CLONING OF A NOVEL TRANSCRIPTION FACTOR-LIKE GENE AMPLIFIED IN HUMAN GLIOMA INCLUDING ASTROCYTOMA GRADE-I

Gene amplification, which is generally considered to occur late in tum or development, is a common feature of high grade glioma, Up until now , there have been no reports on amplification in astrocytoma grade I. In this study, we report cloning and sequencing of a cDNA termed gliom a-amplified sequence (GAS41) which was identified recently in a gliobl astoma cell line by microdissection-mediated cDNA capture, This techni que is tailored to isolate amplified genes from human tumors, An incre ased copy number of GAS41 was found in glioblastoma multiforme and ast rocytoma III, and at a high frequency ill astrocytoma grades I and II, Sequence comparison indicates a high homology between the GAS41 prote in, the yeast and human AF-9 and the human ENL proteins, Both AF-9 and ENL belong to a new class of transcription factors, indicating that G AS41 might also represent a transcription factor. With GAS41 being the first gene found with increased copy number in low grade glioma, this study provides the first evidence that gene amplification can occur i n early tumor development.