Genomic PCR-SSCP analysis of the metastasis associated NM23-H1 (NME1) gene: a study on colorectal cancer.

To facilitate further mutational analysis of NM13-H1, a human metastasis suppressor gene, we have established its genomic organization. NM23-H1 is composed of five exons, spanning a genomic DNA fragment of 10 kb. Using oligonucleotide primers flanking each exon, PCR-SSCP analysis was performed on genomic DNAs of healthy individuals. A common polymorphism, a C to T transition, was detected 30 nucleotides upstream from the 5' splice site flanking exon 1. As NM23-H1 allele loss and altered expression have been reported in colorectal cancer, genomic DNAs of 20 colorectal tumors were analyzed for the presence of gene-specific mutations by PCR-SSCP: no abnormal sequences were detected within the coding and splice site regions of the NM23-H1 gene. This finding suggests that NM23-H1 mutations are rare events in human colorectal cancer.