• Authors: Hong, H., An, O., Chan, T. H. M., Ng, V. H. E., Kwok, H. S., Lin, J. S., Qi, L., Han, J., Tay, D. J. T., Tang, S. J., Yang, H., Song, Y., Bellido Molias, F., Tenen, D. G., Chen, L.
  • Year: 2018
  • Journal: Nucleic Acids Res
  • Applications: in vitro / DNA / jetPRIME
  • Cell types:
    1. Name: Eca-109
      Description: Esophageal squamous cell carcinoma cells, also known as Eca109; Eca 109; EC-109; EC109.
    2. Name: HEK-293T
      Description: Human embryonic kidney Fibroblast
      Known as: HEK293T, 293T


Virus production (lentivirus).


Adenosine-to-inosine (A-to-I) RNA editing entails the enzymatic deamination of adenosines to inosines by adenosine deaminases acting on RNA (ADARs). Dysregulated A-to-I editing has been implicated in various diseases, including cancers. However, the precise factors governing the A-to-I editing and their physiopathological implications remain as a long-standing question. Herein, we unravel that DEAH box helicase 9 (DHX9), at least partially dependent of its helicase activity, functions as a bidirectional regulator of A-to-I editing in cancer cells. Intriguingly, the ADAR substrate specificity determines the opposing effects of DHX9 on editing as DHX9 silencing preferentially represses editing of ADAR1-specific substrates, whereas augments ADAR2-specific substrate editing. Analysis of 11 cancer types from The Cancer Genome Atlas (TCGA) reveals a striking overexpression of DHX9 in tumors. Further, tumorigenicity studies demonstrate a helicase-dependent oncogenic role of DHX9 in cancer development. In sum, DHX9 constitutes a bidirectional regulatory mode in A-to-I editing, which is in part responsible for the dysregulated editome profile in cancer.