Vienna (FWF) – Platinum compounds are the most frequently used therapeutic drugs in modern cancer therapy. Some of them not only inhibit tumour growth but can also cure certain cancers, such as testicular cancer in young men of 25 to 35 years of age. Tumour inhibiting effects have also been detected for Ruthenium compounds, in particular in the case of intestinal tumours. Supported by the Austrian Science Fund (FWF), Bernhard Keppler from the Institute of Inorganic Chemistry at the University of Vienna has developed new types of such compounds, which are due to be clinically tested in the near future.

Testicular cancer is one of the most frequent tumour diseases in young men aged 25 to 35. This kind of cancer can be cured today - thanks to special Platinum compounds. Some new types of Platinum compounds which Bernhard Keppler has synthesised and haracterised for their tumour-inhibiting properties and mechanisms in the scope of an FWF project hold the promise of curing tumours or inhibiting tumour growth. He succeeded in binding these new compounds to specific carrier molecules, such as peptides or proteins. These molecules carry the active ingredient exactly to specific places in the organism, where the drug can develop a targeted effect. "By attaching our Platinum compounds to carrier molecules that deliver them directly to the bone surface, we can selectively treat bone tumours or metastases. The cytotoxic compound is activated only upon contact with the bone surface, which means that the compound is largely non-toxic during its passage through the body until it reaches the bone, where it finally develops its tumour-inhibiting effect", says Keppler.
The methodology for Ruthenium compounds is similar. The Ruthenium metal complexes are inserted into the iron transport protein of the blood instead of the "normal" iron. These proteins deliver iron to the places in the body, where it is needed. Intestinal tumours, for instance, require large quantities of iron. The transport protein delivers the Ruthenium to the tumour area, where it develops its cytotoxic activity. The transport protein, transferrin, acts like a Trojan Horse and
delivers Ruthenium to the tumour, which actually requires iron. "With these compounds we can target even large tumours and treat them successfully", explains Keppler. "Recent tests have shown that our Ruthenium compounds were much more effective than the clinically used therapeutic drugs, in particular in intestinal tumours. They will shortly be subjected to clinical trials to prove this effect." Keppler's working group also investigates Gallium compounds, which develop a synergistic effect with established tumour drugs. They interact with iron-containing cell-adherent enzymes, thus sensitising the cell to tumour therapy.

Contact
Univ. Prof. Dr. Dr. Bernhard Keppler
University of Vienna, Institute of Inorganic Chemistry
T + 43 1 4277 52602