Tumor metastasis is the major cause of poor prognosis and mortality in colorectal cancer (CRC). However, early diagnosis of highly metastatic CRC is currently difficult. In the present study, we screened for a novel biomarker, GDNF family receptor alpha 1 (GFRA1) based on the expression and methylation data in CRC patients from The Cancer Genome Altlas (TCGA), followed by further analysis of the correlation between the GFRA1 expression, methylation, and prognosis of patients. Our results show DNA hypomethylation-mediated upregulation of GFRA1 in invasive CRC, and it was found to be correlated with poor prognosis of CRC patients. Furthermore, GFRA1 methylation-modified sequences were found to have potential as methylation diagnostic markers of highly metastatic CRC. The targeted demethylation of GFRA1 by dCas9-TET1CD and gRNA promoted CRC metastasis in vivo and in vitro. Mechanistically, demethylation of GFRA1 induces epithelial-mesenchymal transition (EMT) by promoting AKT phosphorylation and increasing c-Jun expression in CRC cells. Collectively, our findings indicate that GFRA1 hypomethylation can promote CRC invasion via inducing EMT, and thus, GFRA1 methylation can be used as a biomarker for the early diagnosis of highly metastasis CRC.

肿瘤转移是结直肠癌（CRC）预后差和死亡率低的主要原因。然而，目前很难对高转移性CRC进行早期诊断。在本研究中，我们根据癌症基因组Altlas（TCGA）在CRC患者中的表达和甲基化数据，筛选了一种新型生物标志物GDNF家族受体α1（GFRA1），然后进一步分析了GFRA1表达之间的相关性，甲基化和患者的预后。我们的研究结果表明，DNA低甲基化介导的浸润性CRC中GFRA1的上调，并且与CRC患者的不良预后相关。此外，发现GFRA1甲基化修饰的序列具有作为高度转移性CRC的甲基化诊断标志物的潜力。的目标脱甲基dCas9 -TET1CD和gRNA促进的GFRA1在体内和体外促进CRC转移。从机制上讲，GFRA1的去甲基化通过促进AKT磷酸化和增加CRC细胞中c-Jun的表达而诱导上皮-间质转化（EMT）。总的来说，我们的发现表明GFRA1的低甲基化可以通过诱导EMT促进CRC侵袭，因此GFRA1的甲基化可以用作高度转移性CRC的早期诊断的生物标记。