Oncology Flashcards
What are the phases of the cell cycle?
Interphase - G0, G1, S, G2
M phase - mitosis and cytokinesis (w/in mitosis phase)
What happens in the G1 phase of the cell cycle
preparation for DNA replication- cell growth and protein synthesis
What happens in the S phase of the cell cycle?
DNA replication
What happens in the G2 phase of the cell cycle?
Condensation of genetic material
What are the four stages of mitosis?
Prophase
Metaphase
Anaphase
Telophase (and cytokinesis)
What are the three checkpoints in the cell cycle?
G1/S checkpoint
G2 checkpoint
M checkpoint
What happens at the G1/S checkpoint?
Decision point on whether to divide or enter G0
Checks for size, nutrients, molecular signals, DNA integrity
What happens at the G2 checkpoint?
Decision point on whether to pause in G2 and repair, or undergo apoptosis
Checks for DNA integrity and that DNA replication is complete
What happens at the M checkpoint?
Also known as spindle checkpoint
Makes sure all chromosomes are lined up in spindle and none are floating off in the cell
What checkpoints does p53 regulate?
G1 and G2
What activates p53 in normal cells?
DNA damage
Where in the cell cycle do antimetabolites work?
S phase
Where in the cell cycle do alkylating agents work?
Overall non-specific but do work in S phase
Where in the cell cycle do platinum agents work?
S phase
Where in the cell cycle do antitumor antibiotics work?
S and G2 phase
Where in the cell cycle do vinca alkaloids work?
M phase
Where in the cell cycle do taxanes work?
M phase
What is the MOA of antimetabolites?
Mimic normal purines and pyrimidines
This makes sense why they work in S phase (DNA replication)
What is the MOA of alkylating agents?
Cross-link DNA strands
This makes sense why they work in S phase (DNA replication)
What is the MOA of platinum agents?
Platinum compounds cross-link DNA strands –> Inhibits DNA synthesis
This makes sense why they work in S phase (DNA replication)
What is the MOA of antitumor antibiotics?
Inhibition of topoisomerase II –> obstruction of DNA and RNA synthesis
Multiple MOAs exist
What is the MOA of vinca alkaloids?
Mitotic spindle poisons; inhibit microtubule assembly
What is the MOA of taxanes?
Interfere with microtubule reorganization and disassembly
What are some examples of antimetabolite chemo drugs?
Methotrexante
5-FU
Azathioprine
Cytosine arabinoside (Cytosar)
Hydroxyurea
What are some exaples of alylators?
Cytoxan
Chlorambucil
Melphalan
Lomustine
What are examples of platinum agents?
Cisplatin
Carboplatin
What are examples of antitumor antibiotics?
Doxorubicn
Mitoxantrone
Bleomycin
What are examples of vinca alkaloids?
Vincristine
Vinblastine
Vinorelbine
What are examples of taxanes?
Paclitaxel
Docetaxel
What does the Gompertzian growth curve show?
Initial exponential phase of tumor growth occurs largely before tumor is clinically detectable AKA growth has slowed by the time we detect most tumors, which makes them less responsive to chemotherapy
Why are neutrophils most sensitive to chemotherapy?
They have shortest circulating lifespan of about 10 hours
What drug has a delayed double nadir?
Carboplatin
First nadir at 10-14d
Second nadir at 21d
What breeds of dogs are predisposed to alopecia with chemotherapy?
Anything with a continuously growing hair coat - poodles, Maltese, terriers, old English sheepdogs
What drugs cause indirect GI signs (nausea) via stimulation of the chemoreceptor trigger zone (CRTZ)?
Cisplatin
Streptozotocin
What is a unique side effect of vincristine?
Peripheral neuropathy (ileus, neuropathy)
What is the MOA of Cerenia (maropitant)?
Substance P inhibitor/Neurokinin-1 inhibitor (NK-1 is where substance P acts)
Central and peripherally acting