Overexpression of HRad17 mRNA in human breast cancer: Correlation with lymph node metastasis

Purpose: A novel human gene, designated HRad17, was identified as the human homologue of the Rad17 of Schizosaccharomyces pombe and Rad24 of Saccharom yces cerevisiae. In yeast, these genes play a critical role in maintaining genomic stability. The aim of this study was to evaluate the expression of HRad17 in human breast cancer. Experimental Design: We investigated HRad17 mRNA expression in 64 cases of human breast cancer by means of reverse-transcription-PCR in situ hybridiza tion, and immunohistochemistry. Results: The HRad17 mRNA was overexpressed in 35 cases (54.7%). Twenty-four (68.6%) of 35 cases with HRad17 overexpression in cancer tissues were node -positive, whereas only 8 (27.6%) of 29 cases without HRad17 overexpression s were node-positive. The expression of HRad17 mRNA correlated with both ly mph node metastasis (P = 0.001) and high Ki67 labeling index (P = 0.006). A lthough not significantly different, expression of HRad17 mRNA tended to co rrelate with tumor size (P = 0.06) and expression of mutant p53 protein (P = 0.10). Furthermore, expression of HRad17 mRNA was an independent predicto r of axillary lymph node metastasis as well as of lymphatic permeation by m ultivariate analysis (P < 0.0001). Conclusions: Our study demonstrates that HRad17 might be related to the dev elopment of lymph node metas, tasis in human breast cancers. Although its f unction still remains unclear, the expression of HRad17 mRNA could open up a new window for the diagnostic staging and treatment of human breast cance rs.