YWHAE gene product belongs to the 14-3-3 protein family that mediates signal transduction in plants and mammals. A protein-coding and a non-coding RNA (lncRNA) transcripts have been reported for this gene in human. Here， we aimed to functionally characterize YWHAE encoded lncRNA in colorectal cancer originated cells. RNA-seq analysis showed that YWHAE gene is upregulated in colorectal cancer specimens. Additionally， bioinformatics analysis suggested that YWHAE-lncRNA sponges miR-323a-3p and miR-532-5p that were predicted to target K-Ras 3'UTR sequence. Overexpression of YWHAE-lncRNA， resulted in upregulation of K-Ras gene expression while， overexpression of both miR-323a-3p and miR-532-5p had an inverse... More
YWHAE gene product belongs to the 14-3-3 protein family that mediates signal transduction in plants and mammals. A protein-coding and a non-coding RNA (lncRNA) transcripts have been reported for this gene in human. Here， we aimed to functionally characterize YWHAE encoded lncRNA in colorectal cancer originated cells. RNA-seq analysis showed that YWHAE gene is upregulated in colorectal cancer specimens. Additionally， bioinformatics analysis suggested that YWHAE-lncRNA sponges miR-323a-3p and miR-532-5p that were predicted to target K-Ras 3'UTR sequence. Overexpression of YWHAE-lncRNA， resulted in upregulation of K-Ras gene expression while， overexpression of both miR-323a-3p and miR-532-5p had an inverse effect， detected by RT-qPCR. Consistently， western blot analysis confirmed that YWHAE-lncRNA overexpression upregulated K-Ras/Erk1/2 and PI3K/Akt signaling pathways while， miR-323a-3p and miR-532-5p overexpression suppressed both pathways in HCT116 cells. Furthermore， dual luciferase assay validated the direct interaction of miR-323a-3p and miR-532-5p with K-Ras 3'UTR sequence， and supported the sponging effect of YWHAE-lncRNA over both miRNAs. These results suggested YWHAE-lncRNA as an oncogene that exerts its effect through sponging miR-323a-3p and miR-532-5p and in turn， upregulates K-Ras/Erk1/2 and PI3K/Akt signaling pathways. Consistently， Flow cytometry analysis， MTT assay and measuring cyclin D1 gene expression， confirmed the cell cycle stimulatory effect of YWHAE-lncRNA while， miR-323a-3p and miR-532-5p showed an inhibitory effect on cell cycle progression. Finally， wound healing assay supported the cell migratory effect of YWHAE-lncRNA in HCT116 cells. This study identified a novel mechanism involving YWHAE encoded lncRNA， miR-323a-3p and miR-532-5p in regulating HCT116 cell survival and suggested a potential therapeutic avenue for colorectal cancer.
