LIFE 210 Lecture Notes - Apoptosis, Tumor Suppressor Gene, Leukemia
Document Summary
Cancer cells reproduce without restraint and colonize other tissues. Cancer cells reproduce in defiance of normal restraints of cell growth/division. They invade and colonize territories normally occupied by other cells. A tumor is benign if it is not invasive. Tumor = cancer when it is malignant (invades surrounding tissue and forms metastases) Common types of cancer in the united states. Leukemias and lymphomas: from white blood cells and precursors, as well as from nervous system. Most cancers derive from a single abnormal cell. Can be demonstrated by molecular analysis of chromosomes (same abnormality in all cells) A single mutation is not enough to cause cancer. Cancer occurs by progressive accumulation of random mutations in a single lineage of cells. People exposed to carcinogens develop cancer many years later. Development of cancer requires gradual accumulation of mutations. Usually 5 or more genes need to be mutated for developed cancer. Packaging into heterochromatin: condensed chromatin that inactivates genes.
