BSC 300 Lecture Notes - Lecture 30: Epithelium, Wnt Signaling Pathway, Metastasis
28 Apr 2016
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Document Summary
Three stages of carcinogenesis: initiation: mutation event in a tumor suppressor or proto-oncogene. Not enough alone to trigger a cancerous event. Ideally in this case cell undergoes apoptosis: promotion: high proliferation and some genetic instability, progression: high proliferation and extensive genetic instability. Seven characteristics of cancer: reduced dependency on external signals. Growth factors, ecm contact: acquire tolerance to external and internal stresses. Can survive despite dna damage: immortality: proliferate profusely and indefinitely. Telomerase is activated so signal for quiescent stage is missing: genetic instability: increasing mutation rate and instability as time goes on. Mitosis may be impaired and chromatids don"t separate properly: invasiveness: lack of adhesion molecules and the need to be anchored. Can degrade the ecm so they aren"t attached: abnormal metabolism: increased nutrient absorption and metabolism. High rate of glycolysis for lots of atp and glycerol. Take nutrients from healthy cells: survive in abnormal locations: avoid immune system, inhibit apoptosis, survive in absence of proper signals.
