Cloning a calcium channel α2δ-3 subunit gene from a putative tumor suppressor gene region at chromosome 3p21.1 in conventional renal cell carcinoma

We have identified loss of heterozygosity (LOH) of approx. 1 cM region around locus D3S1289 at chromosome 3p21.1 in a conventional renal cell carcinoma (RCC), During construction of a YAC/BAC contig fur this region and shotgun sequencing of BACs 277p5, 55m24 and 428i24, we detected four new microsatellites. We narrowed down the target region by analysing these new loci to less than 100 kb within the BAC 55m24 and subsequently cloned a human calcium channel alpha2 delta -3 subunit gene. This gene is widely expressed in fetal tissues and different types of adult tumors. The exons of the alpha2 delta -3 subunit gene are distributed along approx. 500 kb DNA sequences. As the LOH involved exclusively intronic sequences and sequencing the entire coding region did not reveal any mutation, the beta2 delta -3 subunit gene is probably not a tumor suppressor gene. (C) 2001 Elsevier Science B.V, All rights reserved.