A nuclear protein complex containing high mobility group proteins B1 and B2, heat shock cognate protein 70, ERp60, and glyceraldehyde-3-phosphate dehydrogenase is involved in the cytotoxic response to DNA modified by incorporation of anticancer nucleoside analogues

Eugene Y. Krynetski, Natalia F. Krynetskaia, Marco E. Bianchi, William E. Evans

Research output: Contribution to journalArticle


Thiopurine treatment of human leukemia cells deficient in components of the mismatch repair system (Nalm6) initiated apoptosis after incorporation into DNA, as revealed by caspase activation and terminal deoxynucleotidyl transferase-mediated nick end100-106 labeling assay. To elucidate the cellular sensor(s) responsible for recognition of DNA damage in cells with an inactive mismatch repair system, we isolated a multiprotein nuclear complex that preferentially binds DNA with thioguanine incorporated. The components of this nuclear multiprotein complex, as identified by protein mass spectroscopy, included high mobility group proteins 1 and 2 (HMGB1, HMGB2), heat shock protein HSC70, protein disulfide isomerase ERp60, and glyceraldehyde 3-phosphate dehydrogenase. The same complex was also shown to bind synthetic oligodeoxyribonucleotide duplexes containing the nonnatural nucleosides 1-β-D-arabinofuranosylcytosine or 5-fluoro-2′-deoxyuridine. Fibroblast cell line derived from Hmgb1-/- murine embryos had decreased sensitivity to thiopurines, with an IC50 10-fold greater than Hmgb1-proficient cells (P <0.0001) and exhibited comparable sensitivity to vincristine, a cytotoxic drug that is not incorporated into DNA. These findings indicate that the HMGB1-HMGB2-HSC70-ERp60-glyceraldehyde 3-phosphate dehydrogenase complex detects changes in DNA structure caused by incorporation of non-natural nucleosides and is a determinant of cell sensitivity to such DNA modifying chemotherapy.

Original languageEnglish
Pages (from-to)100-106
Number of pages7
JournalCancer Research
Issue number1
Publication statusPublished - Jan 1 2003


ASJC Scopus subject areas

  • Cancer Research
  • Oncology

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