Long noncoding RNA SNHG3 promotes glioma tumorigenesis by sponging miR-485-5p to upregulate LMX1B expression

LIM homeobox transcription factor 1-beta (LMX1B) has recently been found to be highly expressed in advanced gliomas and is associated with poor survival. However, the regulatory molecular mechanism of LMX1B expression in gliomas remains unclear. In this study, bioinformatics analysis showed that miR-485-5p may be the potential upstream regulator of LMX1B, and long noncoding RNA (lncRNA) small nucleolar RNA host gene 3 (SNHG3) may function as a competitive endogenous RNA to sponge miR-485-5p. In addition, the expression of SNHG3 and LMX1B in advanced glioma tissues was significantly upregulated, while the expression of miR-485-5p was significantly downregulated. SNHG3 overexpression reduced the expression of miR-485-5p; increased the expression of LMX1B; and promoted the proliferation, migration, and invasion of glioma cells. In contrast, miR-485-5p overexpression reduced the expression of LMX1B and inhibited cell proliferation, migration, and invasion. The luciferase reporter assay and RNA immunoprecipitation assay further confirmed the interaction between SNHG3 and miR-485-5p and between miR-485-5p and LMX1B. In addition, subcutaneous and orthotropic xenograft models confirmed that lncRNA SNHG3 silencing or miR-485-5p overexpression significantly reduced the growth of glioma xenografts and prolonged survival time. These results indicate that lncRNA SNHG3 can regulate the expression of LMX1B by sponging miR-485-5p, thereby promoting the proliferation, migration, and invasion of glioma cells. This study provides the first evidence that the SNHG3/miR-485-5p/LMX1B axis is involved in glioma tumorigenesis and highlights the potential of SNHG3 and miR-485-5p as therapeutic targets for glioma.