Flashcards in cancer biology (carcinogens) Deck (21):
What are clonal cells?
originating from one cell
Are all cancer cells clonal?
but there can be subpopulations caused by more mutations
What are carcinogenesis?
cause of cancer formation
includes events leading to cancer formation
What is progression?
mutations made after tumor event dancer has formed
What is the typical tumor doubling time for breast cancer?
What are carcinogenesis usually studied in?
What was the first identification of carcinogens?
chemicals in 1700
high scrotal cancer in chimney sweeps
this led to animals to test chemicals
What was the ames test?
using bacteria to test for mutagenic abilities
doesn't mean mutagen is carcinogenic, it cause mutations
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
Why is the liver used in the ames test?
because some chemicals need to be activated in the liver
What are the two stages of cancer cell formation?
initiation- mutation in DNA
promotion- mutated cells divide
What are some initiators?
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
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
When does tumors does angiogensis?
~1mm in size
What plays a role in cancer formation?
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
What do cells need to get multiple mutation?
Cancer cells undergo multiple mutations
they need a promoter to constantly force mutations
What is de-differentiation?
when a cancer cell goes backwards more towards a progenitor cell
Why are dedifferentiated cells a bad prognosis?
because you need a large number of mutations for that to happen