Cancer

Question 1

Causes of Cancer

Answer 1

Lifestyle (smoking alcohol), Environmental pollutants, Genetics (Aging, mutations), Impaired immune surveillance

Question 2

Why cancer occurs

Answer 2

due to a problem with control systems

• Arises when multiple control systems are corrupted within a single cell (promote abnormal growth, or protect against uncontrolled growth)
• Once full frown most cell proliferation ceases, but may continue inapporapriately due to genetic mutation (proto-oncogene becomes oncogene)
• Internal safeguards fail: proteins that prevent mutation, fix damaged DNA, trigger apoptosis if damage is severe

Question 3

mutations in cancer

Answer 3

estimate between three – four mutations required to produce common cancers. The cases to disrupt proteins the repair mutated DNA common cause of cancer

Question 4

immunosuppression associated with cancer

Answer 4

weakened immune system causes increased incidence of lymphoma and virus associated with cancer

Question 5

RAG-2

Answer 5

protein necessary to assemble BCR and TCR. Cancer incidence increases if RAG-2 is deficient

Question 6

CTLs and spontaneous tumors

Answer 6

occurs in the majority of cancers, probably not effective

Question 7

CTLs and cancerous blood cells

Answer 7

probably more effective, traffic patterns of cancer cells and blood virgin T cells intersect. Some cancerous blood cells express high levels of B7 (co-stimulation)

Question 8

CTLs and virus associated tumors

Answer 8

probably limited due to hiding viruses are the ones associated with cancers and CTLs not effective against these

Question 9

macrophages and cancer

Answer 9

quick acting, recognize that verse structures, and located in tissues where most tumors arise. Thus they may provide surveillance against cancers.

• Hyperactive macrophages secrete TNF and express it on their surface, which can kill certain types of cancer
• abnormal expression of surface molecules on tumors may allow activated macrophages to differentiate between cancer cells and normal cells

Question 10

NK cells and cancer

Answer 10

quick acting, recognize diverse targets , located in blood, and can destroy some cancer cells

• target cells that express low levels of MHC I and display unusual surface molecules

Question 11

vaccination to prevent cancer

Answer 11

used in virally associated cancers: Hep B, liver, and HPV

Question 12

cells that are tumor promoting

Answer 12

mast cells, CD4 +, Th2 (more so than Th1)

Question 13

cells that are always anti-tumor

Answer 13

NK cells, NKT cells

Question 14

MPDL320A

Answer 14

a manufactured antibody IMMUNE THERAPY that targets a protein called PD-L1 (program death ligand 1)

• enable T cells to effectively attack cancer cells

Question 15

Bacille Calmette-Guerin (BCG)

Answer 15

a form of IMMUNE THERAPY that injects tumors with hyperactive macrophages which can destroy the tumor

• also used to immunize against tuberculosis, but not always effectiv