Increased expression of DNA-dependent protein kinase confers resistance to adriamycin

Biochim Biophys Acta. 1998 Jul 23;1381(2):131-8. doi: 10.1016/s0304-4165(98)00020-8.

Abstract

Acquired resistance to adriamycin (ADR) in an HL60 cell line is shown to be accompanied by an increase in DNA-dependent protein kinase catalytic subunit (DNA-PKcs) at both the protein and mRNA levels (15-20-fold) and an overall 3-fold increase in DNA-PK enzyme activity. The other components of the DNA-PK Ku autoantigen complex, Ku70 and Ku80, were 3-fold increased and unchanged, respectively. Time dependent repair of ADR-induced DNA damage was measured by the neutral comet assay and found to be more efficient in the drug resistant cell line (HL60/ADR). Antisense RNA transfection reduced the protein expression of DNA-PKcs to 50% in HL60/ADR and partially reversed drug resistance. A fibroblast cell line from a severe combined immunodeficient (SCID) mouse was deficient in functional DNA-PKcs and showed increased sensitivity to ADR and other DNA damaging agents compared to wild type. These studies demonstrate that alteration in DNA-PK can contribute to chronic stress response leading to acquired drug resistance. The overexpression of DNA-PK is thus shown to be a novel cellular adaptation mechanistically contributing to the resistance of cancer cells to the anthracycline drug adriamycin, and as such, may have implications for its therapeutic use.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptation, Physiological
  • Animals
  • Antibiotics, Antineoplastic / pharmacology*
  • Antigens, Nuclear*
  • Base Sequence
  • Cell Line
  • DNA Damage
  • DNA Helicases*
  • DNA Primers / genetics
  • DNA Repair
  • DNA-Activated Protein Kinase
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Doxorubicin / pharmacology*
  • Drug Resistance / genetics
  • Drug Resistance / physiology
  • Gene Expression
  • HL-60 Cells
  • Humans
  • Ku Autoantigen
  • Mice
  • Mice, SCID
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Polymerase Chain Reaction
  • Protein Conformation
  • Protein-Serine-Threonine Kinases / chemistry
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • RNA, Antisense / genetics
  • Transfection

Substances

  • Antibiotics, Antineoplastic
  • Antigens, Nuclear
  • DNA Primers
  • DNA-Binding Proteins
  • Nuclear Proteins
  • RNA, Antisense
  • Doxorubicin
  • DNA-Activated Protein Kinase
  • PRKDC protein, human
  • Protein-Serine-Threonine Kinases
  • DNA Helicases
  • XRCC5 protein, human
  • Xrcc6 protein, human
  • Xrcc6 protein, mouse
  • Ku Autoantigen