BSI Lecture 29-30 Mechanisms of Cancer 2 Flashcards
What does angiogenesis mean?
New blood vessel growth.
Small tumors can receive adequate O2 and nutrients by diffusion from ____ ______
Blood vessel
Larger tumors need growth of new ____ ____
Blood vessel
Onset of _____ is due to the imbalance between pro- and anti-angiogenic factors (upregulation of pro-angiogenic proteins/downregulation of anti-angiogenic proteins)
Angiogenesis
_____ is the most potent stimulus for angiogenesis.
VEGF
What does VEGF stand for?
Vascular endothelial growth factor
What is the stimulus for VEGF?
Hypoxia
Hypoxia-inducible transription factor (HIF) binds to VEGF gene and induces _______.
Transcription
Mutations in ___ results in over expression of VEGF
p53
Activation of ___ can also lead to overexpression of VEGF.
ras
______ are cells related to vascular smooth muscle which are located adjacent to and surround the endothelium.
Pericytes
Basement membrane and extracellular matrix are degraded by _________
MMPs (matrix metalloproteinase)
_______-cells migrate into perivascular space towards angiogenic stimuli (VEGF) produced by tumor cells.
Endothelial
When endothelial cells proliferate they can adhere to each other and create a ____, then formation of basement membrane and pericyte attachment will occur.
lumen
______ is the migration of cells into deeper tissues—cancer cells break through the barrier that keeps them localized.
Invasion
The invasive _____ is what categorizes a tumor as malignant.
phenotype
________ is the spread of cancer cells from a primary tumor to distant sites in the body.
Metastasis
What are the steps in Metastasis?
- Tumorigenesis
- Angiogenic switch
- Acquire invasive phenotype
- Survival in circulation
- Extravasation & growth at secondary site
- Angiogenesis in secondary tumor
- Evasion of immune response
T or F? Tumor cells can avoid death by cytotoxic T cells and induce apoptosis of cytotoxic T cells
True
Cytotoxic T cells expresses ___ and ___
FasL ; Fas
Tumor cells express ____ (normal cells usually do not) and downregulate Fas
FasL
Tumor cells can _____ cFLIP
upregulate
Tumor cells (with low _____) are resistant to apoptosis by cytotoxic T cells
Fas
Tumor cells (due to ____ expression) induce apoptosis in cytotoxic T cells
FasL
Human papilloma virus (HPV) inactivates ___ and ____
p53 and Rb
T or F? HPV vaccine protects against two types of HPV that cause 70% of cervical cancers and also protects against two types of HPV that cause 90% of genital warts.
True
T or F? HPV is a cancer that sequester Rb and p53.
False, HPV is a virus that has viral proteins that inhibits Rb(by E7) and p53(by E6)
Normal vasculature is dormant in healthy adults with endothelial cells dividing ~ once every ___ years
10
______ are cells related to vascular smooth muscle which are located adjacent to and surround the endothelium.
Pericytes
What are the 6 precesses of angiogenesis?
- Pericytes detach
- Basement membrane and extracellular matrix degraded by MMPs (Matrix metalloproteinase
- Endothelial cells migrate into perivascular space toward angiogenic stimuli (VEGF) produced by tumor cells
- Endothelial cells proliferate
- Endothelial cells adhere to each other and create a lumen.
- Formation of basement membrane and pericyte attachment
What are MMPs stand for and what do they do?
Matrix metalloproteinase and they degrade the basement membrane and extracellular matrix
