Molecular interactions of cancer and age

Endogenous and exogenous factors and intrinsic chemical instability of biological systems continuously challenge DNA integrity To ensure genetic stability, cellular systems have acquired an intricate network of complementary DNA repair systems. DNA damage and defects in repair and transcription result in cancer and aging. Accumulation of somatic mitochondrial DNA (mtDNA) mutations is a major causal factor in the aging process. The role of mtDNA in cancer seems to be secondary. The aging process-the loss of youthful resilience-likely is caused by the decline of numerous hormones and growth factors. By restoring these hormones and growth factor levels, the decay associated with old age may be eliminated and, in some cases, perhaps reversed.