ISOLATION AND CHARACTERIZATION OF A NOVEL HUMAN LUNG-SPECIFIC GENE HOMOLOGOUS TO LYSOSOMAL MEMBRANE-GLYCOPROTEIN-1 AND MEMBRANE-GLYCOPROTEIN-2 - SIGNIFICANTLY INCREASED EXPRESSION IN CANCERS OF VARIOUS TISSUES

We have isolated and characterized a novel human lung-specific gene an d observed its increased expression in cancers arising from various ti ssues. The cDNA, designated TSC403, contained an open reading frame of 1248 nucleotides encoding 416 amino acids; the deduced amino acid seq uence showed significant similarities to lysosomal membrane glycoprote ins (lamps) 1 and 2, We localized the gene to chromosomal band 3q27, a genomic region that is often amplified in human cancers of several ti ssue types. We detected a high level of the TSC403 transcript in prima ry cancers of the esophagus, colon, fallopian tube, ovary, breast, and liver, although expression of this gene was barely detectable in corr esponding normal tissues. These findings indicated that up-regulation of the TSC403 transcript may be related to the development and/or prog ression of cancer in humans.