Lecture 7: Cell Division and CancerLeading Causes of DeathLeading Sites of New Cancer and Deaths 2003 estimatesCancerHow does Cancer Start? Cellular Damage ControlPowerPoint PresentationSlide 7TumorCancer TerminologyUnderstanding CancerCell DivisionSlide 12Cell CycleSlide 14Decoding the Cell CycleControl of the CycleCell Division DNA Replication SummarySlide 18MitosisSlide 20Slide 21Cell Division MitosisStupmer also… Key Concept:ChromosomesCancer and GeneticsSlide 26Gene RegulationSlide 28Slide 29Cancer and SmokingSmoking and CancerSlide 32Programmed Cell DeathSlide 34Slide 35Slide 36The Cancer has SpreadMetastasisAngiogenesisSlide 40Slide 41Slide 42Angiogenesis and MetastasisSlide 44Markers for CancerSlide 46HeLa CellsReviewEXTRA CREDIT #1Slide 50Slide 51Slide 52Slide 53Slide 54Lecture 7: Cell Division and CancerLecture 7: Cell Division and CancerObjectives:Understand basic concepts of cancerUnderstand cell divisionUnderstand how cell division is regulatedUnderstand programmed cell deathKey Terms: Mitosis, interphase, tumor, metastasis, angiogenesis, neoplasm, benign, malignant, adenoma, carcinoma, tumor suppressor, growth factor, check point, oncogene, programmed cell deathLeading Causes of DeathTotal 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.htmUS Population 20-24 •Accidents•Homicide •Suicide•Cancer •Heart disease •Genetic Disease•HIV (AIDS)•Stroke •Flu and Pneumonia •DiabetesLeading Sites of New Cancer and Deaths 2003 estimatesMale New cases DeathsProstate220,900 28,900Lung 91,800 88,400Colon 72,800 28,300Bladder 42,200 8,600Melanoma (skin) 29,900 naFemale New cases DeathsBreast 211,300 39,800Lung 80,100 68,800Colon 74,700 28,800Uterine 40,100 6,800Ovary 24,400 14,300Cancer Features of Cancer Cells1. Make their own growth signals2. Insensitive to growth stopping signals3. Insensitive to self destruct signals4. Immortal ! : unlimited replication5. Stimulate new blood vessel growth6. Invasive : move out of tumorHow does Cancer Start?Cellular Damage ControlNormal cells protect their DNA InformationDamage control system1. Detect DNA and cellular damage2. Stop cell division (prevent replication of damage)3. Activate damage repair systems4. Activate self destruct systemDAMAGEEVENTStop Cell DivisionActivate Damage RepairDamage Assessment Repair is SuccessfulMild to Moderate DamageSevereDamageProgrammed Cell DeathRepairFailsDamage AccumulationLeads to Cancer##Tumor•An abnormal mass of undifferentiated cells•It often interferes with body functions•It can absorb nutrients needed elsewhere•It can be benign, grow slowly and stay in one area.•It can be malignant, grow rapidly and spread to other parts of the bodyCancer Terminology•Neoplasm-Cells that have no potential to spread to and grow in another location in the body•Benign-Non-cancerous growth that does not invade nearby tissue or spread •Malignant-growth no longer under normal growth control•Metastasis-spread of cancer from its original site to another part of the body•Adenoma-A benign tumor that develops from glandular tissue•Carcinoma-A tumor that develops from epithelial cells, such as the inside of the cheek or the lining of the intestineUnderstanding CancerTo understand cancer, you must understand three fundamental cellular processes1.Cell Division2. Gene Regulation3. Programmed Cell DeathCell DivisionKey concepts of Cell Division1. Cell Cycle2. DNA Replication3. Chromosome Division4. Cell DivisionCell DivisionKey Concept:There are two types of cell divisionMitosis – for growing, results in two identical cells.Meiosis – for sexual reproduction, results in four cells with only one copy of chromosomesCell Cycle •Cycle starts when a new cell forms•During cycle, cell increases in mass and duplicates its chromosomes•Cycle ends when the new cell dividesKey Terms:Cell Cycle, Chromosomes, Cell DivisionWhat do they Mean?Fig. 8.4, p. 130Interphase: Phase between division and starting division again.Three parts of Interphase1. G11st Growth phase- cell makes parts, and does normal things2. S Synthesis phase- DNA replication3. G22nd Growth phase- making parts for cell division4. G0 Zero Growth phase•Like getting stuck in park•Terminal developmentKey Concept:At each step, the cell mustbe in orderLongest part of the cycleCell mass increasesCytoplasmic components doubleDNA is duplicated Decoding the Cell CycleG1SINTERPHASEG2Control of the Cycle•Once S begins, the cycle automatically runs through G2 and mitosis•The cycle has a built-in molecular brake in G1 (p53 tumor suppressor) •Cancer involves a loss of control over the cycle, malfunction of the “brakes”Cell Division DNA Replication SummaryEnzymes•Topoisomerase unwinds strands•DNA Polymerase attaches new complementary nucleotides•DNA Ligase connects the bonds between phosphate sugar backbone of the new nucleotidesChemical Bonds •Break hydrogen bonds with Topoisomerase•Make Hydrogen bonds with DNA Polymerase•Make covalent bonds with DNA LigaseFinal Products•The strand being replicated is the template•Start with one copy of a DNA molecule and end with two copies–New copies have one new strand and one old strand–Both copies are “identical” to the originalMITOSISMitosis Definition:•Period of nuclear division•Followed by cytoplasmic divisionMulti-step processnucleusplasmamembranepair of centrioleschromosomesnuclear envelopeCELL AT INTERPHASE EARLY PROPHASE LATE PROPHASETRANSITION TO METAPASEFig. 8.7a, p. 132The cell duplicates its DNA, prepares for nuclear divisionMitosis begins. The DNA and its associated proteins have started to condense. The two chromosomes color-coded purple were inherited from the female parent. The other two (blue) are their counterparts., inherited from the male parent.Chromosomes continue to condense. New microtubules become assembled. They move one of the two pairs of centrioles to the opposite end of the cell. The nuclear envelope starts to break up.Now microtubules penentrate the nuclear region. Collectively, they form a bipolar spindle apparatus. Many of the spindle microtubules become attatched to the two sister chromatids of each chromosome.MITOSISMETAPHASE ANAPHASE TELOPHASEINTERPHASEFig. 8.7b, p. 133All chromosomes have become lined up at the spindle equator.
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