Loss of heterozygosity at 9p21 loci and mutations of the MTS1 and MTS2 genes in human lung cancers.

To elucidate the involvement of abnormalities of the MTS1/p16 and MTS2/p15 genes located at chromosomal region 9p21 in human lung cancers, we analyzed DNA from 30 primary lung cancers and detected loss of heterozygosity at the 9p21-p23 region in 15 tumors. Single-strand-conformation-polymorphism analysis of polymerase-chain-reaction products from the MTS1 and MTS2 genes and determination of the nucleotide sequences revealed the presence of a mutated MTS1 gene in 2 of 15 tumors with a loss of corresponding loci. No mutations of the MTS2 gene were found. These results suggested that mutations of the MTS1 gene are associated with at least some human lung cancers.