ANOVA, a putative astrocytic RNA-binding protein gene that maps to chromosome 19q13.3

ABSTRACT

Exon amplification from cosmids mapping to the glioma tumor suppressor gene candidate region on chromosome 19q13.3 yielded an exon with high homology to a portion of the NOVA1 gene, which encodes a neuron-specific RNA-binding protein recognized by the paraneoplastic syndrome antibody anti-Ri. Screening of a human brain cDNA library with this exon identified a 1.9 kb cDNA with extensive homology to NOVA1, including three nearly identical KH domains characteristic of a subtype of RNA-binding proteins. Northern blots demonstrated expression of a 2.5 kb mRNA in brain, but in no other tissues. In situ hybridization on human cerebral cortex showed mRNA expression restricted to astrocytes. We have therefore named the gene ANOVA, for astrocytic NOVA1-like gene. Southern blotting and single strand conformation polymorphism analyses did not show tumor-specific alterations of this gene in gliomas and RT-PCR studies showed expression in glioma cell lines, suggesting that ANOVA is not the chromosome 19q glioma tumor suppressor gene. Given that two cloned paraneoplastic antigens are neuronal RNA-binding proteins and that glial proteins may act as paraneoplastic antigens, the ANOVA product may be a target antigen in one of the undefined human paraneoplastic syndromes.