1. Chapter 21 Cancer and the Immune System Dr. Capers
Immunology

2. Kindt • Goldsby • Osborne
Kuby IMMUNOLOGY
Sixth Edition
Chapter 21
Cancer and the Immune System
Copyright © 2007 by W. H. Freeman and Company

3. Cancer Altered self cells Unregulated mitosis Produces tumor
Benign – does not invade healthy tissue
Malignant – grows and becomes invasive
Exhibit metastasis

4. Malignant cancers are classified according to embryonic origin of tissue
Carcinomas
Endodermal or ectodermal
Skin or epithelial lining of internal organs and glands
Colon, breast, prostate, lung
Leukemias and lymphomas
Tumors of hematopoietic cells of bone marrow
Leukemias proliferate as single cells
Lymphomas grow as tumor masses
Sarcomas
Mesodermal connective tissue
Bone, fat, cartilage

5. Malignant transformation
Ability for cell to form cancer
Decreased requirements for growth factors
No longer anchorage dependent
What can cause this?
Various chemical agents
Radiation
viruses

8. Genes that code for
proteins involved in
cell proliferation are
called
proto-oncogenes;
mutations in these
genes can lead to
increased
proliferation

11. Chromosomal translocations
Can lead to movement of proto-oncogenes
This can lead to increased transcription and translation of the protein

12. Induction of cancer is a multi-step process
Multiple and subsequent mutations

13. Tumors of Immune System
Leukemias or Lymphomas
Lymphomas
Solid tumors in lymphoid tissue
Include Hodgkin’s and non-Hodgkin’s lymphomas
Leukemias
Proliferate as single cells
Lymphoid or myeloid lineage
Acute – appear and progress rapidly, tend to rise in immature cells
Chronic – less aggressive and slow, tend to rise in mature cells, tend to be in adults

14. Tumor Antigens Tumor-specific transplantation antigens (TSTAs)
Unique to tumor cells
May arise due to mutation
Are presented on Class I MHC
Tumor-associated transplantation antigens (TATAs)
Proteins expressed on normal cells
Inappropriate expression of embryonic gene
Overexpression of normal protein
Some antigens are tumor specific

15. Oncofetal antigens Found on normal fetal cells
If expressed later in adult, induce immune response
Can lead to cancer
~90% of colorectal cancer have CEA (carcinoembryonic antigen)

16. Tumor Invasion of Immune System
Anti-tumor antibodies
Might actually block sites for CTL to bind
Tumor cells might express less Class I MHC
This prevents CTL-mediated death
Tumor cells may provide poor costimulatory signals

17. Cancer Immunotherapy Manipulation of costimulatory signals
Enhancement of antigen-presenting cells
Cytokine therapy
Interferons
Tumor necrosis factors
Monoclonal Abs may be used for some tumors
Immunotoxins may be linked to kill specific tumor cell, still being researched
Radioactive isotope, drugs