with normal breast tissue. Global miRNA expression profiling was performed on 22 hereditary breast tumors and 15 non-tumoral breast tissues. We identified 19 miRNAs differentially expressed, most of them down-regulated in tumors. An important proportion of deregulated miRNAs in hereditary tumors were previously identified commonly deregulated in sporadic breast tumors. Our results identify miRNAs associated to hereditary breast cancer, as well as miRNAs commonly miss-expressed in hereditary and sporadic tumors, suggesting common underlying mechanisms of tumor progression. In addition, we provide evidence that KRAS is a target of miR-30c, and that this miRNA suppresses breast cancer cell growth potentially through inhibition of KRAS signaling. Single color experiments in a pairwise comparison design.
Project description:Results: Normal tissue contamination caused misclassification of tumors in all predictors, but different breast cancer predictors showed different susceptibility to normal tissue bias. Sensitivity and negative predictive value (NPV) of the PAM50 assay was improved by accounting for normal tissue. Conclusions: Normal tissue sampled concurrently with tumor tissue is an important source of bias in genomic predictors. Adjustments for normal tissue contamination could improve the application of breast cancer genomic predictors in both research and in clinical settings.
Project description:Genome wide DNA methylation profiling of irradiated and non-irradiated breast tumor samples and normal control tissue. The Illumina Infinium 27k Human DNA methylation Beadchip, Genome Build 36 was used to obtain DNA methylation profiles across approximately 27,000 CpGs in breast tumor samples. Samples included 20 non-irradiated tumor samples, 19 irradiated tumor samples and 9 normal controls.
Project description:Accessing the proteome of formalin fixed, paraffin-embedded (FFPE) tissue could lead to discovery of new biomarkers and development of clinically useful assays. A critical step to realizing this potential is developing a simple and reproducible method to obtain proteomic profiles from FFPE tissue. An objective of this work is to develop and optimize a method to obtain proteomic profiles from FFPE breast tissue using a protocol commonly applied in pathology laboratories. The outcome is a method that incorporates steps used for immunohistochemical analyses of FFPE tissue that results in highly reproducible proteomic profiles. Implementing this assay with normal breast tissue and breast tumor tissue produced proteome profiles that reproducibly demonstrate substantial differences between normal vs. tumor tissue.