Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

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Unit Chapters
Genomics
Proteins & Proteomics
Evolution & Phylogenetics
Microbial Diversity
Emerging Infectious Diseases
HIV & AIDS
Genetics of Development
Cell Biology & Cancer
Introduction
What Is Cancer?
Genetics of Cancer
Cell Cycle
What Causes Cancer?
Tumor Biology
Viruses and Cancer
Environmental Factors
Detecting and Diagnosing Cancer
Traditional Treatments
Newer Treatments
Preventing Cancer
Screening, Genetic Tests, and Counseling
Human Evolution
Neurobiology
Biology of Sex & Gender
Biodiversity
Genetically Modified Organisms
Traditional Treatments

Because cancer comprises many diseases, doctors use many different treatments. The course of treatment depends on the type of cancer, its location, and its state of advancement. Surgery, often the first treatment, is used to remove solid tumors. It may be the only treatment necessary for early stage cancers and benign tumors. Radiation kills cancer cells with high-energy rays targeted directly to the tumor. It acts primarily by damaging DNA and preventing its replication; therefore, it preferentially kills cancer cells, which rapidly divide. It also kills some normal cells, particularly those that are dividing. Surgery and radiation treatment are often used together.

Chemotherapy drugs are toxic compounds that target rapidly growing cells. Many of these drugs are designed to interfere with the synthesis of precursor molecules needed for DNA replication; they interfere with the ability of the cell to complete the S phase of the cell cycle. Other drugs cause extensive DNA damage, which stops replication. A class of drugs called spindle inhibitors stops cell replication early in mitosis. During mitosis, chromosome separation requires spindle fibers made of microtubules; spindle inhibitors stop the synthesis of microtubules. Because most adult cells don't divide often, they are less sensitive to these drugs than are cancer cells. Chemotherapy drugs also kill certain adult cells that divide more rapidly, such as those that line the gastrointestinal tract, bone marrow cells, and hair follicles. This causes some of the side effects of chemotherapy, including gastrointestinal distress, low white blood cell count, and hair loss.

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