The Cell Cycle and Understanding Cancer

Cell Cycle Definition: The orderly set of stages that take place between the time a eukaryotic cell divides and the time the resulting daughter cells also divide.

Purpose of the Cell Cycle Determine whether a cell divides, stays the same, or dies Examples: During growth and repair, cells divide Some specialized cells (such as nerve and muscle cells) do not divide unless they are given a signal to divide Cells with damaged DNA cannot divide, and may be programmed to die

The Cell Cycle Alternates between Interphase and Mitosis

Controlled with Checkpoints

Growth Factors: Cyclin-CDK Complex -CDK’s are cyclin-dependent kinases -All eukaryotes have them -They activate proteins that are involved in carrying out the cell cycle -Many different cyclins -In order to move on to next stage, cyclins must be present because they regulate the production of cell cycle proteins for the next stage

Growth Factors: p53 protein Recognizes damaged DNA and stops the cell cycle DNA can either be repaired or cell death will be triggered

Where in the cell cycle would the p53 protein take action?

Part 2: The Cell Cycle and Cancer Cancer: A group of diseases characterized by abnormal cell growth with the potential to spread to other parts of the body Skip to 45 sec after a little bit

Cancer results from an accumulation of mutations in genes that code for proteins that regulate cell division (growth factors) Proto-oncogene: Genes that code for proteins that may cause cancer if mutated (ex. CDK’s) Tumor suppressor gene: Genes that code for proteins that suppress cell division (ex. p53)