cancer chemotherapy Flashcards
The nitrogen mustards (Alkylating agents) contain highly electrophilic groups and form covalent bonds to nucleophilic groups in DNA. true or false?
true
alkylating agents are useful anti‐tumour agents that prevent replication and transcription. true or false?
true
alkylation of nucleic acid bases can result in miscoding. TRUE OR FALSE?
TRUE
what are the toxic side effects of alkylating agents?
alkylation of proteins
what does Melphalan mimic?
phenylalanine and is transported into cells by normal transport proteins
The uracil ring in uracil mustardis electron withdrawingand so this is a less reactive alkylating agent. true or false?
true
what does the uracil ring mimic?
- nucleic acid base
- is concentrated in fast growing cells
what group in estramustine is electron withdrawing?
urethane group
what is the most commonly used alkylating agent?
Cyclophosphamide
Cyclophosphamide is a non‐toxic prodrug which is orally active. true or false?
true
what is the by-producted of the activated Cyclophosphamide by alkylation and what is it associated with?
Acrolein
- Associated with toxicity
what is the most clinically toxic anti-cancer drugs?
- Mitomycin C
Mitomycinis also a prodrug activated in vivo to form an alkylating agent. true or false?
true
is cisplatin a prodrug?
- yes
when is cisplatin activated?
is activated in cells with low chloride ion concentration
cisplatin binds to DNA in regions rich in guanine units. true or false?
true
what kind of strands does cisplatin form that causes localised unwinding of the DNA double helix and inhibits transcription?
Intrastrands
anthracyclines are what types of agents?
Intercalating agents
The planar anthraquinone of anthracyclines moiety intercalates between the DNA base pairs and the carbohydrate moiety binds into the minor groove. true or false?
true
5‐Fluorouracil(5‐FU) is a prodrugthat is metabolised to give 5‐F‐dUMP which then acts an inhibitor of thymidylatesynthase. True or false?
true
How does 5‐F‐uDMP inhibits thymidylate synthase?
- The C-F bond is stronger than the C-H bond which is normally cleaved by thymidylatesynthase
- This causes the enzyme to be inhibited irreversibly
Capecitabineis a produgof 5‐fluorouracilwhich is itself a prodrug. true or false?
true
what is the only chemotherapy drug availabe for treatment of pancreatic cancer?
- Gemcitabine
Gemcitabine is the fluorinated analogue of 2’‐deoxycytidine and it interacts with DNA and RNA polymerases within the cancerous cell which inhibits nucleic acid replication and repair. TRUE OR FALSE?
TRUE
what are kinases?
- They are enzymes that catalyse phosphorylation
overexpression of kinases can lead to cancers. true or false?
true
give examples of type 1 and type 2 kinase inhibitors?
- Type 1 - gefitinib
- type 2 - Imatinib
how do type 1 and 2 kinase inhibiotrs work?
- Type 1:
- bind to the active conformation of the enzyme
- inhibitors bind to the ATP binding site and block access to ATP
- Type 2:
- act on the inactive conformation of the enzyme
- bind to the enzyme and stabilise the inactive conformation
which are more likely to be selective between type 1 and 2 kinase inhibitors?
- Type 2
there is a greater risk that random mutation of the target will weaken binding interactions and lead to drug resistance with type 2 kinase inhibiotrs are they are ore selective. true or false?
true
type III inhibitors bind to regions of the active site not occupied by ATP. true or false?
true
the EGF‐receptor of gifitnib is a tyrosine kinase receptor. true or false?
true
how does gefitinib work?
It inhibits the kinase active site of the epidermal growth factor receptor
gefitinib the morpholine ring increases water solubility. true or false?
true
Imatinib is a selective inhibitor for a hybrid tyrosine kinase (Bcr‐Abl)which is active in certain tumour cells. true or false?
true
what increases the activity, selectivity and water solubility in Imatinib?
piperazine
list the different types of cancer chemotherapy classes of drugs?
- Alkylating agents
- Kinase inibitors
- platinum compounds
- Mitomycin C
- Thiopurines
- inhibitors of thymidylate synthase
- Intercalating agents
- Dna polymerases