Nutrition and Cancer 2020

Question 1

differences between photo-oncogenes and oncogenes

Answer 1

Proto-oncogenes may be changed into oncogenes which will promote cell-growth and division. Note that proto-oncogenes are responsible for the promotion of cell-growth and proliferation of ALL genes where oncogenes particularly target cancer cells.

Question 2

clinical cancer

Answer 2

when an actual mass is detected

Question 3

anti-initiation strategies

Answer 3

serve to limit genetic and epigenetic alterations

• alter carcinogen metabolism
• enhance carcinogen detoxification
• scavenge ROS
• enhance DNA repair

Question 4

anti-promotion/progression strategies

Answer 4

• scavenge ROS
• decrease inflam
• suppress inflam
• enhance apoptosis
• enhance immunity
• discourage angiogenesis

Question 5

gene expression

Answer 5

-genotype to phenotype ( affected by penetrance and epigenetic

Question 6

can gene mutation be inherited?

Answer 6

yes, example: BRCA1 gene which increases the risk of breast cancer- it also has high penetrance so phenotype will likely show

Question 7

polymorphism vs mutations

Answer 7

SNP much more common but much less penetrance

Question 8

epigenetic example specific to cancer development

Answer 8

DNA methylation (turns off gene) of tumour suppressor

Question 9

how can diet play a role in the development of cancer

Answer 9

bioactive food compartments could affect DNA but mostly affects epigenetic ( the expression o mRNA and the post translational modifications)
- example: oxidative damage to DNA from carcinogens in food

Question 10

oxidative damage to DNA may be caused by what?

Answer 10

increased carcinogen sound in food, PUFS (when oxidized), free iron, glycophosphate from pesticides, decreased AN or cofactors for AN enzymes (selenium and copper)

Question 11

which dietary factors are important determinants of human cancer?

Answer 11

• excess weight (and factors that related: elevated insulin and IGF-1) - could account for 1/3 of CA known to be influenced by diet (excess weight= CA of colon, kidney, pan, eco, endometrium, liver, gall)

Question 12

energy restriction does what to cancer development?

Answer 12

reduces dev - we should take away that eating more will cause an increased rate of cancer

Question 13

obesity and breast cancer

Answer 13

greater risk only after menopause

Question 14

fat intake and cancer risk

Answer 14

no association
- one study: animal fat and premenopausal breast CA, but low-fat diets do not support belief that they prevent breast CA (even found higher risk in one!)

Question 15

dietary fat and colon cancer

Answer 15

red meat and processed meat associated with colorectal CA

Question 16

red meat vs processed meat and cancer risk

Answer 16

processed is higher evident but red meat is slightly less evident

Question 17

mechanisms behind meat and cancer

Answer 17

1. preservatives: nitrites alone are not carcinogens but when linked with aa nitrosamines which occur in the stomach- cause cancer
2. heme molecule may promotes formation of nitrosamine compounds
3. high heat- polycyclic aromatic hydrocarbons and heterocyclic amines (carcinogenic) - however no number attached to this?

Question 18

dairy products and cancer

Answer 18

high milk and dairy (>4 servings/day)associated with decreased risk of colon CA, some say increased risk of prostate (advanced and fatal type- could be to do with ca) but no association with regular prostate CA

Question 19

fruit and veg and cancer

Answer 19

> 250 studies say decreased risk of cancer ( but recently level of evidence may be less than originally thought- due to limitations of descriptive and case-control studies - French fry example)

Question 20

fiber

Answer 20

dilute carcinogens (simular to Ca in dairy products), serve as substrate for microbiota- butyrate= anti-proliferative

Question 21

alcohol

Answer 21

very well know cause of CA (oral, larynx, eco, liver) espessical in combo with smoking

Question 22

mechanism for alcohol and Ca risk

Answer 22

anti-folate

- take folate supp reduce risk of breast in alcoholics

Question 23

Calcium and CA

Answer 23

reduce risk of colon- bind toxic substances

- get to RDA, sup if not met