Background
Methods
Chemicals and starting materials
DNA preparation
DNA damage reactions
DNA unwinding assay
Preparation of HeLa cells and cytotoxicity assay
Data analysis
Results
Sequence specificity of the platinum-based compounds in the pUC19/T7 sequence
Interstrand cross-linking efficiency of the platinum-based compounds
Compounda | ICLE (%) | Drug concentration at 50% dsDNA retention (μM) | rb (drug: nucleotide) at 50% dsDNA retention | Last detected data point (μM) |
---|---|---|---|---|
Cisplatin | 6.8 ± 0.5 | 0.09 ± 0.01 | 1.9 × 10− 3 ± 1.4 × 10− 4 | 10 |
[Pt(RR-DACH)Cl2] | 5.6 ± 2.1 | 0.13 ± 0.05 | 2.7 × 10− 3 ± 9.9 × 10− 4 | 3 |
[Pt(RR-DACP)Cl2] | 3.1 ± 0.3 | 0.21 ± 0.02 | 4.1 × 10− 3 ± 3.9 × 10− 4 | 30 |
[Pt(SS-DACP)Cl2] | 5.1 ± 0.2 | 0.12 ± 0.01 | 2.5 × 10− 3 ± 1.1 × 10− 4 | 3 |
[Pt(4FH)Cl2] | 0.04 ± 0.02 | 23.52 ± 8.94 | 4.7 × 10− 1 ± 1.8 × 10− 1 | 300 |
DNA unwinding induced by the platinum-based compounds
Compound | DNA unwinding angle (°) | Drug concentration at coalescence point (μM)α | rb(c) (drug: nucleotide at coalescence point) |
---|---|---|---|
Cisplatin | 13 | 2.5 ± 0.0 | 1.0 × 10− 1 ± 2.0 × 10− 3 |
[Pt(RR-DACH)Cl2] | 15.5 ± 1.9 | 2.2 ± 0.3 | 8.7 × 10− 2 ± 1.1 × 10− 2 |
[Pt(RR-DACP)Cl2] | 16.9 ± 0.0 | 1.9 ± 0.0 | 7.8 × 10− 2 ± 2.0 × 10− 4 |
[Pt(SS-DACP)Cl2] | 13.8 ± 0.6 | 2.4 ± 0.1 | 9.5 × 10− 2 ± 4.0 × 10− 3 |
[Pt(4FH)Cl2] | 0.2 ± 0.0 | 184.5 ± 34.2 | 7.4 ± 1.4 |
Cytotoxic activity of the platinum-based compounds in HeLa cells
Compound | IC50 (μM)α | Drug concentration at which complete cell death was obtained (μM) |
---|---|---|
Cisplatin | 9.3 ± 0.2 | 30 |
[Pt(RR-DACH)Cl2] | 12.3 ± 4.0 | 100 |
[Pt(RR-DACP)Cl2] | 6.9 ± 1.0 | 50 |
[Pt(SS-DACP)Cl2] | 13.7 ± 2.0 | 50 |
[Pt(4FH)Cl2] | 28.8 ± 1.6 | > 200 |