Anticancer I Flashcards
What are the 7 classes of anticancer agents?
Alkylating agents Antimetabolite and nucleoside analogs Antitumor antibiotics Antimitotic agents Miscellaneous antineoplastics Hormonal therapy Combination therapy
What are the different alkylating agents?
Nitrogen mustards Phosphoamide mustards Nitrosoureas Platins Other alkylating agents
What is the main MOA of alkylating agents?
React with DNA, preferentially alkylating the N-7 position of guanine (most common)
Bifunctional alkylating agents product inter- or intra-strand crosslinks preventing DNA separation
What is the MOA of nitrogen mustards?
They activate the chloride
What are some nitrogen mustards?
Melphalan Cyclophosphamide Ifosfamide Chlorambucil Estramustine phosphate
What are some other alkylating anticancer agents?
Busulfan (Myleran)
Thiopeta
Procarbazine (Matulane)
Dacarbazine
What is the MOA of nitrosureas?
Urea NH is deprotonated and the negatively charged oxygen displaces chloride to give a cyclic oxazolidine, which fragments to give 2-chloroethylisocyanate and vinyl diazohydroxide, which decomposes to give electrophilic vinyl cation
What are some nitrosureas?
Carmustine (BiCNU)
Lomustine (CeeNU)
Streptozin (Zanosar)
What are some platins?
Cisplatin
Carboplatin
What is the MOA of antimetabolites?
They care closely related to cellular precursors and thus they prevent use or formation of normal cellular products.
What are the MOAs of pyrimidine-based antimetabolites?
Inhibition of kinases
Inhibition of enzymes involved in pyrimidine biosynthesis
Incorporation into RNA or DNA, causes misreading
Inhibition of DNA polymerase
What is the role of folate?
DNA synthesis
DNA repair
DNA methylation
Cofactor
What are the active forms of folate?
Tetrahydrofolate and dihydrofolate
What do dihydrofolate reductase (DHFR) inhibitors do?
They inhibit DHFR, which leads to:
Decreased levels of FH2 and FH4
Decreased conversion of dUMP into dTMP
Decreased DNA synthesis
What are some DHFR inhibitors?
Methotrexate
Pemetrexed (Alimta)
Pralatrexate (Folotyn)
What does pralatrexate do?
Inhibits enzymes used in purine and pyrimidine synthesis:
thymidylate synthase
dihydrofolate reductase
glycinamide ribonucleotide formyltransferase
What does folinic acid do?
Adjuvant used in cancer chemotherapy to “rescue” bone marrow and GI mucosa cells from methotrexate
What is 5-fluorouracil?
“Mechanism-based” prodrug that acts as a suicide substrate and directly inhibits the thymidylate synthase
What are the 3 main active metabolites of 5-fluorouracil?
Fluorodeoxyuridine monophosphate (FdUMP) Fluorodeoxyuridine triphosphate (FdUTP) Fluorouridine triphosphate (FUTP)
What is the MOA of 5-FU (specifically, it’s active metabolite FdUMP)?
Direct inhibition of TS via the formation of a ternary complex in the nucleotide-binding site. This blocks dUMP from accessing the binding site.
This leads to an increase in dUTP, which causes DNA damage
What are some other pyrimidine-based antimetabolites?
Cytarabine (ARA-C)
Gemcitabine
What are some purine-based antimetabolites?
6-mercaptopurine
6-thioguanine
Fludarabbine phoshpate (Fludara)
Cladribine