BackgroundClear cell renal cell carcinoma (ccRCC) is the most common renal cell carcinoma subtype with a poor prognosis. LncRNA-LET is a long non-coding RNA (lncRNA) that is down-regulated in ccRCC tissues. However, its role in ccRCC development and progress is unclear.MethodsLncRNA-LET expression was detected in ccRCC tissues and ccRCC cells using quantitative real-time PCR. The overexpression and knockdown experiments were performed in ccRCC cells and xenograft mouse model to evaluate role of lncRNA-LET. Cell cycle, apoptosis and JC-1 assays were conducted via flow cytometer. The protein levels were measured through western blot analysis and the interaction between lncRNA-LET and miR-373-3p was identified via luciferase reporter assay.ResultsLncRNA-LET expression was lower in ccRCC tissues than that in the matched adjacent non-tumor tissues (n = 16). In vitro, lncRNA-LET overexpression induced cell cycle arrest, promoted apoptosis and impaired mitochondrial membrane potential, whereas its knockdown exerted opposite effects. Moreover, we noted that lncRNA-LET may act as a target for oncomiR miR-373-3p. In contrast to lncRNA-LET, miR-373-3p expression was higher in ccRCC tissues. The binding between lncRNA-LET and miR-373-3p was validated. Two downstream targets of miR-373-3p, Dickkopf-1 (DKK1) and tissue inhibitor of metalloproteinase-2 (TIMP2), were positively regulated by lncRNA-LET in ccRCC cells. MiR-373-3p mimics reduced lncRNA-LET-induced up-regulation of DKK1 and TIMP2 levels, and attenuated lncRNA-LET-mediated anti-tumor effects in ccRCC cells. In vivo, lncRNA-LET suppressed the growth of ccRCC xenograft tumors.ConclusionThese findings indicate that lncRNA-LET plays a tumor suppressive role in ccRCC by regulating miR-373-3p.

We report a direct method for sequencing tRNA Phe without cDNA by combining 2dimensional hydrophobic RNA end-labeling with an anchor-based algorithm in mass spectrometry-based sequencing (2D-HELS-AA MS Seq). The entire tRNA Phe was sequenced and the identity, location and abundance of all 11 base modifications were determined. Changes in ratios of wybutosine and its depurinated form under different conditions were quantified, pointing to the ability of our technology to determine dynamic changes of nucleotide modifications. Two truncated isoforms at 3´CCA tail of the tRNA Phe (75 nt CC, 80% and 74 nt C, 3%) were identified in addition to the 76 nt tRNA Phe with a full-length 3´CCA tail (17%). We also discovered a new isoform with A-G transitions at both the 44 and 45 positions in the tRNA Phe variable loop.

Background Prostate cancer (PCa) is the most common malignant tumor in developed countries, which has seriously threatened men’s lifestyle and quality of life. The up-regulation of EZH2 is associated with advanced PCa and poor prognosis, making it a promising therapeutic target. However, the EZH2 inhibitors-based treatment is basically ineffective against PCa, which limits its clinical application. Methods Microarray data (GSE107779) from LNCaP cells treated with either siRNA against EZH2 or a EZH2 inhibitor EPZ6438 was analyzed by Limma R package. Western blot, real-time PCR and luciferase reporter assays were used to determine the EZH2-SOX9-TNFRSF11A axis and the activity of NF-κB signaling in PCa cells. CCK-8 assay was used to determine the viability of PCa cells following various treatments. Results Genetic ablation or pharmacological inhibition of EZH2 leads to feedback activation of NF-κB signaling in PCa cells. EZH2-dependent SOX9 expression regulates the activation of NF-κB signaling. TNFRSF11A, also known as receptor activator of NF-κB (RANK), is a downstream target of SOX9 in PCa cells. SOX9 recognizes two putative SOX9 response elements in the promoter region of TNFRSF11A gene to drive TNFRSF11A expression and downstream NF-κB signaling activation. Suppression of the NF-κB signaling by either TNFRSF11A silencing or BAY11-7082 treatment rendered PCa cells to EZH2 inhibitors. Conclusion Collectively, our finding reveals a EZH2-SOX9-TNFRSF11A axis in the regulation of activity of NF-κB signaling in PCa cells and suggests that a combination of EZH2 inhibitors and BAY11-7082 would be an effective approach for the treatment of PCa patients in the future.

No abstract