Lecture 31 - Cancer I Flashcards
What are some properties of cancer cells? (6)
L31 S7
- cells grow out of control
- self sustaining (do not require signal to grow)
- release autocrine growth factors
- don’t respond to anitgrowth factors
- ignore apoptotic signals
- invade areas reserved for other cells
What are the two classifications of tumors and what differentiates them?
L31 S11
Benign:
-noninvasive
Malignant:
-invasive (cancer)
What are the classifications of cancer?
L31 S12
Carcinoma:
-cancer derived from epithelial cells
Sarcoma:
-cancer derived from connective tissue or muscle tissue
Leukemia/lymphoma:
-cancer derived from WBCs or their precursors
What trait of a tumor indicates that it is metastatic?
L31 S23
- tumor breaks through basal lamina and is able to enter the blood stream
- once in the blood stream the tumor cells can leave and proliferate elsewhere in the body
What is angiogenesis and what role does it have in cancer?
L31 S24
Angiogenesis: formation of new blood vessels from existing blood vessels
-tumors release factors that stimulate angiogenesis due to their increased demand for nutrients
Differentiate between oncogenes and tumor suppressor genes.
Explain how mutations in both lead to cancer.
L31 S33
Oncogenes:
- genes, that when mutated, result in an increase in activity or gain of function
- cancer can result from a single mutation in just one copy of an oncogene (dominant)
Tumor suppressor genes:
- genes whose normal function is to suppress tumor formation by inhibiting growth
- loss of function in both copies of the gene results in cancer (recessive)
Mutation of what type of gene other than oncogenes and tumor suppressor genes can result in cancer?
What is the mechanism by which this occurs?
L31 S35
- mutations in genes involved in DNA maintenance such as DNA repair genes or cell cycle checkpoint genes
- loss of function of DNA repair genes can result in accumulation of mutations
- loss of function of cell cycle checkpoint genes can result in DNA damage being replicated
What are mechanisms by which protooncogenes may be activated into oncogenes?
L31 S41-42
Deletion/point mutation:
-can cause hyperactive protein
Regulatory mutation:
-produces an increased amount of protein through mutation of the promoter
Gene amplification:
-multiple copies of the gene resulting in increased production of the gene
Chromosomal rearrangement:
-gene placed after new regulatory region resulting in increased production