Which genes, when mutated, disrupt the cell cycle and trigger uncontrolled cell growth?
There are two classes of genes: • (1) Genes that trigger cell growth and division by initiating specific phases in the cell cycle: proto-oncogenes. • (2) Genes that stop or slow the cell cycle when damage is detected: tumor suppressors. These are also involved in initiating apoptosis if damage is not fixable. • the proto-oncogene is the normal form … when mutates, becomes an oncogene. • Analogy: proto-oncogene is the gas pedal for the cell cycle … tumor suppressors are the brakes. We want both to function properly to drive our cell at the right speed and not go uncontrollably forward!! • An oncogene would be a “stuck gas pedal”, stuck in the “pedal to the metal” position. • Every type of molecule involved in cell signaling can be mutated into an oncogene. • Any cell that is involved in telling the cell to progress through the cell cycle is the product of a proto-oncogene: • signaling proteins • transmembrane receptors • G-proteins • protein kinases • transcription factors • etc • There
