Flashcards in Cancer Chemotherapy Deck (26):
Give three examples of how cancer can arise.
Name the three approaches a consultant will consider regarding cancer treatment.
List the three major differences that exist in cancer cells by comparison to normal body cells.
Name the four type of (traditional) chemotherapy agent.
Outline the primary way in which alkylating agents work.
INTRASTRAND CROSS LINKING OF DNA
How does intrastrand cross linking of DNA prevent cancer cell division
The drug binds to two places on the cancer cell's DNA, inhibiting cell division and cell proliferation
Where specifically on DNA does the drug bind to?
To the 7 nitrogen of guanine residues and alkylates them
What effect does alkylating the residues have and what does this lead to?
Makes them more acidic, leading to the formation of ENOL TAUTOMERS, allowing guanine to mis-pair with thymine residues during DNA synthesis, leading to DNA damage being recognised by apoptotic factors and apoptosis being initiated
What are the three major sub-groups of the alkylating agents?
Platinum Based Compounds
Name all the examples possible of the nitrogen mustards.
What is cyclophosphamide activated by and where is it activated?
P450 mixed function oxidases
What is special about phosphoramide?
It is cytotoxic
What is the function of mesna?
Counteracts the effects of acrolein (propana)
Outline how nitrosoureas are used and what property they possess that makes them so appropriate for this task.
Nitrosoureas are lipophilic so can cross the blood-brain barrier, making them viable for use against tumours of the brain and the meninges
Name all the examples possible of the nitrosoureas.
Outline how platinum based compounds act.
Cl- dissociates upon entry to cell allowing remaining reactive complex to react with water and interact with DNA causing intrastrand cross-linking between N7 & O6 of adjacent guanine molecules. This leads to local denaturation of DNA chain
What is the structure of cisplatin?
Central platinum atom surrounded by 2 chlorine atoms and 2 ammonia groups
List the three main groups of
Give examples of antifolates.
Give examples of antipyramidines.
Give examples of antipurines.
Give an example of a platinum based compound.
How do antifolates such as methotrexate act?
Blocks the metabolism of folic acid via inhibition of the DHFR enzyme (similar structure to folic acid)
Describe the action of antipyramidines.
Interferes with DTMP (thymidylate synthesis) which is used in DNA synthesis during the S phase. Thymine is a DNA base of the nucleotide thymidylate so the blocking of the production of this inhibits DNA replication and thus cell proliferation
Which compound, similar in structure to a nucleotide, does gemcitabine have a similar structure to?