Expression of Interferon Regulatory Factors in Breast Cancer Tissue

摘要

Purpose As neoplasia is the result of unbalanced cell growth and cell death, alternations in the growth control pathway including the immunity within the individual host-tumor relationship has been attributed to the development of breast cancer. Interferon(IFN)-γ based immunity was recently reported to have an antitumor effect and some new methods to assess the state of interferon-γ based immunity have been introduced. Interferon regulatory factor(IRF)-1 and interferon regulatory factor(IRF)-2 are transcriptional factors that mediate the effects of Interferon-γ. It was suggested that the loss of IRF-1 expression is associated with the loss of tumor suppression and the development of IRF-2 expression is associated with oncogenic activation. Thus, we studied the significances of the IRF-1 and IRF-2 expressions as they are related with some clinicopathological parameters to determine the biological behavior of breast cancer including the menopausal status, tumor size, lymph node status, histologic grade, the expression of steroid receptors, the expression of c-erb B2 oncoprotein and the expression of p53 protein. Methods Formalin-fixed paraffin embedded specimens from 82 patients with invasive ductal carcinoma were used to evaluate the expression of IRF-1 and IRF-2 by performing immunohistochemical staining with using an avidin-biotin-peroxidase complex technique. Results The expression of IRF-1 was observed in 80.5% of the study group. However, the expression of IRF-1 did not show any correlation with menopausal status, tumor size, histologic grade, the expression of steroid receptors, the expression of c-erb B2 oncoprotein and the p53 expression. Only lymph node metastasis showed a decreasing tendency of IRF-1 expression, but this was without statistical significance ( p =0.075). The expression of IRF-2 was observed in 58.5% of the study group and it did not show any significant relationship with any of the above mentioned clinicopathological parameters. Conclusion This study suggests that the expression of IRF-1 and IRF-2 does not affect the previously established parameters for determining such biological behaviors of breast cancer as the tumor size, lymph node metastasis, the histologic grade, the expression of steroid receptors, the expression of c-erb B2 and the expression of p53. In spite of these results, We'd like to recommend that another study be done to evaluate the role of IRF-1 and IRF-2 for the proper selection of the patients who are suitable for immunotherapy.