![In vitro and in vivo evaluation of electrochemotherapy with trans-platinum analogue trans-[PtCl2(3-Hmpy)2] Cover](https://paradigm-files.s3.eu-central-1.amazonaws.com/RAON/cover-image.jpg)
Figure 1
Survival of SA-1 sarcoma (A), TBLCI2 sarcoma (B) and TBLCI2Pt sarcoma cells (C) after treatment with cisplatin (CDDP) or compound 2 or cisplatin electrochemotherapy (ECT CDDP) or compound 2 electrochemotherapy (ECT Compound 2), determined using a clonogenic assay. Data are presented as the arithmetic mean and standard error of the mean (AM±SE) of triplicates pooled from three independent experiments. The survival of cells treated with electrochemotherapy was normalized to the survival of cells treated with electric pulses alone. The survival of SA-1, TBLCl2 and TBLCl2Pt cells treated with electric pulses alone was 0.96 ± 0.05, 0.93 ± 0.09 and 0.92 ± 0.10, respectively.
Table 1
IC50 values after electrochemotherapy with cisplatin or compound 2 in various mouse tumour cell lines
| SA-1 | TBLCI2 | TBLCI2Pt | ||||
|---|---|---|---|---|---|---|
| Group | IC50 (μM) | EF | IC50 (μM) | EF | IC50 (μM) | EF |
| CDDP | 276.7‡ | 180.0‡ | 926.6‡ | |||
| Compound 2 | 500.0* | 220.0* | 1066.6* | |||
| ECT CDDP | 28.3♦ | 9.8 | 8.0♦ | 22.5 | 12.0♦ | 77.2 |
| ECT Compound 2 | 80.0 | 6.3 | 41.0 | 5.4 | 206.7 | 5.2 |
IC50 = dose of drug which reduced cell survival to 50%; EF = enhancement factor for electroporation of cells, calculated on the bases of IC50 of electroporated and non-electroporated cells;
‡ p (< 0.05) statistically significant difference compared to treatment with cisplatin electrochemotherapy (ECT CDDP);
‡ p (< 0.05) statistically significant difference compared to treatment with cisplatin electrochemotherapy (ECT CDDP);
‡ p (< 0.05) statistically significant difference compared to treatment with cisplatin electrochemotherapy (ECT CDDP);
* p (< 0.05) significant difference compared to treatment with compound 2 electrochemotherapy (ECT Compound 2)
* p (< 0.05) significant difference compared to treatment with compound 2 electrochemotherapy (ECT Compound 2)
Figure 2
Tumour growth and animal body weight change after cisplatin or compound 2 electrochemotherapy in mouse sarcoma tumours; SA-1, TBLCl2 and TBLCl2Pt. Mice (6-12 per group) were treated with intratumoural injection of cisplatin (CDDP, 13.3 mmol/kg) or compound 2 (13.3 mmol/kg) or with local application of electric pulses at 1 minute after drug injection (ECT CDDP; ECT Compound 2; 8 pulses, 1300 V/cm, 100 μs, 1 Hz). Data are presented as the arithmetic mean and standard error of the mean (AM±SE) of tumour volumes.*p (< 0.05) significant difference compared to treatment with cisplatin electrochemotherapy
Table 2
Antitumour effectiveness of electrochemotherapy with cisplatin or compound 2 in mouse sarcoma tumours; SA-1, TBLCl2 and TBLCl2Pt
| SA-1 | TBLCl2 | TBLCI2Pt | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Group | n | DT (days) (AM±SE) | GD (days) | CR (n, %) | n | DT (days) (AM±SE) | GD (days) | CR (n, %) | n | DT (days) (AM±SE) | GD (days) | CR (n, %) |
| Control | 10 | 1.7±0.2 | 0 | 8 | 2.8±0.3 | 0 | 6 | 3.1±0.2 | 0 | |||
| EP | 10 | 3.1 ±0.3 | 1.4 | 0 | 8 | 5.1±1.0 | 2.3 | 0 | 6 | 4.2±0.9 | 1.1 | 0 |
| CDDP | 10 | 5.2±1.0‡ | 3.5 | 0 | 8 | 5.3±0.7‡ | 2.5 | 0 | 6 | 3.4±0.5‡ | 0.3 | 0 |
| Compound 2 | 12 | 2.3±0.3* | 0.6 | 0 | 9 | 3.5±0.5* | 0.7 | 0 | 6 | 3.2±0.3* | 0.1 | 0 |
| ECT CDDP | 12 | 15.8±2.2* | 14.1 | 0 | 9 | 11.6±1.0 | 8.8 | 6, 66.6 | 6 | 7.6±0.9* | 4.5 | 0 |
| ECT Compound 2 | 12 | 5.1±0.4 | 3.4 | 0 | 9 | 9.4±1.8 | 6.6 | 1, 11.1 | 6 | 5.1±0.6 | 2.0 | 0 |
EP = application of electric pulses; CDDP = cisplatin, intratumoural injection at a dose of 13.3 mmol/kg; Compound 2-intratumoural injection at a dose 13.3 mmol/kg; ECT = electrochemotherapy, application of EP at 1 minute after intratumoural injection of CDDP or compound 2; DT = tumour doubling time; GD = tumour growth delay; CR = complete response; AM = mean; SE = standard error of the mean;
Figure 3
Platinum amount in sarcoma SA-1 tumours (A), platinum amount in the serum (B) and platinum amount bound to DNA in the cells isolated from SA-1 tumours (C). Animals (8 per group) were treated with intratumoural injection of cisplatin (CDDP, 13.3 mM) alone or compound 2 (13.3 mM) alone or with local application of electric pulses 1 minute after intratumoural drug injection (ECT CDDP; ECT Compound 2; 8 pulses, 1300 V/cm, 100 μs, 1 Hz). The data are presented as the arithmetic mean and standard error of the mean (AM±SE) obtained from 8 samples. *p (< 0.05) under (A) and (C) statistically significant difference compared to corresponding drug treatment only; *p (< 0.05) under (B) statistically significant difference compared to cisplatin or cisplatin electrochemotherapy.