MiR-181a-5p inhibits uveal melanoma development by targeting GNAQ and AKT3

Uveal melanoma (UM) is the most common primary intraocular malignant tumor type in adults. Even after the treatment of the ocular tumor, the prognosis of patients with metastasis remains poor. Hence, an urgent unmet need exists to identify novel approaches to treat advanced UM. Previous studies have revealed G subunit alpha Q and alpha 11 (GNAQ/11) mutations in more than 85% of patients with UM, thus indicating the importance of GNAQ and downstream signaling pathways in UM occurrence. Here, we demonstrate that microRNA (miR)-181a-5p, a small non-coding RNA, effectively inhibited the viability, proliferation, and colony formation but induced apoptosis of UM cells. Furthermore, silencing GNAQ or AKT3 mimicked the anti-UM effects of miR-181a-5p, whereas over -expression of GNAQ or AKT3 rescued the anti-UM effects induced by miR-181a-5p. In addition, miR-181a-5p had a stronger effect in decreasing the viability of GNAQ mutant than GNAQ wild-type cells. Moreover, miR-181a-5p suppressed the total expression and phosphorylation of members of the ERK and PI3K/AKT/mTOR signaling path-ways. Importantly, miR-181a-5p potently inhibited the growth of UM xenografts in nude mice. MiR-181a-5p also de-creased the expression of Ki67, GNAQ, and AKT3, and induced the expression of cleaved-caspase3 in UM tumors. These results suggest that miR-181a-5p inhibits UM development by targeting GNAQ and AKT3.

Automated summary

Uveal melanoma (UM) is the most common primary intraocular malignant tumor type in adults. Previous studies have shown that GNAQ/11 mutations are present in more than 85% of patients with UM, indicating their importance in UM occurrence. In this study, miR-181a-5p was found to effectively inhibit the viability, proliferation, and colony formation of UM cells, as well as induce apoptosis. Silencing GNAQ or AKT3 mimicked the anti-tumor effects of miR-181a-5p, while overexpression of GNAQ or AKT3 rescued these effects. MiR-181a-5p also suppressed the expression and phosphorylation of members of the ERK and PI3K/AKT/mTOR signaling pathways.