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 60 differentially expressed sequences were initially identified, of which 21 were cloned and sequenced. Twenty of the cloned sequences represented novel genes, and one sequence represented a kinesin heavy chain (KHC) gene isoform. The KHC isoform was selected for further characterization. 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 variety of normal human tissues demonstrated that this KHC isoform is expressed only in brain tissues, with no detectable expression in placenta, spleen, kidney, lung, liver, or skeletal muscle. Our results confirm the rapid and sensitive nature of the differential display technique in identifying differential gene expression. This method offers a means to identify new genes of biological interest in human brain tumors such as oncogenes, tumor suppressor genes, and tumor-specific markers.