Genome-wide Analysis of Genetic Alterations in Cancer

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We have been investigating the genome-wide copy number alterations of many cancers using comparative genomic hybridization analysis (Figure 1) with a high-density genome array. This method can uncover small genetic alterations (chromosomal loss, gain, amplification and homozygous deletion) including those that have not been identified previously. Based on such high-resolution genetic analysis, we attempt to identify novel oncogenes and tumor suppressor genes in a wide range of malignant tumors.


Figure 1 High density Genome Array-based CGH analysis
(Left) More than 4000 BACs (Bacteria Artificial Chromosome DNAs) or 220,000 oligonucleotide probes that cover the human genome are spotted on a slide glass. DNA from normal tissue and cancer is labeled with different fluorescent dyes and simultaneously hybridized on a slide. Signal ratio of the two samples is analyzed to evaluate copy number change (loss or gain) on each chromosomal locus or gene. (Right) High-density genome array can allow us to detect small deletions and homozygous deletions in cancer.