Tumor Growth & Progression Flashcards
What is a psr?
Probability of self renewal in a cell population scaled from 0.00 (0%) - 1.00 (100%)
What does a psr of 0.50 indicate?
Stable cell population
What does a psr of 0.52 indicate?
malignancy
What does a psr of 0.49 indicate?
Slow decline & decay of a tissue cell # that will eventually shrink and disappear
What is the goal of cancer treatment in regards to psr?
To get the psr of the neoplastic cells below 0.50
What is a tumor growth fraction?
Ratio of cell proliferation to cell loss
What are the factors that influence tumor growth?
tumor angiogenesis:
- Oxygen and nutrient supply
- Metastasis
- Tumor size
- growth factors (VEGF and FGF) & inhibitors (p53?)
What is the purpose of angiostatin?
To stop blood vessel growth and supply to tumors
What is vascular endothelial growth factor?
Growth factor that gives a tumor the ability to undergo angiogenesis and gain capillaries and a blood supply
What is fibroblast growth factor?
Growth factor that gives a tumor a connective tissue stroma for support
What are the general steps (cellular basis) of metastasis of carcinomas?
- Detachment via loss of cadherin molecules
- Attachment to basement membrane/ECM with laminin and fibronectin
- Secretion of proteolytic enzymes (protease) to degrade ECM
- Movement of tumor cells through BM into vessels via cytokines (autocrine motility factor)
What is tumor progression?
The orderly progression from a preneoplastic lesion to a benign tumor and ultimately an invasive cancer
What cancer is the exception to normal tumor progression?
Colon carcinoma
What is important about genetic instability in regards to neoplasms?
Increased rate of random, spontaneous mutations during clonal expansion will increase chances of developing a neoplasm
What molecule is lost when a tumor cell detaches and attempts to metastasize?
Cadherin
What molecules are expressed when a tumor cell that has detached from the primary tumor tries to attach to the basement membrane of a distant tissue?
Laminin and fibronectin