Cancer Flashcards
What is the purpose of chemotherapy?
Prevent cell growth
How does chemotherapy target DNA?
- indirect interaction with DNA
- prevention of nucleic acid synthesis by inhibiting one or more enzymes involved
Give examples of alkylating agents
- Melphalan
- Chlorambucil
- Cyclophosphamide
- Decarbazine
- Bulsulfan
- Temozolamide
How do mustards work?
Attack guanine in DNA, this causes cross linking of DAN strand - they can’t open and be copied for cell division.
Linkage inhibits DNA synthesis - has a cytotoxic effect
Which other cells are also affected by mustards?
Those that divide frequently - GIT, bone marrow, testicles and ovaries
What is the state of the nitrogen on chlorambucil?
nitrogen lone pair is delocalised
What does melphalan minis?
An amino acid - drug enters by phenylalanine amino acid transporter
What is mitomycin C
a pro-drug that requires reductive activation.
What do alkylating agents contain?
Highly electrophilic groups -
How do alkylating agents work?
They form covalent bonds to nucleophilic groups in DNA. They prevent replication and transcription
What can alkylation of nucleic acid bases lead to?
mutations which are carcinogenic
What do neutral inactive molecules act as?
Pro-drugs
What is platinum covalently linked to?
Chloro-substituents
Where are complexes activated?
In cells with low Cl- ion cocn
How does cisplatin work?
Binds to DNA regions rich with guanine units forming intra-strand links