Human Cell

, Volume 25, Issue 3, pp 78–85

Formation of bipolar spindles with two centrosomes in tetraploid cells established from normal human fibroblasts

Authors

    • Division of Morphological Science, Biomedical Research CenterSaitama Medical University
  • Atsushi Seyama
    • Department of PathologySaitama Medical University International Medical Center
Rapid Communication

DOI: 10.1007/s13577-012-0046-3

Cite this article as:
Ohshima, S. & Seyama, A. Human Cell (2012) 25: 78. doi:10.1007/s13577-012-0046-3

Abstract

Tetraploid cells with unstable chromosomes frequently arise as an early step in tumorigenesis and lead to the formation of aneuploid cells. The mechanisms responsible for the chromosome instability of polyploid cells are not fully understood, although the supernumerary centrosomes in polyploid cells have been considered the major cause of chromosomal instability. The aim of this study was to examine the integrity of mitotic spindles and centrosomes in proliferative polyploid cells established from normal human fibroblasts. TIG-1 human fibroblasts were treated with demecolcine (DC) for 4 days to induce polyploidy, and the change in DNA content was monitored. Localization of centrosomes and mitotic spindles in polyploid mitotic cells was examined by immunohistochemistry and laser scanning cytometry. TIG-1 cells treated with DC became almost completely tetraploid at 2 weeks after treatment and grew at the same rate as untreated diploid cells. Most mitotic cells with 8C DNA content had only two centrosomes with bipolar spindles in established tetraploid cells, although they had four or more centrosomes with multipolar spindles at 3 days after DC treatment. The frequency of aneuploid cells increased as established tetraploid cells were propagated. These results indicate that tetraploid cells that form bipolar spindles with two centrosomes in mitosis can proliferate as diploid cells. These cells may serve as a useful model for studying the chromosome instability of polyploid cells.

Keywords

PolyploidyCentrosomeMitotic spindleChromosome instabilityHuman fibroblast

Abbreviations

DAPI

4′,6-Diamidino-2-phenylindole

FISH

Fluorescence in situ hybridisation

PDLs

Population doubling levels

Copyright information

© Japan Human Cell Society and Springer 2012