Differential polymerase chain reaction and immunohistological studies on amplification and expression of cyclin D1 gene in human glioma tissues

Using differential polymerase chain reaction we studied the amplification of the cyclin D1 gene in formalin-fixed, paraffin-embedded surgical specimens of 70 gliomas. We also examined expression of cyclin D1 in these gliomas, and the Ki-67 labeling indices in 24 glioblastomas by immunohistochemistry. Among 70 gliomas, amplification of cyclin D1 gene was found in only one glioblastoma. The expression of cyclin D1 was immunohistochemically detected in only one glioblastoma with cyclin D1 gene amplification. The highest labeling index of Ki-67, 48.0%, was noted in one of cyclin D1 positive glioblastoma (the average labeling index of 30.2% in cyclin D1 negative glioblastomas). These results suggest that amplification of cyclin D1 gene could play a role in the development of glioblastoma but it is unlikely to be the main gene alteration in malignant progression of gliomas in the majority of cases.