Annexin A1 expression in nasopharyngeal carcinoma correlates with squamous differentiation.

Background: Alterations of annexin A1 (ANXA1) expression have been reported in various cancers. However, no data are available about the expression of this protein in nasopharyngeal carcinomas (NPCs). The objective of this study was to investigate the expression of ANXA1 in these tumors.

Methods: We examined noncancerous nasopharyngeal mucosa (4 cases) and NPC (20 cases) for ANXA1 expression using immunohistochemistry.

Results: All tumor tissues showed markedly reduced ANXA1 expression compared with a strong positive signal observed in the corresponding normal epithelia. We found that ANXA1 expression is associated with the histological type in NPC. Only squamous cell carcinomas presented a positive ANXA1 signal in differentiated areas whereas all poorly differentiated tumors exhibited negative staining.

Conclusion: Our data show for the first time that ANXA1 expression is down-regulated in NPC and that its expression seems to be related with the squamous differentiation status of these tumors.