Identification of 14-3-3 protein isoforms in human astrocytoma by immunohistochemistry.

The 14-3-3 proteins are highly conserved, ubiquitous molecules involved in a variety of biologic events, such as cell cycle control, and apoptosis. In our previous study, it has been proved that they are expressed in primary human nervous system tumors. However, the isoform-specific expression of 14-3-3 protein is still need to be identified. This study is the first detection of 14-3-3 isoforms' specific expression in human astrocytoma. In the normal brain tissues, all the seven 14-3-3 isoforms' immunoreactivity was localized mainly in the neurons, while only weak expression of epsilon, zeta and theta was found in some glial cells. However, beta, epsilon, zeta, eta and theta isoforms' immunoreactivity was seen in the majority of astrocytoma samples and its immunoreactivity score was increased markedly with an increase in the pathologic grade of human astrocytomas. These results indicate that the five isoforms may play an important role in tumorigenesis of human astrocytoma.