R. Panchuk, S. Prylutska, N. Skorokhyd, L. Lehka, L. Skivka, V. Hurmach, M. Evstigneev, J. Piosik, W. Berger, Yu. Prylutskyy, P. Scharff, R. Stoika, S. Vari
Institute of Cell Biology NAS of Ukraine,
Keywords: С60 fullerene, anticancer drugs, drug delivery, tumor drug resistance, apoptosis, in vivo, ROS
Summary:Rapid development of multi-drug resistance of tumor cells to chemotherapy caused by the over-expression of specific ABC-transporter proteins and/or multiple defects in genes involved in cell cycle and apoptosis regulation in cancer cells frequently leads to inefficient anticancer chemotherapy. To overcome this serious problem, novel drugs as well as nanocarriers for their addressed delivery are developed. Here, we applied pristine C60 fullerene nanoparticles as a platform for delivery of well-known anticancer drugs such as doxorubicin (Dox) and cisplatin (Cis), as well as a novel angucycline antibiotic landomycin A (LA) that was shown by us (1) as an agent that was capable of circumventing drug resistance in various human tumor cells. The main goal of this study was to investigate the molecular mechanisms of modulation of antitumor activity of these anticancer drugs by their delivery with C60 fullerene nanocarrier both in vitro and in vivo. Perspectives of application of C60 fullerene as an effective drug delivery platform that possesses nano-size (160 nm), good bio-compatibility and a unique innate property of affecting the reactive oxygen species (ROS). It has been shown that C60 fullerene complexes of with Dx, Cis and LA demonstrate up to 2 fold higher cytotoxic activity, compared to these drugs in free form, towards various tumor cell lines in vitro, including cells that are characterized by the overexpression of P-glycoprotein and MRP-1 (2,3). Circumventing of drug resistance by C60-containing nanocarriers is accompanied by more potent induction of apoptosis in target cells, as shown by the Annexin V/PI assay in flow cytometry experiments. This capability of C60+drug complexes to overcome drug resistance of tumor cells was also confirmed by the molecular docking studies demonstrating that C60 fullerene can generate a significant amount of Van-der Waals interactions within each potential binding site of P-glycoprotein and MRР-1. This suggests a possibility of formation of stable complexes between C60 fullerene, P-gp and MRP-1, and consequently, the inhibition of ABC-transporters by C60 fullerene. In vivo studies of these nanocarriers loaded with the anticancer drugs have shown the similar effects. Treatment of Lewis lung carcinoma-bearing male mice of C57Bl/6J line with the C60+Cis and C60+Dox complex led to 2-fold enhancement of the inhibition of tumor growth, compared to the action of free forms of Cis, Dx and C60 fullerene platform. In addition, a diminished mutagenic activity of C60+Cis mixture was observed, and it may suggest a reduction of probability of formation of secondary neoplasms induced by the mutagenicity of cisplatin by itself. In conclusion, our data demonstrated high potentials of C60 fullerene complexes with Cis/Dx/LA in tumor treatment as a promising approach in development of new chemotherapies, especially focused at drug resistant cancers.