Tumorogensis: evasion of apoptosis by the cancer cells Azhar, Joharia

ABSTRACT

Evasion of apoptosis is one of the hall marks of cancer. The overwhelming ability of tumor cells to increase in number is influenced not only by un-limited replicative potential but also to a great degree by their ability to evade apoptosis. Apoptosis is the programmed cell death that ensures the removal of old and genetically altered cells that can not be repaired. So the process is very important for continued preservation of genetic information in all body cells. Cancer cells acquire the overwhelming ability to evade apoptosis, thereby the genetic mutations necessary for carcinogenic phenotype start accumulating. The cancer cell thus becomes immortalized, this genetically mutated, immortalized cell then divides and reproduces genetically mutated daughter cells, and thus tumorogensis develops. Apoptosis is brought about by a family of proteases, called as caspases. The principal function of caspases is proteolysis of specific substrates which facilitates the occurrence of various morphological and biochemical characteristics of apoptosis. They also act as critical signaling molecules in the apoptotic pathway and serve to amplify the signal during caspase cascade. There are a variety of ways by which cells can evade apoptosis. This article looks at a variety of strategies acquired by the cells to evade apoptosis and to become immortalized. A thorough and complete understanding of these strategies can enable us to maximize the benefits of the apoptosis inducing agents, which are often included in the chemotherapeutics of carcinomas. Infact many of the conventional combination therapies utilize apoptosis inducing agents along with radiotherapy