YIJC [H2] CI2.8_Molecular Biology of Cancer

2024 JC1 BIOLOGY LECTURE NOTES CORE IDEA 2: GENETICS AND INHERITANCE TOPIC 2.8: Molecular Biology of Cancer Learning Outcomes: You should be able to: (o) (modified) explain the need to regulate the mitotic cell cycle tightly (knowledge that dysregulation of checkpoints of cell division can result in uncontrolled cell division and cancer is required, but details of the mechanism are not required) (p) identify the causative factors, including genetic, chemical carcinogens, ionising radiation and loss of immunity, which may increase the chances of cancerous growth (q) explain how the loss of function mutation of tumour suppressor genes, including p53, and gain in function mutation of proto-oncogenes, including ras, results in uncontrolled cell division (r) describe the development of cancer as a multi -step process that includes accumulation of mutations, angiogenesis and metastasis Use the knowledge gained in this section in new situations or to solve related problems. References: Campbell, N. A., Reece, J. B., et al. (2018). Biology A Global Approach (Eleventh Edition)  Chapter 12 Mitosis, p284 – 299  Chapter 13 Sexual Life Cycles and Meiosis, p304 - 317 Note: Some of these references (including previous editions) are available in our library. You may wish to borrow them or visit the links to supplement your reading when necessary. Lecture Outline 1 Introduction ................................ ................................ ................................ ............................ 2 2 Checkpoints In The Cell Cycle ................................ ................................ .............................. 4 3 Causative Factors Leading To Cancerous Growth ................................ .............................. 7 4 Important Genes Controlling The Regulation Of Cell Cycle ................................ ............... 8 4.1 Proto-Oncogenes................................ ................................ ................................ ............. 9 4.2 Tumour Suppressor Genes ................................ ................................ ........................... 12 5 Multistep Model Of Cancer Development ................................ ................................ ........... 14 H2

2 1 Introduction The cell cycle is the sequence of events that occurs throughout the life of a cell, from its formation as a new cell by division, to its own division into two daughter cells.  A cell cycle that involves mitosis will give rise to genetically identical cells and this is important for growth, repair and the asexual reproduction of organisms.  This cycle is coupled intricately with DNA replication , which occurs during the synthesis phase of interphase. The cell cycle compromises of two main stages 1. Interphase: Comprises of G1 phase, S phase and G2 phase 2. Mitotic phase (M phase): com