Cell Death by Apoptosis and Cancer Chemotherapy

The ways by which cell death takes place have generated great interest in recent years particularly in the field of cancer. The exact mechanisms which are responsible for tumour regression by drug treatment are also largely unknown and involve both enhanced cell death and arrested cell proliferation. Cell death is caused either by necrosis or by an active process in response to a specific stimulus which leads to elimination of a definite proportion of cells. This process of programmed cell death is referred to as apoptosis (a term coined by developmental biologists) and is a part of the morphogenetic processes, characterized by shrinkage of cells, condensation of nuclear chromatin, nuclear fragmentation and blebbing. Many successful cancer treatments presently undertaken depend upon induction of an apoptotic response in the target tumour cells. As apoptosis is considered to be an active gene-directed process, in tumours the precise mode of cell death after chemotherapy is important. Understanding the role of apoptosis in cancer will greatly broaden our knowledge of all stages of the disease process and its treatment. Thus, the role of apoptotic response modulation during the generation of neoplasia is an important issue and will remain an active area of present day investigations for improving the efficiency of chemotherapy. It is likely to become a valuable weapon in the war against cancer.