Integration of a bacterial gene sequence into a chronic eosinophilic leukemia patient's genome as part of a fusion gene linker.

Analysis of databases from the human genome project (HGP), the 1000 Genomes Project (1KGP), and The Cancer Genome Atlas (TCGA) revealed bacterial DNA integration into the human somatic genome, particularly in tumor tissues. Fusion genes have also been associated with tumorigenesis and 34 PDGFR fusion genes are linked to hematological malignancies. Here, we determined that a 17-bp homologous sequence in Hb8, D188, PBTS2, strain trpE16 and NCTC 2665 integrates into the genome of a chronic eosinophilic leukemia patient as part of the linker for the novel fusion gene. The resulting fusion protein that has CDK5RAP2's self-activating domain and PDGFRa's tyrosine kinase domain but lacks PDGFRa's membrane-binding and ligand-dependent activation properties may act together with the integrated bacterial sequence to readily phosphorylate downstream targets, amplify proliferation signals and promote leukemic cancer progression.