Project description:To find differentially expressed RNAs between breast cancer and benign tissue, we have conducted whole genome microarray expression profiling as a discovery platform to identify genes that play a key role in the breast cancer progression. Primary cancer tissues and paired adjacent noncancerous tissues were snap-frozen in liquid nitrogen immediately after resection and were used to perform genome expression analysis.
Project description:We sought to identify circulating microRNAs (miRNAs) from blood plasma that could be used as biomarkers to detect breast cancer existing in high-risk benign breast tumors. Plasma samples were collected from patients with early-stage breast cancer (CA), high- (HB), moderate- (MB), and no-risk (Be) benign tumors. The miRNAs we have identified have the potential to develop into a crucial blood-based screening tool to help monitor the development of breast cancer in benign breast tumors.
Project description:Background. Although gene expression arrays have been used to generate molecular predictors of relapse and drug sensitivity in breast cancer, no large study describes genes and exons differentially expressed between breast cancer and benign lesions.<br><br> Methods. One hundred and sixty-five tumour samples were obtained by fine needle aspiration (FNA). cDNA were hybridized on Splice ArrayTM. A nearest centroid prediction rule was developed to classify lesions as malignant or benign on a training set, and its performance evaluated on an independent validation set. A two-way ANOVA model was used to identify probesets that present a differential expression between cancer and benign lesions while adjusting for scan dates. P-values were adjusted for False Discovery Rate.<br><br>Findings. Overall 120 breast cancers and 45 benign lesions were included in the study. A 1228-probeset molecular classifier for breast cancer diagnosis was generated from the training set (n=94). This signature accurately classified all samples (100% accuracy, 95% exact CI: 96-100%). In the validation set (n=71), the molecular predictor accurately classified 68 out of 71 tumours (96%, 95% CI: 88-99%). When the 165 samples were taken into account, 37 858 exon-probesets (5.4%) and 3733 genes (20%) were found to be differentially expressed between malignant and benign conditions (adjusted p-value<0.05). Pathway analyses showed that genes involved in spliceosome assembly were significantly enriched in malignant condition (permutation p=0.002). In the same population of 165 samples, 956 exon-probesets presented both a higher intensity and higher splice index in breast cancer, although located on unchanged genes.<br><br> Interpretation. The present study provides a thorough description of differentially expressed exons between breast cancer and benign lesions, and emphasizes the contribution of spliceosome and alternative transcripts to the molecular portrait of breast malignancy. This allowed the development of a molecular classifier for breast cancer diagnosis using FNA.
Project description:Secreted proteins and transmembrane proteins with extracellular domains are frequently glycosylated; this group of proteins includes those that participate in the various intercellular junctions and signaling pathways of an epithelium. In this study we characterized the differences in glycoprotein expression between claudin-low and other breast cell lines using a dataset of 26 breast cell lines in which the glycoproteins were identified and quantitated by liquid chromatography/ tandem mass spectrometry. Our goals are to characterize the glycoproteome of a set of claudin-low lines, compare them to basal, luminal and non-malignant cells and to identify drugs that may be especially effective on these cell lines. These five non-malignant breast cells (3 normal from 3 donors: HMEpC-p3, HMEC-p10 and HMEC#3-P11; 2 benign: MCF10A and MCF12A) data are a part of 26 breast cell lines we analyzed.
Project description:The goal of this experiment was to identify genes that were expressed at higher levels in benign human mammary epithelial cells than in breast cancer cell lines and that were induced by 5AZA treatment in breast cancer cell lines. Six breast cancer cell lines were selected for demethylation studies based on known tumor suppressor gene expression regulation by promoter region hypermethylation: HCC1569 (CCND2), HCC1954 (SCGB3A1, APC, RASSF1A), MCF-7 (RAR-beta2), MDA-MB-231 (ESR1), UACC3199 (BRCA1), and BT-549 (hypermethylator phenotype). Other than MCF10A we specifically avoided immortalized benign human mammary epithelial cell lines for this experiment as these cells frequently show tumor suppressor gene methylation (e.g. p16) and gene expression profiles that are intermediate between normal breast epithelial cells and breast cancer. Instead, we opted to test six first-passage benign human mammary epithelial cell cultures (HME) generated in serum-free media from small fragments of normal breast tissue obtained from young women undergoing fibroadenoma excision. The 5AZA dose (0.5 microM) was selected based on evaluation of growth curves and induction of BNC1, SERPINB, and TKTL1 gene expression measured by RT-PCR in benign and malignant cells. The breast cancer cell lines, HME cultures, and MC10A cells were treated with 0.5 microM 5AZA (Sigma-Aldrich, St. Louis, MO) in DMSO or DMSO alone for six days after which the cells were harvested, and RNA prepared using the Illumina TotalPrep kit (AMIL1791, Life Technologies, Grand Island, NY). Whole genome expression was assessed using the Illumina HumanWG-6-v3 chip
Project description:The goal of this experiment was to identify genes that were expressed at higher levels in benign human mammary epithelial cells than in breast cancer cell lines and that were induced by 5AZA treatment in breast cancer cell lines. Six breast cancer cell lines were selected for demethylation studies based on known tumor suppressor gene expression regulation by promoter region hypermethylation: HCC1569 (CCND2), HCC1954 (SCGB3A1, APC, RASSF1A), MCF-7 (RAR-beta2), MDA-MB-231 (ESR1), UACC3199 (BRCA1), and BT-549 (hypermethylator phenotype). Other than MCF10A we specifically avoided immortalized benign human mammary epithelial cell lines for this experiment as these cells frequently show tumor suppressor gene methylation (e.g. p16) and gene expression profiles that are intermediate between normal breast epithelial cells and breast cancer. Instead, we opted to test six first-passage benign human mammary epithelial cell cultures (HME) generated in serum-free media from small fragments of normal breast tissue obtained from young women undergoing fibroadenoma excision. The 5AZA dose (0.5 microM) was selected based on evaluation of growth curves and induction of BNC1, SERPINB, and TKTL1 gene expression measured by RT-PCR in benign and malignant cells. The breast cancer cell lines, HME cultures, and MC10A cells were treated with 0.5 microM 5AZA (Sigma-Aldrich, St. Louis, MO) in DMSO or DMSO alone for six days after which the cells were harvested, and RNA prepared using the Illumina TotalPrep kit (AMIL1791, Life Technologies, Grand Island, NY). Whole genome expression was assessed using the Illumina HumanWG-6-v3 chip Gene expression was evaluated in 6 breast cancer cell lines, 6 primary breast epithelial cell cultures, and MCF10A cells after 6 days in DMSO or DMSO plus 0.5 microM 5AZA.
Project description:Breast tumors are produced by an uncontrollable cell proliferation mechanism and can be classified as benign (TMB) or malignant (TMM). TMM or breast cancer is the neoplasia with the highest incidence and mortality in Mexican women. Over time, some types of TMB can transform into a TMM. However, the mechanisms involved in such processes remain elusive and limited studies have examined the molecular differences between TMB and TMM. Hence, the aim of this study was to evaluate and compare the proteomic profile of TMB (n = 10) and TMM (n = 6) of Mexican women.
Project description:Introduction: Overall survival of early-stage breast cancer (BC) patients is similar for those who undergo breast conserving therapy (BCT) and mastectomy, however, 10-15% of women undergoing BCT suffer ipsilateral breast tumor recurrence. The risk of recurrence may vary with age or breast cancer subtype. Understanding the gene expression of the cancer-adjacent tissue and/or stromal response to specific tumor subtypes is important for developing clinical strategies to reduce recurrence risk. Methods: We studied gene expression data in cancer-adjacent tissue from 158 BC patients. Complementary in vitro cocultures were used to study cell-cell communication between fibroblasts and specific breast cancer subtypes. Results: Our results suggest that intrinsic tumor subtypes are reflected in histologically normal cancer-adjacent tissue. Gene expression of cancer-adjacent tissues shows that triple negative (Claudin-low or Basal-like tumors) exhibit increased expression of genes involved in inflammation and immune response. While such changes could reflect distinct immune populations present in the microenvironment of different breast cancer subtypes, altered immune response gene expression was also observed in cocultures in the absence of immune cell infiltrates, emphasizing that these inflammatory mediators are secreted by breast-specific cells. In addition, while triple negative BCs are associated with upregulated immune response genes, Luminal breast cancers are more commonly associated with estrogen-response in adjacent tissues. Conclusions: Specific characteristics of BCs are reflected in the surrounding benign tissue. This commonality between tumor and surrounding tissue may underlie second primaries and local recurrences. Biomarkers derived from cancer-adjacent tissue may be helpful in defining personalized surgical strategies or in predicting recurrence risk.