The Role and Mechanism of the Histone Methyltransferase G9a in Tumors: Update

Hangsheng Zhou,1,2,* Jiandong Gui,1,2,* Lijie Zhu,2 Yuanyuan Mi2 1Wuxi Medical College, Jiangnan University, Wuxi, Jiangsu Province, 214122, People’s Republic of China; 2Department of Urology, Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu Province, 214122, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yuanyuan Mi; Lijie Zhu, Department of Urology, Affiliated Hospital of Jiangnan University, No. 1000 Hefeng Road, Wuxi, Jiangsu, 214122, People’s Republic of China, Email miniao1984@163.com; jndxfyzlj@163.comAbstract: Methylation-mediated gene silencing is closely related to the occurrence and development of human tumors. The euchromatic histone lysine methyltransferase 2 (EHMT2, also known as G9a) is highly expressed in many tumors and is generally considered to be an oncogene, which is associated with the poor outcome of many tumors. Combined immunotherapy and immune checkpoint blockade therapy also have good efficacy and certain safety. However, there are still many difficulties in the drugs targeting G9a, and the combined effect and safety of G9a with many drugs is still under study. This article aims to summarize the role and mechanism of G9a and its inhibitors in tumors in the past two years, and to understand the application prospect of G9a from the perspective of diagnosis and treatment.Keywords: cancer, G9a, methyltransferase, function, mechanism