Journal Mobile Options
Table of Contents
Vol. 104, No. 1-4, 2004
Issue release date: 2004
Cytogenet Genome Res 104:289–294 (2004)

Region-specific chromatin decondensation and micronucleus formation induced by 5-azacytidine in human TIG-7 cells

Satoh T. · Yamamoto K. · Miura K.F. · Sofuni T.
aGenome Medical Business Division, Olympus Corporation, Hachioji; bDepartment of Cell Biology, Tokyo Metropolitan Institute of Gerontology, Itabashi; cNovusGene Inc., Hachioji (Japan)

Individual Users: Register with Karger Login Information

Please create your User ID & Password

Contact Information

I have read the Karger Terms and Conditions and agree.

To view the fulltext, please log in

To view the pdf, please log in


A human diploid lung fibroblast cell strain, TIG-7, has a heteromorphic chromosome 15 with an extra short arm carrying a homogeneously staining region (15p+hsr). We demonstrated previously that the 15p+hsr consists of an inactive and G+C-rich rDNA cluster characterized by fluorescence in situ hybridization (FISH) and various chromosome banding techniques. Thus, it was suggested that the region could contain highly methylated DNA. To observe methylation status on the target region directly under the microscope, we used a demethylating agent, 5-azacytidine (5-azaC), to induce decondensation of the chromatin containing methylated DNA. At 24 h after treatment with 0.5 µM 5-azaC, marked decondensation of the 15p+hsr was observed in almost all of the metaphases. Furthermore, we observed micronuclei, which were equivalent to the rDNA of the 15p+hsr demonstrated by FISH in the same preparation. In contrast, the DNA cross-linking agent mitomycin C (MMC) preferentially induced 15p+hsr-negative micronuclei. These findings indicated that chromatin decondensation and subsequent DNA strand breakage induced by the demethylating effect of 5-azaC led specifically to 15p+hsr-positive micronuclei.   

Copyright / Drug Dosage

Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.


  1. Babu A, Macera MJ, Verma RS: Intensity heteromorphisms of human chromosome 15p by DA/DAPI technique. Hum Genet 73: 298–300 (1986).
  2. Belyaev ND, Houben A, Baranczewski P, Schubert I: The acetylation patterns of histone H3 and H4 along Vicia fava chromosomes are different. Chromosome Res 6:59–63 (1998).
  3. Cimini D, Tanzarella C, Degrassi F: Effects of 5-azacytidine on the centromeric region of human fibroblasts studied by CREST staining and in situ hybridization on cytokinesis-blocked cells. Cytogenet Cell Genet 72:219–224 (1996).
  4. Fauth E, Scherthan H, Zankl H: Frequencies of occurrence of all human chromosomes in micronuclei from normal and 5-azacytidine-treated lymphocytes as revealed by chromosome painting. Mutagenesis 13:235–241 (1998).
  5. Fernandez JL, Goyanes V, Lopez-Fernandez C, Gosalvez J: Human alpha-satellite DNAs are not susceptible to undercondensation after 5-azacytidine treatment. Cytogenet Cell Genet 65:92–94 (1994).
  6. Ferraro M, Lavia P: Differential gene activity visualized on sister chromatids after replication in the presence of 5-azacytidine. Chromosoma 91:307–312 (1985).
  7. Friedrich U, Caprani M, Niebuhr E, Therkelsen AJ, Jorgensen AL: Extreme variant of the short arm of chromosome 15. Hum Genet 97:710–713 (1996).
  8. Giancotti P, Grappelli C, Poggesi I, Abatecola M, de Capoa A, Cozzi R, Perticone P: Persistence of increased levels of ribosomal gene activity in CHO-K1 cells treated in vitro with demethylating agents. Mutat Res 348:187–192 (1995).
  9. Glyn MCP, Egertova M, Gazdova B, Kovarik A, Bezdek M, Leitch AR: The influence of 5-azacytidine on the condensation of the short arm of rye chromosome 1R in Triticum aestivum L. root tip meristematic nuclei. Chromosoma 106:485–492 (1997).
  10. Guttenbach M, Schmid M: Exclusion of specific human chromosomes into micronuclei by 5-azacytidine treatment of lymphocyte culture. Exp Cell Res 211:127–132 (1994).
  11. Haaf T, Schmid M: Experimental condensation inhibition in constitutive and facultative heterochromatin of mammalian chromosomes. Cytogenet Cell Genet 91:113–123 (2000).
  12. Haaf T, Feichtinger W, Guttenbach M, Sanchez L, Muller CR, Schmid M: Berenil-induced undercondensation in human heterochromatin. Cytogenet Cell Genet 50:27–33 (1989).
  13. Holden JJ, Hough MR, Reimer DL, White BN: Evidence for unequal crossing-over as the mechanism for amplification of some homogeneously staining regions. Cancer Genet Cytogenet 29:139–149 (1987).
  14. Kokalj-Vokac N, Almeida A, Viegas-Pequignot E, Jeanpierre M, Malfoy B, Dutrillaux B: Specific induction of uncoiling and recombination by azacytidine in classical satellite-containing constitutive heterochromatin. Cytogenet Cell Genet 63:11–15 (1993).
  15. Malheiro I, Porto B, Mello-Sampayo T, Goyanes V: Specific induction of uncoiling in NORs of human acrocentric chromosomes by 5-azacytidine and 5-azadeoxicytidine. Cytobios 83:17–23 (1995).
  16. Marcus M, Goitein R, Gropp A: Condensation of all human chromosomes in G2 phase and early mitosis can be drastically inhibited by 33258-Hoechst treatment. Hum Genet 51:99–105 (1979).
  17. Matsushima T, Hayashi M, Matsuoka A, Ishidate M Jr, Miura KF, Shimizu H, Suzuki Y, Morimoto K, Oqura H, Mure K, Koshi K, Sofuni T: Validation study of the in vitro micronucleus test in a Chinese hamster lung cell line (CHL/IU). Mutagenesis 14:569–580 (1999).
  18. Ott G, Haaf T, Schmid M: Inhibition of condensation in human chromosomes induced by the thymidine analogue 5-iododeoxyuridine. Chromosome Res 6:495–499 (1998).
  19. Rocchi A, di Castro M, Prantera G: Effects of DAPI on human leukocytes in vivo. Cytogenet Cell Genet 23:250–254 (1979).
  20. Satoh T, Obara Y: Nonrandom distribution of sister chromatid exchanges in the chromosomes of three mammalian species. Zool Sci 12:749–756 (1995).
  21. Satoh T, Yamamoto K, Miura KF, Ishidate M Jr: Cytogenetic analysis of heteromorphic short arm of 15p+ in a human diploid cell strain, TIG-7. Chromosome Sci 2:57–62 (1998).
  22. Schmid M, Haaf T, Grunert D: 5-Azacytidine-induced undercondensations in human chromosomes. Hum Genet 67:257–263 (1984a).
  23. Schmid M, Hungerford DA, Poppen A, Engel W: The effects of distamycin A in human lymphocyte cultures. Hum Genet 65:377–384 (1984b).
  24. Sofuni T, Tanabe K, Awa AA: Chromosome heteromorphisms in the Japanese. Nucleolus organizer regions of variant chromosomes in D and G groups. Hum Genet 55:265–270 (1980).
  25. Tommerup N: Idoxuridine induction of micronuclei containing the long or short arm of human chromosome 9. Cytogenet Cell Genet 38:92–98 (1984).
  26. Velazquez M, Visedo G, Ludena P, de Cabo SF, Sentis C, Fernandez-Piqueras J: Cytogenetic analysis of a human familial 15p+ marker chromosome. Genome 34:827–829 (1991).
  27. Yamamoto K, Kaji K, Kondo H, Matuo M, Shibata Y, Tasaki Y, Utakoji T, Ooka H: A new human male diploid cell strain, TIG-7: Its age-related changes and comparison with a matched female TIG-1 cell strain. Exp Gelontol 26:525–540 (1991).
  28. Zakharov AF, Baranovskaya LI, Ibraimov AI, Benjusch VA, Demintseva VS, Oblapenko NG: Differential spiralization along mammalian mitotic chromosomes. 5-Bromodeoxyuridine and 5-bromodeoxycytidine-revealed differentiation in human chromosomes. Chromosoma 44:343–359 (1974).

Pay-per-View Options
Direct payment This item at the regular price: USD 38.00
Payment from account With a Karger Pay-per-View account (down payment USD 150) you profit from a special rate for this and other single items.
This item at the discounted price: USD 26.50