Presentation on theme: "Regulating the Cell Cycle Biology 392 Chapter 10-3."— Presentation transcript:
Regulating the Cell Cycle Biology 392 Chapter 10-3
Cancer One in three people will develop cancer. One in four people will die of cancer. In 2005, about 1.4 million new cases of cancer were diagnosed. More than 1500 Americans die each day of cancer. Over 1,000,000 cases of skin cancer will be diagnosed yearly. Cancer is the leading cause of death among Americans under the age of 85.
US Mortality, 2003 1.Heart Diseases685,089 28.0 2.Cancer556,902 22.7 3.Cerebrovascular diseases157,689 6.4 4.Chronic lower respiratory diseases126,382 5.2 5.Accidents (Unintentional injuries)109,277 4.5 6.Diabetes mellitus 74,219 3.0 7.Influenza and pneumonia 65,163 2.7 8.Alzheimer disease 63,457 2.6 9.Nephritis 42,453 1.7 10.Septicemia 34,069 1.4 Source: US Mortality Public Use Data Tape 2003, National Center for Health Statistics, Centers for Disease Control and Prevention, 2006. RankCause of Death No. of deaths % of all deaths
* For those free of cancer at beginning of age interval. Based on cancer cases diagnosed during 2000 to 2002. Source: DevCan: Probability of Developing or Dying of Cancer Software, Version 6.0 Statistical Research and Applications Branch, NCI, 2005. http://srab.cancer.gov/devcan Lifetime Probability of Developing Cancer, by Site, Men, 2000-2002* ‡ Includes invasive and in situ cancer cases † All Sites exclude basal and squamous cell skin cancers and in situ cancers except urinary bladder. SiteRisk All sites † 1 in 2 Prostate 1 in 6 Lung and bronchus1 in 13 Colon and rectum1 in 17 Urinary bladder ‡ 1 in 28 Non-Hodgkin lymphoma1 in 46 Melanoma1 in 52 Kidney1 in 64 Leukemia1 in 67 Oral Cavity1 in 73 Stomach1 in 82
Lifetime Probability of Developing Cancer, by Site, Women, US, 2000- 2002* SiteRisk All sites † 1 in 3 Breast 1 in 8 Lung & bronchus 1 in 17 Colon & rectum 1 in 18 Uterine corpus 1 in 38 Non-Hodgkin lymphoma 1 in 55 Ovary 1 in 68 Melanoma 1 in 77 Pancreas 1 in 79 Urinary bladder ‡ 1 in 88 Uterine cervix 1 in 135 Source: DevCan: Probability of Developing or Dying of Cancer Software, Version 6.0 Statistical Research and Applications Branch, NCI, 2005. http://srab.cancer.gov/devcan * For those free of cancer at beginning of age interval. Based on cancer cases diagnosed during 2000 to 2002. † All Sites exclude basal and squamous cell skin cancers and in situ cancers except urinary bladder. ‡ Includes invasive and in situ cancer cases
What is Cancer? Disorder in which some of the body’s cells lose the ability to control growth 100’s of different types Do not respond to internal &/or external signals Continuously divide – forming masses of cells called tumors. Cancer cells can break from a tumor and spread throughout the body (metastasize)
What’s happening in the petri dish? How does this represent the healing process? This is normal the cells eventually stop
What causes the cell cycle to continue? Is it automatic? Does it ever stop?
A sample of cytoplasm is removed from a cell in mitosis. The sample is injected into a second cell in G 2 of interphase. As a result, the second cell enters mitosis. Hypothesis: Substance X will cause a cell to start mitosis Substance X = CYCLIN cellular protein that regulates the timing of the cell cycle in eukaryotic cells; helps create spindle
Cell Cycle Regulators INTERNAL Proteins that respond to signals inside the cell Checkpoints during the cell cycle: – Make sure all DNA has been properly made – Make sure all chromosomes have attached to a spindle EXTERNAL Proteins that respond to events outside the cell Speed up or slow down cell cycle Respond to environment and “crowding”
Cell Cycle Regulators Three Checkpoints G 1 G 2 Mitosis (metaphase)
Causes of Cancer Environment sun, chemicals Not exercising obesity is linked to several Genetics (but not necessarily inherited) Mutations in genes that regulate cell cycle Example: p53 gene responsible for halting the cell cycle until all chromosomes have replicated properly Defects in this gene leads to cancer
Progression of Cancer NORMAL CELLS BENIGN fast dividing cells, not really toxic, only cause mechanical damage MALIGNANT toxic, cause local toxicity and inflammation METASTATIC travel from one place to another. The real killer
Kinds of Cancers SOLID TUMORS Carcinomas originate from surface cells (skin, wall of intestine, surface of organs) Sarcomas bone, cartilage, fat, muscle “LIQUID” TUMORS Leukemias circulate in blood stream, from blood Lymphomas developed in lymph system
2006 Estimated US Cancer Deaths* ONS=Other nervous system. Source: American Cancer Society, 2006. Men 291,270 Women 273,560 26%Lung & bronchus 15%Breast 10%Colon & rectum 6%Pancreas 6%Ovary 4%Leukemia 3%Non-Hodgkin lymphoma 3%Uterine corpus 2%Multiple myeloma 2%Brain/ONS 23% All other sites Lung & bronchus31% Colon & rectum10% Prostate9% Pancreas6% Leukemia4% Liver & intrahepatic4% bile duct Esophagus4% Non-Hodgkin 3% lymphoma Urinary bladder3% Kidney3% All other sites 23%
Cancer Treatments Surgery – remove the affected cells Radiation – high-dose X-rays kill cells Chemotherapy – drugs kill cells Hormone Therapy – hormones stop cell growth
Cancer Prevention The best way to prevent cancer is to avoid things that can cause cancer. Ultraviolet radiation in sunlight can damage genes that control the cell cycle. Chemicals in cigarette smoke also affect how cell growth and division is regulated.
Video links http://video.about.com/cancer/Chemotherapy.ht m http://video.about.com/cancer/Chemotherapy.ht m http://video.about.com/cancer/Chronic-Myeloid- Leukemia.htm http://video.about.com/cancer/Chronic-Myeloid- Leukemia.htm http://video.about.com/cancer/CyberKnife- Radiosurgery.htm http://video.about.com/cancer/CyberKnife- Radiosurgery.htm http://video.on.nytimes.com/index.jsp?fr_story=c de8a179a490d9a9fe977c6df92fb8fe3b88a538 http://video.on.nytimes.com/index.jsp?fr_story=c de8a179a490d9a9fe977c6df92fb8fe3b88a538 – (lung cancer and CT scans)