Expression and biological significance of 14-3-3 in gliomas

CAO Weidong; ZHANG Xiang; ZHANG Jianning; YANG Zhijun; ZHEN Haining; CHENG Guang; LI Bing; GAO Dakuan; WANG Xiling; SONG Lei; XIE Li

doi:10.3969/j.issn.1671-2897.2006.04.002

Abstract：Objective To investigate the expression and its biological significance of 14-3-3 proteins in human gliomas. Methods The expression of 14-3-3 proteins was detected in five glioma cell lines (U251MG, U87MG,BT325, SHG44, and C6), 121 cases of formalin-fixed, paraffin embedded archival tumor tissue from patients with glioma, and 10 normal human brain tissues by immunohistochemical avidin-biotin-peroxidase complex (ABC) method. And the biological significance of 14-3-3 proteins expression was analyzed in the etiopathogenesis of glioma.Results In the normal control brains, 14-3-3 immunoreactivity was localized mainly in the neuronal somata and processes, and some glial cells showed only weak immunoreactivity. However, 14-3-3 immunoreactivity was seen in all of the five glioma cell lines and the majority of astrocytomas [78.6% in grade Ⅰ (11/14), 75% in grade Ⅱ (18/24), 76.2% in grade Ⅲ (16/21), and 80% in grade Ⅳ (20/25)]. No differences were found among the positive expression rates of 14-3-3 in different grades of astrocytomas. But the intensity and the degree of 14-3-3 expression showed trends with tumor grade. The 14-3-3 immunoreactivity was also seen in the majority of other gliomas [66.7% in oligodendroglioma (4/6), 100% in anaplastic oligodendroglioma (4/4), 50% in ependymoma (2/4), 66.7% in anaplastic ependymoma (2/3), 100% in choroid plexus papilloma (5/5), 100% in pineocytoma (3/3), and 66.7% in medulloblastoma (8/12) ]. Conclusion Most human gliomas are positive for 14-3-3 proteins in this research. For most human gliomas, one common mechanism for escaping apoptosis may be the up-regulated expression of 14-3-3,and targeting 14-3-3 may be a novel promising strategy for the treatment of gliomas.