Cancer fall '08

starts not in g0 cells in regions with lots of

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Unformatted text preview: ignant tumors Types •In situ •Invasive •Metastatic Malignancy is present Malignancy Starts where?? Starts Not in G0 cells In regions with lots of ongoing cell divisions – Epithelial tissue – Bone marrow Cancer: a failure of genetic control Cancer: Cancer is caused by a series of mutations Cancer: a failure of genetic control Cancer: Terms p53 protein p53 – Attempts DNA repair Attempts in G1 in – If not successful, If promotes apoptosis promotes Cyclin – Protein necessary for Protein cell to progress from G2 to ‘mitotic cell division’ Cancer genetic causes Cancer In large part due to mutations to 2 types In types of genes of 1. Proto-oncogenes code for 1. 2. 2. Enough cyclin to keep cell cycle normal Enough Proteins that inhibit p53 production thereby Proteins restraining apoptosis 2. Tumor-suppressor genes code for (do opposite) (do 2. Tumor-suppressor 1. 2. Proteins to inhibit cyclin Proteins promoting p53 and apoptosis 1. Remember apoptosis destroys tumors Genetic Causes cont. Genetic Oncogenes = a gene that causes cancer – A mutated proto-oconogene – Whatever a proto does, oncogene does better Produces enough cyclin to promote rapid cell repro Stops p53 activity thereby stopping apoptosis Mutated tumor-suppressor gene – No longer inhibits the cell cycle – No longer promotes p53 and thus no apoptosis Other genetic causes Other Absence of telomere shortening – – – TTAGGG Cancers express telomerase, replenishes TTAGG Does not age Angi...
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