PMID- 9583680
OWN - NLM
STAT- MEDLINE
DCOM- 19980519
LR  - 20190508
IS  - 0950-9232 (Print)
IS  - 0950-9232 (Linking)
VI  - 16
IP  - 14
DP  - 1998 Apr 9
TI  - Chromosomal instability is correlated with telomere erosion and inactivation of 
      G2 checkpoint function in human fibroblasts expressing human papillomavirus type 
      16 E6 oncoprotein.
PG  - 1825-38
AB  - Cell cycle checkpoints and tumor suppressor gene functions appear to be required 
      for the maintenance of a stable genome in proliferating cells. In this study 
      chromosomal destabilization was monitored in relation to telomere structure, 
      lifespan control and G2 checkpoint function. Replicative senescence was 
      inactivated in secondary cultures of human skin fibroblasts by expressing the 
      human papillomavirus type 16 (HPV-16) E6 oncoprotein to inactivate p53. 
      Chromosome aberrations were enumerated during in vitro aging of isogenic control 
      (F5neo) and HPV-16E6-expressing (F5E6) fibroblasts. We found that structural and 
      numerical aberrations in chromosomes were significantly increased in F5E6 cells 
      during aging in vitro and fluorescence in situ hybridization (FISH) analysis 
      using chromosome-specific probes demonstrated the occurrence of rearrangements 
      involving chromosome 4 and 6 in genetically unstable F5E6 cells. Flow cytometry 
      and karyotypic analyses revealed increased polyploidy and aneuploidy in F5E6 
      cells only at passages > 16, although these cells displayed defective mitotic 
      spindle checkpoint function associated with inactivation of p53 at passages 5 and 
      16. G2 checkpoint function was confirmed to be gradually but progressively 
      inactivated during in vitro aging of E6-expressing cells. Aging of F5neo 
      fibroblasts was documented during in vitro passaging by induction of a 
      senescence-associated marker, pH 6.0 lysosomal beta-galactosidase. F5E6 cells 
      displayed extension of in vitro lifespan and did not induce beta-galactosidase at 
      high passage. Erosion of telomeres during in vitro aging of telomerase-negative 
      F5neo cells was demonstrated by Southern hybridization and by quantitative FISH 
      analysis on an individual cell level. Telomeric signals diminished continuously 
      as F5neo cells aged in vitro being reduced by 80% near the time of replicative 
      senescence. Telomeric signals detected by FISH also decreased continuously during 
      aging of telomerase-negative F5E6 cells, but telomeres appeared to be stabilized 
      at passage 34 when telomerase was expressed. Chromosomal instability in 
      E6-expressing cells was correlated (P < 0.05) with both loss of telomeric signals 
      and inactivation of G2 checkpoint function. The results suggest that chromosomal 
      stability depends upon a complex interaction among the systems of telomere length 
      maintenance and cell cycle checkpoints.
FAU - Filatov, L
AU  - Filatov L
AD  - Department of Pathology and Laboratory Medicine, Lineberger Comprehensive Cancer 
      Center, University of North Carolina at Chapel Hill 27599-7295, USA.
FAU - Golubovskaya, V
AU  - Golubovskaya V
FAU - Hurt, J C
AU  - Hurt JC
FAU - Byrd, L L
AU  - Byrd LL
FAU - Phillips, J M
AU  - Phillips JM
FAU - Kaufmann, W K
AU  - Kaufmann WK
LA  - eng
GR  - CA42765/CA/NCI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - England
TA  - Oncogene
JT  - Oncogene
JID - 8711562
RN  - 0 (E6 protein, Human papillomavirus type 16)
RN  - 0 (Oncogene Proteins, Viral)
RN  - 0 (Repressor Proteins)
RN  - 0 (Tumor Suppressor Protein p53)
RN  - EC 2.7.7.49 (Telomerase)
RN  - EC 3.2.1.23 (beta-Galactosidase)
SB  - IM
MH  - Cell Line
MH  - Cellular Senescence/genetics
MH  - Chromosome Aberrations/*genetics
MH  - Chromosomes, Human, Pair 4
MH  - Chromosomes, Human, Pair 6
MH  - Fibroblasts/enzymology/metabolism
MH  - G2 Phase/*genetics
MH  - Humans
MH  - In Situ Hybridization, Fluorescence
MH  - Oncogene Proteins, Viral/biosynthesis/*genetics
MH  - Papillomaviridae/*genetics
MH  - Polymorphism, Restriction Fragment Length
MH  - *Repressor Proteins
MH  - Spindle Apparatus/genetics
MH  - Telomerase/biosynthesis
MH  - Telomere/*genetics/pathology
MH  - Translocation, Genetic/genetics
MH  - Tumor Suppressor Protein p53/drug effects/metabolism
MH  - beta-Galactosidase/analysis
EDAT- 1998/05/16 00:00
MHDA- 1998/05/16 00:01
CRDT- 1998/05/16 00:00
PHST- 1998/05/16 00:00 [pubmed]
PHST- 1998/05/16 00:01 [medline]
PHST- 1998/05/16 00:00 [entrez]
AID - 10.1038/sj.onc.1201711 [doi]
PST - ppublish
SO  - Oncogene. 1998 Apr 9;16(14):1825-38. doi: 10.1038/sj.onc.1201711.