NEURAL CELL-ADHESION MOLECULE L1 IN GLIOMAS - CORRELATION WITH TGF-BETA AND P53

Aims-To assess immunohistochemically whether the neural cell adhesion molecule L1, which is a member of the immunoglobulin superfamily and h as been shown recently to be a stimulating factor for glioma migration , is expressed in glioma tissues, and to investigate factors that can regulate this expression. Methods-Twenty seven glioma tissue specimens including 13 glioblastomas, seven anaplastic astrocytomas, and seven astrocytomas were examined. Immunohistochemical analyses of L1, p53, a nd transforming growth cell factor beta (TGF-beta) were performed on e ach tumour using both polyclonal and monoclonal antibodies. Results-Ni ne (33%) specimens (six glioblastomas and three anaplastic astrocytoma s) had L1 positive immunostaining. p53 positive staining was detected in 10 (43%) of 23 glioma specimens (seven glioblastomas and three anap lastic astrocytomas). TGF-beta positive immunostaining was observed in 12 (52%) of the 23 glioma specimens (six glioblastomas, four anaplast ic astrocytomas, and two astrocytomas). There was a statistical correl ation between both p53 and L1 expression and TGF-beta and L1 expressio n. No such correlation was found between p53 and TGF-beta expression. Conclusions-These results suggest that mutation of the p53 gene or exp ression of TGF-beta may upregulate the expression of the L1 gene, thus resulting in high grade migration of glioma cells.