Molecular epidemiology focuses on the contribution and interaction of genetic and environmental risk factors, identified at the molecular level, to disease
Uses techniques of molecular biology, like PCR, next generation sequencing (NGS), ELISA, western blot, etc.
Aims to identify:
Biomarkers of genetic susceptibility
Biomarkers of exposure
Biomarkers of effect
Biomarkers of disease
Genetic susceptibility
Some genotypes are protective against a risk factor, meaning that exposure causes less risk for disease than the general population
Some genotypes are susceptible against a risk factor, meaning that exposure causes more risk for disease than the general population
Example study 1: “Associations between XRCC1 and ERCC2 polymorphisms and DNA damage in peripheral blood lymphocyte among coke oven workers” (Leng et al, 2004)
Showed that certain differences (polymorphisms) in the genes XRCC1 and ERCC2 were associated with decreased DNA-repair capacity toward PAH-induced DNA damage
Example study 2: “Urinary 1-hydroxypyrene concentrations in Chinese coke oven workers relative to job category, respirator usage, and cigarette smoking” (Chen et al, 2007)
Showed that smoking oven workers had higher urinary concentration of 1-hydroxypyrene than non-smokers
1-hydroxypyrene is a marker of air pollution exposure
NAT2 is a gene involved in biotransformation of drugs (more here)
Some people have a slow version of the gene (slow acetylators)
Some people have a rapid version of the gene (rapid acetylators)
Studies have shown that slow acetylators have higher risk of CRC
Polymorphisms in p53, mEH and XRCC1 are also associated with CRC
Polymorphisms in GSTM and NAT2 influence the amount of DNA damage accumulated based on diet
Rapid acetylators sustain more DNA damage during a meat-containing diet than slow acetylators
GSTM1 negative people sustain more DNA damage during a meat-containing diet than GSTM1 positive people
