Cloning and identification of a novel human glioma differentiation related geneGDR1

In order to identify the genes associated with glioblastoma differentiation, some ESTs, expressed differentially in the control cell and the differentiated human glioblastoma cell line BT-325 induced by the all-trans retinoid acid, have been isolated by the method of DDRT-PCR. Of the 46 ESTs sequenced, 19 are from new genes. A full-length 1 535-bp cDNA, termed geneGDR1, has been isolated from the human cDNA library using the probe designed according to one of the novel ESTs, HGBB098. The open reading frame ofGDR1 gene encodes a putative protein containing 334 amino acid residues. Blast against the current GenBank DNA and protein sequence database did not reveal significant homology with any known proteins. RT-PCR shows thatGDR1 mRNA level increased in the differentiated BT-325 cells after being treated with RA. The different expression patterns ofGDR1 mRNA in human tissues have been detected through the multiple tissue Northern blot hybridization.