Chemotherapy Drugs Flashcards
What are the differences between a benign tumour and a malignant tumour?
Malignant tumour -Loss of function -Invasive -Ability to metastasize Benign tumour -Lack invasive properties -Unable to metastasize
What is an oncogene?
An oncogene is a gene that has the potential to cause cancer. In tumor cells, they are often mutated or expressed at high levels. Most normal cells will undergo a programmed form of rapid cell death (apoptosis) when critical functions are altered.
In tumours there are mutations in apoptotic genes. ______ is expressed with stabilises ______. There is an overexpression of growth factors. Leading to ________ which is growth of new blood vessels.
- telomerase
- telomeres
- angiogenesis
How does a primary tumour metastasise?
- primary tumour produces enzymes which breakdown ECM
- Invades nearby tissue
- grows new blood vessels (angiogenesis)
- cells transported via blood or lymphatic vessels
=SECONDARY TUMOUR
What are the difficulties in treating cancer?
- may be asymptomatic until late stages
- detection methods not 100% reliable
may be hard to find primary tumour - cancer cells are very similar to normal cells
- difficult to exploit biochemical differences ie. therapy to toxic to normal tissue
in a solid tumour cells occupy 1 of 3 compartments. What are these?
A. dividing cells
B. Resting cells (in G) phase capable of dividing
C. cells no longer dividing but contribute to tumour volume
* only cells in compartment A susceptible to most cytotoxic drugs
Drugs affect all RAPIDLY DIVIDING normal tissues. What are the toxic effects of chemotherapy?
- Bone marrow suppression ?
- impaired wound healing
- loss of hair (hair follicle cells are rapidly dividing cells)
- Damage to GI epithelium (inc. mouth)
- Growth stunted in children
- Reproductive system - sterility
- teratogenicity ?
- bleeding/ bruising (due to lack of platelets/ clotting factors)
- nausea and vomiting
- kidney damage
What are the possible targets for anti-cancer drugs?
- hormonal regulation of tumour growth
- defective cell cycle controls
What are the different classes of anticancer drugs?
- cytotoxic (alkylating, antimetabolities, antibiotics, plant derivatives)
- Hormones and their antagonist
- Monoclonal antibodies
- Protein kinase inhibitors
Cytotoxic drugs such as alkylating, antimetabolities, antibiotics and plant derivative. How do they work?
- Block DNA synthesis/ prevent cell division
How do hormone and their antagonist work?
- suppress opposing hormone secretion or inhibit their actions
How do monoclonal antibodies work?
- target specific cancer cells
How do protein kinase inhibitors work?
- block cell signalling pathways in rapidly diving cells
Alkylating agents work by targeting cells in S phase and form convalent bonds with DNA to prevent uncoiling. this inhibits replication. What are the side effects of alkylating agents with pro-longed use?
- sterility (especially in men)
- increase risk of non-lymphocytic leukaemia (AML)
Classes of alkylating agents are - nitrogen mustards - nitrosoureas - Platinum compounds - others What are examples of nitrogen mustards?
- mechlorethamine (1st anti-cancer drug)
- cyclophosphamide
- melphalan
- chlorambucil
- bendamustine
- estramustine (prostate cancer)
Examples of nitrogen mustards are melphan, chlorambucil and bendamustine. What types of cancer are these used to treat?
- melphan - multiple myeloma, childhood neuroblastoma, localised soft-tissue sarcoma of the extremities
- chlorambucil/ bendamustine - lymphomas, chronic leukaemias
cyclophosphamide is a prodrug and can be administer orally. its activated in the …
liver to phosphoramide mustard and acrolein
- acrolein causes haemorrhagic cystitis, this can be prevented by administering large volumes of fluid.
nirosoureas are highly lipid. carmustine is given by IV. Lomustine is given orally. What kind of cancers do they treat?
Carmustine - multiple myeloma, non-hodgkins lymphomas and brain tumours (glioblastomas
Lomustine - hodgkins disease resistant to conventional therapy, malignant melanoma and certain solid tumours