Cancer #3 Flashcards
Carcinomas
cancers that a rise from epithelial cells
~ 90% of cancers
~ solid
Sarcomas
cancers that originate in supporting tissues
e.g. bone (osteo), fibrous tissue (fibre) or muscle (myo)
~ solid
Leukemias
cancer of leukocytes, malignant blood cells that proliferate in the blood stream
~ liquid
Lymphomas
cancers of lymphocytes, typically form solid masses in lymph nodes
~ liquid
Driver gene mutation
mutation that directly or indirectly confers a selective growth advantage to the cell in which it occurs
(cancer requires a collection, 5-8, of driver mutations)
Passenger mutation
mutation that has no direct or indirect effect on the selective growth advantage of the cell in which it occurred
What are the four most important properties of cancer cells? (can be caused by oncogene activation)
~ self-sufficiency in growth signallung ~ insensitivity to signals suppressing growth ~ enabling replicative immortality ~ genome instability and mutation ~ ability to avoid apoptosis
What is the common characteristic found in cancer susceptibility genes?
genes have roles as +ve or -ve regulators of cell proliferation
Oncogenes
dominantly acting cancer-susceptibility genes
~ normally protons-oncogenes
~ arise from genetic change that increases in the protein’s activity
~ mutations are genetically dominant
Proto-oncogene
function in growth signalling pathways that promote cell proliferation or inhibit apoptosis
Name the six functional classes of cellular oncogenes.
~ growth factors/mitogens ~ growth factors/mitogen receptors ~ signal transduction component ~ transcription factors ~ cell cycle regulators/drivers ~ cell death inhibitors
Mitogens
stimulate cell division by binding to a receptor in the cell membrane and activating signal transduction pathways that acts through Ras to stimulate
growth factors/mitogen receptors oncogenic mutations e.g. EGFR
EGFR = epidermal growth factor receptor
Very common in lots of cancers, mutations include:
~ amplification = more receptors
~ deletion = truncated reporter that fires w/o mitogen
signal transduction component oncogenic mutations
mutated Ras looses its intrinsic GTPase activity = permanently active = constant downstream signally w/o activation
transcription factors oncogenic mutations
Mutation in Myc protein:
~ amplification (lots of gene)
~ point mutation (stabilises Myc)
~ translocation (increased gene expression)
