Association of n - acetyl transferase genetic polymorphisms with colorectal cancer / Guitar Samy Aly ; supervised Ibtisam Farid , Tarek AlMahboub , Randa Mohamed Sabry Zaki

Thesis (PH.D.) - Cairo University - Faculty Of Medicine - Department Of Clinical and Chemical Pathology

Aromatic amines and heterocyclic amines are present in cigarette smokeHeterocyclic amines are also present in the diet as protein pyrolysis products formed when meat is cooked well doneThese carcinogens produce tumors at a number of sites but require host - mediated metabolic activation to mutate DNA and initiate carcinogenesisBoth N - Acetyltransferases , NAT1 and NAT2 , are important enzymes in the biotransformation of these carcinogensThey catalyze their N - acetylation (usually deactivation) and O - acetylation (usually activation) Genetic polymorphisms in NAT1 and / or NAT2 may modify risk associated with carcinogen exposuresFor cancers in which N - acetylation is a detoxification step such as aromatic amine - related urinary bladder cancer , NAT2 slow acetylator phenotype is expected to be at higher riskIn contrast , for cancers in which N - acetylation is negligible and O - acetylation is activation step such as for heterocyclic amine - related colon cancer , NAT2 rapid acetylator phenotype is expected to be at higher riskHuman epidemiological studies suggest that the NAT1 and NAT2 acetylation polymorphisms modifypredisposition to urinary bladder , colorectal , breast , head and neck , lung , and possibly prostate cancers

Issued also as CD