Intro to molecular pathology Flashcards
What have Molecular techniques led to?
- Better understanding of mechanisms of disease
- New diagnostic methods
- New prognostic markers (molecular markers)
- New treatments
- Predict which patients will respond to Tx
- Early detection of residual or recurrent disease
- Screening for diseases
Purpose of IHC?
To detect and identify specific proteins.
Uses antibody with a brown dye.
Protein-based/tissue based molecular technique.
Can help diagnose/ identify the protein, provide a prognosis, provide info on treatment options, and can be used in screening.
Purpose of ISH? (FISH and CISH)
To detect a particular gene/DNA/RNA Sequence to see if it’s been over/under expressed.
Nucleic acid-based molecular technique.
Uses a complementary DNA/RNA sequence with a fluorescent dye or chromogen.
Methods of identifying gene abnormalities?
- ISH
- PCR
- Sequencing / Next gen. sequencing
What enzymes are commonly involved in carcinogenesis?
Tyrosine kinases
What does Vogelstein’s theory suggest?
Cancers require multiple steps/mutations to occur.
How are Oncogenes altered in mutation?
- Translocation or amplification
e. g, c-ras, c-myc, c-abl, c-ret
How are Tumour suppressor genes altered in mutation?
-Loss of heterozygosity or methylation
Found in all neoplasias
e.g, Retinoblastoma, p53, APC
What is Li-Fraumeni syndrome?
Autosomal dominant disorder
- LOH
- One missing/abnormal copy of p53 inherited and the remaining copy undergoes an acquired mutation/deletion.
- Predisposes to a wide range of tumours.
What do mismatch repair genes do?
Proof read the DNA and correct mistakes before the cells divide.
What do defects in mismatch repair genes cause?
Microsatellite instability
- Test using IHC or mutation analysis
What are arrays?
Arrangement of DNA, RNA, or Protein on a large platform to examine large numbers of cases in one study
What is bioinformatics?
Method of analysing data on tissues from gene or protein microarray studies.
