Overexpression of annexin 1 in the development and differentiation of urothelial carcinoma

This study investigates the expression of annexin 1 in urothelial carcinoma (UC) and its relation with clinicopathologic factors, and evaluates its potential clinical significance. Annexin 1 expression was analyzed by immunohistochemical staining with manual tissue microarrays and Western blot in UC. Immunohistochemical analysis of UC in tissue microarrays showed that annexin 1 protein was 76.5% (150/196) positive, which was markedly increased compared with that in the normal urothelium 20.8% (5/24) (p < 0.01). In addition, the positive expression rate of annexin 1 was higher in the high-grade UC (81.7%; 143/175) than in the low-grade UC (33.3%; 7/21). Western blot revealed that the expression of annexin 1 was low in low-grade UC, and markedly increased in high-grade UC. In conclusion, annexin 1 overexpression is observed in UC, which suggests it may be associated with tumorigenesis and its expression correlates with the differentiation of UC.