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

To facilitate further mutational analysis of NM23-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.