No abstract

Extracellular vesicles (EVs) are small membranous vesicles that contain an abundant cargo of different RNA species with specialized functions and clinical implications. Here, we introduce an updated online database (http://www.exoRBase.org), exoRBase 2.0, which is a repository of EV long RNAs (termed exLRs) derived from RNA-seq data analyses of diverse human body fluids. In exoRBase 2.0, the number of exLRs has increased to 19 643 messenger RNAs (mRNAs), 15 645 long non-coding RNAs (lncRNAs) and 79 084 circular RNAs (circRNAs) obtained from ∼1000 human blood, urine, cerebrospinal fluid (CSF) and bile samples. Importantly, exoRBase 2.0 not only integrates and compares exLR expression profiles but also visualizes the pathway-level functional changes and the heterogeneity of origins of circulating EVs in the context of different physiological and pathological conditions. Our database provides an attractive platform for the identification of novel exLR signatures from human biofluids that will aid in the discovery of new circulating biomarkers to improve disease diagnosis and therapy.

KMT5A (known as PR-Set7/9, SETD8 and SET8), a member of the SET domain containing methyltransferase family specifically targeting H4K20 for methylation, has been implicated in multiple biological processes. In the present study, we identified that KMT5A was elevated in 50 pairs of papillary thyroid cancer tissue samples and in cell lines K1 and TPC-1 by qRT-PCR and western blotting, as well as by immunohistochemical staining. CCK-8 assay and flow cytometric analysis revealed that inhibition of KMT5A attenuated proliferation and induced apoptosis. Transwell assays revealed that cell migration and invasion were suppressed in KMT5A-knockdown cells. Moreover, the inhibition of KMT5A arrested the cell cycle in the G1/S phase of papillary thyroid cancer cells. The TCGA data revealed that elevated KMT5A expression was significantly correlated with extrathyroidal extension, lymph node metastasis and advanced pathological stage of papillary thyroid cancer. Furthermore, we observed that inhibition of KMT5A suppressed the expression of SREBP1, SCD, FASN and ACC, key molecules involved in lipid metabolism and decreased the level of malondialdehyde in papillary thyroid cancer cells. In conclusion, KMT5A may be a novel oncogenic factor, specifically a regulator for lipid metabolism in papillary thyroid carcinoma.

The present study aimed to investigate the effects of menstrual blood-derived stem cells (MenSCs) on endometrial injury repair. MenSCs were isolated from human menstrual blood and were cultured in vitro. Flow cytometric analysis of cells in the third generation demonstrated that MenSCs exhibited higher expression levels of cluster of differentiation (CD)90 and lower expression levels of CD146, which suggested that the MenSCs were cultured successfully. A mechanical damage model of unilateral (right) endometrium was established in BALB/c nude mice, which were divided into four groups, Normal, negative control (NC), Model and MenSC. MenSCs transfected with adenovirus-enhanced green fluorescent protein were transplanted into the right uterine cavity of mice in the MenSC and NC groups. The protein expression levels of keratin, vimentin, and vascular endothelial growth factor (VEGF) and the average endometrial thickness were measured by immunohistochemistry; the average optical density of vimentin, VEGF and keratin in the MenSC-treated group was significantly higher compared with the untreated Model group. Fertility tests were performed to determine the pregnancy rate of each group; following endometrial damage in BALB/c nude mice, endometrial thickness was decreased in the Model group, whereas model mice treated with MenSC exhibited increased endometrial thickness and increased the pregnancy rates. Therefore, MenSCs may promote the repair of endometrial lesions in mice by promoting the expression of vimentin, VEGF and keratin.

Yes-associated protein 1 (YAP1) stimulates cell proliferation, epithelial-to-mesenchymal transition, invasion and metastasis in several cancers. Here, we investigated the involvement of YAP1 in papillary thyroid carcinoma (PTC) by assessing YAP1 mRNA and protein levels in PTC tissues and matched normal thyroid epithelial tissues from 50 patients. YAP1 mRNA and protein levels were higher in PTC tumor tissues than in control tissues, and correlated positively with the levels of proliferation-related genes (KI67 and c-MYC). We also used lentiviral vectors to overexpress or silence YAP1 expression in the K1 PTC cell line so that we could investigate the effects of YAP1 on cancer cell proliferation. YAP1 overexpression enhanced PTC cell proliferation by activating ERK1/2 and AKT, and these effects were impaired by treating the cells with the MEK inhibitor U0126 or the AKT inhibitor GSK690693. Finally, YAP1 overexpression dramatically induced growth of tumors from PTC cells in a xenograft mouse model. These results suggest that YAP1 enhances cell proliferation in PTC, and thus may be a promising target in the treatment of PTC.

Family with sequence similarity (FAM46) proteins are newly identified metazoan-specific poly(A) polymerases (PAPs). Although predicted as Gld-2-like eukaryotic non-canonical PAPs, the detailed architecture of FAM46 proteins is still unclear. Exact biological functions for most of FAM46 proteins also remain largely unknown. Here, we report the first crystal structure of a FAM46 protein, FAM46B. FAM46B is composed of a prominently larger N-terminal catalytic domain as compared to known eukaryotic PAPs, and a C-terminal helical domain. FAM46B resembles prokaryotic PAP/CCA-adding enzymes in overall folding as well as certain inter-domain connections, which distinguishes FAM46B from other eukaryotic non-canonical PAPs. Biochemical analysis reveals that FAM46B is an active PAP, and prefers adenosine-rich substrate RNAs. FAM46B is uniquely and highly expressed in human pre-implantation embryos and pluripotent stem cells, but sharply down-regulated following differentiation. FAM46B is localized to both cell nucleus and cytosol, and is indispensable for the viability of human embryonic stem cells. Knock-out of FAM46B is lethal. Knock-down of FAM46B induces apoptosis and restricts protein synthesis. The identification of the bacterial-like FAM46B, as a pluripotent stem cell-specific PAP involved in the maintenance of translational efficiency, provides important clues for further functional studies of this PAP in the early embryonic development of high eukaryotes.

Sirtuin 6 (SIRT6) is a member of the SIRT family NAD+‑dependent deacetylases reported to function in controlling organism homeostasis, lifespan, and diseases. This study investigated the role of SIRT6 in papillary thyroid cancer (PTC). Data of 391 PTC patients was extracted from The Cancer Genome Atlas database to investigate the expression of SIRTs (SIRT1‑7) and their relationship with clinicopathological parameters. Additional 45 pairs of PTC tumor tissues and corresponding non‑tumor tissues were studied using microarray analysis for SIRT6 expression. Surgically resected, pathologically diagnosed tissues from 130 in‑house PTC patients were used for confirmation of SIRT6 expression. SIRT6 silenced K1 and TPC‑1 cells were generated to explore the influence of SIRT6 on cancer cell aggressiveness in vitro. SIRT6 mRNA and protein levels were upregulated in PTC tumor tissues and its overexpression was an independent biomarker for nodal metastasis (odds ratio=1.794, 95% confidence interval: 1.256‑1.920, p=0.012). SIRT6 expression was related to poor recurrence‑free survival, however, not significantly. Silencing SIRT6 downregulated PTC cell aggressiveness in vitro by suppressing ERK and Mcl‑1. In conclusion, these results suggest that SIRT6 enhances cell aggressiveness in PTC via BRAF/ERK/Mcl‑1 pathway, and thus may be a promising target in the treatment of the disease.

Patients with stage II or III colorectal cancer (CRC) exhibit various clinical outcomes after radical treatments. The 5-year survival rate was between 50 and 87%. However, the underlying mechanisms of the variation remain unclear. Here we show that AMPKα1 is overexpressed in CRC patient specimens and the high expression is correlated with poor patient survival. We further reveal a previously unrecognized function of AMPKα1, which maintains high level of reduced glutathione to keep reduction-oxidation reaction (redox) homeostasis under stress conditions, thus promoting CRC cell survival under metabolic stress in vitro and enhancing tumorigenesis in vivo. Mechanistically, AMPKα1 regulate the glutathione reductase (GSR) phosphorylation possibly through residue Thr507 which enhances its activity. Suppression of AMPKα1 by using nano-sized polymeric vector induces a favorable therapeutic effect, especially when in combination with oxaliplatin. Our study uncovers a novel function of AMPKα1 in redox regulation and identifies a promising therapeutic strategy for treatment of CRC.