CYP2A6 is an enzyme found in the liver that metabolizes such chemicals as the st
ID: 263645 • Letter: C
Question
CYP2A6 is an enzyme found in the liver that metabolizes such chemicals as the stimulant nicotine (which is a carcinogen), cancer treatment prodrug tegafur, and anti-retroviral (HIV) drug efavirenz (Sustiva).
CYP2A6 breaks down nicotine and efavirenz into non-active metabolites that are removed from the body.
CYP2A6 changes tegafur (a non-active chemical) into 5-fluorouracil, which has anti-cancer activity. That's why it is called a "prodrug": it is delivered as a non-active form but then the body transforms it into the actual useful drug.
The abnormal allele variant (the abnormal DNA sequence) you examined in Part 1 causes loss of CYP2A6 activity. If an individual is homozygous for the abnormal allele (having two abnormal DNA sequences), then they lack all CYP2A6 enzyme activity.
Given this information, speculate on how a person in each of these situations might be affected, compared to someone with the normal allele, if they were homozygous for the abnormal allele:
1. A person who smokes - (What is the effect on stimulation and the potential for cancer?)
2. A person being treated with efavirenz for HIV
3. A person with cancer being treated with tegafur
In your initial post, describe how you think each person or their treatment might be affected.
Explanation / Answer
CYP2A6 is an enzyme found in the liver that metabolizes such chemicals as the st