CYP1A1 polymorphism interactions with smoking status in oral cancer risk: evidence from epidemiological studies

Abstract

The cytochrome CYP1A1 gene has been implicated in the etiology of oral cancer. However, the results have been inconsistent. In this study, a meta-analysis was performed to clarify the associations of polymorphisms in CYP1A1 gene with oral cancer risk. Published literatures from PubMed, MEDLINE, EMBASE, and China National Knowledge infrastructure (CNKI) databases were retrieved. A total of 12 studies were included in this meta-analysis. We found that significant positive associations between CYP1A1*2A polymorphism and oral cancer risk in recessive model (CC vs. TC + TT, OR = 1.93), dominant model (CC + TC vs. TT, OR = 1.33), and additive model (CC vs. TT, OR = 1.97). In subgroup analysis based on the ethnicity of study population, significant associations were found in all three genetic models for Asians (recessive OR = 2.29, 95% CI = .42-3.71; dominant OR = 1.54, 95% CI = 1.03-2.31; additive OR 2.39, 95% CI = 1.47-3.88) but not non-Asians. For the smoking stratification, the result indicated a significant association between CYP1A1*2A polymorphism and oral cancer among the smoking subjects (OR = 1.83, 95% CI = 1.47-2.26). This meta-analysis indicated a marked association of CYP1A1*2A polymorphisms with oral cancer risk, particularly among Asians, whereas there were significant interactions between the polymorphisms and cigarette smoking on oral cancer risk.

Association of CYP1A1 and GSTM1 Polymorphisms With Oral Cancer Susceptibility

“…In our study, CYP1A1 rs4646903 was verified to increase the risk of oral cancer, particularly in Asians, whereas CYP1A1 rs1048943 polymorphism did not show significant relationship with oral cancer susceptibility, when we pooled all data together, but demonstrated a statistically significant association when data were limited to Asians, which was consistent with the results of most previous studies. 2 , 24 , 37 , 40 , 45 , 47 , 53 , 56 , 58 , 71 , 72 However, there were some studies with opposite results to ours. Among them, Losi-Guembarovski et al 51 and Amtha et al 58 found that there was no significant association between CYP1A1 rs4646903 polymorphism and oral cancer risk.…”

“… 6 , 39 The null genotype of GSTM1 polymorphism could result in the inactivation of GSTM1 enzyme and thus decrease the capacity of detoxifying carcinogens. 71 So far, several epidemiological studies have evaluated the association of CYP1A1 and GSTM1 polymorphisms with oral cancer susceptibility. In our study, CYP1A1 rs4646903 was verified to increase the risk of oral cancer, particularly in Asians, whereas CYP1A1 rs1048943 polymorphism did not show significant relationship with oral cancer susceptibility, when we pooled all data together, but demonstrated a statistically significant association when data were limited to Asians, which was consistent with the results of most previous studies.…”

Molecular biomarkers to assess health risks due to environmental contaminants exposure

“…Individuals carrying the CYP1A1*2A allele are predisposed to higher DNA adduct levels and an increased percent of aberrant cells when exposed to environmental tobacco smoke (ETS) (144). Likewise, in an Asian population, the presence of the MspI polymorphism correlated with reduced birth weight following high PM10 exposure (155), oral cancer risk associated with tobacco smoking and chronic obstructive pulmonary disease (156).…”

Functional Polymorphisms inCOX-2Gene Are Correlated with the Risk of Oral Cancer

“…In recent years, increasing incidence of oral cancers, especially in younger age groups, has posed a serious threat to public health [ 2 ]. In most countries, oral cancer is more frequent in men than women because of the more prevalent risky habits in men such as alcohol consumption, cigarette smoking, and betel quid chewing [ 3 , 4 ]. Oral cancers are aggressive and frequently invade as well as metastasize to distant organs, thus making them difficult to cure [ 5 ].…”