Effects of amino acid substitution polymorphisms of two DNA methyltransferases on susceptibility to sporadic colorectal cancer.
OBJECTIVE
The present study was designed to consider whether amino acid substitution polymorphisms in O6-methylguanine-DNA methyltransferase (MGMT) and DNA methyl transferase 1 (DNMT1) genes may be associated with the genetic susceptibility to sporadic colorectal cancer.


METHODS
We assessed eight non-synonymous polymorphisms of these two genes by PCR/pyrosequencing. Our population consisted of 208 individuals with sporadic colorectal cancer and 213 controls. Allele frequencies and genotypes were compared between the two groups.


RESULTS
The calculated odds ratios indicated no association between DNMT1 and colorectal cancer. However, there was a significant association between two polymorphisms in MGMT with sporadic colorectal cancer: Arg128Gln (OR, 5.53; 95% CI) and Gly160Arg (OR, 3.04; 95% CI).


CONCLUSIONS
These findings could be indicative of factors contributing to high occurrence of Iranian colorectal cancer patients.
Khatami
Fatemeh
F
Research Center for Gastrointestinal and Liver Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran. sKhatami@rigld.ir
Noorinayer
Babak
B
Mohebi
Seyed Reza
SR
Ghiasi
Somayeh
S
Mohebi
Reza
R
Hashemi
Mohhamad
M
Zali
Mohammad Reza
MR
D000328:Adult; D019943:Amino Acid Substitution; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000235:genetics*; D015254:DNA Modification Methylases / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D012097:Repressor Proteins / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000235:genetics*
C411744:DMAP1 protein, human; D012097:Repressor Proteins; D025521:Tumor Suppressor Proteins; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes