PMID- 8921504
OWN - NLM
STAT- MEDLINE
DCOM- 19970225
LR  - 20190512
IS  - 0267-8357 (Print)
IS  - 0267-8357 (Linking)
VI  - 11
IP  - 5
DP  - 1996 Sep
TI  - Fragmentation of centromeric DNA and prevention of homologous chromosome 
      separation in male mouse meiosis in vivo by the topoisomerase II inhibitor 
      etoposide.
PG  - 435-43
AB  - The mechanism of action of the topoisomerase II inhibitor etoposide (VP-16) was 
      investigated in male mouse meiosis using the spermatid micronucleus (MN) test and 
      two molecular cytogenetic approaches: (i) fluorescence in situ hybridization 
      (FISH) with a mouse centromere specific minor satellite DNA probe; and (ii) 
      immunolabelling of kinetochore proteins with CREST autoimmune serum. VP-16 caused 
      significant increases in the frequencies of MN at all meiotic stages studied. 
      VP-16 induced MN showed significantly elevated frequencies of centromeric 
      hybridization signals compared to the controls. Similarly, after CREST 
      immunostaining the majority of MN induced by the drug showed kinetochore signals 
      when meiotic S phase and diplotene-diakinesis were treated. This would suggest 
      that most induced MN were due to lagging of whole chromosomes. However, more than 
      80% of the small MN observed were signal-positive and a large pool of minute MN 
      almost exclusively (92%) contained a kinetochore or centromere-DNA signal. This 
      indicates that VP-16 causes chromosome fragmentation at centromeres. In addition, 
      arrested first division (MI) anaphase figures with stretched bivalent(s) at the 
      spindle equator were observed when diplotene-diakinesis and MI were targeted. 
      Moreover, many small and medium size MN had two centromere or kinetochore signals 
      at opposite sides, suggesting that inhibition of topo II at MI causes lagging of 
      whole bivalents. Together, these results indicate that VP-16 acts by several 
      genotoxic mechanisms at male meiosis: (i) fragmentation of centromeres possibly 
      as a result of inhibition of the DNA strand religation reaction in a 
      topoisomerase II mediated decatenation process of sister centromeres; and (ii) 
      the induction of aneuploidy as a result of failures in separation of homologous 
      chromosome arms possibly due to disturbances of chiasma resolution and 
      decatenation processes during MI. Our results indirectly suggest that 
      topoisomerase II plays an important role in male meiosis and its activity is 
      needed at the metaphase-anaphase transition of both meiotic divisions for proper 
      chromosome disjunction.
FAU - Kallio, M
AU  - Kallio M
AD  - Department of Medical Genetics, University of Turku, Finland.
FAU - Lahdetie, J
AU  - Lahdetie J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Mutagenesis
JT  - Mutagenesis
JID - 8707812
RN  - 0 (DNA, Satellite)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Immune Sera)
RN  - 0 (Topoisomerase II Inhibitors)
RN  - 6PLQ3CP4P3 (Etoposide)
SB  - IM
MH  - Anaphase/drug effects
MH  - Aneuploidy
MH  - Animals
MH  - CREST Syndrome/immunology
MH  - Centromere/drug effects/*genetics
MH  - Chromosomes/*drug effects
MH  - DNA Damage/drug effects
MH  - DNA Fragmentation/drug effects
MH  - DNA, Satellite
MH  - Enzyme Inhibitors/pharmacology
MH  - Etoposide/*pharmacology
MH  - Fluorescent Antibody Technique, Indirect
MH  - Immune Sera
MH  - In Situ Hybridization, Fluorescence/methods
MH  - Kinetochores/drug effects/immunology
MH  - Male
MH  - Meiosis/*drug effects
MH  - Mice
MH  - Micronucleus Tests
MH  - Spermatids/drug effects
MH  - Time Factors
MH  - *Topoisomerase II Inhibitors
EDAT- 1996/09/01 00:00
MHDA- 1996/09/01 00:01
CRDT- 1996/09/01 00:00
PHST- 1996/09/01 00:00 [pubmed]
PHST- 1996/09/01 00:01 [medline]
PHST- 1996/09/01 00:00 [entrez]
AID - 10.1093/mutage/11.5.435 [doi]
PST - ppublish
SO  - Mutagenesis. 1996 Sep;11(5):435-43. doi: 10.1093/mutage/11.5.435.