Flashcards in cancer biology (carcinogens) Deck (21):
1
What are clonal cells?
originating from one cell
2
Are all cancer cells clonal?
yes
but there can be subpopulations caused by more mutations
3
What are carcinogenesis?
cause of cancer formation
includes events leading to cancer formation
4
What is progression?
mutations made after tumor event dancer has formed
5
What is the typical tumor doubling time for breast cancer?
100 days
6
What are carcinogenesis usually studied in?
animal models
7
What was the first identification of carcinogens?
chemicals in 1700
high scrotal cancer in chimney sweeps
this led to animals to test chemicals
8
What was the ames test?
using bacteria to test for mutagenic abilities
doesn't mean mutagen is carcinogenic, it cause mutations
9
describe the ames test?
1) grind up liver
2)solution (growth factors)
3)plate (no growth) control
1) steps above but mix with possible mutagen. if growth then it causes mutations
10
Why is the liver used in the ames test?
because some chemicals need to be activated in the liver
11
What are the two stages of cancer cell formation?
initiation- mutation in DNA
promotion- mutated cells divide
12
What are some initiators?
Chemicals
physical agents
viruses-oncongenes
13
What are the five scenarios to cancer or no cancer formation?
1) initiator then promoter- cancer
2) initiator then promoter after longer time - cancer
3)initiator promotor spread out - no cancer
4) promoter first then initiator - no cancer
5)initiator one after another n promoter - cancer
14
Why is there no cancer in when the promoter is spread over a period of time?
it gives time for repair mechanisms to work between promoters
15
When does tumors does angiogensis?
~1mm in size
16
What plays a role in cancer formation?
genetics
environment
17
initiation/promotion can depend on what?
developmental stage of cell and cell of origin
ex. is it still dividing
ex. some carcinogens don't cause cancer in some types
18
What do cells need to get multiple mutation?
Cancer cells undergo multiple mutations
they need a promoter to constantly force mutations
19
What is de-differentiation?
when a cancer cell goes backwards more towards a progenitor cell
20
Why are dedifferentiated cells a bad prognosis?
because you need a large number of mutations for that to happen
21