DIFFERENTIAL DISPLAY OF MESSENGER-RIBONUCLEIC-ACID - A USEFUL TECHNIQUE FOR ANALYZING DIFFERENTIAL GENE-EXPRESSION IN HUMAN BRAIN-TUMORS

IN THIS STUDY, a differential display method for messenger ribonucleic acid was successfully used to identify genes differentially expressed between normal human brain and malignant glioma tissues. A total of 6 0 differentially expressed sequences were initially identified, of whi ch 21 were cloned and sequenced. Twenty of the cloned sequences repres ented novel genes, and one sequence represented a kinesin heavy chain (KHC) gene isoform. The KHC isoform was selected for further character ization. Northern blots of total ribonucleic acid isolated from normal brain and a glioblastoma were probed with our KHC probe and confirmed the differential expression of this gene. Expression analysis of a va riety of normal human tissues demonstrated that this KHC isoform is ex pressed only in brain tissues, with no detectable expression in placen ta, spleen, kidney, lung, liver, or skeletal muscle. Our results confi rm the rapid and sensitive nature of the differential display techniqu e in identifying differential gene expression. This method offers a me ans to identify new genes of biological interest in human brain tumors such as oncogenes, tumor suppressor genes, and tumor-specific markers .