Cancer Flashcards
what is cancer?
abnormal regulation of cell growth and division.
invasion of areas where they don’t belong
increased cell division/decreased apoptosis
what is the difference between a benign and malignant?
malignant can spread
what causes cancer?
accumulation of mutations, older more likely to contract it
what are cancer stem cells?
invoke a new cancer when transferred into a new animal
what is contact-inhibition?
normal cells stop growing when they touch, cancers just go all out man
what is metastasis?
spread of cancer cells, digest basal lamina and squeeze between them to travel in blood vessel. adheres to blood vessel wall to squeeze into a new space
what is angiogenesis?
formation of new blood vessels inside cancer ball of cells. vascular endothelial growth factor secreted
what is ames test of mutagenicity?
testing compounds to see how well they cause mutations (if highly mutagenic will likely cause cancer) (compound, histidine-dependent salmonella, and liver to see how its gonna be modified)
what are cancer-critical genes?
if u fuck up these genes ur gonna get cnacer
what are 2 classes of genetic mutations in cancer?
- proto-oncogenes- genes that have proteins associated with cell cycle regulation
- tumor-suppressor genes-inhibit cell cycle, needs mutation on both chromosome copies
how do proto-oncogenes get mutated?
deletion/point mutation in coding sequence, regulatory mutation (promoter sequence), gene amplification, chromosome rearrangement
how do tumor suppressor genes get mutated?
nondisjunction causes chromosome loss->duplication
mitotic recombination
gene conversion during mitotic recombination
suppressor gene is gone
point mutation, not expressed for working properly
what are epigenetic genes?
genes sequences not affected, it’s about how your genes are packaged into chromatin.
genes accidentally packed in heterochromatin and it never gets expressed->division
genes accidentally methylation
what is a driver mutation?
the cell that drives the cells around it towards cancer
what is a passenger mutation?
cells that get affected by a driver mutation
what are 3 signaling pathways that are commonly involved in tumors?
Rb, RTK/Ras/PI3K, P53
how does HPV turn malignant?
virus integrates itself into the genes
how does viral protein e7 affect Rb?
it binds to Rb and so the proliferation factor thats supposed to be inhibited isnt so its over active
how does viral protein e6 affect p53?
e6 binds to p53 to inactivate it and so cell cycle does not stop
what is RhoC?
small GTPase that regulates actin-based cell motility
can be linked to metastasis
what is epithelial-to-mesenchymal transition?
loss of adhesiveness, loss of cadherins
normal cells usually have ____ dna repair pathways.
2
why do tumor cells lose a dna repair pathway?
genetic instability
how do tumor cells use multidrug resistance?
they amplify Mdr1 to pump drugs out of a cell
