ABSTRACT
In the previous cytogenetic study of new human stem cell line 4BL at the 205th passage we observed the ploidy of chromosomal set and regular aberrations. To investigate the nature of monosomy of certain chromosomes the array CGH and FISH analyses have been used. The aberrations of chromosomes have been identified in all the cases of monosomies previously revealed by G-banding. The largest changes of the DNA balance have been detected in the chromosomes 2, 4, 10, 13 and 17. The probable cause of the monosomies of chromosomes 4, 10, 13 and 17 is massive loss of the genetic material. The monosomy of the second chromosome pair is caused by significant transformation one of the homologs in a type of numerous duplications and formation of der(2)t(2;?)(q21;?). Due to application of array CGH the regions of the structural aberrations of the chromosomes 2, 4, 10, 13 and 17 have been concretized, what permitted to perform their clarifying identification by multicolored FISH method. The results obtained by us confirm the hypothesis about coordinated appearance of the deletions and duplications and their stabilization impact on the transformed chromosomes.
Subject(s)
Base Sequence , Chromosome Duplication , Monosomy , Ploidies , Sequence Deletion , Stem Cells/metabolism , Cell Line , Chromosome Banding , Comparative Genomic Hybridization , Humans , In Situ Hybridization, Fluorescence , Karyotyping , Stem Cells/pathologyABSTRACT
Long-term cultivation of human cells, including stem cells, can lead to substantial transformation of the karyotype and occurrence of genetic instability. The aim of this research was a comparative cytogenetic study of the karyotype of a new human stem cell line 4BL at 160 and 205 passages. The absence of 10 and 13 pairs of chromosomes and the monosomy of chromosomes 4, 8, 10, 11, 13, 15, 17, 21, X were observed; also six regular marker chromosomes were detected. Chromosomes 1, 15 and 21 are involved in translocations t(l;11), t(5;15), t(12; 15), t(16;21). Modal class of the karyotype is within 41-43 chromosomes at both 160 and 205 passages. The frequency of polyploid cells have been increased from 2.8% at 160 passage up to 36% at 205 passage. Cells with a near-haploid karyotype were not detected at 205 passage (in contrast to 24.6% at 160 passages) and a decline of the level of premature separation of chromatids was observed. We assume stabilization of karyotype of the cell line 4BL at 205 passage and consider that further research is needed to predict the direction of karyotypic evolution of these cells in vitro.
