Hypersensitivity to DNA cross-linking agents associated with up-regulation of glucose-regulated stress protein GRP78

Cancer Res. 1997 Nov 15;57(22):5112-6.

Abstract

We have shown previously that NAD/poly(ADP-ribose) polymerase-deficient cells that overexpress Mr 78,000 glucose-regulated stress protein (GRP78) are resistant to topoisomerase II inhibitors, such as etoposide, m-amsacrine, and doxorubicin. However, these cells have been found to be hypersensitive to DNA cross-linking agents, including melphalan, cisplatin, and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). These observations prompted us to examine whether overexpression of GRP78 is associated with modulation of cytotoxicity of clinically useful DNA-cross-linking agents such as melphalan, BCNU, and cisplatin. We up-regulated GRP78 in V79 Chinese hamster cells by 2-5-fold using two independent approaches that include exposure to 6-aminonicotinamide, or 2-deoxyglucose. Subsequently, these GRP78-overexpressing cells were trypsinized, plated in regular medium without GRP78-inducing agents, and allowed a 5-h attachment time before being treated with melphalan, BCNU, or cisplatin for 1 h to determine clonogenic survivals. In addition, repair of DNA cross-links induced by those agents were determined by alkaline elution assay. Our results show that the GRP78-overexpressing V79 cells are hypersensitive to DNA cross-linking agents compared to the control V79 cells. Furthermore, repair of drug-induced DNA cross-links appears to be considerably slower in these cells relative to that found in control V79 cells. Thus, our results suggest that (a) up-regulation of GRP78 is associated with an impairment of DNA cross-link repair, (b) up-regulation of GRP78 is associated with potentiation of cytotoxicity induced by alkylating and platinating agents, and (c) up-regulation of GRP78 can be considered as a potentially useful tool to modulate the cytotoxicity of clinically useful alkylating and platinating agents.

Publication types

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

MeSH terms

  • 6-Aminonicotinamide / pharmacology
  • Animals
  • Antimetabolites / pharmacology
  • Antineoplastic Agents, Alkylating / pharmacology*
  • Carmustine / pharmacology
  • Carrier Proteins / metabolism*
  • Cell Line / drug effects
  • Cisplatin / pharmacology
  • Cricetinae
  • DNA Repair*
  • DNA, Neoplasm / drug effects*
  • Deoxyglucose / pharmacology
  • Endoplasmic Reticulum Chaperone BiP
  • Heat-Shock Proteins / metabolism*
  • Melphalan / pharmacology
  • Molecular Chaperones / metabolism*
  • Teratogens / pharmacology
  • Up-Regulation*

Substances

  • Antimetabolites
  • Antineoplastic Agents, Alkylating
  • Carrier Proteins
  • DNA, Neoplasm
  • Endoplasmic Reticulum Chaperone BiP
  • Heat-Shock Proteins
  • Molecular Chaperones
  • Teratogens
  • 6-Aminonicotinamide
  • Deoxyglucose
  • Cisplatin
  • Melphalan
  • Carmustine