4- Causes of neoplasia

Question 1

Intrinsic factor that causes neoplasm

Answer 1

DNA damage > mutations in critical cancer-related genes

Question 2

Name a extrinsic factor that causes neoplasms

Answer 2

Chemical environmental agents
Physical environmental
Oncogenic viruses

Question 3

What are procarcinogens?

Answer 3

Require metabolic activation by enzymes in order to become carcinogens (cause cancer)

Question 4

Name an example of physical environmental agents that cause cancer

Answer 4

Ionising radiation
UV radiation (Sun)

Question 5

Give 2 direct mechanisms of oncogenic viruses

Answer 5

Dominant oncogene mechanism
Insertional mechanism
Hit & Run mechanisms

Question 6

Explain Dominant oncogene mechanism

Answer 6

Mutated genes in viruses that drive tumour development

Obtained by host animal cells or within the viral genome

Question 7

Explain insertional mechanism

Answer 7

Insertion of viral DNA that in return activate target cell oncogene

Typical of viruses that do not possess their own oncogene

Question 8

Explain hit & run mechanisms

Answer 8

Viral genome cause neoplasm be transient residence in target cells
- not persistent in host cell

Question 9

Indirect mechanism of oncogenic viruses

Answer 9

Suppression of animals immune system
Stimulation of target cell proliferation

Question 10

What is a direct acting chemical carcinogen

Answer 10

Effective in the form in which they enter the body

Question 11

What are indirect-acting chemical carcinogens

Answer 11

Procarcinogens (require metabolic activation by enzymes)