Ten-Eleven-Translocation Genes in Cancer

The Ten-Eleven-Translocation (TET) family of genes, including TET1, TET2, and TET3, play critical roles in the oxidation of 5-methylcytosine marks in both DNA and RNA, thereby regulating the epigenome and epitranscriptome in cells. These genes are frequently mutated in both hematopoietic malignancies and in solid cancers. TET2, in particular, is one of the most frequently mutated genes in clonal hematopoiesis in the general population, which impacts both the transformation of hematopoietic malignancies and the immune responses in solid tumors. While much has been learned in the 14 years since the discovery of TETs' biochemical function and mutations, many important questions remain. This review covers several aspects of TET-related biology to discuss key yet unanswered questions. What are the functions of different forms of TET mutations found in human cancers? How does TET2 mutation enable pre-malignant hematopoietic expansion? How does TET2 mutation cooperate with partner lesions to cause transformation? And how do TET mutations affect immune responses in solid cancers.