In vitro biochemical and pharmacological evaluation of a novel cytotoxic dinuclear platinum(II) complex with 3-amino-5-methyl-5-phenylhydantoin.
An in vitro pharmacological evaluation of a novel dinuclear platinum complex ([KL(2)](2)[Pt(2)I(6)], where L is 3-amino-5-methyl-5-phenylhydantoin; Ad-1) was carried out. The cytotoxicity of [KL(2)](2)[Pt(2)I(6)] against human tumor cell lines was assessed using the MTT [-3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide] assay. The complex exerted concentration-dependent cytotoxic effects that were comparable or even superior to that of cisplatin. Moreover, the novel complex retained significant activity against CaCo-2 and Neuro-2A cells, which showed primary resistance to cisplatin. As evidenced by the rising level of genomic DNA fragmentation following treatment with [KL(2)](2)[Pt(2)I(6)], the cytotoxic effects are at least partly mediated by induction of apoptosis. The DNA binding of [KL(2)](2)[Pt(2)I(6)] and cisplatin were assessed using a 40-base fragment, whereby the present GG-motif is the recognition sequence of the nuclease BamH1. The DNA platination was determined after BamH1 treatment, 5% PAGE, and ethidium bromide staining. Cisplatin completely inhibited the BamH1-mediated fragmentation of the target DNA molecule. [KL(2)](2)[Pt(2)I(6)] also significantly inhibited the fragmentation of the target DNA sequence. The platination induced by [KL(2)](2)[Pt(2)I(6)] was better repaired by the nucleotide excision repair than the cisplatin lesions. As evidenced by electrophoresis mobility shift assay, the Ad-1-modified DNA was efficiently recognized and bound by the high mobility group box (HMGB)-1 protein, a member of the HMG domain proteins, which implies that the latter are most probably important for the cytotoxicity mode of action of this agent.
Momekov
Georgi Ts
GTs
Department of Pharmacology, Pharmacotherapy and Toxicology, Medical University-Sofia, Sofia, Bulgaria.
Ugrinova
Iva
I
Pasheva
Evdokia A
EA
Bakalova
Adriana G
AG
Varbanov
Hristo Pl
HP
Ferdinandov
Dilyan V
DV
Ivanov
Darvin Sl
DS
Konstantinov
Spiro M
SM
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D018938:Caco-2 Cells; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D053938:DNA Fragmentation / Q000187:drug effects; D004260:DNA Repair; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D024202:Electrophoretic Mobility Shift Assay; D018922:HL-60 Cells; D024243:HMGB1 Protein / Q000378:metabolism; D006801:Humans; D006827:Hydantoins / Q000737:chemistry / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D020014:K562 Cells; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000737:chemistry / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects
C543701:3-amino-5-methyl-5-phenylhydantoin; D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; D024243:HMGB1 Protein; D006827:Hydantoins; D009944:Organoplatinum Compounds; D002945:Cisplatin