Objective   To investigate the mRNA expression of the WIF-1 gene and the methylation of its promoter in breast cancer, and to determine the correlation between the epigenetic aberrant WIF-1 DNA methylation and the clinicopathological significance of WIF-1 in breast cancer.

  Methods  RT-PCR and sensitive methylation-specific-PCR (MSP) were used to detect WIF-1 mRNA expression and the methylation of the WIF-1 promoter in 30 breast cancer samples as well as in tumor-adjacent tissue samples and 9 benign breast tissues.

  Results   The WIF-1 mRNA expression in 30 breast cancer samples significantly decreased compared with those of the other two groups. In addition, WIF-1 methylation was more frequent in breast-tumor tissues compared with those in tumor-free tissues. Meanwhile, WIF-1 mRNA expression in breast cancer tissues involved the abnormal methylation of its promoter. Clinicopathological correlation analysis showed that the abnormal methylation of the WIF-1 gene promoter was not associated with age, TNM stage, histotype, or lymph node metastasis.

  Conclusion   WIF-1 mRNA expression loss due to abnormal methylation may be a crucial factor in breast cancer development and can thus be used in the prognosis and progression of the disease.