Homo sapiens
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ABSTRACT:
PROVIDER: PRJNA193533 | ENA |
REPOSITORIES: ENA
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Project description:Using the orthotopic breast cancer xenograft model of basal-like breast cancer MDA-MB-231 line, we have found that the expression of miRNAs encoded by MIR17HG was significantly decreased in cells isolated from spontaneous lung metastases compared to cells from primary tumors grown in orthotopic sites. We investigated the role of a MIR17HG family member, miR-18a, in primary tumor growth and pulmonary metastasis from the orthotopic site. We demonstrated that enforced expression of exogenous miR-18a, significantly limited continuous growth of primary tumors in mammary gland fat pads and reduced spontaneous lung metastasis. Further investigation on the mechanism of miR-18a action led to the finding that the expression of HIF1A, a key regulator of tumor metastasis, was regulated by miR-18a. Enforced miR-18a expression significantly decreased HIF1A expression at both mRNA and protein levels, resulting in altered transcriptional response and decreased survival of cells in response to Cobalt(II) chloride (CoCl2), a hypoxia-mimicking agent. Conversely, miR-18a knockdown significantly increased HIF1A expression levels and enhanced cell survival in response to CoCl2. Analysis of expression data of human breast tumor tissues showed that miR-18a expression is inversely correlated with HIF1A expression in basal-like breast tumors, supporting a role of miR-18a in restricting HIF1A expression in this subtype of breast cancer. In addition, we demonstrated that hypoxia inhibits miR-18a expression, likely through MYC inactivation. Furthermore, gene expression and functional analysis revealed that miR-18a also plays a role in regulating cell adhesion, migration and invasion. Taken together, this study provides evidence for a novel role of miR-18a to inhibit breast cancer metastasis. Our results suggest that miR-18a downregulation might provide tumor cells survival/growth advantage under hypoxic pressure in basal-like breast cancer. A lung metastatic subline, designated as MB231RN-LM, was derived from MDA-MB-231 breast cancer cells through in vivo selection. The MB231RN-LM cells were stably transfected with has-miR-18a or control vector and treated with 200uM Cobalt(II) chloride (CoCl2, a hypoxia-mimicking agent) for 4 hr. A total of 8 samples were subjected to microarray analysis, with two biological repeats for each experiment condition.
2013-07-31 | E-GEOD-45362 | biostudies-arrayexpress
Project description:Using the orthotopic breast cancer xenograft model of basal-like breast cancer MDA-MB-231 line, we have found that the expression of miRNAs encoded by MIR17HG was significantly decreased in cells isolated from spontaneous lung metastases compared to cells from primary tumors grown in orthotopic sites. We investigated the role of a MIR17HG family member, miR-18a, in primary tumor growth and pulmonary metastasis from the orthotopic site. We demonstrated that enforced expression of exogenous miR-18a, significantly limited continuous growth of primary tumors in mammary gland fat pads and reduced spontaneous lung metastasis. Further investigation on the mechanism of miR-18a action led to the finding that the expression of HIF1A, a key regulator of tumor metastasis, was regulated by miR-18a. Enforced miR-18a expression significantly decreased HIF1A expression at both mRNA and protein levels, resulting in altered transcriptional response and decreased survival of cells in response to Cobalt(II) chloride (CoCl2), a hypoxia-mimicking agent. Conversely, miR-18a knockdown significantly increased HIF1A expression levels and enhanced cell survival in response to CoCl2. Analysis of expression data of human breast tumor tissues showed that miR-18a expression is inversely correlated with HIF1A expression in basal-like breast tumors, supporting a role of miR-18a in restricting HIF1A expression in this subtype of breast cancer. In addition, we demonstrated that hypoxia inhibits miR-18a expression, likely through MYC inactivation. Furthermore, gene expression and functional analysis revealed that miR-18a also plays a role in regulating cell adhesion, migration and invasion. Taken together, this study provides evidence for a novel role of miR-18a to inhibit breast cancer metastasis. Our results suggest that miR-18a downregulation might provide tumor cells survival/growth advantage under hypoxic pressure in basal-like breast cancer.
2013-07-31 | GSE45362 | GEO
Project description:Purpose The analysis of breast cancer residual tumors after neoadjuvant chemotherapy (nCT) may be useful for identifying new biomarkers. MicroRNAs are known to be involved in oncogenic pathways and treatment resistance of breast cancer. Our aim was to determine the role of miR-18a, a member of the miR-17-92a cluster, in breast cancer behavior and outcome after nCT. Methods Pre- and post-nCT tumor miR-18a expression was retrospectively assessed by qRT-PCR in 121 patients treated with nCT and was correlated with survival outcomes and with clinical and pathological characteristics. Breast cancer-derived MCF-7 and MDA-MB-231 cell lines were transfected with miR-18a and anti-miR-18a to evaluate the biological effects of this molecule. In addition, whole-transcriptome expression analysis was performed. Results High miR-18a expression in post-nCT residual tumors was found to be associated with a significantly worse overall survival [hazard ratio (HR): 2.80, 95% confidence interval (CI): 1.01–7.76] and a strong trend towards a poorer disease-free survival (HR: 2.44, 95% CI: 0.99–5.02) compared to low miR-18a expressing post-nCT residual tumors. Clinical and experimental data were found to be in conformity with the proliferative effects of miR-18a, which showed a significant correlation with Ki67 and MYBL2 expression, both in pre- and post-nCT tumors and in public databases. In vitro analysis of the role of miR-18a in breast cancer-derived cell lines showed that a high expression of miR-18a was associated with a low expression of the estrogen receptor (ER), a decreased sensitivity to tamoxifen and an enrichment in luminal B and endocrine resistance gene expression signatures. Conclusions From our data we conclude that post-nCT miR-18a expression in breast cancer serves as a negative prognostic marker, especially in luminal tumors. Clinical, in vitro and in silico data support the role of miR-18a in breast cancer cell proliferation and endocrine resistance and suggest its potential utility as a biomarker for additional adjuvant treatment in patients without a pathologic complete response to neoadjuvant therapy.
2019-05-27 | GSE102121 | GEO
Project description:We report differential gene expression in BJAB-KSHV/BJAB cells treated with Cobalt chloride/BJAB-KSHV cells treated with Cobalt Chloride compared to BJAB cells
2018-05-19 | GSE114625 | GEO
Project description:Transcription profiling by array of human breast cancer cell lines treated with fulvestrant
2025-01-24 | E-GEOD-22533 | ExpressionAtlas
Project description:Transcription profiling by array time series of human MCF7 breast cancer cells treated with estradiol
2025-01-16 | E-GEOD-11352 | ExpressionAtlas
Project description:Transcription profiling by array of human breast cancer MCF-7 cells treated with 17-AAG
2025-01-23 | E-MTAB-339 | ExpressionAtlas
Project description:To identify microRNAs impacting estrogen receptor ERα expression in breast cancer, we have screened ER-positive breast cancer cells with a library of pre-miRs, and systematically monitored the ERα expression by protein lysate microarrays. There was a significant enrichment of the in silico predicted ERα targeting microRNAs among the hits. The most potent pre-miRs miR-18a/b, miR-193b, miR-206, and miR-302c, were confirmed to directly target ERα and to repress estrogen-responsive genes. The effect of miRNA overexpression on gene expression profile of MCF-7 cells was studied. Furthermore, miR-18a and miR-18b showed increased expression in ERα-negative as compared to ERα-positive clinical tumors. In summary, we present systematic and direct functional and correlative clinical evidence on microRNAs inhibiting ERα signaling in breast cancer. MCF-7 cells (300 000 per well on 6-well plates) were transfected with an siRNA for ERα or with Ambion pre-miR� constructs for miR-18a, miR-193b, miR-206, miR-302c, or pre-miR negative control #1 (scrambled pre-miR) at 20 nM, and incubated for 24h.
2010-04-09 | E-GEOD-14847 | biostudies-arrayexpress
Project description:To uncover hypoxia-induced miRNA-mRNA interactions landscape in colorectal cancer cell lines we performed integrated miRNA/mRNA sequencing of Caco-2 and HT-29 cells. Hypoxia was chemically induced via 24 h cobalt(II) chloride and oxyquinoline treatments.
2020-09-29 | GSE158632 | GEO
Project description:To identify microRNAs impacting estrogen receptor ERα expression in breast cancer, we have screened ER-positive breast cancer cells with a library of pre-miRs, and systematically monitored the ERα expression by protein lysate microarrays. There was a significant enrichment of the in silico predicted ERα targeting microRNAs among the hits. The most potent pre-miRs miR-18a/b, miR-193b, miR-206, and miR-302c, were confirmed to directly target ERα and to repress estrogen-responsive genes. The effect of miRNA overexpression on gene expression profile of MCF-7 cells was studied. Furthermore, miR-18a and miR-18b showed increased expression in ERα-negative as compared to ERα-positive clinical tumors. In summary, we present systematic and direct functional and correlative clinical evidence on microRNAs inhibiting ERα signaling in breast cancer.
2009-08-18 | GSE14847 | GEO