Annexin 1/Annexin A1 [MD309]

The protein Annexin A1 is encoded by the ANXA1 gene, which is upregulated in hairy cell leukemia. Annexin A1 inhibits the NF-kB signal transduction pathway (which is exploited by cancerous cells to proliferate and avoid apoptosis) by binding to the p65 subunit, and has been of interest for use as a potential anti-cancer drug. It may also contain tumor suppressive and protective characteristics, which have been evidenced by its ability to protect against DNA damage induced by heat in breast cancer cells. Annexin A1 is strongly expressed on the cell membrane and occasionally in the cytoplasm of tumor cells in 97% of samples from patients with hairy cell leukemia. By contrast, B-cell lymphomas other than hairy cell leukemia are ANXA1 negative. Thus, ANXA1 is a molecule specific to hairy cell leukemia that can be used to differentiate this disease from other B-cell lymphomas.