Association between cytosolic serine hydroxymethyltransferase (SHMT1) gene polymorphism and cancer risk: A meta-analysis

Background: The serine hydroxymethyltransferase (SHMT1) is the key enzyme in the folate metabolic pathway to provide one-carbon unit that plays an important role in biosynthesis. Abnormal biosynthesis involved in DNA synthesis and methylation can lead to activation of oncogenes and inactivation of tumor suppressor genes. And the abnormal biosynthesis is closely related to a variety of common tumors' occurrence and development. A SNP in SHMT1 C1420T may effect the procession of biosynthesis and finally influence cancer occurrence. Methods: Comprehensive searches were performed on PubMed and EMBASE database. We used odds ratio (OR) and 95% confidence interval (95% CI) to assess the strength of associations between SHMT1 C1420T polymorphism and cancer risk. Q-test, I-2, and funnel plot were used to assess the heterogeneity and publication bias. Results: Totally, 19 studies containing 9799 cases and 11,841 controls were performed in this meta-analysis. The results showed that there was no association between SHMT1 C1420T polymorphism and cancer risk. But in the subgroup analysis, the significant associations were found in colorectal cancer and Asian population. Publication bias was not observed in the analysis. Conclusions: Our results indicate that the SHMT1 C1420T polymorphism do not have a significant association with the risk of cancer overall. Otherwise, SHMT1 C1420T polymorphism may have a protective effect on colorectal cancer and Asian population. (C) 2014 Elsevier Masson SAS. All rights reserved.