Understanding Cell Division and Cancer: Key Concepts and Objectives, Slides of Biology

Download Understanding Cell Division and Cancer: Key Concepts and Objectives and more Slides Biology in PDF only on Docsity! Lecture 6: Cell Division & Cancer Docsity.com Lecture 7: Cell Division and Cancer Objectives: Understand basic concepts of cancer Understand cell division Understand how cell division is regulated Understand programmed cell death Key Terms: Mitosis, interphase, tumor, metastasis, angiogenesis, neoplasm, benign, malignant, adenoma, carcinoma, tumor suppressor, growth factor, check point, oncogene, programmed cell death Assignment: Read: chapter 8, 9, 14, 43 Docsity.com How does Cancer Start? Cellular Damage Control Normal cells protect their DNA Information Damage control system 1.Detect DNA and cellular damage 2.Stop cell division (prevent replication of damage) 3.Activate damage repair systems 4.Activate self destruct system Docsity.com DAMAGE EVENT Stop Cell Division Activate Damage Repair Damage Assessment Repair is Successful Mild to Moderate Damage Severe Damage Programmed Cell Death Repair Fails Damage Accumulation Leads to Cancer Docsity.com ## Docsity.com Fibroids - affects 40% of all women Benign Cancer Undifferentiated growth with no obvious adverse effects Uterine fibroids Docsity.com Invasive Cancer Lung cancer Breast cancer Melanoma Melanoma on the arm -Metastasized = invasive Undifferentiated growth with adverse effects Docsity.com Leading Causes of Death Total US Population • Heart Disease • Cancer • Stroke • Lung diseases • Accidents • Diabetes • Flu and Pneumonia • Alzheimer's disease • Kidney Disease • Infections (Most current data available are for U.S. in 2001) www.cdc.gov/nchs/fastats/lcod.htm US Population 20-24  Accidents • Homicide • Suicide • Cancer • Heart disease • Genetic Disease • HIV (AIDS) • Stroke • Flu and Pneumonia • Diabetes Docsity.com Carcinogens = Acetaldehyde (flavoring agent: especially orange, apple and butter flavors) Allspice Apricot Apple Azathioprine (given with organ transplants) Bacon Banana Basil Beer Beet BHA (preservative) Broccoli Brussels sprouts Cabbage Caffeine Calcium arsenate (pesticide) Foods and drugs: Natural or synthetic pesticides, additives, preservatives, coloring, chemicals Carrot Cauliflower Cantaloupe Celery Cherries Chloroform (treats water) Chocolate Coffee Cinnamon Cyclosporin (treats hepatitis, arthritis, etc.) Creosote (herbicide/pesticide) DDT (pesticide) Diethylstilbestrol (synthetic hormone) Estradiol (naturally occurring female hormone) Garlic Grapefruit Grapes Hamburger Honey Horseradish Lemon Lentils Lettuce Licorice Lime Lindane (insecticide) Mace Mango Menthol Mushroom Mustard Nicotine Nutmeg Onion Orange Parsnip Peach Pear Peas Pepper Phenacetin (pain-killer) Plum Pineapple Polyacrylamide (treats water) Potato Potato chips Raspberries Saccharin (sweetener) Sesame Seeds Sweet potato Synthetic estrogen (treats menopause) Tea Tomato White Bread Wine Any substance that can trigger cancer Docsity.com Causes of Cancer 2. Oncogenes 4. Viruses 3. Promoters 1. Carcinogens -food and drugs -environmental -industrial -agricultural Docsity.com Carcinogens Cont. Environmental = natural Electromagnetic Radiation = Turpenes -Heat -Gamma rays -X-rays -UV radiation -Beta rays Light Docsity.com Causes of Cancer 2. Oncogenes 4. Viruses 3. Promoters 1. Carcinogens -food and drugs -environmental -industrial -agricultural Docsity.com Carcinogens Cont. Agricultural Docsity.com Understanding Cancer To understand cancer, you must understand three fundamental cellular processes 1. Cell Division 2. Gene Regulation 3. Programmed Cell Death Docsity.com Cell Cycle • Cycle starts when a new cell forms • During cycle, cell increases in mass and duplicates its chromosomes • Cycle ends when the new cell divides Key Terms: Cell Cycle, Chromosomes, Cell Division What do they Mean? Docsity.com {NTERPHASE Gi Interval of cell growth, before DNA replication (chromosomes unduplicated) Ss Interval of cell growth, when DNA replication is completed Each daughter cell (chromosomes starts interphase duplicated) Interval following DNA replication; cell prepares to divide Fig. 8.4, p. 130 Docsity.com  Decoding the Cell Cycle Interphase: Phase between division and starting division again. Three intervals of Interphase 1. G1 1st Growth phase- cell makes parts, and does normal things 2. S Synthesis phase- DNA replication 3. G2 2nd Growth phase- making parts for cell division 4. G0 Zero Growth phase • Like getting stuck in park • Terminal development Key Concept: At each step, the cell must be in order Longest part of the cycle Cell mass increases Cytoplasmic components double DNA is duplicated G1 S G2 Docsity.com SIS MIT © 2002 Brooks/Cole - Thomson Leaming INTERPHASE GT Interval of cell growth, before DNA replication s (chromosomes eh ore unduplicated) DNA replication is completed Each daughter ce (chromosomes starts interphase duplicated) Docsity.com Cell Division Mitosis Key Concept: • During mitosis each cell gets a high fidelity copy of each chromosome • Multiple check points prevent run-away cycling Cancer cells are in run-away mode, the checkpoints are broken or ignored Docsity.com Key Concept: • Each chromosome has two strands of DNA • Each chromosome has one copy of each gene* • Each somatic cell has two of each chromosome • Each somatic cell has two copies of each gene* Docsity.com Meiosis = produces gametes, sex cells or germ cells Meiosis I Reduction Meiosis II Equatorial Division Docsity.com 2"4 Divisions: Reduction of meeicsis v ey oA ‘:— Meiosis ey XK . . First Division: Mitotic — ” ili Metaphase i a a _ - - sy ra ae a ea _ 4 1, ff 4 | | m | af a ,% — wz = —" ‘——<_— | (= < > >| ™~ a a a / a ee i rat Docsity.com Understanding Cancer To understand cancer, you must understand three fundamental cellular processes 1. Cell Division 2. Gene Regulation 3. Programmed Cell Death Docsity.com Gene Regulation Imortalization • Normal cells only divide about 50 times in a petri dish (if you can get them to divide) • Cancer cells just keep dividing (HeLa and MCF-7 cells) • Telomers (ends of chromosomes) usually spell the end for normal cells, but they don’t wear out Angiogenesis Blood vessel formation Cancer cells trick blood vessels into supplying nutrients Cancer cells secrete the growth factors that they are using Docsity.com Cancer and Smoking • The smoke from a cigarette contains about 1010 particles/ml and 4800 chemical compounds • There are over 60 carcinogens in cigarette smoke that have been evaluated for which there is 'sufficient evidence for carcinogenicity' in either laboratory animals or humans • These compounds damage DNA in the cells of the lung. The mechanism behind the damage is unknown. • Damage leads to mutations Docsity.com Smoking and Cancer • The kicker – Somehow p53 gets more mutations than other randomly selected sites – The mutations keep p53 from binding to DNA – This means that p53 can no longer prevent DNA replication when there is other damage x x x DNA Transcription Translation p53 STOP mp53 GO MUTANT NORMAL Docsity.com Causes of Cancer 2. Oncogenes 4. Viruses 3. Promoters 1. Carcinogens -food and drugs -environmental -industrial -agricultural Docsity.com Viruses: Human Papilloma virus (HPV) 40 million Americans are infected with HPV Evidence of HPV in 90% to 95% of cervical cancers 12,800 new cases of invasive cervical cancer 2002 US statistics: Of the survivors, 90% are sterile 4,800 women died from the disease (37%) 1998 1999 2000 2001 2002 Docsity.com How to diagnose? Regular pap smear Colposcopy Biopsy Olin Health Center How to treat? Trichloroacetic acid Surgery Cryotherapy Laser Surgery Vaginal warts = Benign, undetected PIV, other STDs, pregnancy injury, biological stress Stressors that promote virus expression = Docsity.com Programmed Cell Death The cell death program 1. Activated by cell surface receptors 2. Makes pores in Mitochondria 3. DNA is chopped up 4. Blebbing (not popping) 5. Adsorption by neighbors Nematodes, frog tails, webbed fingers, and HIV Docsity.com Programmed Cell Death Colon Cancer • Crypt • Polyp • Malignant polyp Colon Cancer Progression Docsity.com Colon Cancer Prevention? Endoscopy… Lumen Veins = Absorption Polyps Healthy Tissue Precancerous? Docsity.com animation Click to view animation. Metastasis Cancer cells leave the tumor and establish new colonies in other tissues Docsity.com Angiogenesis • Depends on growth factors released by the invading cancer cells Docsity.com Docsity.com Angiogenesis and Metastasis ‘Small localized tumor Blood vessel 1 Cancer cells invade surrounding tissues and vessels Angiogenesis 2. Ca near calls are transported Angiogenesis by the circulatory system to distant sites Tumor that can grow and spread 3. Cancer cells reinvade and grow at new location Markers for Cancer • Markers are proteins found in blood • Marker Level correlates with certain cancer types • Some tumor markers are antigens, others are enzymes. • Example: prostate-specific antigen (PSA) is a marker for prostate cancer in males Docsity.com • Growing cells in culture allows researchers to investigate processes and test treatments without danger to patients • Most cells cannot be grown in culture Cancer Research Henrietta Lacks HeLa Cells Docsity.com What does this mean FOR THE FOLLOWING? Can we reverse aging? -Burns -Scars -Regenerating tissue Pattern of regrowth Docsity.com -Master genes -There are only so many cell divisions before you die. Hormones drive cell division in All Animals -Molting hormone -Juvenile Hormone -Ecdysone Insects -Causes wrinkles, loss of skin tension Aging = death of somatic tissue -Your molecular clock is turned on at puberty. Docsity.com The War on Cancer Prevention Diagnosis Treatment Docsity.com Cancer is not a disease that can be cured-- eliminated from the population… Cancer related checkups every 3 years for people 20- 40, every year for people over 40 Women: 18+ or sexually active = annual Pap tests and pelvic examinations. If multiple partners = more frequent Pap tests…. 20-40 = Professional breast exam every 3 years, monthly self-exams over 40 = yearly mammograms Men: 45+ = Prostate blood tests annually Cancer is undifferentiated cell division. Cancer can be prevented by awareness, monitoring, and proactive treatment. Docsity.com “Science is organized knowledge... Wisdom is organized life.” --Immanuel Kant (1724-1804) German philosopher and founder of critical philosophy Are humans different from animals? -smarter, stronger, more dominant? -more evolved? -possessing something different? soul, spirit, conscience, consciousness… Imbued by their Creator with certain inalienable rights….Jefferson Docsity.com