Understanding the Cell Cycle: Regulation and Cancer Mechanisms

1. Cell Cycle I Oh

2. What is the basic function of the cell cycle? • Accurately duplicate the vast amount of DNA in chromosomes • Segregate the copies precisely into geneticallyidenticaldaughtercells Figure 17-2 Molecular Biology of the Cell, 4th Edition

3. What are the phases and checkpoints of the cell cycle? • G1 – gap between M and S phases • S – DNA replication • G2 – gap between S and M phases • M - mitosis Checkpoints: G1 G2 M Figure 17-13 Molecular Biology of the Cell, 4th Edition

4. The cell cycle is primarily regulated by cyclically activated protein kinases

5. Cdk activity is regulated by inhibitory phosphorylation and inhibitory proteins Why is cell cycle progression governed primarily by inhibitory regulation? Figure 17-18, 17-19. Molecular Biology of the Cell, 4th Edition

6. Cell cycle control depends on cyclical proteolysis Figure 17-20. Molecular Biology of the Cell, 4th Edition

7. Mechanisms controlling S-phase initiation Figure 17-30. Molecular Biology of the Cell, 4th Edition

8. DNA damage leads to cell cycle arrest in G1 Figure 17-33. Molecular Biology of the Cell, 4th Edition

9. Overview of the cell cycle control system Figure 17-34. Molecular Biology of the Cell, 4th Edition

10. Summary of major cell cycle regulatory proteins Table 17-2. Molecular Biology of the Cell, 4th Edition

11. Extracellular signals dictate the cell cycle • Mitogens  Cell division • Growth factors  Cell growth • Survival factors --| Apoptosis (tell the cell not to die)

12. Mitogens stimulate cell division Figure 17-41. Molecular Biology of the Cell, 4th Edition

13. Extracellular Growth Factors Stimulate Cell Growth Figure 17-44. Molecular Biology of the Cell, 4th Edition

14. Extracellular Survival Factors Suppress Apoptosis Figure 17-47. Molecular Biology of the Cell, 4th Edition

15. Cell Cycle II Weber

16. CANCER IS A DISEASE OF GENETIC MUTATIONS ACCUMULATION OF MANY MUTATIONSCAUSES CANCER

17. YOU MUST REMEMBER THAT ALL MUTATIONS ARE RANDOM YOU WILL MUTATE DRIVERS AND PASSENGERS

18. WHAT MAKES A CANCERCELL ACANCERCELL? UNLIMITEDGROWTH UNLIMITEDMOVEMENT

21. THE DEFINITION OF A TUMOR SUPPRESSOR Classical Features: Loss of function mutations Targeted allelic loss- Methylation or Deletion Inherited mutations that predispose to cancer Somatic mutation in spontaneous tumors Ability to inhibit transformed cells in vitro

23. ACTIVATING THE p53 RESPONSE

24. ACCESSING THE CELL CYCLE MACHINERY

25. The Ink4a/Arf Locus

27. SELECTIVE PRESSURE THROUGH STRESS From environment: Dealing with it: -Low oxygen -Low nutrients -Radiation -Ligands -Arrest/Senesce -Apoptosis MUTATE From self: -Random mutant -ROS -Grow too fast

28. Not just division… But growth

29. Active translation 60S 40S AAAAAAAAAA-3’ 5’ UTR UTR Understanding what translation is really all about Growth signals Ribosome biogenesis rRNA synthesis rRNA processing rRNA export PI-3k/mTOR Pathway And Regulators of Ribosome biogenesis

30. GFR Neurofibromin Neurofibromatosis type 1 (NF1) Ras PI3K PTEN Tuberin/ Hamartin Cowden Syndrome Lhermitte-Duclos disease Akt Tuberous sclerosis complex mTOR Rheb eIF4E S6K NPM ARF p68

31. Cancer Cell Biology Stewart

32. Murine cells --- two cooperating oncogenes are sufficient to transform cells SV40 LgT H-ras Tumors

33. Telomere Function distinguishes between the chromosome end and a double strand break protects the chromosome from end-to-end fusions

34. ALT Stop hTERT Rb p53 Stable telomere maintenance The telomere hypothesis Senescence Telomere Length Crisis 1 in ~107 Time

35. T-ag t-ag SV40ER, TERT, and H-rascooperate to transform normal human cells SV40 ER H-ras TERT Tumors Hahn et al, 1999

36. Revised: Functional steps toward cancer Hanahan and Weinberg, Cell 2011 Hanahan and Weinberg, Cell 2000

37. Stroma Stroma Functional steps toward cancer Hanahan and Weinberg, Cell 2011 Hanahan and Weinberg, Cell 2000

38. Is the stroma a participant??? null, Volume 144, Issue 5, 2011, 646–674

39. Tumors are complex “organs”

40. The stroma supplies many key signals that lead to duct formation Glibert Smith’s group has used murine neural stem cells, bone marrow progenitors, cells from testis or human tumor cells and created a new ductal tree in a cleared fatpad! The stroma can dictate differentiation! Hennighausen and Robinson

41. “Humanizing the fatpad allows the outgrowth of human cells Human epithelial cells Human fibroblasts

42. Irradiated fibroblasts or irradiation of the host stimulates tumor formation Irradiated fibroblasts Irradiated host Radiated prior to epithelial implantation Normal or preneoplastic mammary cells Barcellos-Hoff, 2000

43. Stroma plays an important role in tumorigenesis “Normal” Fibroblast Cancer -associated Fibroblast Pre-neoplastic Cell Tumorigenic Cell “Normal” Fibroblast Olumi, 1999

44. Formation of a “premetastatic” niche requires the stroma Sceneay, 2013

45. The stroma impacts tumor cell dormancy Sceneay, 2013 Sceneay, 2013

46. Stroma contributes to the cancer “continuum” null, Volume 144, Issue 5, 2011, 646–674

47. A limited cellular lifespan is a potent tumor suppressive mechanism --- in the stroma

48. “Normal” Fibroblast Pre-neoplastic Cell Cancer -associated Fibroblast Tumorigenic Cell “Normal” Fibroblast “Old/Senescent” Fibroblast Old stroma promotes tumorigenesis

49. Young SIPS RS SIPS SIPS SIPS RS RS RS Young Young Young SIPS SIPS SIPS Growth factors, ECM, and inflammatory genes are all highly upregulated in senescent fibroblasts Pazolli et al. 2009

50. Senescence Senescence evasion Stromal Promotion Normal Premalignant Tumor Box 2. Senescence Stimuli Replicative senescence (RS) - induced by dysfunctional telomeres Stress-induced senescence (SIS) – induced by oncogene overexpression, DNA damage, tumor suppressor activation, reactive oxygen species, non physiological culture conditions and other types of stress. Altered ECM ECM Senescent fibroblast Young fibroblast Senescent epithelial cell Endothelial cell Preneoplastic cell Immune cell Epithelial cell Cancer cell