Changes of gene expression in human astrocytic brain tumors

Differential hybridization of high density grids of arrayed human fetal bra in cDNA library was used for identification of new tumor markers, Nine clon es containing cDNAs complementary to the transcripts of differentially expr essed genes were selected for further analysis after confirmation of their changed expression in brain astrocytic tumors by Southern hybridization. In this work we characterize three clones with cDNA copies of transcripts ove rexpressed in glioblastoma multiforme. F0246 mRNA encodes the protein parti ally homologous to human TRAF6, one of the tumor necrosis factor (TNF) rece ptor-associated factors involved in signal transduction from various member s of the TNF receptor superfamily. cDNA insert of M243 clone is complementa ry to human mitochondrial 16S rRNA. The increasing expression level of mt 1 6S rRNA gene in glioblastoma multiforme and in other types of malignant tum ors may serve as a general tumor marker. G2490 cDNA contains an open readin g frame for the protein with a 86% homology to hypothetical 9.8 kD protein ZK652.3 encoded by chromosome 3 of Caenorhabditis elegans. Highly conservat ive structure of protein in evolutionary distant organisms may testify to t he importance of its function.