Rapid SINE-mediated detection of cisplatin:DNA adduct formation in vitro and in vivo in blood

Cisplatin (cis-dichlorodiammine platinum II) is one of the most effective antitumor agents to date. Its usefulness is limited, however, by toxicity to healthy tissues, most notably, its nephrotoxicity. To maximize the chemotherapeutic potential of cisplatin and minimize its adverse effects, it is imperative to monitor formation of cisplatin:DNA adducts throughout treatment. We developed a novel, highly sensitive, SINE (Short Interspersed DNA Element)-mediated, PCR-based assay for detection of cisplatin adducts in vitro and in vivo, in DNA from mouse blood cells. The assay relies on the abundance, dispersion and conservation of SINEs in mammalian genomes. The B1 elements at a copy number of 50,000-80,000 are the most abundant SINEs in the mouse genome. Due to their strong sequence conservation, primers complementary to the B1 consensus sequence anneal to the majority of their targets in the genome and allow simultaneous amplification of long random segments of genomic DNA. Thus, in conjunction with the fact that cisplatin adducts block the progression of thermostable polymerase, B1 element-anchored PCR makes a sensitive tool for assessing the overall integrity of the transcribed regions in the mouse genome. The high sensitivity of the assay allows detection of DNA damage at the low cisplatin dosage of 1-8 mg/kg that is considered as sub-chemotherapeutic in experimental animal models. The sensitivity range therefore, makes this assay suitable for the development of predictive correlation for both, the efficacy of treatment as well as induction of nephrotoxicity. Copyright (C) 1999 Elsevier Science B.V.