The Hallmarks of Cancer
Sustained angiogenesis
Angiogenesis is the process by which new blood vessels are formed. Cancer cells appear to be able to kickstart this process, ensuring that such cells receive a continual supply of oxygen and other nutrients.
Evading programmed cell death
Apoptosis is a form of programmed cell death (cell suicide), the mechanism by which cells are programmed to die in the event they become damaged. Cancer cells are characteristically able to bypass this mechanism.
Insensitivity to anti-growth signals
Cancer cells are generally resistant to growth-preventing signals from their neighbours.
Tissue invasion and metastasis
Cancer cells can break away from their site or organ of origin to invade surrounding tissue and spread (metastasize) to distant body parts.
Self-sufficiency in growth signals
Cancer cells do not need stimulation from external signals (in the form of growth factors) to multiply.
Deregulated metabolism
Cancer cells exhibiting the Warburg effect prevent mitochondria from completing normal aerobic respiration.
Limitless replicative potential
Non-cancer cells die after a certain number of divisions. Cancer cells escape this limit and are apparently capable of indefinite growth and division (immortality). But those immortal cells have damaged chromosomes, which can become cancerous.
Evading the immune system
The selective pressure of the competent immune system "edits" the tumor by selecting for cells that can avoid immune destruction. Thus, by the time they are macroscopic, these tumors are poorly immunogenic, and more resistant to immune-mediated destruction.
Genome instability
Genome instability can refer to the accumulation of extra copies of DNA or any abnormal changes in DNA tertiary structure that can cause either the loss of DNA. Genome instability is likely the major underlying cause of mutations in cancer is DNA damage.
Inflammation
Recent discoveries have highlighted the role of local chronic inflammation in inducing many types of cancer. Inflammation leads to angiogenesis and more of an immune response.
