Chemotherapy drugs Flashcards
What is cancer?
When a normal cell undergoes uncontrolled proliferation to become a malignant tumour.
Compared to benign tumours what is a malignant tumour?
One that causes the cells to have loss of function, it is invasive and has the ability to metastasize and go from one location to another. A benign tumour lacks invasive properties and is unable to metastasize.
What are some of the causes of cancer?
DNA mutations that are either inherited or acquired.
Give an example of an inherited DNA mutation
Defective BRCA1/2 gene which causes breast cancer.
Deficiencies in DNA repair enzymes
Give examples of acquired DNA mutations
Viruses (HPV - cervical cancer), carcinogens (asbestos, smoking & radiation), alcohol, drugs, sun exposure, geographical location.
How is cell growth normally regulated?
Growth factors, cell cycle transducers, apoptotic genes & telomeres
What are proto-oncogenes?
Proteins that increase cell division, decrease differentiation and decrease cell death
What are oncogenes?
Proteins that increase cell division and promote cell survival, leading to cancer.
If a gene mutation occurs in the promoter region, what happens?
There’s an increase in transcription
What happens when a gene mutation causes gene amplification ?
More copies of the proto-oncogene are made
What is chromosome translocation?
Where a bit of a chromosome containing proto-oncogenes is moved to a new site where protein expression is more likely to occur and can lead to cancer
What can happen when a proto-oncogene fuses with another gene?
Can make a protein that has more activity
What happens during metastasis?
When a primary tumour produces enzymes that break down ECM (extracellular matrix), which allows cells to then invade nearby tissues and causes growth of new blood vessels (angiogenesis). Cells are then transported via blood or lymphatic vessels to cause a secondary tumour.
What are the main types of cancer treatments?
Surgery to remove solid tumours, radiotherapy, chemotherapy or a combination of the 3.
What are the aims of chemotherapy?
Kill all malignant cells
After chemotherapy, we cannot rely on the immune system to kill the rest, why not?
Immune system can’t recognise the cancer cells are they are too similar to normal cells.
Toxic effects of chemotherapy
Suppression of bone marrow (which makes RBC's & WBC's) Impaired wound healing Loss of hair Damage to GI tract Stunted growth in children Can cause problems with reproduction Teratogenicity Nausea & Vomiting
What are the 4 main classes of anti cancer drugs?
Cytotoxic, Hormones, Monoclonal antibodies & Protein kinase inhibitors
How do cytotoxic drugs work as anti cancer drugs?
By blocking DNA synthesis and preventing cell division
How do hormones work as anti cancer drugs?
They suppress opposing hormone secretion or inhibit actions of hormones
How do monoclonal antibodies work as anti cancer drugs?
By targeting specific cancer cells
How do protein kinase inhibitors work as anti cancer drugs?
By blocking cell signalling pathways in rapidly dividing cells
What is an alkylating agent?
A cytotoxic anti cancer drug
what do alkylating agents do?
Target cells in S phase of cell cycle and form crosslinks with DNA (covalent bonds) to prevent uncoiling of the DNA strands thus inhibiting replication