Cancer Chemotherapy - Duan Flashcards
Is cancer self or foreign?
self
what are the factors that promote cell proliferation in cancer?
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/F: cancer cells use the same metabolic processes and nutrients as host cells
true
Growth Factor G-protein CR is involved in what part of the cell cycle?
G0 resting
What is the MOA of Mitomycin C?
cross-links DNA; bifunctional alkylate
When in the cell cycle does Mitomycin work?
G1
Cytosine arabinoside, hydroxyurea, 6-MP, MTX, 5-FU all have what MOA and are therefore used in what part of the cell cycle?
block DNA synth, S phase
Etoposide has what MOA and is effective in what part of the cell cycle?
inhibits topoisomerase II based DNA degradation and works in the G2 phase
Vincristine, vinblastine, and taxanes block mitotic (blank) formation and therefore are active during what part of the cell cycle?
block mitotic spindle formation and are active during Mitosis
Mechlorethamine, cyclophosphamide, and Ifosfamide are all (blank) mustards
nitrogen mustards
Carmustine, lomustine, and streptozotocin are all what type of agent?
Nitrosoureas
T/F: nitrosoureas interact with DNA specifically
false
T/f: alkylating agents are active even during G0
true
(blank) agents impair cell function by forming covalent bonds with the (blank) groups in biologically important molecules
amino, carboxyl, sulfhydryl, and phosphate
Which nitrogen in guanine in DNA is most susceptible to alkylation?
N7 of guanine
what was the first chemotherapy agent used in humans?
nitrogen mustards
What is the main source of toxicity from nitrogen mustards?
DNA cross linkage
The (blank) side chain in nitrogen mustards undergo an intramolecular cyclization to form carbonium ions intermediates
chloroethyl side chain
The aziridine ring of nitrogen mustards attacks the (blank) of DNA base or protein, (blank) of DNA or phosphate, or the (blank) of protein
N of DNA base or protein, =O of DNA or phosphate, and -SH of protein
Alkylation of the the 7 N in guanine in DNA makes it more (acidic/basic) causing it to mispair with what base?
acidic, thymine
Nitrogen mustards cause a base pair substitution of?
A-T for GC
Nitrogen mustards can open the imidazole ring or depurination by (blank) of the alkylated guanine residue
excision
The 2nd chloroethyl side chain in bifunctional alkylating agents can alkylate a second guanine and cause (blanking) of two nucleic acid side chains
cross-links
T/F: Cross-linking can happen both between and within strands
true
Chlorambucil and melphalan work to form crosslinking (between/within) strands
between
Cis-platinum cross links (between/within) strands
within
(Between/within) strand cross linking has a high correlation with cytotoxicity
between
What are the three major classes of adverse reactions to nitrogen mustards?
- teratogenic
- immunosuppressive
- carcinogenic
What are the two types of cancers that nitrogen mustards were used for?
lymphomas and leukemias
what is the most reactive nitrogen mustard?
mechlorethamine
What are the drugs used to MOPP up Hodgkin’s disease?
mechlorethamine + oncovin (Vincristine) +
procarbazine + prednisone
Since mechlorethamine is toxic to proliferating cells, the three major side effects include:
bone marrow suppression
infertility
GI toxicity (via IV)
(blank) is more commonly known as Cytoxan or Neosar
cyclophosphamide
What are the two methods of admin of Cytoxan?
oral or IV
What is the 2 step MOA of Cytoxan?
- bioactivation of prodrug via P450
2. DNA cross link of guanine N7
What are the clinical uses for Cytoxan?
Never Neglect ALL BaCoN Nephrotic syndrome Non-hodgkin's lymphoma Acute lymphoid leukemia Breast cancer Carcinoid Neuroblastoma
What are the B.A.D. side effects of Cytoxan?
Bone marrow suppresion
Alopecia
Disturbed GI
hemorrhagic cystitis
The CHOP regimen is used to treat what cancer?
Non-hodgkin’s lymphoma
Which nitrogen mustard is activated in the liver by ring hydroxylation?
Ifosfamide (Ifex)
Ifex is used to treat (carcinoma/sarcoma) along iwth germ cell testicular cancer, cervical, lung, bone, ovarian, and breast
sarcoma
Why do we give ifosfamide in conjunction with Mesna?
to reduce the urinary toxicity
what added serious side effect does ifosfamide carry compared to cylcophosphamide?
increased platelet suppresion and urothelial damage
Nitrosoureas form 2-chloroethyl carboniums that have what three MOAs?
- crosslink DNA strands
- break DNA strands
- carbaboylate proteins
What are the scary SE of nitrosoureas?
HIGHLY CARCINOGENIC profound and cumulative myelosuppresion renal failure alopecia hepatotoxicity pulmonary toxicity