The P53 Gene and Human Vestibular Schwannomas

Abstract

Human vestibular schwannomas (VS) arise from the Schwann cells of the vestibular branch of vestibulo-cochlear nerve or the eighth cranial nerve. Although p53 gene mutations, both germ line and somatic, have been reported in many brain tumors, a scant contribution of p53 gene is speculated for human vestibular schwannomas. However, altered structure and expression of p53 gene and age dependent phosphorylation of p53 protein specifically at the Ser 392 position only in younger patients have been reported in human VS tumors and these results show an important role for p53 in human vestibular schwannomas. A functional NF2 gene and its protein, merlin, are known to be absent in human VS tumors. In the absence of merlin the human VS tumor cells should lack NF2-mediated p53 stabilization. But the p53 protein is shown to be accumulated in both sporadic and familial human VS tumors. A number of pathways have been described that lead to increase in the level of the p53 protein in the VS tumor cells. In this article we have reviewed the structure and function of p53 gene, its possible role in causation of VS tumor and various pathways that leads to increase in the level of p53 protein in the VS tumor cells. doi: 10.5214/ans.0972.7531.2006.130304