[The role of alternative lengthening of telomeres mechanisms in carcinogenesis and prospects for using an anti-telomerase drugs in malignant tumors treatment].

The review analyzes telomere lengthening mechanisms in cancer cells of two different tumor types--carcinomas and sarcomas. Basic attention is given to sarcomas which cells lengthen their telomeres through alternative mechanisms for lengthening telomeres (ALT). The features of ALT mechanisms functioning in these cells have been examined in detail. Moreover, the actually existing anti-telomerase drugs and their efficiency in carcinomas treatment were analyzed. The experimental data showing that, contrary to theoretical expectations, activation of ALT was not observed on a background of such anti-telomerase, are presented. This portends a good prognosis in the treatment of the patients with carcinoma. Finally, on the basis of the data analyzed the candidates for a role of targets are proposed for development of anti-ALT antineoplastic therapy. Expected efficiency and toxicity of such drugs are considered in detail.