KEY WORDS

tamoxifen; neu/c-erB-2; protein tyrosine phosphorylation; DNA; glioma The effects of tamoxifen, an antiestrogen, on the inhibition of protein tyrosine phosphorylation in neu/c-erbB-2 receptor, DNA synthesis and proliferation were evaluated using the malignant glioma cell lines U25 IMG and T98G which overexpressing neu/c-erbB-2. Pretreatment of two cell lines with tamoxifen resulted in a dose dependent inhibition of tyrosine phosphorylation as well as DNA synthesis and cell growth in two cell lines correlatively. The results support the hypothesis that activated protein tyrosine kinase receptors are involved in the proliferation of glioma cells. Tamoxifen may be useful in the treatment of malignant glioma