NRAS Contributes to Retinoblastoma Progression Through SNHG 16/miR-183-5p/NRAS Regulatory Network

Purpose: The oncogene of wild type neuroblastoma RAS viral oncogene homolog (NRAS) has been found to involve in the tumorigenesis of cancers. However, the role of NRAS in retinoblastoma (RB) progression remains largely unknown. Methods: The expression levels of NRAS, miR-183-5p and small nucleolar RNA host gene 16 (SNHG16) were measured using quantitative real-time polymerase chain reaction assay or Western blot assay, respectively. Cell proliferation and apoptosis were analyzed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay or flow cytometry, respectively. Transwell assay was used to determine cell migration and invasion abilities. The interaction between miR-183-5p and NRAS or SNHG16 was analyzed using bioinformatics analysis and dual-luciferase reporter assay. Results: NRAS was elevated in RB tissues and cell lines, knockdown of NRAS could inhibit proliferation, migration and invasion but induced apoptosis in vitro and suppressed tumor growth in vivo. NRAS was confirmed to be a target of miR-183-5p and was negatively regulated by miR-183-5p in RB cells. Moreover, overexpressed NRAS reversed miR-183-5p mediated inhibition on RB cell progression. Besides that, SNHG16 directly interacted with miR-183-5p and reduced miR-183-5p expression in RB cells. The suppression of RB cell progression induced by SNHG16 silencing could be partially attenuated by the inhibition of miR-183-5p. Besides that, SNHG16 could regulate NRAS expression through competitively binding to miR-183-5p in RB cells. Conclusion: NRAS functioned as an oncogene to contribute to RB progression by SNHG16/miR-183-5p/NRAS regulatory network, indicating a novel and promising therapeutic target for RB.