Biphasic expression of RhoGDI2 in the progression of breast cancer and its negative relation with lymph node metastasis.

RhoGDI2 has been shown to be a metastasis-related gene in several cancers. In human breast cancer, little clinical study of RhoGDI2 has been reported. In this study, we investigated the expression level of RhoGDI2 by immunohistochemistry, as well as the correlation of RhoGDI2 with clinicopathological parameters in 71 breast cancer specimens. We also examined RhoGDI2 expression at mRNA and protein levels of four human breast cancer cell lines differing in in vivo metastasis. Along with the extent of mammary epithelia proliferation and carcinogenesis, a biphasic pattern of RhoGDI2 expression (increase and then decrease) was observed, which was also found in these examined cells. Furthermore, univariate and multivariate analysis revealed that reduced expression of RhoGDI2 in the most malignant epithelia was significantly associated with lymph node metastasis (P<0.01). Our results suggest that RhoGDI2 may be implicated in the progress of malignancy and act as a metastasis-related marker in breast cancer.