Deficient gene specific repair of cisplatin-induced lesions in Xeroderma pigmentosum and Fanconi's anemia cell lines

Abstract

Cisplatin is a chemotherapeutic agent known to cause DNA damage. The cytotoxicity of this drug is believed to result from the formation of DNA intrastrand adducts (IA) and DNA interstrand crosslinks (ICL). While there are many studies on DNA repair of cisplatin damage at the overall level of the genome in various human cell lines, there is little information on the gene-specific repair. In this report, we have measured the formation and repair of cisplatin induced DNA adducts in the dihydrofolate reductase (DHFR) and ribosomal RNA (rRNA) genes in three cell lines: normal human fibroblasts, Fanconi's anemia complementation group A (FAA) and Xeroderma pigmentosum complementation group A (XPA). It is generally thought that XPA cells lack nucleotide excision repair and that FAA cells are deficient in the repair of DNA ICL. We find that normal human fibroblast cells repair 84% of the ICL in the DHFR gene after 24 h, whereas XPA and FAA cell lines only repaired 32 and 50% of the ICL respectively. Furthermore, 69% of the cisplatin IA in the DHFR gene were repaired in 24 h in normal human fibroblasts compared to 22% for XPA and 24% for FAA cells. The repair of the rRNA gene was less efficient than in the DHFR gene, but the relative pattern between the different cell lines was similar to that of the DHFR gene. We thus find that FAA cells are deficient not only in the gene specific repair of cisplatin ICL, but also in the gene specific repair of the more common cisplatin IA. XPA cells are normally thought to be without any nucleotide excision repair capacity, but our data could support a slight ICL unhooking activity.

Nonerythroid αII spectrin is required for recruitment of FANCA and XPF to nuclear foci induced by DNA interstrand cross-links

“…FA is characterized by progressive bone marrow failure, a marked predisposition to development of cancer, particularly acute myeloid leukemia, spontaneous chromosome instability and hypersensitivity to DNA interstrand crosslinking agents (Glanz and Fraser, 1982;Auerbach, 1995;Auerbach et al, 1998). Correlated with sensitivity to these agents is a defect in ability to repair DNA interstrand crosslinks (Papadopoulo et al, 1987;Averbeck et al, 1988;Lambert et al, 1992;Zhen et al, 1993;Lambert et al, 1997;Lambert and Lambert, 1999). There are eight complementation groups of FA and, although the genes responsible for six of the…”

Fate of RNA Polymerase II Stalled at a Cisplatin Lesion

“…Studies presented here focus on another type of lesion repaired by NER/TCR: cisplatin cross-links (16,17). Cisplatin derivatives are frequently used in chemotherapy and produce different kinds of adducts including: 1,2-and 1,3-intrastrand cross-links between adjacent purines, interstrand adducts, and monoadducts (18).…”

Behavior of T7 RNA Polymerase and Mammalian RNA Polymerase II at Site-specific Cisplatin Adducts in the Template DNA

“…cis-Diamminedichloroplatinum (II) (cisplatin) preferentially reacts with purine bases in the DNA in vitro and in vivo to form the cis-[Pt-(NH 3 ) 2 {d(GpG)-N7(1),N7(2)}] (cis 1,2-d(GG)), with a frequency of 65%, the cis-[Pt-(NH 3 ) 2 {d(ApG)-N7(1),N7(2)}], with a frequency of 25%, the cis-[Pt-(NH 3 ) 2 {d(GpTpG)-N7-(1),N7(3)}] (cis 1,3-d(GTG)) with a frequency of 5-10%, and a small percentage of interstrand cross-links and monofunctional adducts (21). Cisplatin-induced adducts are repaired by global genomic nucleotide excision repair and by TCR (22)(23)(24). These adducts may impose a more serious problem for an elongating RNA polymerase compared with a CPD, because they cause substantial unwinding and bending of the DNA helix (reviewed in Ref.…”