BPDE-like DNA adduct level in oral tissue may act as a risk biomarker of oral cancer.
OBJECTIVE
Most reports have shown that PAH-related DNA adducts are positively correlated with the smoking status of oral cancer patients. However, these reports did not focus on a specific carcinogen in cigarette smoke. The purpose of this study was to elucidate the role of the BPDE (7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene)-DNA adduct in the development of oral cancer in Taiwanese patients.


METHODS
We enrolled 158 oral cancer patients and 64 non-cancer controls to investigate whether there were differences in susceptibility to cigarette smoke exposure in the formation of DNA adducts between cancer patients and controls. Immunohistochemistry and ELISA (enzyme-linked immunosorbent assay) were used to evaluate BPDE-DNA adduct levels in this study.


RESULTS
Our data showed that the BPDE-DNA adduct levels were positively correlated with gender, smoking status, betel nut chewing and alcohol consumption. The difference in DNA adduct levels could be explained by genetic polymorphisms of glutathione S-transferase M1 (GSTM1), but not by cytochrome P-4501A1 (CYP1A1). Patients with high DNA adduct levels (≧34.03 adducts/10(8) nucleotides) had an approximately 9.936-fold risk of oral cancer compared with those with low DNA adduct levels (<34.03 adducts/10(8) nucleotides) (p<0.001).


CONCLUSIONS
We suggest that genetic background and carcinogen exposure may increase the risk of developing oral cancer.
Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.
Chun-Yi
CY
Chuang
Jai-Nien
JN
Tung
Mao-Chang
MC
Su
Buor-Chang
BC
Wu
Chun-Han
CH
Hsin
Yi-Juai
YJ
Chen
Kun-Tu
KT
Yeh
Huei
H
Lee
Ya-Wen
YW
Cheng
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000032:analysis*; D000428:Alcohol Drinking / Q000009:adverse effects; D001114:Areca / Q000009:adverse effects; D014408:Biomarkers, Tumor / Q000032:analysis*; D002273:Carcinogens / Q000032:analysis*; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D018736:DNA Adducts / Q000032:analysis*; D004198:Disease Susceptibility; D005260:Female; D059647:Gene-Environment Interaction; D005982:Glutathione Transferase / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology*; D011110:Polymorphism, Genetic / Q000235:genetics; D012307:Risk Factors; D012737:Sex Factors; D012906:Smoke / Q000009:adverse effects; D012907:Smoking / Q000009:adverse effects; D014026:Nicotiana / Q000009:adverse effects
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D014408:Biomarkers, Tumor; D002273:Carcinogens; D019363:Cytochrome P-450 CYP1A1; D018736:DNA Adducts; D005982:Glutathione Transferase; D012906:Smoke; C569463:CYP1A1 protein, human