Abstract LB-384: A-to-I miR-378a-3p editing prevents melanoma progression via regulation ofPARVA expression

Abstract

Abstract Although recent studies have shown that adenosine-to-inosine (A-to-I) RNA editing occurs in microRNAs (miRNAs), the effects of A-to-I miRNAs editing on melanoma growth and metastasis are yet to be determined. Previously we have reported that metastatic melanoma cell lines and tumor specimens have reduced expression of ADAR1 and consequently are impaired in their ability to perform A-to-I microRNA (miRNA) editing. Here we report that miR-378a-3p is undergoing A-to-I editing only in the non-metastatic but not in metastatic melanoma cells. The function of the edited form is different from its wild-type counterpart. The edited form of miR-378a-3p preferentially binds to the 3'UTR of the PARVA oncogene and inhibits its expression, thus preventing the progression of melanoma towards the malignant phenotype. Indeed, edited miR- 378a-3p but not its WT form inhibits melanoma metastasis in vivo. These results further emphasize the role of RNA editing in melanoma progression. Citation Format: Einav Shoshan, Guermarie Velazquez-Torres, Enrique Fuentes-Mattei, Cristina Ivan, Menashe Bar-Eli. A-to-I miR-378a-3p editing prevents melanoma progression via regulation ofPARVA expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-384.