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Control of Cell Cycle. Cells know when to divide because they receive signals from surrounding cells Normal Cells are Mortal Anchorage dependent Density Dependent. Skin Cell Culture. Checkpoints during Cell Cycle. G1 checkpoint Is cell large enough? Does cell have proper nutrients?
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Cells know when to divide because they receive signals from surrounding cells • Normal Cells are • Mortal • Anchorage dependent • Density Dependent
Checkpoints during Cell Cycle • G1 checkpoint • Is cell large enough? • Does cell have proper nutrients? • G2 checkpoint • Did DNA replicate properly? • Spindle Assembly checkpoint • Did the spindle properly attach to chromosomes?
If cell is not dividing properly, what happens? • Apoptosis
Genes that ensure cells do not divide too often or not enough • Proto-oncogene (“accelerator”) • Tumor suppressor gene (“brake”)
How did they find out the function of proto-oncogenes and tumor suppressor genes?
Cancer Cells are • Immortal • Not density dependent • Not anchorage dependent