Anillin expression is a marker of favourable prognosis in patients with renal cell carcinoma.

The clinical course of renal cell carcinoma (RCC) can be difficult to predict. In this study we evaluated the prognostic value of anillin and Ki-67 in predicting survival in RCC. Immunohistochemical analysis using anillin and Ki-67 antibodies was performed on tissue microarrays constructed from paraffin-embedded specimens from 152 patients with primary RCC. The mean follow-up time was 90 months. Levels of anillin and Ki-67 staining were correlated with clinical factors, pathological features and survival. Anillin expression in cytoplasmic and nuclear fractions of the RCC cell line 786-O was examined using Western blot analysis. Cytoplasmic anillin immunopositivity was detected in 121 (83%) tumours. Nuclear anillin expression was present in 40 (27%) tumours and increased Ki-67 activity in 98 (66%) tumours. A positive association was found between nuclear anillin and Ki-67 proliferation activity (p=0.005). The mean RCC-specific survival times for anillin immunopositive and immunonegative tumours were 158 (95% CI 143-173) and 109 (78-141) months, respectively, with p=0.03. Increased Ki-67 activity showed a tendency towards a poorer prognosis, although this was not statistically significant. In the Cox regression analysis for cytoplasmic anillin, nuclear anillin or Ki-67 rate, and age, gender, stage and nuclear grade, the only significant factor in RCC-specific survival was stage (p<0.001). Western blot analysis showed anillin expression in both nuclear and cytosolic fractions of the RCC cell line. To conclude, anillin expression can be observed both in the cytoplasm and nuclei in patients with RCC. Cytoplasmic anillin expression is a marker of favourable prognosis in RCC patients.