Pathophys 2 Flashcards
What types of genetic alterations are there in cancer?
- Subtle alterations
- Chromosomal number changes
- Chromosomal translocations
- Amplifications
- Exogenous sequences
What is FISH and what does it detect easily?
Floursecent In Situ Hybridization
easily detect chromosomal translocations
What are amplifications?
Seen only in cancer cells
5 to 100 fold mutliplication of a small region
‘amplicons’- contains 1 or more genes that enhance proliferation
Generally in advanced tumors
What are exogenous sequences?
Tumour viruses- which contribute genes resulting in abnormal cell growth
HPV—>cervical cancer
What is the evidence that mutations cause cancer?
5 pieces of evidence?
- Most carcinogens are mutagens
- Some cancers segregate families
- Oncogenes and tumour suppressor genes
- Chromosomal insability
- Maliginant tumours are clonal
When you live longer, does the rate of mutation increase or decrease?
decrease
What are the genes responsible for tumourigenic cell growth?
Mutated (or activated) oncogenes + loss of mutation of tumour suppressor genes= Malignant transformations
How are oncogenes and suppressor genes regulated?
by positive/negative molecular factors
how are proto-oncogenes activated?
by mutation
what two types of genes contribute to Carcinogenesis?
Oncogenes
Suppressor
what is an oncogene?
A mutated gene that its protein product is produced in higher quantities, or has increased activity and therefore acts in a dominant manner to initiate tumor formation
What is retinoblastoma?
Tumour of the eye stem cell
average age of 8 months bilateral
1 in 20,000
Whats the two hit hypothesis?
Explain how there can be an accumulation of mutations that lead to cancer
