Apoptosis cellular mechanisms

Damage repair DNA repair enzymes may become more ef cient in repairing defects caused by cisplatin. Inhibition of apoptosis due to activation of antiapoptotic cellular mechanisms. 

Figure 20.5 Proposed model for the cellular mechanisms of gold(lll) porphyrin 1a induced apoptosis in HONE1 ceiis. Goid (III) porphyrin la directiy caused depietion of A P. ieading to the aiteration of Bci-2 famiiy proteins, AIF nucleus translocation, and cytochrome c release, which further activated caspase-9 and caspase-3, and subsequently caused PARP-1 cleavage. ROS were also generated. The altered cellular oxidative state affected cytotoxicity of gold(lll) porphyrin la by regulating mitochondrial permeabilization.

Doxorubicin is an anthracychne antibiotic. Cells treated with doxorubicin have been shown to manifest the characteristic morphologic changes associated with apoptosis or programmed cell death. Doxorubicin-induced apoptosis may be an integral component of the cellular mechanism of action relating to therapeutic effects, toxicities, or both. 

N. Wang, Y. Feng, M. Zhu, C. Tsang, K. Man, Y. Tong, and S. Tsao, Berberine induces autophagic cell death and mitochondrial apoptosis in liver cancer cells the cellular mechanism. J. Cell Biochem., Ill (2010) 1426-36. 

Abstractions. Various levels of abstractions are involved in the analysis of complex cellular events. A set of transitions can be described as a single process (e.g., the MARK pathway), and a set of related processes may be classified under one cellular mechanism (e.g., apoptosis). Some explicit examples of abstractions are shown in Figure 6. In cases in which it is not identified which state among a set of states constitutes the substrate or effector of a transition, or in which target transition of an effector is unclear, we may need to abstract these states (or transitions) as a single state (or transition) to represent the available information despite its incomplete nature. 

Bortner CD, Cidlowski JA. Cellular mechanisms fi>r the repression of apoptosis. Annu Rev Pharmacol Toxicol 2002 42 239-281. 

Palombo and colleagues (40) investigated the effects of different types and concentrations of CLA and linoleic acid on colorectal and prostate cancer (PC3) cell proliferation and cytotoxicity. Linoleic add was without effect at all concentrations and in all cells, which appears to be a consensus in all reports. PC3 cells were the least sensitive to CLA treatment of the cells studied. These authors also found an induction of a homogeneous caspase activity (caspases 2,3,6-10) indicative of an induction of apoptosis, but they did not investigate other underlying cellular mechanisms to explain their findings. 

Despite the popularity of in vitro experimentation concerning the cellular mechanisms of carcinogenic prevention by essential oil components (mainly by inducing apoptosis), there is no evidence that the direct administration of essential oils can cure cancer. There is evidence to suggest that the mevalonate pathway of cancer cells is sensitive to the inhibitory actions of dietary plant isoprenoids (e.g., Elson and Yu, 1994 Duncan et al., 2005). Animal testing has shown that some components can cause a signi cant reduction in the incidence of chemically induced cancers when administered before and during induction (e.g., Reddy et al., 1997 Uedo et al., 1999). 

Apoptosis is known as programmed cell death and represents also a control mechanism within the cell that reacts to the changes in its environment. This active cellular death process is characterized by distinctive morphological changes... 

After activation, cytotoxic T cells emerge from lymphoid organs to infiltrate the graft and trigger the immune response. These cells have been shown to induce graft destruction via two mechanisms (1) secretion of the cytotoxic proteins perforin and granzyme B, and (2) induction of cellular apoptosis... 

Tissues consist of smaller repeating units on the scale of hundreds of micrometers in vivo. The 3D architecture of these repeating tissue units underlies the coordination of multicellular processes, emergent mechanical properties, and integration with other organ systems via the microcirculation [11], Furthermore, the local cellular environment presents biochemical, cellular, and physical stimuli that orchestrate cellular fate processes such as proliferation, differentiation, migration, and apoptosis. Thus, successful fabrication of a fully functional tissue must include both an appropriate environment for cell viability and function at the microscale... 

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