Recombination cluster around FGFR2-WDR11-HTPAPL locus on human chromosome 10q26

FGFR2 is an oncogene amplified in diffuse-type gastric cancer, and WDR11 is a tumor suppressor gene disrupted in glial tumor. WDR11-FGFR2 locus on human chromosome 10q26 is one of cancer-related recombination hot spots. In this study, we investigated recombination and nucleotide substitution around the WDR11-FGFR2 locus during evolution by using bioinformatics. Inter-chromosomal comparison revealed that the human BAG3-FGFR2-TACC2 region was paralogous to the human BAG4-FGFR1-TACC1 region. Inter-specific comparison on the BAG3-FGFR2-TACC2 region revealed that HTPAPL-WDR11-FGFR2 locus containing species-specific insertion or deletion was one of evolutionary recombination hot spots. Between human and mouse, coding-region nucleotide substitution rate and amino-acid substitution rate were significantly lower in the HTPAPL-WDR11-FGFR2 locus than in the surrounding locus (P<0.0001). The HTPAPL-WDR11-FGFR2 locus was more susceptible to recombination than to nucleotide substitution. Detailed comparison of human and mouse genomes could identify evolutionary recombination hot spots overlooked during gross comparison of human and mouse genomes. Because DNA double-strand break is the initial step in various types of recombination including chromosomal translocation, rearrangement, deletion, gene amplification, retroviral integration and retrotransposition, it is reasonable that the HTPAPL-WDR11-FGFR2 locus is the recombination hot spot during evolution as well as during carcinogenesis. Therefore, comparative genomics might be applicable to identification of recombination hot spots and genes related to cancer.