Association of methylenetetrahydrofolate reductase C677T-A1298C polymorphisms with risk for esophageal adenocarcinoma, Barrett's esophagus, and reflux esophagitis

Methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms in oral squamous cell carcinoma in south-east Iran

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) gene encodes an essential enzyme involving in folate metabolism. Due to the role of folate in DNA integrity, polymorphisms of MTHFR are interesting targets for cancer risk studies. Our goal was to evaluate the prevalence of MTHFR C677T and A1298T single nucleotide polymorphisms in oral squamous cell carcinoma (OSCC).

METHODS

The study was conducted on 57 OSCC patients diagnosed within 2004-2013 along with 62 non-OSCC subjects. DNA was extracted by standard kit protocol. Subsequently, tetra-ARMS (amplification refractory mutation system)-PCR was applied to identify the selected polymorphisms.

RESULTS

Data showed that CT and TT genotypes of C677T polymorphisms significantly increased the risk of OSCC [odds ratio (OR) = 2.2, 95% CI: 1-5, P = 0.04]. Although allelic distribution was not significantly different between patients and controls, T allele of C677T polymorphism was closely associated with the risk of OSCC (OR = 2.5; 95% CI: 0.9-6.9; P = 0.07). Results indicated that C677T/A1298C: CC/AC and C677T/A1298C: CC/AA haplotypes were the most common combinations in OSCC patient and control groups, respectively. (OR = 1.5, 95% CI: 0.6-3.8, P > 0.05).

CONCLUSION

Our results highlight the possible impact of C677T polymorphism in increasing the risk of OSCC development.

Dietary Risk Reduction Factors for the Barrett's Esophagus-Esophageal Adenocarcinoma Continuum: A Review of the Recent Literature

Esophageal adenocarcinoma (EA) incidence is among the most rapidly increasing of any cancer type in the U.S., and prognosis is poor. Prevalence of the potential precursor lesion, Barrett's esophagus (BE), is also increasing. Candidates for safe and effective risk reduction strategies are needed, potentially including dietary components. In this qualitative review, we summarize recently published epidemiologic studies, in context of earlier work, on dietary intake and BE-EA outcomes. Potential cohort study/intervention trial candidates which could be increased to reduce BE-EA development include intake of: (1) fruits and vegetables; vegetables; fruit (EA only); (2) β-carotene and vitamins C and E; (3) folate (EA only); and (4) total fiber (EA only). Also, (5) red and processed meat intake could be targeted for dietary reduction/omission to reduce EA development. Few dietary constituents have been evaluated among EA patients to examine associations with mortality, thus interventions conducted among EA patients are premature.

Polymorphisms of MTHFR and susceptibility to oesophageal adenocarcinoma in a Caucasian United Kingdom population

AIM: To identify if methylene tetra-hydrofolatereductase (MTHFR) C677T polymorphisms are associated with oesophageal adenocarcnomas in a Caucasian population and to test whether folic acid and homocysteine levels are linked with cancer risk.

METHODS: A case control study comprising of 58 non cancer and 48 cancer patients, MTHFR C667T genotyping was made and serum folate, homocysteine and vitamin B12 levels were made. Tumour stage, differentiation and survival was recorded. A P value of less than 0.05 was taken to be significant. The χ² used to compare discrete variables and the Mantel-Cox was used to compare survival. A P value less than 0.05 was deemed to be significant.

RESULTS: MTHFR polymorphisms is associated with an increased risk of several cancers. A link between MTHFR C677T polymorphisms and oesophageal squamous cell carcinoma and gastric cardia adenocarcinoma has been demonstrated in at risk Chinese populations. In a Western European population the role of the MTHFR gene has not previously been investigated in the setting of oesophageal adenocarcinoma. No association between folic acid levels and cancer patients was found. The unstable MTHFR 667 TT genotype occurred in 11% cancers and 7% controls, but statistical significance was not reached, homocysteine levels and folic acid levels were not affected, cancer patients with TT genotype displayed a trend for a shorter survival 7 mo vs 20 mo. Serum vitamin B12 levels were higher in the cancer group. The MTHFR 667 TT genotype is much lower than previous population studies.

CONCLUSION: We conclude that serum folic acid and MTHFR polymorphisms are not associated with an increased risk of oesophageal adenocarcinoma, although cancers with unstable TT genotype may indicate a more aggressive disease course.

Genetic variations in MTHFR and esophageal squamous cell carcinoma susceptibility in Chinese Han population

Esophageal cancer is the sixth most common cancer worldwide. Esophageal squamous cell carcinoma (ESCC) is a fatal malignancy associated with low 5-year survival rate. The aim of this study was to assess the association between methylenetetrahydrofolate reductase (MTHFR) tagging single nucleotide polymorphisms (SNPs) rs1801133 C>T, rs3753584 A>G, rs4845882 G>A, rs4846048 A>G and rs9651118 T>C genotypes and ESCC susceptibility in a hospital-based case-control study. We conducted genotyping analyses for these five SNPs with 629 ESCC cases and 686 controls in a Chinese Han population. Ligation detection reaction method was used to identify genotypes of these MTHFR SNPs. Our results demonstrated that MTHFR rs1801133 C>T was associated with the risk of ESCC; however, MTHFR rs4845882 G>A and rs4846048 A>G SNPs were associated with the decreased risk of ESCC, and MTHFR rs3753584 A>G and rs9651118 T>C SNPs were not associated with ESCC risk. Our findings suggests that MTHFR rs1801133 C>T, rs4845882 G>A and rs4846048 A>G SNPs may be genetic modifiers for developing ESCC in Chinese Han population.

Genetic polymorphism of MTHFR A1298C and esophageal cancer susceptibility: a meta-analysis

BACKGROUND

Associations between the methylenetetrahydrofolate reductase (MTHFR) A1298C polymorphism and esophageal cancer risk have been reported in many articles recently, but results were controversial. Therefore the present meta-analysis was conducted to to provide a more precise estimation.

METHODS

Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of associations.

RESULTS

Finally, six case- control studies involving a total of 1,302 cases and 2,391controls for the A1298C polymorphism were included. The meta-analysis showed that significantly increased risk for Asians (CC versus AA, OR=3.799, 95%CI=1.541-9.365, P=0.004; CCversusCA+AA, OR=3.997, 95%CI=1.614-9.900, P=0.003) and Caucasians (CC versus AA, OR=1.797, 95%CI=1.335-2.418, P=0.000; CC+CA versus AA,OR=1.240, 95%CI=1.031-1.492, P=0.022; CCversusCA+AA, OR=1.693, 95%CI=1.280-2.240, P=0.000). In addition, there was an association with risk for both ESCC (CC versus AA, OR=2.529, 95%CI=1.688-3.788, P=0.000; CCversusCA+AA, OR=2.572, 95%CI=1.761-3.758, P=0.000) and esophageal adenocarcinoma (EAC) (CC versus AA, OR=1.592, 95%CI=1.139-2.227, P=0.007; CC+CA versus AA,OR=1.247, 95%CI=1.016-1.530, P=0.035; CCversusCA+AA, OR=1.466, 95%CI=1.069-2.011, P=0.018).

CONCLUSION

This meta-analysis suggested associations of the A1298C polymorphism with increased risk of esophageal cancer in both Asians and Caucasians. In addition, we found that the MTHFR A1298C polymorphism might influence risk ofESCC and EAC in the overall studies.

Aurora kinase A (AURKA) and never in mitosis gene A-related kinase 6 (NEK6) genes are upregulated in erosive esophagitis and esophageal adenocarcinoma

Gastroesophageal reflux disease is a risk factor for esophageal adenocarcinoma yet studies that have investigated the relationship between erosive esophagitis and esophageal adenocarcinoma have usually focused on symptom-related evidence or polymorphisms. There are no epigenetic gene expression studies on this topic. In this study, we aimed to evaluate the relationship between erosive esophagitis and esophageal adenocarcinoma to identify whether there is a genetic predisposition for esophageal adenocarcinoma. The Human Epigenetic Chromatin Modification Enzyme RT(2) Profiler(™) PCR array (PAHS-085A) was used to detect the expression of 84 key genes encoding enzymes. This was carried out prospectively for samples from 60 patients (20 patients as a control group, 20 patients with erosive esophagitis and 20 patients with esophageal adenocarcinoma). AURKA, AURKB, NEK6 were expressed at significantly higher levels in esophageal adenocarcinoma compared to the control group. MBD2 was expressed at significantly lower levels in the esophageal adenocarcinoma group compared to the control group. AURKA, AURKC, HDAC9 and NEK6 were expressed at significantly higher levels in erosive esophagitis compared to the control group. There was no difference in upregulated gene expression between the erosive esophagitis and esophageal adenocarcinoma. MBD2 was significantly downregulated in esophageal adenocarcinoma compared to erosive esophagitis. NEK6 and AURKA were significantly upregulated in esophageal adenocarcinoma and erosive esophagitis compared to the control group. This is a novel study on the genetic predisposition for erosive esophagitis and esophageal adenocarcinoma. AURKA and NEK6 are two promising genetic markers for erosive esophagitis and esophageal adenocarcinoma.