Exploitation of the tumor microenvironment for creation of selective antitumor drugs

The generalized data about the peculiarities of tumor microenvironment are presented. They distinctly indicate that tumor microphysiology is character ized by regions of slow blood flow, hypoxia, low extracellular pH. These fa ctors can markedly influence the biological features and the therapeutic re sponse of tumors to anticancer means. Some efforts to create the selective antitumor drugs exploiting the tumor microenvironment, in particular hypoxi a and acidification, are discussed. Own original approach to elaborate the hypoxia-selective cytotoxins on the basis of "inorganic" cobalt (III) compl exes are presented. Preliminary in vivo testing have shown that these compl exes display significant antitumor and modifying activities. The possible m echanisms of biological effects of these complexes on the tumor are discuss ed.