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Unformatted text preview: Describe how defective control of programmed cell death can contribute to cancer Explain the role of apoptosis in development, in the elimination of autoreactive B cells and T cells, and in certain neurodegenerative disorders Describe the cytological changes that occur while a cell is undergoing apoptosis Explain how a proteolytic cascade of caspases causes the cytological events of apoptosis Compare and contrast the extrinsic pathway of apoptosis (triggered, for example, by cytotoxic T lymphocytes) with the intrinsic pathway of apoptosis (triggered, for example, by severe DNA damage or lack of oxygen) Recognize that the survival of any cell depends on the integration of a large number of internal and external cues Explain how mutations in many different programmed cell death genes can contribute to the development of cancer Explain the relationship between the checks and balances controlling cell division and cell death and the fact that most cancer cells contain several mutations Vocab: Necrosis, apoptosis, caspase, procaspase, intrinsic pathway, extrinsic pathway, initiator caspase, executioner caspase, apoptosome, Fas ligand, Bcl2, “Bcl2-related proteins” (not each one), p53 Outline:- Programmed cell death and cancer- Necrosis vs apoptosis- Caspases vs apoptosis- Extrinsic pathway of apoptosis- Intrinsic pathway of apoptosis- Integration of external and internal cues- P53, apoptosis, and cancer- Both increased cell division AND decreased cell death can contribute to tumorigenesis o Homeostasis: you start off with four, multiple and still end up with 4 o Tumor: is when the imbalance of having more cells at the basal level Too much division Not enough cell death- There are two general categories of cell death: o Apoptosis: programmed cell death (Normal) Excess neurons are eliminated by apoptosis o Necrosis: processed of cell death involving the breakdown of a cell and its very messy o Necrosis looks horrible and causes inflammation to the area o Apoptosis is very neat (the inner clues: the inner leftlet has the negative phospholipid that is only found in the inner leftlet will flip out! Recycle all the good stuff and keep the environment neat o As part of the apoptotic program, the DNA is digested by an endonuclease that is activated specifically during apoptosis Necrosis Apoptosis Cell Volume Increased Decreased Chromatin Fragmented Condensed Plasma Membrane Disrupted Intact (altered structure*) Inflammation Frequent None Role Pathologic Usually Physiologic Cell Fate Lysis Consumption DNA Degraded Cleaved Describe how defective control of programmed cell death can contribute to cancer Explain the role of apoptosis in...
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- Spring '11
- Apoptosis, cell death