Modulation of activity of known cytotoxic ruthenium(III) compound (KP418) with hampered transmembrane transport in electrochemotherapy in vitro and in vivo.

To increase electrochemotherapy (ECT) applicability, the effectiveness of new drugs is being tested in combination with electroporation. Among them two ruthenium(III) compounds, (imH)[trans-RuCl4(im)(DMSO-S)] (NAMI-A) and Na[trans-RuCl4(ind)2] (KP1339), proved to possess increased antitumor effectiveness when combined with electroporation. The objective of our experimental work was to determine influence of electroporation on the cytotoxic and antitumor effect of a ruthenium(III) compound with hampered transmembrane transport, (imH)[trans-RuCl4(im)2] (KP418) in vitro and in vivo and to determine changes in metastatic potential of cells after ECT with KP418 in vitro. In addition, platinum compound cisplatin (CDDP) and ruthenium(III) compound NAMI-A were included in the experiments as reference compounds. Our results show that electroporation leads to increased cellular accumulation and cytotoxicity of KP418 in murine melanoma cell lines with low and high metastatic potential, B16-F1 and B16-F10, but not in murine fibrosarcoma cell line SA-1 in vitro which is probably due to variable effectiveness of ECT in different cell lines and tumors. Electroporation does not potentiate the cytotoxicity of KP418 as prominently as the cytotoxicity of CDDP. We also showed that the metastatic potential of cells which survived ECT with KP418 or NAMI-A does not change in vitro: resistance to detachment, invasiveness, and re-adhesion of cells after ECT is not affected. Experiments in murine tumor models B16-F1 and SA-1 showed that ECT with KP418 does not have any antitumor effect while ECT with CDDP induces significant dose-dependent tumor growth delay in the two tumor models used in vivo.

Non-Clinical In Vitro Evaluation of Antibiotic Resistance Gene-Free Plasmids Encoding Human or Murine IL-12 Intended for First-in-Human Clinical Study.

Interleukin 12 (IL-12) is a key cytokine that mediates antitumor activity of immune cells. To fulfill its clinical potential, the development is focused on localized delivery systems, such as gene electrotransfer, which can provide localized delivery of IL-12 to the tumor microenvironment. Gene electrotransfer of the plasmid encoding human IL-12 is already in clinical trials in USA, demonstrating positive results in the treatment of melanoma patients. To comply with EU regulatory requirements for clinical application, which recommend the use of antibiotic resistance gene-free plasmids, we constructed and developed the production process for the clinical grade quality antibiotic resistance gene-free plasmid encoding human IL-12 (p21-hIL-12-ORT) and its ortholog encoding murine IL-12 (p21-mIL-12-ORT). To demonstrate the suitability of the p21-hIL-12-ORT or p21-mIL-12-ORT plasmid for the first-in-human clinical trial, the biological activity of the expressed transgene, its level of expression and plasmid copy number were determined in vitro in the human squamous cell carcinoma cell line FaDu and the murine colon carcinoma cell line CT26. The results of the non-clinical evaluation in vitro set the basis for further in vivo testing and evaluation of antitumor activity of therapeutic molecules in murine models as well as provide crucial data for further clinical trials of the constructed antibiotic resistance gene-free plasmid in humans.

Synthesis and Characterization of Novel Ruthenium(III) Complexes with Histamine.

Novel ruthenium(III) complexes with histamine [RuCl(4)(dmso-S)(histamineH)] . H( (2) )O (1a) and [RuCl(4)(dmso-S)(histamineH)] (1b) have been prepared and characterized by X-ray structure analysis. Their crystal structures are similar and show a protonated amino group on the side chain of the ligand which is not very common for a simple heterocyclic derivative such as histamine. Biological assays to test the cytotoxicity of the compound 1b combined with electroporation were performed to determine its potential for future medical applications in cancer treatment.

The development of a monolith-based purification process for Orthopoxvirus vaccinia virus Lister strain.

The purification of large viruses remains an important field of research and development. The development of efficient purification trains is restricted by limited analytical methods, as well as by the complexity of large viruses, as well as the high variability in starting material from cell culture. Vaccinia virus holds great potential as an oncolytic and immunotherapeutic vaccine against a broad spectrum of cancers. In this work, monolith-based capture and polishing chromatographic steps for vaccinia virus Lister strain has been developed. Virus produced in CV-1 cells was harvested and passed through a 0.8µm pre-filter before loading onto CIEX, AIEX and HIC CIM monoliths. Without the need for nuclease treatment, up to 99% of the total DNA loaded can be removed from the vaccinia feed stream by the CIM OH monolith, which also reduces the total protein concentration in the product pool to LLOQ levels, and achieves infectious virus recoveries of 90%. Binding capacities of greater than 1×109pfu of vaccinia per mL of matrix were obtained on both CIM SO3 and CIM OH monoliths. Multiple orthogonal analytical methods have been used to develop process knowledge and understanding.

The influence of electroporation on cytotoxicity of anticancer ruthenium(III) complex KP1339 in vitro and in vivo.

In our study, the ruthenium-based anticancer agent KP1339 was tested in combination with electroporation for its cytotoxic effect on CHO and SA-1 cell lines in vitro and on SA-1 murine tumour model in vivo. Cells were treated with different doses of KP1339 for 15 or 60 min with or without electroporation in vitro. Cell viability was measured with the MTS assay. In vivo, mice bearing SA-1 tumours were treated with different doses of KP1339 with or without electroporation. Tumour growth was measured at various time points after treatment. Intratumoural ruthenium content was analysed as a measure of KP1339 accumulation to correlate it with antitumour effectiveness. Our results show that electroporation does not potentiate the cytotoxicity of KP1339 in vitro, but significantly potentiates antitumour effectiveness in vivo. Electroporation enhanced ruthenium uptake immediately after treatment, consequently causing persistently higher intratumoural ruthenium content throughout the whole observation period (48 h). In addition, ruthenium content rose continuously in electroporated and intact tumours throughout the whole observation period. The observed antitumour effectiveness is the result of both the direct cytotoxicity of KP1339 and an antivascular effect of electroporation.