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Profiling of Estrogen-regulated MicroRNAs in Breast Cancer Cells
Published on: February 21, 2014
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MicroRNA-574-3p, identified by microRNA library-based functional screening, modulates tamoxifen response in breast
T Ujihira1, K Ikeda2, T Suzuki3
11] Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama, Japan [2] Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo, Japan.
Scientific Reports
|January 7, 2015
Summary
This study identified microRNAs (miRNAs) involved in tamoxifen response in breast cancer. Downregulation of miR-574-3p was linked to tamoxifen resistance, suggesting it as a potential therapeutic target.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Estrogen receptor α (ERα) is a key target in breast cancer therapy.
- Tamoxifen resistance is a significant clinical challenge in ERα-positive breast cancer.
- MicroRNAs (miRNAs) play crucial roles in gene regulation and cancer progression.
Purpose of the Study:
- To identify microRNAs (miRNAs) associated with tamoxifen response in breast cancer.
- To investigate the role of specific miRNAs in acquired endocrine resistance.
- To explore potential miRNA-based therapeutic strategies for tamoxifen-resistant breast cancer.
Main Methods:
- Functional screening of a lentiviral miRNA library in MCF-7 breast cancer cells treated with 4-hydroxytamoxifen (OHT).
- Microarray analysis to quantify miRNA precursor integration and identify differentially expressed miRNAs.
- In silico analysis and luciferase reporter assays to validate miRNA-target interactions.
Main Results:
- Five 'dropout' miRNAs (downregulated) and six 'retained' miRNAs (upregulated) were identified in response to OHT treatment.
- miR-574-3p was found to be downregulated in clinical breast cancer tissues and its inhibition reversed tamoxifen-mediated growth suppression.
- Clathrin heavy chain (CLTC) was validated as a direct target of miR-574-3p, with inverse expression patterns.
Conclusions:
- Functional miRNA screening is effective for discovering genes involved in tamoxifen response.
- miR-574-3p downregulation contributes to tamoxifen resistance in breast cancer by upregulating CLTC.
- Targeting miR-574-3p or its downstream effectors may offer novel therapeutic avenues for endocrine-resistant breast cancer.
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