What is apoptosis
Apoptosis is a process of programmed cell deaths (cell suicide) triggered by diverse internal and external signals. Apoptosis is an essential process by which our body eliminates old cells, abnormal cells, or damaged cells.
After a cell is stimulated by an apoptotic signal, the cell undergoes a sequence of organized degradation of cellular components characterized by membrane blebbing and cell shrinkage, condensation of chromatin, fragmentation of DNA, and engulfment of the dead cell by neighboring phagocytic cells.
Apoptosis is a tightly regulated process that plays a crucial role in maintaining our body’s homeostasis. There are many diseases associated with too much or too less apoptosis. Exaggerated apoptotic cell death is characteristic of stroke and neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS).
Acquired immune deficiency syndrome (AIDS) is characterized by too much apoptotic cell death of T-helper cells that play a critical in our body’s immune system. Too less or inhibited apoptosis has been identified in many malignancies and autoimmune disorders.
Role of apoptosis in cancer development
In general, cancer develops from a cell that has damage to its DNA. When DNA damage occurs in a cell, a tumor suppressor gene called p53 is activated and expressed into a tumor suppressor protein p53. The protein induces apoptosis of the damaged cell preventing it from becoming cancer cell.
This antitumor activity of p53 protein is completely lost or reduced if the p53 tumor suppressor gene is mutated or damaged by various environmental chemicals or agents, including carcinogenic chemicals containing in the cigarette smoking, radiation, or chemicals in workplaces, the cells can progress to cancer. Many existing and new anticancer treatments are based on stimulation of apoptotic pathways in cancer cells by which cancer cells undergo apoptotic cell death.