Cancer Genetics Flashcards
What is a cancer?
An abnormal growth of cels which tend to proliferate in an uncontrolled manner, and in some cases, to metastasize
What causes cancer cells to behave abnormally?
Changes in the DNA sequence of key genes which are known as cancer genes
What are the two causes for mutations in DNA?
Tumour supressor genes being silenced or oncogenes being over-expressed
What are oncogenes?
Genes which stimulate the cell cycle
What are tumour supressor genes?
Genes which halt the cell cycle
What are the 6 hallmarks of cancer?
SAAIIL
Self Sufficiency Avoid apoptosis Angiogenesis Invasion and metastasis Insensitive to anti-growth signals Limitless division
What is a benign tumour?
A mass of well-differentiated cells that grows slowly, is capsulated and lacks the ability to invade neighbouring tissue or metastasise
What is a malignant tumour?
A tumour which is not self limited in growth, cells are poorly differentiated and capable of invading into adjacent tissues = metastasis
What four things can cause cancer?
- Radiation
- Chemicals
- Viruses
- Hereditary alteration in genes which make a person more susceptible to cancer
What is the difference between benign and malignant tumours?
benign grow slow, malignant fast
benign is well differentiated, malignant is not
benign is capsulated, malignant is not
benign cannot metastasize or invade neighbouring tissue, malignant can
What type of cancers have epithelial tissue origin?
Carcinomas
What are common types of carcinomas?
Lung, breast and colon cancer`
What is the name given to cancers which arise from cells found int he supporting tissues of the body?
Sarcomas
What are cancers that arise in lymph nodes and tissues of the body’s immune system called?
Lymphomas
What are cancers that arise from immature blood cells that grow in the bone marrow called?
Leukaemia
What is the most common cancer in children?
Acute lymphoblastic leukaemia
What type of mutation can be passed on to off-spring?
Germline mutations can be passed on
What type of mutatins cannt be passed on to off-spring?
Somatic mutations
A gene change in which cells cause germline mutations?
Reproductive cells
What are somatic mutations also known as?
Acquired or sporadic mutations
What are the seven types of mutations?
deletions insertions aneuploidy inversions translocations single base mutations chromosome instability
What is a deletion mutation?
When one or more nucleotide is removed from the DNA
what is a duplication mutation?
When one or more copies of a gene or region of a chromosome are made
What is an inversion?
Reversing the orientation of a chromosomal segment
What is a driver mutation?
A mutation which contributes to cancer growth
What is a passenger mutation?
A mutation which occurs during cancer growth
What type of studies can help identify cancer germline mutations?
Positional cloning linkage studies through gene mapping and gene indentification
What are the three types of point mutations?
Silent, non-sense and mis-sense