GENE-EXPRESSION PROFILES IN NORMAL AND CANCER-CELLS

As a step toward understanding the complex differences between normal and cancer cells in humans, gene expression patterns were examined in gastrointestinal tumors. More than 300,000 transcripts derived from at least 45,000 different genes were analyzed. Although extensive simila rity was noted between the expression profiles, more than 500 transcri pts that were expressed at significantly different levels in normal an d neoplastic cells were identified. These data provide insight into th e extent of expression differences underlying malignancy and reveal ge nes that may prove useful as diagnostic or prognostic markers.