Abstract
Apollon, an anti-apoptosis molecule containing IAP repeat, was first cloned by Naito et al. Immunohistochemical staining of Apollon was performed on 43 cases of oral squamous cell carcinoma. The cases were divided into 4 groups according to treatments such as radiotherapy, chemotherapy, chemoradiotherapy and without therapy between biopsy and surgical operations. Compared with biopsy, the number of cancer cells positive for Apollon at surgery was higher only in radiotherapy group. Using a human oral cancer cell line SAS, real-time PCR revealed overexpression of the Apollon gene after the exposure to X-rays and the induction was canceled by simultaneous treatments with CDDP. Tumor tissues formed after inoculating SAS cells into nude mice subcutaneously showed the same tendency as in vitro cultures. These suggest that Apollon mediates radioresistance of oral squamous cell cancer and simultaneous chemotherapeutic treatments reduce the resistance partly through the suppression of Apollon gene expressions.
