Tumor-host interactions

Question 1

how does host recognize tumor

Answer 1

tumor antigens

Question 2

3 types of tumor antigens

Answer 2

1. products of mutated genes
2. overexpresses or aberenttly expressed genes
3. tumor antigens produced by oncogenic viruses

Question 3

what are products of mutated genes

Answer 3

mutations in proto-oncogenes and tumor supressor genes

Question 4

2 types of over/aberantly expresses proteins

Answer 4

1. if express one that was normally only minimally expressed will set off signals
2. proteins that were normally hidden (testes)

Question 5

what kills prododucts of oncogenic viruses

Answer 5

CD8 cells recognize and kill

Question 6

2 types of cell mediated immunity against tumor

Answer 6

1. CD8
2. NK cells - don’t need prior sensitization
   - kill cells without MHC

Question 7

do macrophages kill

Answer 7

yes, in concert with T and NK cels

Question 8

what do antibodies do

Answer 8

not much help

- monoclonal ABs being developed against specific receptors

Question 9

6 ways that tumors escape detection

Answer 9

1. selection of antigen negative cells
2. loss or reduced expression of MHC -may activate NK cells
3. lack of co-stim
4. immunosupression (TGF-B production)
5. antigen masking
6. apoptosis of cytotoxic T-cells (fas-fasl) binding

Question 10

5 effects of tumor on host

Answer 10

1. physical/load effects
2. functionality of tumors
3. paraneoplastic sndrome
4. cachexia
5. immunosupression

Question 11

what types of tumors cause phsycial/load effects

Answer 11

both benign and malignant

Question 12

what is load effects

Answer 12

1. obstruction or impingment
2. impaired organ function
3. pain
4. CNS dysfunction

Question 13

what is effect of functionality of tumors

Answer 13

tumors arising from cells with secretory functions

Question 14

type of tumor to create more functionality

Answer 14

benign more common

Question 15

def. paraneoplastic syndrome

Answer 15

symptom complex that cannot be explained by local or metastatic spread of tumor
- from hormones not normally produced there

Question 16

3 common paraneoplastics

Answer 16

ACTH, ADH, PTH - all from SCC of lung

Question 17

is hypercalcemia from parathyroid tumor paraneoplastic?

Answer 17

no

Question 18

is hypercalcemia from skeletal mets paraneoplastic?

Answer 18

no

Question 19

is hypercalcemia from SCC of clung paraneoplastic?

Answer 19

yes

Question 20

what is cachexia

Answer 20

progressive loss of body fat and lean muscle mass with weakness and anorexia - MandM

Question 21

why does cachexia occur

Answer 21

most likely due to cytokine production

- esp TNF and IL-1

Question 22

how does CA suppress immune system

Answer 22

TGF-B production