Cancer and cell Regulation

• Timing and rate of cell division


  Crucial to normal growth, development and maintenance
• Frequency of cell division

  • Varies with the type of cell
• Cell cycle


  Regulated at certain checkpoints by both internal and external controls
• Checkpoints


  Stop and go-ahead signals that regulate the cell cycle
• Major checkpoints


  • G1 checkpoint
  • G2 checkpoint
  • M checkpoint
• G1 checkpoint looks for


  • Cell size
  • Nutrients
  • Growth Factors
  • DNA damage
• G2 checkpoint looks for


  • Cell size
  • DNA replication
• M checkpoint


  Checks that all spindle fibers have attached to the centromere
• Apoptosis


  The death of cells that occurs as a normal and controlled part of an organism's growth or development
• Rate of cell division in non-cancerous cells


  • Wide range related to the function of each cell type
  • Some cells lose capacity to divide as they differentiate and mature
• Mammalian red blood cells only have 100 to 120 days to function as oxygen (and carbon dioxide) transporters after extruding their nuclei</b>
• Most normal cells undergo 20 to 30 rounds of cell division before carrying out programmed suicide (Apoptosis)
• Cancer cells


  • Do not respond normally to the bodies control systems
  • Characterized by uncontrolled cell division
• Cancer cells are different from normal cells in two fundamental ways: they divide out of control and they can pile up on one another
• Rate of division in cancerous cells


  • Cells with enough mutations may lose control of cell division, leading to the development of cancer
  • Cancer cells have been found to create an enzyme called telomerase, signaling the continuation of cell division
  • Mutations in other cancer cells don't allow the cells to produce or recognize proteins that signal cell suicide
• Common types of carcinomas


  • Lung
  • Breast
  • Colon
  • Bladder
  • Prostate
• Other common cancer types


  • Leukemias (Bloodstream)
  • Lymphomas (Lymph nodes)
  • Sarcomas (Fat, Bone, Muscle)
• Tumor


  Abnormal lump of cells
• Benign tumor


  Tumor remaining in one place in the body
• Malignant tumor (cancer)


  Tumor capable of spreading through the body
• Metastasis


  Spread cancer that started in one place and is now also in another
• Causes of cancer


  • Random changes in DNA during cell division
  • Carcinogens: environmental factors that cause cancer
• Well-known carcinogens


  • Tobacco smoke
  • Radiation (e.g., X-rays, UV rays from tanning beds/sunlight)
  • Some viruses (e.g., the human papillomavirus [HPV] and hepatitis B)
  • Certain chemicals in plastics
  • Many organic solvents
• If a group of people is exposed to a carcinogen, some will develop cancer while others will not
• Cancer screening


  Getting checks for cancer even without symptoms
• Screening can help determine if you inherited DNA linked to cancer
• Ways to reduce risk for cancer


  • No smoking or vaping
  • Healthy diet with less fatty meats
  • Eating "super foods" rich in healthy substances
• Diagnosing cancer


  • Growing tumour can result in a variety of symptoms, but many early stages have no noticeable symptoms
  • Various imaging technologies can be used to identify abnormalities
  • Biopsy is the only way to confirm a diagnosis of cancer
• Main treatment methods for cancer


  • Surgery
  • Chemotherapy
  • Radiation
  • Biophotonics
• Biophotonics


  Newer technology that uses beams of light to detect and treat cancer, with fewer side effects than conventional radiation treatment and can more accurately target the cancerous tissue