Programmed Cell Removal

It is the design of species with fixed sizes and constant organ/body weight (b.w.) that a proper balance is maintained between mitosis and programmed cell death 

If apoptosis were evolved optimally, it would detect all unusual cells and remove them before cancer could become a problem. However, cancer is insidious in that it does not alter membrane epitopes in the early premalignant or focal phases and later in tumor progression, apoptosis is actively inhibited by specific oncogenic agents until the cancer takes control and is independent (Criollo et al. 2007 Klein et al. 2007 Renehan et al. 2001). 

Apoptosis resistance most always becomes a feature of developing cancer cells (Hanahan and Weinberg 2000). It is suggested that in the caspase-dependent and caspase-independent apoptotic pathways, specific defects can contribute to tumor 

---

Apoptosis or programmed cell death is one of the regulatory mechanisms for the removal of unwanted cells. Apoptosis is induced by the stimulation of several different cell surface receptors in association with caspase activation. Apoptosis of a cell is thus a complicated process and can be assayed by various methods. Among widely used methods, the TUNEL assay is described here. 

Programmed cell death (apoptosis) is part of many developmental programs and provides for removal of unneeded cells without inflammation... 

The process involves a number of steps the interaction with or damage to DNA in a cell wiU lead to a tumour only if the cell divides and that damage is expressed. Only then does the uncontrolled division of the cell result in cancer. There are, however, protective mechanisms which can come into play. The DNA damage may be repaired, or if it is too extensive the cell may undergo a process called apoptosis or programmed cell death (see box above). This is a way in which the body removes single cells that have been damaged. Only if these processes are ineffective or overloaded will a tumour result. 

Programmed cell death the removal of single damaged cells. arrythmia(s)... 

Programmed cell death allows the removal of overpopulated cells, pathogen-infected cells, malformed cells, or cells that have sustained genetic damage (1). Several disease states are hnked either to a lack of apoptotic response or to unwanted cell death... 

Cell death is widely recognized to play an important role in the development and function of tissues and organs in all multicellular organisms, including fishes. Cell death can be induced by specific developmental cues that promote active, targeted cell removal ( programmed cell death)127 or can be the passive consequence of... 

Necrotic cell death differs markedly from apoptosis, a morphologically distinct pathway to cell death under the control of conserved genetic elements (Table 1). Apoptotic cell death (a.k.a. programmed cell death or cell suicide) is an active cell death mechanism that functions to remove unwanted cells from a tissue in a controlled, orderly fashion. It generally affects cells in isolation, which exhibit a suite of conserved morphological and biochemical features that contrast sharply with those observed during necrosis. 

---