Learning Center Articles

Role of immune system : Cancer

Role of immune system

  • Immune response is to reject or destroy cancer cells
    • May be inadequate as cancer cells arise from normal human cells
  • Some cancer cells have changes on their surface antigens
    • Tumor-associated antigens (TAAs)
  • Cytotoxic  T cells
    • Kill tumor cells directly
    • Produce cytokines
  • Natural killer cells and activated macrophages can lyse tumor cells
  • B cells produce antibodies that bind to tumor cells
  • Oncofetal antigens
    • Found on tumor cell surfaces, inside tumor cells, and fetal cells
  • Examples of oncofetal antigens
    • Carcinoembryonic antigen (CEA)
      • On cancer cells of GI tract
      • Normal cells (fetal gut, liver, and pancreas)
    • α-Fetoprotein (AFP)
      • Malignant liver cells and fetal liver cells
    • CA-125 (ovarian carcinoma)
    • CA-19-9 (pancreatic and gallbladder cancer)
    • PSA (prostate cancer)
    • CA 15-3, CA 27-29, HER-2 (breast cancer)
    • kRAS (colon cancer oncogenes)
    • EGFR (lung cancer)