Clinical significance of microRNA-155 expression in human breast cancer

J Surg Oncol. 2012 Sep 1;106(3):260-6. doi: 10.1002/jso.22153. Epub 2011 Nov 21.


Background: The aim of this study is to investigate clinical significance of miR-155 expression in breast cancer.

Methods: TaqMan real-time RT-PCR was performed to detect miR-155 expression in breast cancer tissues. The correlation of miR-155 expression with clinicopathological factors and prognosis of breast cancer patients was analyzed. Then, the prognostic value of miR-155 expression was analyzed by univariate and multivariate analyses. Moreover, the effect of miR-155 expression on phenotypes of breast cancer cell was determined by antisense technology.

Results: The relative expression of miR-155 was significantly higher in breast cancer tissues than in corresponding nontumor tissues. High miR-155 expression was correlated with higher tumor grade, advanced tumor stage and lymph node metastasis (P = 0.012, 0.001, and 0.003, respectively). Kaplan-Meier survival analysis indicated that the disease-free and overall survival rates of high miR-155 group were significantly lower than those of low miR-155 group (P = 0.038 and 0.029, respectively). Multivariate analysis showed that high miR-155 expression was a poor prognostic factor (P = 0.009). Furthermore, antisense targeting miR-155 could inhibit growth, induce cell arrest in G(0) /G(1) phase, enhance apoptosis, and increase radiosensitivity in breast cancer cells.

Conclusions: MiR-155 expression might be an independent prognostic factor and a therapeutic target for human breast cancer.

MeSH terms

  • Apoptosis
  • Breast / metabolism
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / mortality
  • Breast Neoplasms / pathology
  • Breast Neoplasms / radiotherapy
  • Cell Line, Tumor
  • Disease-Free Survival
  • Female
  • Flow Cytometry
  • Humans
  • Lymphatic Metastasis
  • MicroRNAs / metabolism*
  • Middle Aged
  • Multivariate Analysis
  • Prognosis
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Survival Rate


  • MIRN155 microRNA, human
  • MicroRNAs