Department of Epidemiology and Biostatistics, Key Laboratory for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
Arch Toxicol. 2021 Mar;95(3):1117-1128. doi: 10.1007/s00204-021-02978-5. Epub 2021 Jan 21.
N6-Methyladenosine (mA) is the most prevalent modification of RNA in eukaryotes, and is associated with many cellular processes and even the development of cancers. We hypothesized that single-nucleotide polymorphisms (SNPs) in mA modification genes, including its "writers", "erasers" and "readers", might affect the mA functions and associate with the susceptibility to pancreatic ductal adenocarcinoma (PDAC). We first conducted a two-stage case-control study in Chinese population to interrogate all SNPs in 22 mA modification genes. In the discovery stage, a total of 2735 SNPs were genotyped in 980 patients and 1991 controls. Then, the promising SNP was replicated in another independent population consisting of 858 cases and 2084 controls. As a result, we found the rs7495 in 3'UTR of hnRNPC was significantly associated with increased risk of PDAC in both stages (combined odds ratio = 1.22, 95% confidence interval = 1.12-1.32, P = 2.39 × 10). To further reveal the biological function of rs7495 and hnRNPC, we performed a series of biochemical experiments. Luciferase reporter assays indicated that rs7495G allele promoted hnRNPC expression through disrupting a putative binding site for has-miR-183-3p. Cell viability assay demonstrated that knockdown of hnRNPC suppressed the proliferation of PDAC cells. RNA-seq analysis suggested that as an mA "reader", hnRNPC played an important role in RNA biological processes. In conclusion, our findings elucidated that rs7495G could confer higher risk of PDAC via promoting the expression of hnRNPC through a miRNA-mediated manner. These results provided a novel insight into the critical role of mA modification in tumorigenesis.
N6-甲基腺苷（m6A）是真核生物中最普遍的 RNA 修饰，与许多细胞过程有关，甚至与癌症的发生有关。我们假设 m6A 修饰基因中的单核苷酸多态性（SNP），包括其“书写器”、“擦除器”和“读取器”，可能会影响 m6A 的功能，并与胰腺导管腺癌（PDAC）的易感性相关。我们首先在中国人群中进行了一项两阶段病例对照研究，以研究 22 个 m6A 修饰基因中的所有 SNP。在发现阶段，在 980 名患者和 1991 名对照中总共对 2735 个 SNP 进行了基因分型。然后，在另一个由 858 名病例和 2084 名对照组成的独立人群中对有希望的 SNP 进行了复制。结果发现，hnRNPC 3'UTR 中的 rs7495 与两个阶段 PDAC 的风险增加显著相关（合并优势比=1.22，95%置信区间=1.12-1.32，P=2.39×10）。为了进一步揭示 rs7495 和 hnRNPC 的生物学功能，我们进行了一系列生化实验。荧光素酶报告基因实验表明，rs7495G 等位基因通过破坏 hnRNPC 的一个潜在结合位点来促进 hnRNPC 的表达。细胞活力测定表明，hnRNPC 的敲低抑制了 PDAC 细胞的增殖。RNA-seq 分析表明，作为 m6A“读取器”，hnRNPC 在 RNA 生物学过程中发挥重要作用。总之，我们的研究结果表明，rs7495G 通过 miRNA 介导的方式促进 hnRNPC 的表达，从而增加 PDAC 的发病风险。这些结果为 m6A 修饰在肿瘤发生中的关键作用提供了新的见解。
