Browsing by Subject "TRACTS"

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  • Dziubanska-Kusibab, Paulina J.; Berger, Hilmar; Battistini, Federica; Bouwman, Britta A. M.; Iftekhar, Amina; Katainen, Riku; Cajuso, Tatiana; Crosetto, Nicola; Orozco, Modesto; Aaltonen, Lauri A.; Meyer, Thomas F. (2020)
    The mucosal epithelium is a common target of damage by chronic bacterial infections and the accompanying toxins, and most cancers originate from this tissue. We investigated whether colibactin, a potent genotoxin(1) associated with certain strains of Escherichia coli(2), creates a specific DNA-damage signature in infected human colorectal cells. Notably, the genomic contexts of colibactin-induced DNA double-strand breaks were enriched for an AT-rich hexameric sequence motif, associated with distinct DNA-shape characteristics. A survey of somatic mutations at colibactin target sites of several thousand cancer genomes revealed notable enrichment of this motif in colorectal cancers. Moreover, the exact double-strand-break loci corresponded with mutational hot spots in cancer genomes, reminiscent of a trinucleotide signature previously identified in healthy colorectal epithelial cells(3). The present study provides evidence for the etiological role of colibactin in human cancer. Identification of a DNA-damage signature induced by colibactin, a toxin expressed by some strains of Escherichia coli, is enriched in human colorectal cancers.
  • Darki, Fahimeh; Massinen, Satu; Salmela, Elina; Matsson, Hans; Peyrard-Janvid, Myriam; Klingberg, Torkel; Kere, Juha (2017)
    The axon guidance receptor, Robo1, controls the pathfinding of callosal axons in mice. To determine whether the orthologous ROBO1 gene is involved in callosal development also in humans, we studied polymorphisms in the ROBO1 gene and variation in the white matter structure in the corpus callosum using both structural magnetic resonance imaging and diffusion tensor magnetic resonance imaging. We found that five polymorphisms in the regulatory region of ROBO1 were associated with white matter density in the posterior part of the corpus callosum pathways. One of the polymorphisms, rs7631357, was also significantly associated with the probability of connections to the parietal cortical regions. Our results demonstrate that human ROBO1 may be involved in the regulation of the structure and connectivity of posterior part of corpus callosum.