LC-Cancer+19.1

=**Cancer: Lesson 19.1**= - Initiation: A single cell undergoes a mutation that causes it to begin to divide repeatedly. - Promotion: A tumor develops, and the tumor cells continue to divide. As they divide, they undergo mutations. - Progression: One cell undergoes a mutation that gives it a selective advantage over the other cells. This process is repeated several times, and, eventually, there is a cell that has the ability to invade surrounding tissues.
 * Cancer**: Malignant tumor whose non differentiated cells exhibit loss of contact inhibition, uncontrolled growth, and the ability to invade tissue and metastasize
 * Apoptosis**: Programmed cell death involving a cascade of specific cellular events leading to death and destruction of the cell.
 * Telomere**: Tip of the end of a chromosome.
 * Carcinogenesis**: Development of cancer.
 * Angiogenesis**: Formation of new blood vessels; one mechanism by which cancer spreads.
 * Metastasis**: Spread of cancer from the place of origin throughout the body; caused by the ability of cancer cells to migrate and invade tissues.
 * Proto-oncogene:** Normal gene that can become an oncogene through mutation.
 * Tumor-suppressor Gene**: Gene that codes for a protein that ordinarily suppresses cell division; inactivity can lead to a tumor.
 * Oncogene**: Cancer-causing gene.
 * Growth Factor**: Chemical signal that regulates mitosis and differentiation of cells that have receptors for it; important in such processes as fetal development, tissue maintenance and repair, and hematopoiesis; sometimes a contributing factor in cancer.
 * Cyclin**: Protein that regularly increases and decreases in concentration during the cell cycle.
 * Oncology:** The study of cancer
 * Oncologist**: Physician who specializes in one or more types of cancers.
 * Carcinoma**: Cancer arising in epithelial tissue.
 * Sarcoma**: Cancer that arises in muscles and connective tissues.
 * Leukemia**: Cancer of the blood-forming tissues leading to the overproduction of abnormal white blood cells.
 * Lymphoma**: Cancer of lymphatic tissue (reticular connective tissue).

1. What characteristics of cancer cells allow them to grow uncontrollably? - Cancer cells grow uncontrollably, because unlike healthy cells, they continue to multiply even after adhering to their neighbor cells. Also, cancer cells do not respond to the chemical signals controlling the increase or decrease in multiplying. 2. Mutations in what two types of genes lead to uncontrollable growth? - Proto-oncogenes and Tumor-suppressor genes can mutate into genes with uncontrollable growth. 3. What are the most common types of cancer? - The most common cancers include breast, colon, leukemia, prostate, and pancreas.