The three-dimensional organization of telomeres in the nucleus of mammalian cells.
BACKGROUND
The observation of multiple genetic markers in situ by optical microscopy and their relevance to the study of three-dimensional (3D) chromosomal organization in the nucleus have been greatly developed in the last decade. These methods are important in cancer research because cancer is characterized by multiple alterations that affect the modulation of gene expression and the stability of the genome. It is, therefore, essential to analyze the 3D genome organization of the interphase nucleus in both normal and cancer cells.


RESULTS
We describe a novel approach to study the distribution of all telomeres inside the nucleus of mammalian cells throughout the cell cycle. It is based on 3D telomere fluorescence in situ hybridization followed by quantitative analysis that determines the telomeres' distribution in the nucleus throughout the cell cycle. This method enables us to determine, for the first time, that telomere organization is cell-cycle dependent, with assembly of telomeres into a telomeric disk in the G2 phase. In tumor cells, the 3D telomere organization is distorted and aggregates are formed.


CONCLUSIONS
The results emphasize a non-random and dynamic 3D nuclear telomeric organization and its importance to genomic stability. Based on our findings, it appears possible to examine telomeric aggregates suggestive of genomic instability in individual interphase nuclei and tissues without the need to examine metaphases. Such new avenues of monitoring genomic instability could potentially impact on cancer biology, genetics, diagnostic innovations and surveillance of treatment response in medicine.
Chuang
Tony Chih Yuan
TC
Manitoba Institute of Cell Biology, CancerCare Manitoba, University of Manitoba, 675 McDermot Avenue, Winnipeg, MB, R3E 0V9, Canada. tcychuang@hotmail.com
Moshir
Sharareh
S
Garini
Yuval
Y
Chuang
Alice Ya-Chun
AY
Young
Ian T
IT
Vermolen
Bart
B
van den Doel
Richard
R
Mougey
Virginie
V
Perrin
Mathilde
M
Braun
Martina
M
Kerr
Paul Donald
PD
Fest
Thierry
T
Boukamp
Petra
P
Mai
Sabine
S
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology*; D002453:Cell Cycle; D002467:Cell Nucleus; D002469:Cell Separation; D002478:Cells, Cultured; D005434:Flow Cytometry; D022781:Hepatocytes / Q000166:cytology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D017403:In Situ Hybridization; D007399:Interphase; D051379:Mice; D008807:Mice, Inbred BALB C; D016615:Telomere / Q000737:chemistry* / Q000378:metabolism