Detection of Differentially Expressed Genes in Cancer Using Differential Display

It is estimated that the human genome contains 25,000–35,000 genes; however, only about 15% of these are expressed in any given cell and different cells and tissues express different gene subsets. Gene expression is tightly regulated under normal physiologic conditions but is often disrupted during malignant transformation and tumor progression. Analysis of differential gene expression in such events as cancer is essential to better understand these complicated processes so that new diagnoses and forms of treatment can be developed. RNA differential display technology offers a straightforward and efficient way to detect differential gene expression in a variety of physiologic and pathologic circumstances including cancer (1 ,2 ). By comparing messenger RNA expression patterns between tumor cells and their normal counterparts on the same gel, altered gene expression in tumor cells can be easily detected. This technique has been widely and successfully applied not only in cancer research but also in many other areas of biologic research and has resulted in thousands of publications in the few years since it was developed (3 –5 ).