Annexin A1 expression is correlated with malignant potential of renal cell carcinoma

Objectives: To evaluate the expression of annexin A1 protein in patients with renal cell carcinoma. Methods: Annexin A1 expression was examined in renal cell carcinoma specimens from 27 patients, and their disease-free survival was analyzed using the log–rank test. Annexin A1 knockdown in the human renal cell carcinoma cell line Caki-1 was carried out, and its proliferation, invasion, motility and adhesion were compared with those of control cells. Results: In 13 out of 27 patients, annexin A1 was highly expressed in the membrane of renal cell carcinoma tumor cells, whereas in the rest of the patients, annexin A1 expression was weak or negligible in the membrane of those cells. Patients with high annexin A1 expression had significantly poorer disease-free survival than those with weak or negligible annexin A1 expression (P = 0.031). In the renal cell carcinoma cell line, annexin A1 knockdown cells showed significantly decreased proliferation, invasion, motility and adhesion relative to control cells, and expressed lower relative levels of membrane-type 1 matrix metalloproteinase and hypoxia-inducible factor 1-alpha transcripts, showing a potential pathway regulated by annexin A1. Conclusion: Annexin A1 is associated with renal cell carcinoma malignant potential and could serve as a marker of poor prognosis.