Repair of mitomycin C cross-linked DNA in mammalian cells measured by a host cell reactivation assay.

Journal Article (Journal Article)

DNA repair capacity in a cell could be detected by a host-cell reactivation assay (HCR). Since relation between DNA repair and genetic susceptibility to cancer remains unclear, it is necessary to identify DNA repair defects in human cancer cells. To assess DNA repair for breast cancer susceptibility, we developed a modified HCR assay using a plasmid containing a firefly luciferase gene damaged by mitomycin C (MMC), which forms interstrand cross-link (ICL) adducts. In particular, interstrand cross-link is thought to induce strand breaks being repaired by homologous recombination. The MMC-ICLs were verified by electrophoresis. Damaged plasmids were transfected into apparently normal human lymphocytes and NER-deficient XP cell lines and the DNA repair capacity of the cells were measured by quantifying the activity of the firefly luciferase. MMC lesion was repaired as much as UV adducts in normal lymphocytes and the XPC cells. However, the XPA cells have a lower repair capacity for MMC lesion than the XPC cell, indicating that the XPA protein may be involved in initial damage recognition of MMC-ICL adducts. Since several repair pathways including NER and recombination participate in MMC-ICL removal, this host cell reactivation assay using MMC-ICLs can be used in exploring DNA repair defects in human cancer cells.

Full Text

Duke Authors

Cited Authors

  • Ahn, B; Kang, D; Kim, H; Wei, Q

Published Date

  • October 31, 2004

Published In

Volume / Issue

  • 18 / 2

Start / End Page

  • 249 - 255

PubMed ID

  • 15529003

International Standard Serial Number (ISSN)

  • 1016-8478


  • eng

Conference Location

  • Korea (South)