Molecular and Cellular Basis of Cancer Flashcards
What are the hallmarks of cancer?
MAGIIE
Metastasis Angiogenesis Growth Inability to stop growth Immortality Evasion of death
Why is cancer not necessarily hereditary?
Most cancers arise from sporadic mutations instead of inherited mutations
What causes initiation?
Exposure of cells to a carcinogenic agent
What happens during initiation?
Permanent DNA damage occurs due to exposure to carcinogen. It is irreversible and has a memory.
What is the significance of initiation having a memory?
When a promoter is applied, tumours will always be formed regardless of time scale
What does a promoter do?
Induce tumours from initiated cells but cannot cause tumours on their own
What is a carcinogen?
A chemical that initiates carcinogenesis
What is a direct-acting carcinogen?
Require no metabolic conversion to become carcinogenic
What is an indirect-acting carcinogen?
Must be metabolised before they bind to DNA
What is a driver mutation?
A mutation that gives a selective advantage to a clone in its environment. Causes malignant
What is a passenger mutation?
A mutation that is not significant and does not contribute to cell survival
What is intra tumoral heterogeneity?
When different tumour differ morphologically
What are oncogenes?
Code for oncoproteins that promote abnormal cell growth and proliferation
What happens when RAS is mutated?
Decrease in GTPase activity, causes increase in GTP-bound form of RAS which causes cancer
When happens when CDK4/D cyclin is mutated?
Mitosis is not arrested at the G1/S checkpoint, therefore uncontrolled mitosis occurs
