MicroRNA-222 Expression as a Predictive Marker for Tumor Progression in Hormone Receptor-Positive Breast Cancer.
- Author:
Song Hee HAN
1
;
Hyun Jeong KIM
;
Jae Moon GWAK
;
Mimi KIM
;
Yul Ri CHUNG
;
So Yeon PARK
Author Information
- Publication Type:Original Article
- Keywords: Breast neoplasms; Epithelial-mesenchymal transition; miR-222; Prognosis
- MeSH: Actins; Breast Neoplasms*; Breast*; Cadherins; Down-Regulation; Epithelial-Mesenchymal Transition; Estrogens; Genes, erbB-2; Humans; Immunohistochemistry; Multigene Family; Muscle, Smooth; Osteonectin; Phenobarbital; Prognosis; Real-Time Polymerase Chain Reaction; Receptor, Epidermal Growth Factor; Tamoxifen
- From:Journal of Breast Cancer 2017;20(1):35-44
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: The microRNA-221/222 (miR-221/222) gene cluster has been reported to be associated with the promotion of epithelial-mesenchymal transition (EMT), downregulation of estrogen receptor-α, and tamoxifen resistance in breast cancer. We studied the expression of miR-222 in human breast cancer samples to analyze its relationship with clinicopathologic features of the tumor, including estrogen receptor status, expression of EMT markers, and clinical outcomes. METHODS: Quantitative real-time polymerase chain reaction was performed to detect the expression of miR-222 in 197 invasive breast cancers. Expression of EMT markers (vimentin, smooth muscle actin, osteonectin, N-cadherin, and E-cadherin) was evaluated using immunohistochemistry. RESULTS: High miR-222 levels were associated with high T stage, high histologic grade, high Ki-67 proliferation index, and HER2 gene amplification. Its expression was significantly higher in the luminal B and human epidermal growth factor receptor 2-positive (HER2+) subtypes than in the luminal A and triple-negative subtypes. In the hormone receptor-positive subgroup, there was a significant negative correlation between miR-222 and estrogen receptor expression, and miR-222 expression was associated with EMT marker expression. In the group as a whole, high miR-222 expression was not associated with clinical outcome. However, subgroup analyses by hormone receptor status revealed that high miR-222 expression was a poor prognostic factor in the hormone receptor-positive subgroup, but not in the hormone receptor-negative subgroup. CONCLUSION: This study showed that miR-222 is associated with down-regulation of the estrogen receptor, EMT, and tumor progression in hormone receptor-positive breast cancer, indicating that miR-222 might be associated with endocrine therapy resistance and poor clinical outcome in hormone receptor-positive breast cancer.
