Oncogenes, Cell Growth, and Cancer (1) Flashcards
What are the two types of genes in malignant development?
Oncogenes
Tumour-suppressor genes
Give examples of tumour-suppressor genes
p53, Rb, APC
Give examples of oncogenes
c-erbB2, Ras, PI3-K, Myc
Where is the initial mutation likely to occur?
Hotspot
What is the effect of overexpressed telomerase in cancer cells?
Extends telomeres - cell division does not stop
What is the result of a mutation in E-cadherin/RhoC?
Invasion - cancer cells grow in cluster
Which enzymes produced by cancer cells break down extracellular material and what are their effect?
Matrix metalloproteinases
Allows cells to move
What is required for cell movement?
RhoC GTPase
Define oncogene
Gene that induces cancer formation when activated by mutations/overexpression
Define proto-oncogene
Normal gene before mutation - highly conserved between different species
What is the main class of oncogene?
Growth factor receptor molecules
Which characteristics of cancer stem cells are shared with normal tissue stem cells?
Self-renewal Proliferative quiescence - infrequent replication - requires certain conditions Multipotency Persistance - long-term survival Drug-resistance Rare
Which characteristics are unique to cancer stem cells?
Tumorgenicity
Proliferative capacity - can rapidly increase population size
What are the two types of tumours?
Benign
Malignant
What are the characteristics of benign tumours?
Unrestrained growth
Do not form metastatic tumours
