Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
|
How can tumors cause sustained angiogenesis?
|
By stimulating host blood vessel growth
|
|
|
What factors do tumors secrete to stimulate angiogenesis?
|
VEGF and bFGF
|
|
|
Once newly formed vessels are made, how does angiogenesis CONTINUE?
|
The endothelial cells also secrete growth factors
|
|
|
What are 4 features of tumor vessels that make them different from normal vessels?
|
-Leaky
-Produced continuously -Tortuous and irregular -Allow for metastasis |
|
|
What are 3 angiogenesis inhibitors that can be given as treatment?
|
-Endostatin
-Tumstatin -Anti-VEGF and VEGF-R2 |
|
|
What is the primary cause of cancer-related morbidity and mortality?
|
Invasion and metastasis
|
|
|
2 things need to happen for a metastasis to occur:
|
1. Invasion of ECM
2. Vascular dissemination |
|
|
So what are the 2 properties that predispose a cancer to metastasis?
|
-Tumor cell properties
-Stromal properties |
|
|
What are 4 theories of metastatic mechanisms?
|
1. Tumor develops variants capable of metastasizing
2. Tumor starts out with a metastatic gene signature 3. Tumor starts out with signature ability, AND develops variants 4. Tumor relies on STROMAL ecm to allow it to metastesize |
|
|
What happens in general when tumors invade surrounding tissue?
|
-Cells loosen from each other
-Tumor degrades and remodels the basement membrane -Creates passageway for migration |
|
|
What gets degraded in the course of basement membrane degradation?
|
Type IV collagen
|
|
|
What factors get released during invasion?
|
-Angiogenic factors
-Anti-angiogenic factors |
|
|
What are the anti-angiogenic factors again?
|
-Endostatin
-Tumstatin |
|
|
How do tumor cells create a passageway for migration?
|
1. The tumor cells themselves release proteases
2. Tumor induces stromal fibroblasts and macrophages to release proteases |
|
|
What keeps tumor cells attached to the basement membrane?
|
Laminin and Fibronectin receptors attached to their appropriate ligands in the BM.
|
|
|
What happens to the laminin receptors on tumor cells as they invade tissue?
|
They are expressed all around the cell instead of just on the basolateral side
|
|
|
What is increased density of laminin receptors on tumor cells associated with?
|
More rapid invasion and metastasis.
|
|
|
What are the 5 main steps in the Metastatic Cascade?
|
1. Breech the BM under 1' tumor
2. Traverse interstitium 3. Get into bloodstream 4. Vascular dissemination 5. Home to new tissue site |
|
|
What happens to tumor cells when they get into the bloodstream?
|
They clump
|
|
|
What are 2 things that make tumor cells clump in the bloodstream?
|
1. Homotypic adhesions between tumor cells
2. Heterotypic adhesions between tumor cells and platelets |
|
|
Why would tumor cells LIKE being clumped via platelets?
|
It protects them from immune detection and enhances their ability to implant in the BM.
|
|
|
What do tumors typically consider "unfavorable soil" for tumor seedlings?
|
Skeletal muscle
|
|
|
What tissue has been shown to drive changes that promote cancer?
|
Stromal tissue - the extracellular matrix.
|
|
|
Why is it useful to know that the stroma influences carcinogenesis?
|
It provides another potential therapeutic target.
|
