Preferential binding of cisplatin to mitochondrial DNA of Chinese hamster ovary cells

• Published in: Mutation research. Mutation research letters Vol. 346; no. 4; pp. 221 - 230
• Main Authors: Olivero, Ofelia A., Semino, Cristina, Kassim, Ahmed, Lopez-Larraza, Daniel M., Poirier, Miriam C.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 1995; Elsevier
• Subjects: Biological and medical sciences; Cisplatin; DNA adduct; Drug toxicity and drugs side effects treatment; Electron microscopy; Medical sciences; Miscellaneous (drug allergy, mutagens, teratogens...); Mitochondrial DNA; Pharmacology. Drug treatments; PBS; HMG; mtDNA; BPDE 1; DNA adduct; Mitochondrial DNA; DELFIA; CHO; Electron microscopy; Cisplatin; cis-Pt(NH 3) 2d-(ApG); cis-Pt(NH 3) 2d-(GpG); ELISA; gDNA; Antineoplastic agent; Vertebrata; Cell line; Mammalia; Transmission electron microscopy; Rodentia; Cytotoxicity; Molecular interaction; Molecular adduct; Hamster; CHO cell line
• ISSN: 0165-7992
• DOI: 10.1016/0165-7992(95)90039-X

Some chemical carcinogens localize preferentially in mitochondrial DNA (mtDNA) when compared with genomic DNA (gDNA). Here we compare the ability of cisplatin ( cis-diamminedichloroplatimum[II]) to induce DNA adducts in both genomic and mtDNA of Chinese hamster ovary (CHO) cells in culture. Cytotoxicity was examined by cell survival 4, 8 and 24 h afer exposure to 50 μM cisplatin. Cisplatin-DNA adducts were measured in DNA from nuclear and mitochondrial fractions by dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA), a sensitive competitive microtiter-based immunoassay utilizing antiserum elicited against cisplatin-modified DNA. An additional comparison of cisplatin-DNA binding in both compartments was performed by immunoelectron microscopy using the cisplatin-DNA antiserum and colloidal gold. DELFIA analysis of cisplatin-DNA adducts in gDNA and mtDNA showed a six-fold higher incorporation of drug into mtDNA as compared to gDNA. Morphometric studies of colloidal gold distribution in photomicrographs of CHO cells showed mtDNA to contain a four-fold higher concentration of cisplatin as compared to nuclear DNA. Therefore, both methods demonstrated a preferential binding of cisplatin to mtDNA versus gDNA.