Analysis of the role of rs2031920 and rs3813867 polymorphisms within the cytochrome P450 2E1 gene in the risk of squamous cell carcinoma

CYP2D6, CYP2E1 Gene Polymorphisms and Gastrointestinal Cancer Risk in Rural Maharashtra: A Hospital Based Case-Control Study

BACKGROUND

Cytochrome P450 (CYP) is a family phase I metabolizing enzymes important in xenobiotics metabolism. Genetic polymorphisms of CYPs have been comprehensively studied for their association with a range of diseases including cancer risk. In this study we assessed single nucleotide polymorphism (SNP) CYP2D6 and CYP2E1 genes and their role in gastrointestinal (GI) cancer susceptibility in the rural population of Maharashtra.

METHODS

Genotyping of CYP2D6*4, CYP2E1*5B, CYP2E1*6, CYP2E1*7B genes among 200 GI cancer cases and equal number of controls was studied by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The Odds ratio (OR) with 95% confidence interval and p-value were evaluated to get the level of association of polymorphisms with risk of GI cancer, where p ≤0.005 was considered as statistically significant.

RESULTS

After the analysis of CYP2D6 and CYP2E1 gene polymorphisms, we noticed that CYP2D6*4 (rs3892097) with heterozygous genotype (G/C) showed negative association with GI cancer risk (OR=0.43, 95% CI: 0.25-0.74; p=0.002) and CYP2E1*6 (rs6413432) variant genotype showed positive association (OR=2.85, 95% CI: 1.40-5.81; p=0.003) showed positive association with GI cancer risk in studied population.

CONCLUSION

The findings obtained from this study concluded that the polymorphic CYP2D6 was negatively associated; however CYP2E1*6 polymorphism was significantly associated with GI cancer risk in studied population.

CYP2E1 C-1054T and 96-bp I/D genetic variations and risk of gestational diabetes mellitus in chinese women: a case-control study

BACKGROUND

Cytochrome P450 2E1 (CYP2E1) plays a key role in the metabolism of xenobiotic and endogenous low-molecular-weight compounds. This study aimed to determine if the genetic variations of 96-bp insertion/deletion (I/D) and C-1054T (rs2031920) in CYP2E1 were associated with the risk of gestational diabetes mellitus (GDM).

METHODS

CYP2E1 polymorphisms were genotyped in a case-control study of 1,134 women with uncomplicated pregnancies and 723 women with GDM. The effects of genotype on the clinical, metabolic, and oxidative stress indices were assessed.

RESULTS

The CYP2E1 C-1054T variant was associated with an increased risk of GDM based on the genotype, recessive, dominant, and allele genetic models (P < 0.05). The TT + CT genotype remained a significant predictive factor for GDM risk after correcting for maternal age and pre-pregnancy body mass index (OR = 1.277, 95% CI: 1.042-1.563, P = 0.018). Moreover, fasting insulin concentrations and homeostatic model assessment of insulin resistance were significantly higher in GDM patients carrying the T allele than in those with the CC genotype (P < 0.05). Furthermore, the combined genotype II + ID/TT + CT of the 96-bp I/D and C-1054T polymorphisms further increased the risk of GDM when the combined genotype DD/CC was set as the reference category (OR = 1.676, 95% CI: 1.182-2.376, P = 0.004).

CONCLUSIONS

The T allele of the C-1054T polymorphism and its combination with the I allele of the 96-bp I/D variation in CYP2E1 are associated with an increased risk of GDM in the Chinese population. The - 1054T allele may be associated with more serious insulin resistance in patients.

Association between CYP2E1 C-1054T and 96-bp I/D genetic variations and the risk of polycystic ovary syndrome in Chinese women

PURPOSE

To investigate the association of cytochrome P450 2E1 (CYP2E1) C-1054T (rs2031920) and 96-bp I/D genetic variations with the risk of polycystic ovary syndrome (PCOS), and to estimate the effects of genotypes on the clinical, metabolic, hormonal, and oxidative stress indicators.

METHODS

This case-control study included 762 control women and 1034 patients with PCOS. Genotypes were determined using polymerase chain reaction and/or restriction fragment length polymorphism analysis. Clinical and biochemical parameters were also analyzed.

RESULTS

Frequencies of the TT + CT genotype (35.4 vs. 28.9%) and T allele (19.6 vs. 16.0%) of the CYP2E1 C-1054T polymorphism were significantly higher in the PCOS group than in the control group (OR = 1.350, 95% CI 1.103-1.652, P = 0.004 for the dominant model). Genotype TT + CT remained a significant predictor of PCOS in a logistic regression model including age, body mass index (BMI), and recruitment year of participants (OR = 1.345, 95% CI 1.071-1.688, P = 0.011). No statistical differences were found in the genotype and allele frequencies of CYP2E1 96-bp I/D polymorphism. However, the combined genotype DD/TT + CT was related to an increased risk of PCOS when the DD/CC wild-type combined genotype was used as a reference. Patients with the I allele of 96-bp I/D polymorphism had a lower BMI but higher plasma apolipoprotein B and oxidized low-density lipoprotein cholesterol levels than those with the DD genotype.

CONCLUSION

CYP2E1 C-1054T, but not 96-bp I/D, genetic polymorphism is associated with an increased risk of PCOS in Chinese women.

Validation study of susceptibility loci for esophageal squamous cell carcinoma identified by GWAS in a Han Chinese subgroup from Eastern China

Esophageal squamous cell carcinoma (ESCC) occurs at a relatively high frequency in China and is one of the most prevalent cancers in the world. Genome-wide association studies (GWAS) have identified 24 single-nucleotide polymorphisms (SNPs) that could be associated with ESCC in Chinese patients. This retrospective study aimed to validate the association between these 24 SNPs and ESCC in a Han Chinese subgroup from East China. A total of 2280 and 1900 patients with ESCC (case group) and non-esophageal cancer (control group) were included from a single center. Genotyping of the 24 polymorphisms was performed using the Sequenom MassARRAY system. Unconditional logistic regression analyses were conducted for every polymorphism. It was found that rs12188136 (P=0.027, OR=1.158, 95% CI=1.016-1.319 for AG/AA) was associated with ESCC. Binary logistic regression analyses revealed a significant negative association of rs875339 in RORA (P=0.014, OR=0.762, 95% CI=0.613-0.947 for TT/CC). Under the dominant model, rs6854472 was slightly associated with ESCC risk (P=0.048, OR=1.192, 95% CI=1.002-1.418). Under the recessive model, a significant negative association was observed for rs875339 (P=0.010, OR=0.758, 95% CI=0.615-0.935). In a word, this large-scale replication study validated that rs12188136 and rs6854472 are associated with ESCC in a Han Chinese subgroup from Eastern China, and that rs875339 is negative associated with ESCC.