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Updated: Jun 4, 2026
Profiling of Estrogen-regulated MicroRNAs in Breast Cancer Cells
Published on: February 21, 2014
MicroRNA expression analysis in triple-negative (ER, PR and Her2/neu) breast cancer
Jelena Radojicic1, Apostolos Zaravinos, Thomas Vrekoussis
1Department of Surgical Pathology, Medical Faculty, University of Crete, Crete, Greece.
Abstract:
miRNAs are small, regulatory molecules approximately 21-24 nucleotides in length. They function at the post-transcriptional level by controlling the expression of more than 50% of human protein-coding genes and play an essential role in cell signaling pathways. The objective of the present study was to explore the expression profile of oncomiRs and tumor-suppressor miRs, and to define their possible correlations in triple-negative (ER, PR and Her2/neu) primary breast cancers. Forty-nine primary triple-negative breast cancer cases, along with 34 matched tumor-associated normal samples were investigated for the expression of 9 miRNAs using qPCR. Relationships between the expression of miR-10b, miR-21, miR-122a, miR-145, miR-205, miR-210, miR-221, miR-222 and miR-296 and the pathologic features of the tumors were examined, as were the influences of miR expression on patient overall and cancer-specific survival. miR-21, miR-210 and miR-221 were significantly overexpressed, whereas miR-10b, miR-145, miR-205, miR-122a were significantly underexpressed in the triple-negative primary breast cancers. Significant correlations among all of the studied miRs were scored both in the breast cancer and control tissue. Expression of miR-222 and miR-296 did not exhibit any significant difference between the breast cancer and normal tissue. There was a non-significant trend for high expression levels of the microRNAs, miR-21, miR-210, miR-221 and miR-222, to be associated with worse patient disease-free and overall survival. miR-21, miR-210 and miR-221 expression plays a significant role in triple- negative primary breast cancers.
Insights
MicroRNAs (miRNAs) regulate gene expression and are crucial in cell signaling. This study found specific miRNAs, including miR-21, miR-210, and miR-221, are significantly altered in triple-negative breast cancer and may impact patient survival.
Area of Science:
- Molecular Biology
- Genetics
- Oncology
Background:
- MicroRNAs (miRNAs) are small non-coding RNAs regulating gene expression post-transcriptionally.
- They are implicated in various cellular processes, including cell signaling and cancer development.
- Triple-negative breast cancer (TNBC) is an aggressive subtype lacking targeted therapies, necessitating research into novel biomarkers and therapeutic targets.
Purpose of the Study:
- To investigate the expression profiles of specific oncomiRs and tumor-suppressor miRs in primary TNBC.
- To determine the correlations between miRNA expression and clinicopathological features of TNBC.
- To assess the impact of miRNA expression on patient survival outcomes in TNBC.
Main Methods:
- Quantitative real-time PCR (qPCR) was used to analyze the expression of nine selected miRNAs (miR-10b, miR-21, miR-122a, miR-145, miR-205, miR-210, miR-221, miR-222, miR-296).
- The study included 49 primary TNBC samples and 34 matched adjacent normal tissues.
- Statistical analyses were performed to correlate miRNA expression with clinicopathological data and patient survival.
Main Results:
- miR-21, miR-210, and miR-221 were significantly overexpressed in TNBC tissues compared to normal tissues.
- miR-10b, miR-145, miR-205, and miR-122a were significantly underexpressed in TNBC.
- Correlations were observed among the expression levels of studied miRNAs in both cancer and normal tissues.
- miR-222 and miR-296 showed no significant differential expression between TNBC and normal tissues.
- A non-significant trend indicated that high expression of miR-21, miR-210, miR-221, and miR-222 was associated with poorer disease-free and overall survival.
Conclusions:
- miR-21, miR-210, and miR-221 play significant roles in the biology of triple-negative breast cancer.
- These miRNAs represent potential diagnostic or prognostic biomarkers for TNBC.
- Further research is warranted to explore their therapeutic potential in TNBC treatment.
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