CDNA CLONING AND CHROMOSOMAL MAPPING OF A PREDICTED COILED-COIL PROLINE-RICH PROTEIN IMMUNOGENIC IN MENINGIOMA PATIENTS

There is increasing evidence that tumor expressed genes induce immune responses in cancer patients, To identify meningioma expressed antigen s, we established a meningioma expression library which was screened w ith autologous serum, Out of 20 positive cDNA clones eight share high sequence homologies as determined by sequence analysis, These eight cl ones can be grouped into three classes which differ in length and whic h are characterized by specific sequence variations, The longest open reading frame was found to be 2412 bp encoding an immunoreactive antig en termed meningioma expressed antigen 6 (MEA6), Using five sequence s pecific primer pairs, somatic hybrid panel mapping revealed locations of the three classes on several human chromosomes including chromosome s 2, 3, 6, 7, 9, 13 and 14, The mapping results were confirmed by fluo rescence in situ hybridization. RT-PCR showed consistent expression of all classes in several meningiomas and additional tissues using the s ame set of primer pairs as for chromosomal mapping, The expression dat a were confirmed by northern blot analysis, For the predicted amino ac id sequence BLASTX revealed a homology to a human C219-reactive peptid e which was previously isolated by an antibody directed against p-glyc oprotein. Sequence properties of the MEA protein include an acidic act ivation domain, a proline-rich region and two coiled-coil domains indi cating protein binding and activation functions.