Functional TET2 gene polymorphisms increase the risk of neuroblastoma in Chinese children.

The 5-methylcytosine (m5C) is the key chemical modification in RNAs. As one of the demethylases in m5C, TET2 has been shown as a tumor suppressor. However, the impact of TET2 gene polymorphisms on neuroblastoma has not been elucidated. 402 neuroblastoma patients and 473 controls were genotyped for TET2 gene polymorphisms using the TaqMan method. The impact of TET2 gene polymorphisms on neuroblastoma susceptibility was determined using multivariate logistic regression analysis. We also adopted genotype-tissue expression database to explore the impact of TET2 gene polymorphisms on the expression of host and nearby genes. We used the R2 platform and Sangerbox tool to analyze the relationship between gene expression and neuroblastoma risk and prognosis through non-parametric testing and Kaplan-Meier analysis, respectively. We found the TET2 gene polymorphisms (rs10007915 G > C and rs7670522 A > C) and the combined 2-5 risk genotypes can significantly increase neuroblastoma risk. Stratification analysis showed that these significant associations were more prominent in certain subgroups. TET2 rs10007915 G > C and rs7670522 A > C are significantly associated with reduced expression of TET2 mRNA. Moreover, lower expression of TET2 gene is associated with high risk, MYCN amplification, and poor prognosis of neuroblastoma. The rs10007915 G > C and rs7670522 A > C are significantly related to the increased expression of inorganic pyrophosphatase 2 mRNA, and higher expression of PPA2 gene is associated with high risk, MYCN amplification, and poor prognosis of neuroblastomas. In summary, TET2 rs10007915 G > C and rs7670522 A > C significantly confer neuroblastoma susceptibility, and further research is needed to investigate the underlying mechanisms.