BIO 478
CANCER CELL
Growth-Proliferation Stages in a Normal Cell
• Growth Factors
• Growth Factor Receptors
• Signaling Proteins
• Nuclear Transcription Factors
• Genes that Control the Mitosis Cycle
Growth Factors
• Growth factors are needed for a normal cell to grow and divide.
• These factors bind to their specific receptors on the cell surface.
Growth Factor Receptors
• These receptors have tyrosine kinase activity.
• With the binding of the growth factor to its
specific receptor, the receptor is activated and cleavage is initiated.
Signaling Proteins
• Following the stimulation of the receptor, some proteins are coded as the second messenger.
• It is the Ras protooncogen which plays a mediating role in signal transmission.
• In the next step, MAP kinase is activated.
• With the second messengers, the warning is transmitted to the kernel.
Nuclear Transcription Factors
• Genes related to cleavage in the nucleus are stimulated.
• These are myc, fos, jun proteins.
• The most commonly used myc is protooncogen.
Genes Controlling the Mitosis Cycle
• Cyclin and Cyclin dependent kinase genes are in this category.
• Cyclins function during the mitosis cycle.
• Malignancies are seen in their mutations.
• Cell cycle and growth inhibition controls mutations that cause loss
• Loss of telomeres
