Table 1.

Key studies: A-to-I RNA editing and human disease

Disease	Finding	Model	Reference(s)
Amyotrophic lateral sclerosis (ALS)	Downregulation of ADAR2 expression and GluA2 editing in ALS	Human patients	[20,21]
	Conditional ADAR2 knockout produces ALS-like symptoms that are rescued by edited GluA2	In vivo, mice	[23]
	Unedited GluA2 causes mislocation of TDP-43 also observed in sporadic ALS	In vivo, mice	[24]
		In vitro, mouse cells
		In vitro, human cells
Astrocytoma	Correlation between ADAR2 activity and malignancy	Pediatric astrocytoma tissue	[28]
		In vitro, human cells
	Constant expression of ADAR2 but upregulation of ADAR1
	Overexpression of ADAR2 results in decreased proliferation and mobility
	Influx of Ca2+ results in an activation of the Akt pathway, which is rescued by edited GluA2	In vitro, human cells	[29]
	ADAR2 edits CDC14B mRNA, promoting its translation. This leads to degradation of Skp2, which upregulates p21 and p27. This prevents S-phase transition and tumor growth	Mouse xenograft	[30]
Aicardi-Goutières syndrome (AGS)	Novel Adar1 mutations associated with AGS	Human patients	[53]
Hepatocellular carcinoma (HCC)	ADAR1 activity correlated with tumor aggressiveness ADAR1 edits AZIN1, which increases its inhibition of antizyme	Human tumor specimens	[62]
		Mouse xenograft
		In vitro, human cells
	This upregulates ODC and CCND1, increasing proliferation and mobility
		Computational model
Measles virus	Biased hypermutation in matrix gene	Human patients	[71]
	Hypermutation promotes viral infection	In vivo, mouse	[73]
		In vitro, mouse cells
	ADAR1 promotes viral infection	In vitro, human cells	[74]
Metastatic melanoma	Cancer amplifies genes encoding microRNAs that target ADAR1	Mouse xenograft	[60]
		In vitro, human cells
	This interferes with the regulation of >100 microRNAs and promotes tumorigenicity