Table of Contents
Metal-Based Drugs
Volume 3 (1996), Issue 1, Pages 15-23

Comparison of the Antiproliferative Activity of Two Antitumour Ruthenium(III) Complexes With Their Apotransferrin and Transferrin-Bound Forms in a Human Colon Cancer Cell Line

1Tumour Biology Center, Clinical Research, Breisacher Straβe 117, Freiburg D-79106, Germany
2Anorganisch-Chemisches Institut der Universität Heidelberg, Im Neuenheimer Feld 270, Heidelberg D-69120, Germany
3Laboratorio di Chimica Inorganica e Bioinorganica, Universita degli Studi di Firenze, Via G. Capponi 7, Firenze I-50121, Italy
4Institute of Toxicology and Chemotherapy, German Cancer Research Center, Im Neuenheimer Feld 280, Heidelberg D-69120, Germany

Received 6 November 1995; Accepted 24 November 1995

Copyright © 1996 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Two ruthenium(III) complexes, namely trans-indazolium[tetrachlorobis(indazole)- ruthenate(III)], HInd[RuInd2Cl4] and trans-imidazolium[tetrachlorobis(imidazole)- ruthenate(III)], HIm[RuIm2Cl4] exhibit high anticancer activity in an autochthonous colorectal carcinoma model in rats. Recently, it has been shown that both complexes bind specifically to human serum apotransferrin and the resulting adducts have been studied through spectroscopic and chromatographic techniques with the ultimate goal of preparing adducts with good selectivity for cancer cells due to the fact that tumour cells express high amounts of transferrin receptors on their cell surface.

In order to investigate whether the cellular uptake of the complexes was mediated by apotransferrin or transferrin, we compared the antiproliferative efficacy of HInd[RuInd2Cl4] and HIm[RuIm2Cl4] with its apotransferrin- and transferrin-bound form in the human colon cancer cell line SW707 using the microculture tetrazolium test (MTT).

Our results show that especially the transferrin-bound forms exhibit high antiproliferative activity, which exceeds that of the free complex, indicating that this protein can act as a carrier of the ruthenium complexes into the tumor cell.