[Karyotypic anomalies and chromosomal sites of increased fragility in colorectal cancer].

Karyotypic structural aberrations in tumor cells and chromosome constitutive fragile sites (cFSs) in peripheral blood lymphocytes were studied in ten patients with colorectal adenocarcinoma Most chromosome breakpoints (38 out of 40, i.e., 95.0%) were shown to be located within cFSs in tumor cells. Expression of 24 out of 137 cFSs in patients was higher than that in healthy donors. Four of these cFSs (6q26, 7q36, 16q23, and 17q21), were involved in the formation of nonrandom tumor cell chromosome markers most characteristic of colorectal neoplasms. The frequency of damages induced within these sites was analyzed in each patient. Expression of 7q36, 16q23, and 17q21 was increased in blood cells of patients carrying specific chromosome rearrangements with the breakpoints within these sites. The association between nonrandom chromosome aberrations in tumor cells and cFSs in normal cells is discussed.