Fig. 5: LINC00205 regulated the expression and activity of miR-26a.

A Gene Set Enrichment Analysis (GSEA) using the miRDB subset explored the target sets of microRNAs enriched in the group of high expression of LINC00205. B The interaction network of miR-26a targets. USP15, EZH2, HMGA2 were the key nodes of the miR-26a regulatory gene expression network. C Left panel: qRT-PCR analysis for miR-26a expression in 28 paired primary GC tissues and adjacent tissues. U6 was used as an internal control. Right panel: The level of circulating miR-26a in the plasma samples. The plasma samples of GC patients were collected before operation (n = 21) and the healthy controls were taken from a physical examination (n = 22). D The correlation of LINC00205 among miR-26a, USP15, EZH2, and HMGA2 expression levels in GC tissues (n = 28). E Left panel: LINC00205 contained a sequence domain complementary to the seed motif of miR-26a, Gm14033(mouse) has high homology with LINC00205(human). Right panel: (I) Luciferase reporter activities of chimeric vectors carrying luciferase gene and a fragment of LINC00205 containing wild-type binding site or mutant binding site for miR-26a were detected in HEK293 cell line. (ii) USP15 is a potential target of miR-26a in humans. Luciferase reporter activities of chimeric vectors carrying either wild-type or mutant 3'UTR of USP15 were also detected in HEK293 cell line. F LINC00205 binds to miR-26a and regulates its activity in BGC823 cells. n = 6 independent experiments, *P < 0.05 vs miR-26a sensor. G The RIP assay revealed that LINC00205 was enriched by AGO2 in BGC823 cells. ***P < 0.001 vs IgG. H RNA affinity isolation in GC cells using biotin-labeled LINC00205 probes. Western blot was used to detect enrichments of AGO2. n = 3. I miR-26a was pulled down by LINC00205 probe, and the expression of miR-26a was analyzed by qRT-PCR. J The product of qRT-PCR was identified by agarose gel electrophoresis. Bio-NC, negative control of LINC00205.