Speaker
Description
The karyotypes of the majority of tumor cell lines are highly abnormal with numerical changes and rearranged chromosomes. We studied the chromosome complement and genetic stability of cultured human cells of different origins using the modern and advanced method of molecular cytogenetics Multicolor Fluorescence in situ Hybridization (mFISH). This method, applying chromosome-specific fluorescently labeled probes, allows the identification of each pair of human chromosomes and all rearrangements between them and thus makes it possible to identify precisely all chromosomes and obtain accurate karyotypes. In the present study, we reconstructed karyotypes of two tumor human cell lines, namely, breast carcinoma Cal 51 and glioblastoma U87, and normal dermal human fibroblasts (NDHF), which are currently used in LRB JINR. For this, the standard protocols of cell harvesting, fixation, and slide preparation were optimized for each cell line to prepare the best quality metaphase spreads for the analysis.
We found that NDHF has a normal human karyotype 22, XY with a low level of spontaneous aberrations and numerical changes. The same was found in the Cal 51 line (22, XX), which is extremely rare to observe in tumor cell lines. In contrast, human glioblastoma U87 shows a highly rearranged but stable hypotetraploid karyotype (modal number of chromosomes 80) with multiple translocated and truncated chromosomes and additional spontaneous aberrations found in 75% of cells. The most frequent spontaneous aberrations are truncated chromosomes, translocations, dicentric chromosomes, Robertsonian translocations, and complex aberrations.
