BIO 303 Lecture Notes - Lecture 15: Oncogene, Paracrine Signalling, Metastasis
Document Summary
Ch 15 - regulation of cell number - normal and cancer cells. In higher eukaryotes, cell survival and proliferation are highly regulated by integrated controls that continually evaluate the state of the cell and its environment. Normal cell proliferation is modulated by regulation of the cell cycle. Apoptosis eliminates damaged cells and cells needed by only temp during during development. The accumulation of mutations in cancer cells allows them to escape apoptosis and proliferation controls. Stem cells proliferate and diff in response to local signs to replace dead cells. Apoptosis eliminates cells as a consequence of internal and external signs. Cancers develop through accumulation of mutations in a clone of somatic cells. Hundreds of mutational events leading to neoplasia (cancer formation) have been identified. Proliferation is controlled by cell cycle checkpoints. Protein kinases and protein phosphates modulate activities of proteins regulating the cell cycle. Multicellular organisms - somatic cells may be eliminated by apoptosis.
