Cancer Chemotherapy-Duan Flashcards
What was the first anticancer drug?
mustine (for hodgkins lymphoma)
Cancer is caused by (blank) with a shift in the control mechanisms for cell proliferation and differentiation
altered host cells
What all does a cancer cell do?
shorter (accelerated) cell cycle
excessive proliferation
higher activity of nucleic acid and protein synthesis
altered cell-cell communication
invasive (disrupt normal healthy tissues)
migration to distant sites (metastasis)
T or F
cancer cells use the same nutrients and metabolic process as normal host cells.
T
What exactly is chemotherapy?
drugs that can destroy cancer cells (hopefully not normal cells)
An understanding of the (blank) is essential for the proper use of the current generation of anticancer agents and the search for new drugs.
cell-cycle kinetics
WHat is the order of the cell cycle?
G0-> G1-> S-> G2-> M-> G1
What do you need to give to G0 to make it turn into G1?
growth factor, G-protein CR
What does mitomycin c do?
cross links DNA via alkylations to inhibit DNA and protein synthesis
What cell cycle specific drugs block DNA synthesis?
cytosine arabinoside hydroxyurea 6-MP MTX 5-FU
What cell cycle specific drug blocks DNA and protein synthesis?
etoposide
(blank) inhibits topoisomerase II and causes DNA degredation
Etoposide
What blocks mitotic spindle formation?
vincristine, vinblastine, and taxanes
What are the 2 main categories of alkylating agents?
nitrogen mustards
nitrosoureas
What are the three kinds of nitrogen mustards?
mechlorethamine
cyclophosphamide
ifosfamide
What are the three kinds of nitrosoureas?
carmustine
lomustine
streptozotocin
(blank)interact with DNA non-specificaly and are active even for the resting cells in GO
alkylating agents
How do alkylating agents affect cells in GO?
damage the cell now and kill it during the next cell division
Are alkylating agents cell cycle/phase specific?
no
What is the MOA of alkylating agents?
impair cell function by forming covalent bonds with amino, carboxyl, sulfhydryl and phosphate groups in important molecules
The electron rich nitrogen at the (blank) in DNA is particularly susceptible to alkyation from an alkylating agent.
N7 position of guanine
What was the first chemotherapy agent used in humans?
nitrogen mustards
What is a nitrogen mustard?
prototype alkylating agent
main toxicity comes from DNA cross linkage
What is the MOA of nitrogen mustards?
chloroethyl side chains forms strong electrophile that causes akylation of nitrogen 7 of guanine residues in DNA
WHy does alkylation of the 7 nitrogen of guanine residues in DNA cause cross linking and thus DNA synthesis messing up?
guanine replaces a thymine resulting in opening of the imidazole ring->mono alkylation results-> if second alkylation then cross-inking of chains results
What 2 drugs causes crosslinking between strands of DNA?
chlorambucil and melphalan
What drug causes cross linking within the same strand
cis-platinum
What are the adverse reactions of nitrogen mustards?
teratogenic
immunosuppresive
carcinogenic
What are the clinical uses of nitrogen mustards
lymphomas
leukemias
What is mechlorethamine?
a nitrogen based analogue of mustard gas (which is sulfur-based) and was derived from chemical warfare research.
What is the the primary drug in the combination chemotherapy regimen used to treat hodgkins disease?
mechlorethamine
What are the four drugs used in the combination chemotherapy regiment used to treat hodgkins disease?
Mechlorethamine
Oncovin (vincristine)
Procarbazine
Prednisone
Mechlorethamine is more toxic to (blank) cells. What are some negative effects of this drug?
proliferating
bone marrow depression (limiting use)
Infertility
GI toxicity
What class of drug is cyclophosphamide?
individual nitrogen mustards
How does cyclophosphamide work?
it is a broad spectrum drug that can be taken orally or via IV
What is the MOA of cyclophosphamide?
1) “prodrug” converted to phosphoramide mustard and acrolein by P450.
2) ‘DNA cross-link (N7 of guanine)
What are the major clinical uses of cyclophosphamide (cytoxan, neosar)?
non-neoplastic diseases (nephrotic syndrome) non-hodgkin's lymphomas (Chop regimen) Acute lymphoid leukemia Breast cancer Carcinoid Neuroblastoma
What are the adverse effects of cyclophosphamide?
bone marrow depression
alopecia
disturbed GI
hemorrhagic cystisis
What is ifosfamide?
an analog of cyclophosphamide
How do you activate ifosfamide?
in liver by ring hydroxylation
(blank) to treat germ cell testicular cancer, pediatric and adult sarcomas (soft tissue and osteogenic), and several other cancers including cervical cancer, lung cancer, bone cancer, ovarian cancer, and breast cancer
multidrug regimen w/ ifosfamide (ifex)
What are the adverse effects of ifosfamide?
bone marrow depression alopecia disturbed GI hemorrhagic cystisis HUGE platelet suppression SEVERE urotherial damage INTERNAL bleeding (w/out mesna)
Why should you use ifosfamide (ifex) with mesna?
to reduce urinary toxicity
What is the mode of action of nitrosoureas?
spontaneous degredation to from 2 chlorethyl carbonium ion
-> crosslink DNA strands, break DNA strands, and carbamoylate protein
What are the adverse effects of nitrosoureas?
highly carcinogenic and mutagenic profound, cumulative myelosupresion renal failure (long-term use) alopecia hepatotoxicity pulmonary toxicity (busulfan)
What are 3 individual nitrosoureas?
carmustine
lomustine/semustine
streptozotocin
How do you give carmustine?
via IV and it is highly lipophilic
How do you give lomustine/semustine?
orally
What are the clinical uses of carmustine and lomustine/semustine?
Brain tumor treatment (including glioma, gliobastoma multiforme, medulloblastoma, astrocytoma)
GI neoplasma
Hodgkins disease
What are carmustine and lomustine/semustine awesome for treating brain tumors?
because they are highly lipophilic and can cross the blood-brain barrier
What is this:
water-soluble, not orally effective; methylate DNA and RNA and is particularly toxic to pancreatic islet cells
streptozotocin
What are the clinical uses of streptozotocin?
insulinoma (pancreatic islet cell carcinoma and carcinoid, excessive insulin secretion), metastatic cancer of the pancreatic islet cells
What is an important alkyl sulfonates?
busulfan
What does busulfan do?
selectively myelosupressive and inhibits granulocytopoiesis
What are the clinical uses of busulfan?
chronic myelogenous leukemia (CML) and other myeloproliferative disorders
What are the adverse effects of busulfan (alkyl sulfonates)?
myelosuppresion
“busulfan lung”: a rare but fatal pulmonary fibrosis
What are these:
structurally similiar to important endogenous molecules in the synthesis of DNA and RNA
Antimetabolites
What are the three general groups of antimetabolites?
purine analogs, pyrimidine analogs, and folate antagonists
What do antimetabolites do?
act as enzyme inhibitor
create false products to inhibit nucleic acid synthesis
What am I talking about:
the effect is to slow down the synthesis of nucleic acis (s-phase specific)
antimetabolites
What do purine antagonists do?
inhibit purine ring biosynthesis NT interconversion (6-MP)
What do pyrimidine antagonists do?
Inhibits pyimidine synthesis (pala azaribine)
What do folate anatgonists do?
inhibit dehydrofolate reduction and blocks purine and TMP synthesis (MTX)
What does 5-fluorouracil (5-Fu)?
inhibits dTMP synthesis
What does Cytarabine do?
inhibits DNA synthesis
What is 6-mercaptopurine (6-MP)?
purine antagonist
What is this:
a land marker in anticancer and immunosuppresive therapy
purine antagnist (6-MP)f
What is the MOA of 6-MP and what phase is it specific for?
S-phase
structural analog of adenine that is activated by enzymatic (HGPRT) which inhibits the first step in de novo synthesis of purine: impeding DNA replication and RNA transcription
What is the clinical use of 6-MP?
maintenance therapy for acute lymphoid leukemia (ALL) in chidren
What are the adverse effects of purine antagonist (6-MP)?
Bone marrow suppression
Immunosuppression
GI disturbance
Liver toxicity
How can you get resistance to purine antagonist 6-MP?
decreased activation (lack of HGPRTase) increased breakdown of 6-TIMP by alkaline phosphatase
What is the mechanism of purine antagonist 6-thioguanine and what phase is it specific for?
S-phase specific
enzymatic (HGPRT) conversion toa nucleotide which in tubr becomes incorporated into DNA as dTGTP. AND it is an enzyme inhibitor
What is the clinical use of 6-thioguanine?
leukemias
particularly valuable in treating acute granulocytic leukemia when given with cytarabine
What are the adverse effects of pure antagonist 6-thioguanine?
bone marrow suppression, mild nausea
How can you get resistance to purine antagonist 6-thioguanine?
decreased conversion of the drug
What is the MOA of pyrimidine antagonist 5-fluorouracil (5FU) and what phase does it affect?
s-phase
pyrimidine is bioactivated to 5fdump which complexes with folic acid. This complex inhibits thymidylate synthesis (TS inhibition), causing decreased dTMP and termination of DNA synthesis.
What does 5-fluorouracil require to exert its cytotoxic activity?
enzymatic conversion to nucleotide (ribosylation and phosphorylation)
What are the clinical uses of pyrimidine antagonist 5-fluorouracil?
basal cell carcinoma solid tumors of digestive system lymphomas leukemias KERATOSES OF THE SKIN
What are the adverse reactions of pyrimidine antagonist (5-fluorouracil)?
bone marrow depression (leucopenia, thrombocytopenia)
Alopecia
Disturbance of GI system
Hand and foot syndrome (palmar-plantar erythrodysesthesia)
How do you give the pyrimidine antagonists (cytidine analogs such as cytarabine, cytosine arabinosie, araC)?
via continuous IV infusion
What is the mechanism of the pyrimidine antagonist cytidine analogs and what phase is it specific for?
S phase
nucleotide formed in the target cell terminates DNA chain elongation
What is the clinical use of pyrimidine antagonists (Cytidine analogs)?
first-line choice for acute myelogenous leukemia and lymphomas
What are the adverse effects of pyrimidine antagonists (cytidine analogs)?
bone marrow depression, severe bone marrow hypoplasia
What kind of drug is methotraxate?
a folate antagonist
What is the mode of action of methotrexate and what phase does it affect?
S-phase specific
structural analog of folic acid
reversibly inhibits dihydrofolate reductase, resulting in decreased dTMP; directly inhibits the folate-dependent enzymes of de novo purine and thymidylate synthesis
What do you use folate antagonist methotrexate for?
acute lymphoblastic leukemia (ALL) choriocarcinoma osteocarcinoma rheumatoid arthritis (severe) psoriasis multidrug regiments for other cancers
How do you get resistance to methotrexate?
decreased uptake
What are the adverse reactions to methotrexate?
neurotoxicity (intrathecal use) nephrotoxicity interstitial pnemonitis hepatoxicity BAD
What do you use in combination with MTX to rescue normal cells?
How does it work?
leucovorin
it is a reduced folate analog that normal cells can absorb in presence of MTX (usually given 24 hours after MTX)