Molecular mechanisms of cancer cells survival.

It is of great interest for cancer therapy to elucidate and overcome the mechanisms that cancer cells develop to fight back the defense systems of the organism and anticancer treatments. The anticancer defense of the organism consists of four processes: 1. Activity of the cellular immunity; 2. Production of cytokines; 3. Activation of tumor-suppressor genes; 4. Blocking of the enzyme telomerase. Several molecular mechanisms that cancer cells develop for survival are described: 1. Reactivation of the telomerase; 2. Suppression of apoptosis; 3. Elimination of effector cells; 4. Shedding of soluble receptors; 5. Neutralization of tumor-suppressor genes; 6. Developing of a drug efflux pump; 7. Neoangiogenesis; 8. Overcoming and utilizing hypoxia; 9. Other rescue mutations; 10 Access- restriction factors.Some new approaches for overcoming the survival mechanisms of cancer cells are briefly outlined.