1. Department of Oncological and Experimental Pathology, Masaryk Memorial Cancer Institute, Zluty kopec 7, 65653 Brno, Czech Republic, Department of Biochemistry, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic, and Biomedical Research Foundation, Academy of Athens, 4 Soranou Ephessiou, 115 27 Athens, Greece