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ABSTRACT:
PROVIDER: PRJEB74646 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:To identify novel gene amplification events that may contribute to breast cancer progression, we examined copy number variation in 161 primary breast cancer samples using the Affymetrix 250K_Nsp and 250K_Sty microarrays or the Affymetrix SNP5.0 microarray. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from primary breast cancer samples. Copy number variations were determined from probeset signal intensities.
2010-06-23 | E-GEOD-16619 | biostudies-arrayexpress
Project description:Advances in genomic signatures have begun to dissect breast cancer heterogeneity, and application of these signatures will allow the prediction of which pathways are important in tumor development. Here we used genomic signatures to predict involvement of specific E2F transcription factors in Myc-induced tumors. We genetically tested this prediction by interbreeding Myc transgenics with mice lacking various activator E2F alleles. Tumor latency decreased in the E2F1 mutant background and significantly increased in both the E2F2 and E2F3 mutants. Investigating the mechanism behind these changes revealed a reduction in apoptosis in the E2F1 knockout strain. E2F2 and E2F3 mutant backgrounds alleviated Myc effects on the mammary gland, reducing the susceptible tumor target population. Gene expression data from tumors revealed that the E2F2 knockout background resulted in fewer tumors with EMT, corresponding with a reduction in probability of Ras activation. In human breast cancer we found that a low probability of E2F2 pathway activation was associated with increased relapse-free survival time. Together these data illustrate the predictive utility of genomic signatures in deciphering the heterogeneity within breast cancer and illustrate the unique genetic requirements for individual E2Fs in mediating tumorigenesis in both mouse models and human breast cancer. MMTV-Myc tumors were generated in an E2F wild-type, E2F1 null, E2F2 null and E2F3 heterozygous background. When the primary tumor reached the endpoint, the tumors were flash frozen. 20 tumors from each genotype were selected for microarray analysis.
2011-12-29 | E-GEOD-24594 | biostudies-arrayexpress
Project description:We sought to define the repertoire of genetic alterations in synchronous primary and metastasis of invasive breast cancer
2017-01-31 | GSE80806 | GEO
Project description:Advances in genomic signatures have begun to dissect breast cancer heterogeneity, and application of these signatures will allow the prediction of which pathways are important in tumor development. Here we used genomic signatures to predict involvement of specific E2F transcription factors in Myc-induced tumors. We genetically tested this prediction by interbreeding Myc transgenics with mice lacking various activator E2F alleles. Tumor latency decreased in the E2F1 mutant background and significantly increased in both the E2F2 and E2F3 mutants. Investigating the mechanism behind these changes revealed a reduction in apoptosis in the E2F1 knockout strain. E2F2 and E2F3 mutant backgrounds alleviated Myc effects on the mammary gland, reducing the susceptible tumor target population. Gene expression data from tumors revealed that the E2F2 knockout background resulted in fewer tumors with EMT, corresponding with a reduction in probability of Ras activation. In human breast cancer we found that a low probability of E2F2 pathway activation was associated with increased relapse-free survival time. Together these data illustrate the predictive utility of genomic signatures in deciphering the heterogeneity within breast cancer and illustrate the unique genetic requirements for individual E2Fs in mediating tumorigenesis in both mouse models and human breast cancer.
2011-12-29 | GSE24594 | GEO
Project description:The present study was carried out on a proband affected by Partial Androgen Insensitivity Syndrome (PAIS) and his family. The patient developed the primary RSC at 27 years. Three years after primary surgery, the patient developed a second primary (metachronous) rectal cancer relapsed one year later. The PAIS was also diagnosed in his cousin. Both cousins were found positive for the same missense androgen receptor (AR) gene mutation that was inherited from their asymptomatic mothers. The aim of this study was to identify constitutional genetic events that could have played a role in early onset of RSC in the proband. SNP-array analyses were carried out to investigate Copy Number Variations and Uniparental Disomy events as possible genetic causes linked to Colorectal Cancer pathogenesis.
2016-06-05 | GSE69613 | GEO
Project description:While genetic mutation is a hallmark of cancer, many cancers also acquire epigenetic alterations during tumorigenesis including aberrant DNA hypermethylation of tumor suppressors as well as changes in chromatin modifications as caused by genetic mutations of the chromatin-modifying machinery. However, the extent of epigenetic alterations in cancer cells has not been fully characterized. Here, we describe the first complete methylome maps at single nucleotide resolution of a low-passage breast cancer cell line and primary human mammary epithelial cells. We find widespread DNA hypomethylation in the cancer cell, primarily at partially methylated domains (PMDs) in normal breast cells. Unexpectedly, genes within these regions are largely silenced in cancer cells. The loss of DNA methylation in these regions is accompanied by formation of repressive chromatin, with a significant fraction displaying allelic DNA methylation where one allele is DNA methylated while the other allele is occupied by histone modifications H3K9me3 or H3K27me3. Our results show a mutually exclusive and complementary relationship between DNA methylation and H3K9me3 or H3K27me3. These results suggest that global DNA hypomethylation in breast cancer is tightly linked to the formation of repressive chromatin domains and gene silencing, thus identifying a potential epigenetic pathway for gene regulation in cancer cells and suggesting a possible new approach toward the development of cancer therapeutics. ChIP-methylC-Seq on H3K9me3, H3K27me3, and H3K36me3 in breast cancer HCC1954. 36 cycles of sequencing on Illumina platform.
2011-09-16 | E-GEOD-29120 | biostudies-arrayexpress
Project description:Germline copy number variations and breast cancer risk
| PRJNA674608 | ENA
Project description:ERα is a major driver for breast cancer initiation and progression.However,the fundamental mechanisms,including global cistromic and genomic transcriptional responses that are required to elicit breast cancer initiation and progression in response to ERα, have not been elucidated. We used chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) to identify estrogen regulated genes that directly recruit ERα in the p53 null mouse mammary gland
2022-02-06 | GSE77977 | GEO
Project description:Studying properties of non-cancerous high-risk human breast epithelial cells is challenged by limitations in acquiring primary epithelial cells for investigation. Here we used conditional reprogramming cell (CRC) technology to isolate n=27 serial samples of non-cancer derived mammary epithelial cells ipsilateral to breast cancer, considered at risk cells for future breast cancer development. Comparative samples included cancer (n=8) and contralateral (n=3) and prophylactic mastectomy (n=1) non-cancer derived breast epithelial cells. Significant in vitro behavioral differences between samples were connected to baseline transcriptome characteristics. An exploratory analysis identified patterns of aberrantly expressed pregnancy development genes in both at risk and cancer samples. In conclusion, it is possible to approach the investigation of breast cancer risk utilizing human primary breast epithelial cells for targeted in vitro and genetic studies.
2022-04-22 | GSE185314 | GEO
Project description:Background:Breast cancer is the second most frequent type of cancer affecting women. We are increasingly aware that changes in mRNA splicing are associated with various characteristics of cancer. The most deadly aspect of cancer is metastasis, the process by which cancer spreads from the primary tumor to distant organs. However, little is known specifically about the involvement of alternative splicing in the formation of macroscopic metastases. Our study investigates transcript isoform changes that characterize tumors of different abilities to form growing metastases. Results:To identify alternative splicing events (ASEs) that are associated with the fully metastatic phenotype in breast cancer, we used Affymetrix Exon Microarrays to profile mRNA isoform variations genome-wide in weakly metastatic (168FARN and 4T07) and highly metastatic (4T1) mammary carcinomas. Statistical analysis identified significant expression changes in 7606 out of 155,994 (4%) exons and in 1725 out of 189,460 (1%) intronic regions, which affect 2623 out of 16,654 (16%) genes. These changes correspond to putative alternative isoforms - several of which are novel - that are differentially expressed between tumors of varying metastatic phenotypes. Gene pathway analysis showed that 1224 of genes expressing alternative isoforms were involved in cell growth, cell interactions, cell proliferation, cell migration and cell death and have been previously linked to cancers and genetic disorders. We chose ten predicted splice variants for RT-PCR validation, eight of which were successfully confirmed (MED24, MFI2, SRRT, CD44, CLK1 and HNRNPH1). These include three novel intron retentions in CD44, a gene in which isoform variations have been previously associated with the metastasis of several cancers. Conclusions:Our findings reveal that various genes are differently spliced and/or expressed in association with the metastatic phenotype of tumor cells. Identification of metastasis-specific isoforms may contribute to the development of improved breast cancer stage identification and targeted therapies. Keywords: Seek pre-mRNA changes associated with the fully metastatic phenotype in breast cancer We used RNA tumor tissues derived from three murine mammary carcinoma cell lines (168FARN, 4T07 and 4T1); four biological replicates of 168FARN, four biological replicates of 4T07, and four biological replicates of 4T1 were hybridized independently at McGill university site.
2010-06-08 | E-GEOD-21994 | biostudies-arrayexpress