Opposite phenotypes of cancer and aging arise from alternative regulation of common signaling pathways.

Phenotypic features of malignant and senescent cells are in many instances opposite. Cancer cells do not "age"; their metabolic, proliferative, 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 genes participating in apoptosis/growth arrest or growth signal transduction pathways in cells. This fact may be applicable in the development of new anti-aging treatments. Genes that are contrarily regulated in cancer and aging cells (e.g., proto-oncogenes or tumor suppressors) could be candidate targets for anti-aging interventions. Their "cancer-like" regulation, if strictly controlled, might help to rejuvenate the human organism.