Project description:The ets transcription factor ELF5 specifies the differentiation of mammary progenitor cells to establish the milk-secreting lineage. ER- and poor prognosis basal breast cancers arise from this progenitor cell and these cancers express high levels of Elf5. Knockdown of ELF5 expression in basal breast cancer cell lines, or forced expression in luminal breast cancer cell lines, resulted in reduced cell proliferation. Transcript profiling and chromatin immunoprecipitation revealed that the transcriptional activity of ELF5 specified the gene expression patterns that distinguish basal from luminal breast cancer, including suppression of FOXA1, GATA3 and ER, key estrogen-action genes. Tamoxifen treatment of luminal MCF7 cells upregulated Elf5 expression and cells that acquired resistance to Tamoxifen became dependent on ELF5 for proliferation. ELF5 is a regulator of breast cancer cell proliferation, transcriptionally specifies the basal molecular subtype and is utilised by ER+ breast cancer cells to escape proliferative arrest caused by Tamoxifen. Elf5 was knocked down via siRNA in basal HCC1937 cell lines, in triplicate. Elf5 was induced in luminal T47D and MCF7 cell lines via a doxycycline inducible expression vector, in duplicate.
Project description:For deep understading of miR-1285-5p in breast cancer, we have employed whole genome microarray expression profilings as a discovery platform to identify target genes of miR-1285-5p. Using human breast cancer cell lines (MCF7, MDA-MB-231, HCC1937 and HCC1954), 31 down-down regulated genes were identified by overexpression of miR-1285-5p reagardless of tumor biology. Functional interaction of miR-1285-5p with two genes (TMEM194A and SLC30A9) from this gene sets was evaluated by r-rt-PCR, Western blot and luciferase transporter assay.
Project description:In order to identify new targets for basal-like breast cancers, we performed Methyl-Seq of 10 breast cancer cell lines. Basal-like cell lines (MDAMB231, MDAMB436, HCC1937, SUM149, SUM1315 and MCF10A) were compared to luminal cell lines (MCF7 and T47D). Moreover we could also study BRCA1 influence on methylome of basal-like breast cancer. 4 of our cell lines are indeed BRCA1 mutated (MDAMB436, HCC1937, SUM149 and SUM1315) and we also developed 2 cell lines that come from the BRCA1 mutated SUM1315 cell line stably transfected with empty LXSN plasmid (SUM1315-LXSN) or with a BRCA1 coding plasmid (SUM1315-BRCA1).
Project description:In order to identify new targets for basal-like breast cancers, we performed RNA-Seq of 10 breast cancer cell lines. Basal-like cell lines (MDAMB231, MDAMB436, HCC1937, SUM149, SUM1315 and MCF10A) were compared to luminal cell lines (MCF7 and T47D). Moreover we could also study BRCA1 influence on transcriptome of basal-like breast cancer. 4 of our cell lines are indeed BRCA1 mutated (MDAMB436, HCC1937, SUM149 and SUM1315) and we also developed 2 cell lines that come from the BRCA1 mutated SUM1315 cell line stably transfected with empty LXSN plasmid (SUM1315-LXSN) or with a BRCA1 coding plasmid (SUM1315-BRCA1).
Project description:BRCA1 deregulation is a frequent event in the pathogenesis of breast as well as other cancers. In addition to the DNA repair functions of BRCA1, it is involved in a wide range of cellular processes such as cell cycle, chromatin remodeling or transcription. However, the molecular events underlying BRCA1-associated tumorigenesis are still largely unknown. In order to deepen our understanding of BRCA1-associated tumorigenesis, we integrated data from mRNA and miRNA microarray experiments on the HCC1937 breast cancer cell line, and the isogenic HCC1937 stably expressing BRCA1, to obtain significant miRNA-mRNA relationships associated to the presence of the BRCA1 gene. Our results demonstrate that integration of mRNA and miRNA associated to BRCA1 expression was useful to discover new miRNA-gene interactions as molecular events underlying BRCA1-mediated tumorigenesis. Transcriptional profiling of the BRCA1-null HCC1937 cell line and HCC1937 cells after stable transfection of BRCA1. Two-condition experiment: Universal Human Reference RNA (Stratagene, catalog #740000) (Cy3) vs. cell line (Cy5). Biological replicates: 3 HCC1937, 3 BRCA1-transfected HCC1937 cells.
Project description:We adapted the DiR barcode-based parallel reporter assay systems strategy to systematically identify the breast cancer related SNPs that affect gene expression by modulating activities of regulatory elements. Among 293 SNPs linked with GWAS-identified breast cancer-risk SNPs, we found seven functional regulatory SNPs in MCF7 cells. Further mechanism study indicates that one SNP regulates gene expression in breast cancer malignancy. The DiR system has great potential to advance the functional study of risk SNPs that have associations with polygenic diseases. Our findings hold great promise in benefiting breast cancer patients with prognostic prediction.
Project description:Background: The transcription factor EVI1 regulates cellular proliferation, differentiation, and apoptosis, and contributes to an aggressive course of disease in myeloid leukemias and other malignancies. Notwithstanding, knowledge about the target genes mediating its biological and pathological functions remains limited. We therefore aimed to identify and characterize novel EVI1 target genes in human myeloid cells. Methods: U937T_EVI1, a previously established human myeloid cell line expressing EVI1 in a tetracycline regulable manner, was subjected to genome wide gene expression microarray analysis. qRT-PCR was used to confirm the regulation of MS4A3 by EVI1. Reporter constructs containing various parts of the MS4A3 upstream region were employed in luciferase assays, and direct binding of EVI1 to the MS4A3 promoter was investigated by chromatin immunoprecipitation. U937 derivative cell lines experimentally expressing EVI1 and/or MS4A3 were generated by retroviral transduction, and tested for their tumorigenicity by subcutaneous injection into severe combined immunodeficient mice. Experimental results were tested for statistical significance using ANOVA and Student's t-test (two-tailed). Results: Gene expression microarray analysis identified 27 unique genes that were up-regulated and 29 that were down-regulated in response to EVI1 induction in the human myeloid cell line, U937. The most strongly repressed gene was membrane-spanning-4-domains subfamily-A member-3 (MS4A3), and its down-regulation by EVI1 was confirmed by qRT-PCR in additional, independent experimental model systems. Reporter gene assays and chromatin immunoprecipitation showed that EVI1 regulated MS4A3 via direct binding to a promoter proximal region. Experimental re-expression of MS4A3 in an EVI1 overexpressing cell line counteracted the tumor promoting effect of EVI1 in a murine xenograft model. Conclusions: Our data reveal MS4A3 as a novel direct target of EVI1 in human myeloid cells, and show that its repression plays a role in EVI1 mediated tumor aggressiveness. Time course of 2 biological replicates, plus 2 control samples; 20 arrays in total
Project description:Background: The transcription factor EVI1 regulates cellular proliferation, differentiation, and apoptosis, and contributes to an aggressive course of disease in myeloid leukemias and other malignancies. Notwithstanding, knowledge about the target genes mediating its biological and pathological functions remains limited. We therefore aimed to identify and characterize novel EVI1 target genes in human myeloid cells. Methods: U937T_EVI1, a previously established human myeloid cell line expressing EVI1 in a tetracycline regulable manner, was subjected to genome wide gene expression microarray analysis. qRT-PCR was used to confirm the regulation of MS4A3 by EVI1. Reporter constructs containing various parts of the MS4A3 upstream region were employed in luciferase assays, and direct binding of EVI1 to the MS4A3 promoter was investigated by chromatin immunoprecipitation. U937 derivative cell lines experimentally expressing EVI1 and/or MS4A3 were generated by retroviral transduction, and tested for their tumorigenicity by subcutaneous injection into severe combined immunodeficient mice. Experimental results were tested for statistical significance using ANOVA and Student's t-test (two-tailed). Results: Gene expression microarray analysis identified 27 unique genes that were up-regulated and 29 that were down-regulated in response to EVI1 induction in the human myeloid cell line, U937. The most strongly repressed gene was membrane-spanning-4-domains subfamily-A member-3 (MS4A3), and its down-regulation by EVI1 was confirmed by qRT-PCR in additional, independent experimental model systems. Reporter gene assays and chromatin immunoprecipitation showed that EVI1 regulated MS4A3 via direct binding to a promoter proximal region. Experimental re-expression of MS4A3 in an EVI1 overexpressing cell line counteracted the tumor promoting effect of EVI1 in a murine xenograft model. Conclusions: Our data reveal MS4A3 as a novel direct target of EVI1 in human myeloid cells, and show that its repression plays a role in EVI1 mediated tumor aggressiveness.
2015-08-30 | GSE60100 | GEO
Project description:Chromatin immunoprecipitation assay with sequencing of Paenibacillus polymyxa SC2