tumor immunology

Question 1

Tumor

Answer 1

cells with uncontrolled cell growth

Question 2

Cancer

Answer 2

when a tumor continues to grow and invade healthy tissue.

Question 3

Oncology

Answer 3

the study of tumors

Question 4

Benin tumors

Answer 4

localized, encapsulated, limited size

Question 5

Malignant tumors

Answer 5

continue to increase in size, invade adjacent tissues

Question 6

Metastasis

Answer 6

enter the circulation and spread

Question 7

Carcinoma

Answer 7

endodermal/ ectodermal origin

Question 8

Sarcoma

Answer 8

other cell types : mesodermal origin

Question 9

Leukaemia

Answer 9

circulating cells of the immune system

Hematopoietic origin

Question 10

Lymphoma

Answer 10

solid lymphoid tissue

Hematopoietic origin

Question 11

Myeloma

Answer 11

bone marrow (plasma cell)

Hematopoietic origin

Question 12

Metastasis

Answer 12

spread to distant organs

Question 13

Normal Cell Growth promoting

Answer 13

Proto-oncogenes

Question 14

Normal Cell Growth restricting

Answer 14

Tumor-suppressor genes

Question 15

Molecular Basis of Cancer

Answer 15

Mutation of proto-oncogenes to oncogenes

Altered tumor-suppressor genes:
* p53 mutation

Question 16

Colorectal cancer

Answer 16

successive mutations of several (5-6) independent genes

Question 17

Burkitt’s lymphoma

Answer 17

Gene Translocation

Expression of MYC gene is altered

associated with a viral infection – Epstein Barr virus

Question 18

Failure of the immune system ->

Answer 18

Tumor

Question 19

What are tumor antigens

Answer 19

1. Tumor Specific Antigens (TSAs)

2. Tumor Associated Antigens (TAAs)

Question 20

Tumor Specific Antigens (TSAs)

Answer 20

found only on cancer cells

may arise due to: 

• Mutation (Mutated P53)
• Viral antigens (ooncogenic viruses)

Question 21

Tumor Associated Antigens (TAAs)

Answer 21

expressed only at certain stage of differentiation

or

Over expression of a normal antigen

Question 22

Alpha-fetoprotein (AFP)

Answer 22

secreted by fetal liver

Question 23

Carcino-embryonic antigen (CEA )

Answer 23

Found in the gut, liver and pancreas of fetus. Detected at low level in healthy adults

Question 24

Cancer/testis antigen: (CT antigen)

Answer 24

expressed on immature sperm cells or trophoblasts ( in early embryo) but not is somatic cells

Question 25

Melanoma-associated antigen (MAGE)

Answer 25

normally expressed on cells of testis (immunologically privileged site)

Question 26

How Tumor Avoid Immune Attack

Answer 26

* MHC I down-regulated – loss of CTL (CD8) * Antigen-less variants OR antigen variant (mutated) * Antigen masking by sialic acid containing mucopolysaccharides * Lack of co-stimulatory molecules (B7) – T cell anergy * FasL expression – T cell apoptosis * TGF-β production: suppress Th1 and promote T-reg * Suppress the immune system by recruiting T-reg – which produce down regulating cytokines, TGF-β , IL-10 * Manipulating/ shedding – MIC (MHC I associated chain or Stress induced molecules (known as Killer activating ligand) * Cancer of privileged sites

Question 27

TGF-β, IL-10

Answer 27

suppresses auto-reactive T cells by TREG

Question 28

High frequency of Treg

Answer 28

indicates a poor prognosis

Question 29

Abnormally high level of monoclonal Ig

Answer 29

indicate a plasma cell tumor

Question 30

Detection of alpha-Fetoprotein ( AFP)

Answer 30

associated with liver cancer

Question 31

Carcinoembryonic antigen (CEA)

Answer 31

indicate malignancy – several, colorectal, pancreas etc

Question 32

Prostate-specific antigen (PSA)

Answer 32

indicate prostate cancer

Question 33

Cancer antigen -125 (CA-125)

Answer 33

ssociated with ovarian cancer, uterine (fallopian) tubes, endometrium (lining of the uterus), lung, breast, and gastrointestinal tract

Question 34

Radiolabeled Monoclonal Antibody B72.3

Answer 34

recognizes all human carcinomas – used in tumor localization

Question 35

IFN-alpha

Answer 35

NK cell activation

Question 36

IFN-gamma

Answer 36

activates CTL, up-regulates MHC expression

Question 37

IL-2

Answer 37

T cell, NK cell proliferation

Question 38

Increasing co-stimulation

Answer 38

Anti-CTLA4 monoclonal antibodies

Question 39

BCG – induce inflammation

Answer 39

bladder cancer therapy

Question 40

Monoclonal antibodies

Answer 40

target the immunosuppressive mediators secreted by tumor *** anti-TGF-beta

Question 41

Anti-tumor monoclonal antibodies, with or without conjugation to toxic drug, radiation

Answer 41

immunotoxins