RECIPROCAL SUBTRACTION DIFFERENTIAL RNA DISPLAY - AN EFFICIENT AND RAPID PROCEDURE FOR ISOLATING DIFFERENTIALLY EXPRESSED GENE-SEQUENCES

A reciprocal subtraction differential RNA display (RSDD) approach has been developed that permits the rapid and efficient identification and cloning of both abundant and rare differentially expressed genes. RSD D comprises reciprocal subtraction of cDNA libraries followed by diffe rential RNA display. The RSDD strategy was applied to analyze the gene expression alterations resulting during cancer progression as adenovi rus-transformed rodent cells developed an aggressive transformed state , as documented by elevated anchorage-independence and enhanced in viv o oncogenesis in nude mice. This approach resulted in the identificati on and cloning of both known and a high proportion (>65%) of unknown s equences, including cDNAs displaying elevated expression as a function of progression (progression-elevated gene) and cDNAs displaying suppr essed expression as a function of progression (progression-suppressed gene). Sixteen differentially expressed genes, including five unknown progression-elevated genes and six unknown progression-suppressed gene s, have been characterized. The RSDD scheme should find wide applicati on for the effective detection and isolation of differentially express ed genes.