Translocation of annexin I from cellular membrane to the nuclear membrane in human esophageal squamous cell carcinoma.

Aim: To investigate the alteration of the annexin I subcellular localization in esophageal squamous cell carcinoma (ESCC) and the correlation between the translocation and the tumorigenesis of ESCC.
Methods: The protein localization of annexin I was detected in both human ESCC tissues and cell line via the indirect immunofluorescence strategy.
Results: In the normal esophageal epithelia the annexin I was mainly located on the plasma membrane and formed a consecutive typical trammels net. Annexin I protein also expressed dispersively in cytoplasm and the nuclei without specific localization on the nuclear membrane. In esophageal cancer annexin I decreased very sharply with scattered disappearance on the cellular membrane, however it translocated and highly expressed on the nuclear membrane, which was never found in normal esophageal epithelia. In cultured esophageal cancer cell line annexin I protein was also focused on the nuclear membrane, which was consistent with the result from esophageal cancer tissues.
Conclusion: This observation suggests that the translocation of annexin I protein in ESCC may correlate with the tumorigenesis of the esophageal cancer.