Growth and migration markers of rat C6 glioma cells identified by serial analysis of gene expression

Tumors derived from rat C6 cell implants into rat brain exhibit similar mor phological characteristics and degree of vascularization to human glioblast omas. To establish a molecular basis for C6 gliosarcoma malignancy, we have constructed a molecular profile of the most abundantly expressed genes, us ing serial analysis of gene expression (SAGE). Sequence tags (1168) represe nting 738 individual transcripts were collected and tag-to-gene mapping was carried out using the UniGene data set for rat. Differentially expressed C 6 transcripts were identified by comparison of tags collected for C6 cells with a similar number (1002) of tags from a rat primary astrocyte library. Genes found to be expressed at increased levels in C6 cells are associated with cell surface interactions, migration, or metastasis formation and prol iferation. These include the receptor for hyaluronan-mediated motility (RHA MM), S-100 related protein 42A, galectin I, preproenkephalin, osteopontin, autocrine motility factor, alpha -tubulin, adl antigen, and cofilin. In add ition, a tag with no database match probably representing a previously unch aracterized transcript was differentially expressed in C6 cells. Transcript s showing reduced expression in C6 cells relative to astrocytes included th e extracellular matrix glycoprotein osteonectin/SPARC (secreted protein, ac idic, rich in cysteine), actin-binding proteins thymosins beta -4 and beta -10, the cysteine protease inhibitor cystatin C, the actin-gelling protein SM22/transgelin, and ferritin-H. SAGE results were confirmed by Northern bl ot for all transcripts tested, reaffirming the value of the SAGE technique for expression profiling in cancer biology. (C) 2000 Wiley-Liss, Inc.