Project description:Genome wide DNA methylation profiling of peripheral blood mononuclear cells (PBMCs) in normal and BC samples. The Illumina Infinium 850k Human DNA methylation Beadchip was used to obtain DNA methylation profiles across approximately 820,000 CpGs in PBMC samples. Samples included 50 newly diagnosed BC patients and 30 normal controls.
Project description:Genome wide DNA methylation profiling of non-tumoral and infiltrating ductal breast cancer (tumoral) samples. The HumanMethylation450 BeadChip was used to obtain DNA methylation profiles across approximately 450,000 CpG in non-tumoral and tumoral samples. Non-tumoral samples included six frozen non-neoplastic breast tissues from reduction mammoplasties and tumoral samples included eight frozen tumors from each BC subtype, i.e. luminal A (LA), luminal B (LB), luminal-HER2 (LH), HER2 (H) and triple-negative (TN) (Total: 40 tumors).
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:Breast cancer and normal breast tissue samples to estimate the effect of contamination of breast cancer samples with normal breast tissue
Project description:Despite known age-related DNA methylation (aDNAm) changes in breast tumors, little is known about aDNAm in normal breast tissues. Breast tissues from a cross-sectional study of 121 cancer-free women, were assayed for genome-wide DNA methylation. mRNA expression was assayed by microarray technology. Analysis of covariance was used to identify aDNAm’s. Altered methylation was correlated with expression of the corresponding gene and with DNA methyltransferase protein DNMT3A, assayed by immunohistochemistry. Publically-available TCGA data were used for replication. 1,214 aDNAm’s were identified; 97% with increased methylation, and all on autosomes. Sites with increased methylation were predominantly in CpG lslands and non-enhancers. aDNAm’s with decreased methylation were generally located in intergenic regions, non-CpG Islands, and enhancers. Of the aDNAm’s identified, 650 are known to be involved in cancer, including ESR1 and beta-estradiol responsive genes. Expression of DNMT3A was positively associated with age. Two aDNAm’s showed significant associations with DNMT3A expression; KRR1 (OR 6.57, 95% CI: 2.51-17.23) and DHRS12 (OR 6.08, 95% CI: 2.33-15.86). A subset of aDNAm’s co-localized within vulnerable regions for somatic mutations in breast cancer. Expression of C19orf48 was inversely and significantly correlated with its methylation level. In the TCGA dataset, 84% and 64% of the previously identified aDNAm’s were correlated with age in both normal-adjacent and tumor breast tissues, with differential associations by histological subtype. Given the similarity of findings in the breast tissues of healthy women and breast tumors, and the effects on gene expression, aDNAm’s may be one pathway for increased breast cancer risk with age.