Annexin II represents metastatic potential in clear-cell renal cell carcinoma

BACKGROUND: Annexin II (ANX2) is a multi-functional protein involved in cell proliferation and membrane physiology and is related to cancer progression. The purpose of this study was to assess ANX2 expression in clear-cell (cc) renal cell carcinoma (RCC). METHODS: The ANX2 expression in 18 primary ccRCCs was examined by real-time reverse transcriptase (RT)–PCR and western blot analyses. Furthermore, immunohistochemical study was performed using paraffin section of 154 primary ccRCCs and 24 metastases. The association between ANX2 expression and the clinicopathological factors and prognosis was analysed. RESULTS: The ANX2 was upregulated at both mRNA and protein levels in 14 of 18 primary ccRCCs. Immunohistochemical analysis showed that ANX2 was positive in 73 (47.4%) of 154 primary ccRCC and in 21 (87.5%) of 24 metastatic tumours. The ANX2 expression in the primary tumours showed significant associations with a higher stage, a higher nuclear grade. In patients without metastasis, the 5-year metastasis-free rate in patients with ANX2-positive tumour was significantly lower than that in those with ANX2-negative tumour (63.0% vs 90.1%; P<0.0001). Multivariate analysis showed that ANX2 expression is an independent predictor for metastasis. CONCLUSION: Our findings suggest that ANX2 expression might be a novel predictor of the metastatic potential of ccRCC.