Scientists can compare the genes from their own biological samples to this dictionary of normal expression. "Genes identified by the database as abnormally active in a particular disease could become potential targets, guiding researchers to better candidates for new drug therapies, immune-based vaccine treatments, and potential biomarkers to help with diagnosis," explained Javed Khan, M.D., chief of the Oncogenomics Section of NCI's Pediatric Oncology Branch. A study validating the database appears in the March 2005 issue of Genome Research.
"The NCI database is an important addition to the growing body of knowledge about gene expression in normal human tissues," added James Jacobson, Ph.D., acting branch chief of the Diagnostics Research Branch in NCI's Division of Cancer Treatment and Diagnosis. "These data give investigators a baseline against which to compare gene expression data obtained from tumor or other disease specimens, and should be a valuable resource for the research community."
The normal organ database uses a technology known as gene expression microarrays, more commonly known as gene chips, to provide a kind of fingerprint that researchers and clinicians can use to compare cells and tissue they suspect may have cancerous or other malfunctioning genes. To create these fingerprints, Khan and his team assembled a complementary DNA (cDNA) microarray, using a pair of glass slides on which thousands of known genes have been printed in tiny spots. Cells can be tested by manipulating them so that genes activated in the cel