Biochemistry 2280A Lecture Notes - Chromosome Abnormality, Myc, Chronic Myelogenous Leukemia
12 Dec 2012
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Document Summary
Divide in the absence of growth factors: unregulated growth. Are immortal do not respond to signals that normally trigger cell death: normal cells undergo programmed cell death (will divide around 20 times and die), but cancer cells keep dividing and dividing. Are genetically unstable: more point mutations, copy number variation, major chromosome abnormalities. Cancer cells can multiply in abnormal places: normal cells will not grow out of the normal environment, where as cancer cells will. A mutant form of a normal gene whose presence causes cancer. Examples of major oncogenes include myc, ras, fos, jun, abl key cell regulators. Overactivity mutation (gain of function: normal gene = proto-oncogene, a normal cell under goes a single mutation event, creating oncogene, which activates mutation enabling oncogene to stimulate cell proliferation. What types of changes can result in an oncogene: point mutations slight change in the allele can cause cancer, gene amplification normal protein greatly overproduced.
