Self-sufficiency in growth signals: cancer cells acquire an autonomous drive to proliferate—pathological mitosis—by virtue of the activation of oncogenes such as ras or myc. 2. Insensitivity to growth-inhibitory (antigrowth) signals: cancer cells inactivate tumor suppressor genes, such as retinoblastoma (Rb), that normally inhibit growth 3. Evasion of programmed cell death (apoptosis): cancer cells suppress and inactivate genes and pathways that normally enable cells to die. 4. Limitless replicative potential: cancer cells activate specific gene pathways that render them immortal even after
...more
