Cellular and Molecular Mechanisms in Cancer Flashcards
3 characteristics of cancer at the cellular level
Excessive cellular proliferation
Uncontrolled growth
Tissue infiltration
2 things that happen during G1
The cell increases in size
Synthesis of new proteins and organelles
What happens in G2
Organelles and molecules required for cell division are produced
3 factors that put cell into G0
Cell-cell contact
Cell differentiation
Anti-mitogenic factors
3 factors that bring cell out of G0
Mitogens
Growth factors
Nutrients
What happens beyond the restriction point
Growth factors and mitogens are not needed
4 hallmarks of cancer
Genomic instability
Inappropriate cell proliferation, evasion of cell death
Angiogenesis
Invasion and metastasis
RB gene
A TSG
Inactivation of RB leads to progression through the restriction point in cell cycle
Inactivation of both copes of RB leads to retinoblastoma
p53
A TSG
Most commonly mutated gene in cancer
When it is functional, can can encourage the cell to become quiescent or can induce apoptosis
When it is not functional, cells can evade cell death
BRCA 1 or 2 gene
TSGs
Intact, these genes code for proteins that allow for DNA repair using homologous recombination
When absent, the cell can’t repair DNA as well as it used to
Does RB need to be hypo or hyperphosphorylated to allow for gene transcription?
Hyper
Cyclin D and CDK4/4 promote the cell progression by phosphorylating it
How do cancer cells avoid attack of the immune system?
They have the PD1 ligand on them, so immune system cells recognize them as self
What are 2 general types of tissues that are more prone to neoplasm?
Proliferating tissues/tissues that are more undifferentiated (skin, lung, gut)
Hormonally regulated tissues (breast, prostate)
At what size to tumors start to recruit new blood vessels?
Over 2 mm
2 positive regulators of angiogenesis
Vascular endothelial growth factor (regulated by ras)
Basic fibroblastic growth factor
