Abstract 3378: Variance in the distance between chromosome territories 9 and 22 in lymphocytes from peripheral blood healthy subjects: A proof of concept for a possible risk factor in chronic myeloid leukemia

Abstract

Abstract The objective of our study was to assess the variations in the 3D organization of Chromosome Territories (CT) of chromosomes 9 and 22 in lymphocytes from healthy subjects. The differences in the distances of CTs 9 and 22 between subjects may provide a new perspective in the predisposition for specific chromosome translocations. We quantified the intra- and inter-subject variation in the distance of CT 9 and 22 as a proof of concept for new questions on the physiological and pathological effects of these differences. Methods: Blood samples from healthy subjects were processed for the isolation of lymphocytes with Ficoll as the gradient media. After the isolation, we fixed the cells directly onto coverslips for a 3D Fish protocol with 9 and 22 whole chromosome probes. Our protocol has been standardized to maintain the integrity of the nucleus with only minor changes in its volume. After the hybridization, we used the Elyra System of Zeiss to obtain super resolution images in Z stack. The images were processed with the Imaris software for its 3D reconstruction, measurement (distances, volumes and colocalization) and analysis. Results: The CTs 9 and 22 behave differently in peripheral blood lymphocytes. The CT 22 has a more internal position (closer to the center of the nucleus) in comparison with the CT 9, which can be seen most of the times in contact with the border of the nucleus. The CT 22 occupies a smaller volume than CT 9, which has almost a twice as larger volume. The CTs 9 have a polarized distribution inside the nucleus, therefore the distance between the CT 9-9 was larger (~7.3 μm ± 0.9) than the distance between CT 22-22. Although the position of the CTs was highly variable in cells from the same individual, we found a statistically significant difference in the inter-individual distance between CT 9-9 and the minimal distance between CT 9-22. Conclusion: Our study suggests that there are differences in the distribution of CT in lymphocytes isolated from peripheral blood between our subjects. These differences could prove to be a new individual characteristic with important implications in the predisposition for specific diseases, mainly to those related with chromosomal rearrangements. Citation Format: David G. Vallejo, Eunice Fabian, Luis A. Herrera. Variance in the distance between chromosome territories 9 and 22 in lymphocytes from peripheral blood healthy subjects: A proof of concept for a possible risk factor in chronic myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3378.