Objective: To clarify expression and subcellular localization of XIAP and XAF1 protein in human normal oral keratinocytes (hNOK) and Tca8113 cells human tongue carcinoma cell line.
Methods: The hNOKs and Tca8113 cells were cultured in vitro. Expression and subcellular localization of XIAP and XAF1 protein were examined by combination of indirect immunofluorescence and confocal laser scanning microscopy.
Results: XIAP expression was weak in the hNOKs and fluorescence staining localized chiefly in the cytoplasm and perinuclear areas. In the Tca8113 cells, high level of XIAP protein could be detected in both the cytoplasm and the nucleus. In the hNOKs, XAF1 distributed mostly in the nucleus. Homogeneous nuclear and cytoplasmic distribution of XAF1 could be visualized in the Tca8113 cells.
Conclusions: In cancerization of oral mucosa, XIAP protein could play an important antiapoptotic role by overexpression, while XAF1 protein does not appear to antagonize effectively the role of XIAP.