HMGB2 in endocrine resistant breast cancer
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Illumina Genome Analyzer II
ORGANISM(S): Homo sapiens
SUBMITTER: Gordon Brown
PROVIDER: E-MTAB-1865 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:ER-dependent gene expression was investigated in the LY2 endocrine resistant cell line by treatment with ICI 182780. Cells were steroid depleted for 3 days prior to treatment with ICI for 6 hours. Four biological replicates were processed and analysed.
2014-09-18 | E-MTAB-1870 | biostudies-arrayexpress
Project description:We profile the binding of Steroid Receptor Co-activator (SRC1) in LY2 cells, a tamoxifen-resistant cell line, in the presence and absence of tamoxifen using ChIP-sequencing technology. The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity leading to the development of a steroid-independent tumour. The p160 steroid coactivataor protein SRC-1, through interactions with developmental proteins and other non-steroidal transcription factors, drives this tumour adaptability. Here, using discovery studies, we identify ADAM22, a non-protease member of the ADAMs family, as a direct, ER-independent target of SRC-1. Molecular, cellular and in vivo studies confirmed SRC-1 as a regulator of ADAM22. At a functional level, a role for ADAM22 in cellular migration and differentiation was observed. In vivo data from a mouse xenograft model indicated that ADAM22 expression was higher in 4-OHT-treated endocrine-resistant tumours than in tumours derived from isogenic, sensitive cells. Furthermore, in breast cancer patients, ADAM22 expression is an independent predictor of poor disease free survival. SRC-1 can function as a molecular switch which converts a steroid-responsive tumour to a steroid-resistant tumour. The ER-independent SRC-1 target ADAM22 is a potential drug target and a companion predictive biomarker in the treatment of endocrine-resistant breast cancer. Examination of SRC-1 binding in LY2 cells in the presence or absence of tamoxifen treatment. 2 replicates each.
2011-11-01 | E-GEOD-28987 | biostudies-arrayexpress
Project description:SRC-1 (NCOA1) is a steroid receptor coactivator that has been associated with various aspects of the progression of breast cancer disease such as tamoxifen resistance, metastasis, cell proliferation and invasiveness. In a tamoxifen resistant breast cancer cell line (LY2), SRC-1 has been found to interact with the developmental transcription factor HoxC11. ChIP-sequencing of HoxC11 in LY2 cells shows where the transcription factor binds throughout the genome. LY2 cells were treated with either tamoxifen or vehicle and immunoprecipitated with anti-Hoxc11
2014-01-14 | E-GEOD-54027 | biostudies-arrayexpress
Project description:Introduction: Although changes in microRNA (miRNA) expression correlate with breast cancer diagnostic markers, comparatively little is known about miRNA regulation by selective estrogen receptor modulators (SERMs), e.g., tamoxifen (TAM), or their role in endocrine-resistance. Methods: A microarray approach was used to identify miRNAs differentially expressed and regulated by 4-hydroxyTAM (4-OHT) in MCF-7/TAM-sensitive versus LY2 TAM/endocrine-resistant human breast cancer cells after 6 h treatment. The expression of specific miRNAs was validated by quantitative, real-time PCR. Control miRNAs and time-course studies showed important gene-, time-, and cell- specific differences in miRNA expression. Results: 97 miRNAs were differentially expressed in MCF-7 versus LY2 cells. Bioinformatic analyses to impute the biological significance of these miRNAs by identifying 36 predicted gene targets of these miRNAs from amongst those reported to be regulated by MCF-7 cells was performed and agreement was found in direction of anticipated regulation for 12 of those putative targets. Among the miRNAs differentially expressed in MCF-7 versus LY2 cells, and that putatively target mRNAs regulated by 4-OHT in MCF-7 cells, are: miRs- 10a, 21, 22, 29a, 93, 125b, 181, 200a, 200b, 200c; 205, 221, and 222. Q-PCR assessment showed agreement with microarray data: miR- 10a, 22, 125b, 181, and 222 are higher in LY2 whereas miR-21 and miR-200a are lower in LY2 than MCF-7. 4-OHT increased miR-10a, miR-21, miR-22, miR-125b, miR-181a, miR-200a, and miR-222 in MCF-7 cells and reduced miR-10a in LY2 cells. E2 reduced the miR-21expression in MCF-7 cells. Treatment with ICI 182,780 revealed that ER suppresses miR-10a, miR-21, miR-22, miR-200a, miR-221, and miR-222 expression in MCF-7 cells. Time-dependent changes in select miRNA expression were observed in control, E2, and 4-OHT-treated MCF-7 cells. ESR1/ER? was significantly lower in LY2 than MCF-7, commensurate with higher let-7 family member, miR-221, and miR-222 expression in LY2. Reflecting inverse association with miR-200 family expression, the expression of ZEB1 was higher in LY2 than MCF-7 cells and concomitantly, E-cadherin expression was absent in LY2 cells indicating that LY2 have undergone epithelial to mesenchymal transition. Conclusions: Our studies identifying miRNAs with opposite expression between the two cell lines, indicate the involvement of these miRNAs in endocrine resistance. The purpose of this experiment is: 1. To identify miRNAs that are regulated (up or down) by 4-OHT in MCF-7 and LY2 cell lines (comparison of values from EtOH versus 4-OHT treated cells). 2. To identify miRNAs that are differentially regulated under basal (EtOH) conditions between MCF-7 and LY2 cell lines. 3. To identify miRNAs that are differentially regulated by 4-OHT in MCF-7 versus LY2 cells.
2011-03-30 | E-GEOD-28267 | biostudies-arrayexpress
Project description:Introduction: Although changes in microRNA (miRNA) expression correlate with breast cancer diagnostic markers, comparatively little is known about miRNA regulation by selective estrogen receptor modulators (SERMs), e.g., tamoxifen (TAM), or their role in endocrine-resistance. Methods: A microarray approach was used to identify miRNAs differentially expressed and regulated by 4-hydroxyTAM (4-OHT) in MCF-7/TAM-sensitive versus LY2 TAM/endocrine-resistant human breast cancer cells after 6 h treatment. The expression of specific miRNAs was validated by quantitative, real-time PCR. Control miRNAs and time-course studies showed important gene-, time-, and cell- specific differences in miRNA expression. Results: 97 miRNAs were differentially expressed in MCF-7 versus LY2 cells. Bioinformatic analyses to impute the biological significance of these miRNAs by identifying 36 predicted gene targets of these miRNAs from amongst those reported to be regulated by MCF-7 cells was performed and agreement was found in direction of anticipated regulation for 12 of those putative targets. Among the miRNAs differentially expressed in MCF-7 versus LY2 cells, and that putatively target mRNAs regulated by 4-OHT in MCF-7 cells, are: miRs- 10a, 21, 22, 29a, 93, 125b, 181, 200a, 200b, 200c; 205, 221, and 222. Q-PCR assessment showed agreement with microarray data: miR- 10a, 22, 125b, 181, and 222 are higher in LY2 whereas miR-21 and miR-200a are lower in LY2 than MCF-7. 4-OHT increased miR-10a, miR-21, miR-22, miR-125b, miR-181a, miR-200a, and miR-222 in MCF-7 cells and reduced miR-10a in LY2 cells. E2 reduced the miR-21expression in MCF-7 cells. Treatment with ICI 182,780 revealed that ER suppresses miR-10a, miR-21, miR-22, miR-200a, miR-221, and miR-222 expression in MCF-7 cells. Time-dependent changes in select miRNA expression were observed in control, E2, and 4-OHT-treated MCF-7 cells. ESR1/ERα was significantly lower in LY2 than MCF-7, commensurate with higher let-7 family member, miR-221, and miR-222 expression in LY2. Reflecting inverse association with miR-200 family expression, the expression of ZEB1 was higher in LY2 than MCF-7 cells and concomitantly, E-cadherin expression was absent in LY2 cells indicating that LY2 have undergone epithelial to mesenchymal transition. Conclusions: Our studies identifying miRNAs with opposite expression between the two cell lines, indicate the involvement of these miRNAs in endocrine resistance.
2011-03-30 | GSE28267 | GEO
Project description:Transcription factors are often regarded as having two distinct components: a DNA binding domain (DBD) to allow binding to the regulatory region of a target gene and a trans-acting functional domain (FD) to modulate gene expression. Recently, it is becoming clear that the DBDs of transcription factors alone are incapable of providing sufficient specificity to account for the highly complex genomic structures in eukaryotes. Other regions, outside of the DBD, may play a role in transcription factor DNA binding specificity in vivo. In order to test this hypothesis, we examined a model zinc finger transcription factor, Krüppel-like factor 3 (KLF3) with a FD that recruits partner proteins for its repressive activity and a three zinc finger DBD. Previously, we showed that deletion of the entire KLF3 FD reduced DNA binding across the genome. This implied the importance of the FD for in vivo DNA binding specificity. In the current study, we fused the KLF3 FD onto an unrelated, but well characterised Artificial Zinc Finger (AZF) targeting a standard target gene, VEGF-A. We compared the genomic DNA binding profile of this chimeric KLF3 construct, termed KLF3FD-AZF, to that of the AZF alone. Chromatin Immunoprecipitation followed by next generation sequencing was used to assess genomic wide DNA-binding of these AZFs. Remarkably, in these gain-of-function experiments, we again observed that the KLF3 FD is critical for in vivo DNA binding specificity. The addition of KLF3 FD increased the number of binding sites by more than two fold compared to the AZF alone. KLF3 FD also directed more binding to the promoter regions. Further investigations of these acquired sites identified a substantial portion of these sites as the known endogenous KLF3 bound regions, whilst others contain sequences that are similar but not identical to the predicted AZF target sequence. These results clearly demonstrate that the specific localisation of this model transcription factor to target genes is not solely dependent on the DBD and that the regions outside of this domain may also play an important role. ChIP-Seq experiments were performed on four HEK293 cell lines, two each stably expressing AZF or KLF3FD.AZF or KLF3FD only (two biological replicates). Input samples were included as controls.
2016-01-05 | E-GEOD-69739 | biostudies-arrayexpress
Project description:Advanced breast cancer is characterised by enhanced tumour adaptability to therapeutic pressure and the metastatic microenvironment. Transcriptome differences in three ER positive (ER+) cell models are uncovered through this RNA-seq analysis of MCF7 (endocrine sensitive), LY2 (endocrine resistant) and T347 (derived from an ER-positive, treatment resistant brain metastatic patient tumour) cells.
2023-05-16 | GSE176534 | GEO
Project description:The steroid co-activator protein SRC-1 plays an important role in endocrine therapy resistant breast cancer. Its expression is associated with large high grade tumours, HER2 positivity, disease recurrence and resistance to endocrine therapy. SRC-1's role in affecting the transcriptome of the breast cancer endocrine resistant setting is uncovered through this RNA-seq analysis of LY2 cells grown with or without the presence of SRC-1
2018-06-04 | GSE99647 | GEO
Project description:CTCF binding polarity determines chromatin looping CTCF ChIPseq was performed in E14 embryonic stem cells and neural precursor cells
2015-10-29 | E-GEOD-71158 | biostudies-arrayexpress
Project description:The steroid co-activator protein SRC-1 plays an important role in endocrine therapy resistant breast cancer. Its expression is associated with large high grade tumours, HER2 positivity, disease recurrence and resistance to endocrine therapy. While SRC-1 typically functions to activate gene expression, some evidence has pointed towards a potential role in repression. This study looks into the effects of a stable knockdown of SRC-1 in a tamoxifen resistant cell line, LY2, and the effects of this knock down on the methylation landscape.
2018-06-04 | GSE99648 | GEO