Cancer as Rejuvenescence
Comparative analysis of malignant and senescent cells shows that their phenotypic features are in many instances contrary. Cancer cells do not age; their metabolic and growth characteristics are opposite to those observed with cellular aging (both replicative and functional). In many such characteristics, cancer cells resemble embryonic cells. One can say that cancer manifests itself as a local uncontrolled rejuvenation in an organism. Available evidence from human and animal studies suggests that the opposite phenotypic features of aging and cancer arise from the opposite regulation of common genes, such as those participating in apoptosis/growth arrest or in growth signal transduction pathways in the cell. For instance, in aging cells and organisms, proto-oncogenes are often downregulated, while tumor suppressors are permanently expressed. In cancer cells the situation is just the opposite
cancer aging apoptosis growth arrest signal transduction tumor suppressors oncogenes