Chromosome copy number and LOH analysis of colorectal carcinoma specimens

Structural changes of chromosomes play important roles in the carcinogenesis of colorectal carcinoma (CRC). Here, by using SNP-typing arrays, we have tried to screen for recurrent chromosome copy number changes and loss-of-heterozygosity in the genome of colorectal carcinoma. Genomic DNA was isolated from tumor and paired normal tissues of CRC (n=94), and was hybridized to Affymetrix Mapping 50K Xba 240 arrays. Chromosome copy number and LOH likelihood score was inferred at every SNP locus with CNAG2.0 software (http://www.genome.umin.jp). Keywords: Comparative genomic hybridization Tumor samples and paired normal tissues (n=94 for each) were hybridized to the microarrays. Signal intensity data as well as genotype data were compared between a pair of tumor and normal samples with CNAG2.0. The resultant copy number and LOH likelihood score for each sample are thus calculated from two datasets (tumor and normal).