Cell Cycle Control and Cancefr Flashcards
(50 cards)
What happens in normal cell division if there is a problem that isn’t fixed?
apoptosis (cell suicide pathway)
what happens in unregulated cell division if there is a problem that isn’t fixed?
it goes through checkpoint anyways
what is signal transduction?
external signal -> internal response
- reception, transduction, activation of cellular response
- signal/growth factor binds to its receptor
what are the properties of normal cells?
- anchorage dependence
- contact inhibition (density-dependent, a natural process where cell growth and movement stop when cells come into contact with each other, forming a monolayer)
what’s the difference between benign and malignant tumors?
benign: noncancer
malignant: cancerous
what is metastasis?
when cancer spreads from original tumor
what are proto-oncogenes?
genes that encode signals, receptors, signaling molecules, and control proteins
what are oncogenes?
mutated or overactive versions of proto-oncogenes through point mutation, gene amplification, or translocation (transduction pathways always stimulated -> increased cell division)
what do tumor suppressor proteins do?
inhibit cell division
what if a tumor suppressor protein is mutated?
cell cycle checkpoints are ignored and damaged cells proliferate
what happens if ABL fuses with BCR?
ABL (proto-oncogene) fuses with BCR, is not expressed correctly -> cells over-proliferate -> leukemia
what happens with a BRCA mutation?
BRCA mutation -> damaged DNA still goes through mitosis -> increased risk for breast and ovarian cancer
what happens if p53 is mutated?
p53 mutation -> damaged DNA/cells go through mitosis
- p53 is the “master watchman” for preventing cancer
how can tumor suppressor genes be silenced?
- abnormal methylation (epigenetic)
hyper-methylated -> gene off -> no tumor suppressor made
what happened to mice who were engineered to make telomerase in all their cells?
cancer
what does RNAi (RNA inhibition) do for cancer?
gets rid of telomerase in cancer cells
what is traditional chemotherapy?
- injection of chemicals into bloodstream to kill dividing cells
- non-selective
- Taxol: prevents kinetochore microtubules from shortening
what is radiation therapy?
high energy
particles damage DNA more in cancer cells that normal cells-> cells destroyed/injured and can’t repair damage
localized
where are the cell cycle control checkpoints?
G1, G2, Mitosis (by signaling molecules present in the cytoplasm)
what is the most important checkpoint?
G1
what happens during G1 checkpoint?
- is cell division necessary?
- does it have enough growth factors?
what happens during G2 checkpoint?
- was DNA replicated correctly?
- Is the cell large enough?
what happens during M checkpoint?
- are all the chromosomes attached to microtubules?
what happens if “no” at a checkpoint?
halted, cell may die