Circular RNA circBFAR promotes glioblastoma progression by regulating a miR-548b/FoxM1 axis.

Glioblastoma multiforme (GBM) is the most common and aggressive type of tumor of the primary nervous system. Treatment options for GBM include surgery, chemotherapy, and radiation therapy; however, the clinical outcomes are poor, with a high rate of recurrence. An increasing number of studies have shown that circular RNAs (circRNAs) serve important roles in several types of cancer. Gene Expression Omnibus (GEO) database was utilized to identify the differentially expressed circRNAs and their biological functions. Then, we detected the circular RNA bifunctional apoptosis regulator (circBFAR) was significantly increased in three GEO datasets. However, the role of circBFAR has not been reported in GBM. In this study, the expression of circBFAR was significantly increased both in GBM tissues or cell lines and was negatively correlated with overall survival in patients with GBM. Knockdown of circBFAR inhibited proliferation and invasion both in vitro and in vivo. Increased expression of circBFAR resulted in a reduction of miR-548b expression in glioma cells. A luciferase reporter and RIP assay indicated that miR-548b was a direct target of circBFAR, and miR-548b may negatively regulate the expression of FoxM1. Rescue experiments showed that overexpression of FoxM1 could counter the effect of circBFAR silencing on the proliferation and invasion of glioma cell lines. Moreover, we identified that circBFAR regulates FoxM1 by interacting with miR-548b in glioma cells. In conclusion, the present study demonstrated that a circBFAR/miR-548b/FoxM1 axis regulates the development of GBM and highlights potentially novel therapeutic targets for the treatment of GBM.

Oxidative stress and endoplasmic reticulum stress contribute to L. paracasei subsp. paracasei M5L exopolysaccharide-induced apoptosis in HT-29 cells.

Colorectal cancer is the third most malignant cancer occurring around the world. Effective prevention and treatment have been increasingly the focus of global attention. Long-term diet of fermented dairy inhibits proliferation of colon cancer cell, which is considered that not only live lactic acid bacteria but also the secreted exopolysaccharides exert the function. In this scenario, this study aimed to investigate the mechanism of growth inhibition on HT-29 cells induced in vitro by exopolysaccharides isolated from Lactobacillus paracasei subsp. paracasei M5L (M5-EPSs). HT-29 cells which were treated by a set of concentrations of M5-EPSs have been investigated of cell viability, characteristic changes, cell cycle distribution, and redox system. The results demonstrated that M5-EPSs treatments induced HT-29 cell apoptosis and resulted in upregulation of ROS levels and downregulation of antioxidant enzyme activities, leading to an imbalance in the oxidation system in HT-29 cells. In response to M5-EPSs, endogenous ER stress (ERS) markers, including GRP78, ATF4, and CHOP, were transcriptionally altered so that activating the ERS in HT-29 cells. After NAC treatment, the oxidative stress was inhibited, and the expression of GRP78 and CHOP was significantly decreased, indicating that oxidative stress can significantly affect the ERS pathway. Furthermore, it suggested that the occurrence of apoptosis was associated with Bcl-2 gene family. In conclusion, this study demonstrated that M5-EPSs can induce HT-29 cells apoptosis by destroying the redox system through activation of the ERS signaling pathway.

Prognostic and immunological role of Fam20C in pan-cancer.

BACKGROUND: The family with sequence similarity 20-member C (Fam20C) kinase plays important roles in physiopathological process and is responsible for majority of the secreted phosphoproteome, including substrates associated with tumor cell migration. However, it remains unclear whether Fam20C plays a role in cancers. Here, we aimed to analyze the expression and prognostic value of Fam20C in pan-cancer and to gain insights into the association between Fam20C and immune infiltration. METHODS: We analyzed Fam20C expression patterns and the associations between Fam20C expression levels and prognosis in pan-cancer via the ONCOMINE, TIMER (Tumor Immune Estimation Resource), PrognoScan, GEPIA (Gene Expression Profiling Interactive Analysis), and Kaplan-Meier Plotter databases. After that, GEPIA and TIMER databases were applied to investigate the relations between Fam20C expression and immune infiltration across different cancer types, especially BLCA (bladder urothelial carcinoma), LGG (brain lower grade glioma), and STAD (stomach adenocarcinoma). RESULTS: Compared with adjacent normal tissues, Fam20C was widely expressed across many cancers. In general, Fam20C showed a detrimental role in pan-cancer, it was positively associated with poor survival of BLCA, LGG, and STAD patients. Specifically, based on TCGA (The Cancer Genome Atlas) database, a high expression level of Fam20C was associated with worse prognostic value in stages T2-T4 and stages N0-N2 in the cohort of STAD patients. Moreover, Fam20C expression had positive associations with immune infiltration, including CD4+ T cells, macrophages, neutrophils, and dendritic cells, and other diverse immune cells in BLCA, LGG, and STAD. CONCLUSION: Fam20C may serve as a promising prognostic biomarker in pan-cancer and has positive associations with immune infiltrates.

Controlled Release Strategies for the Combination of Fresh and Lyophilized Platelet-Rich Fibrin on Bone Tissue Regeneration.

The aim of the present study was to investigate growth factors release kinetics for the combination of fresh platelet-rich fibrin (F-PRF) and lyophilized PRF (L-PRF) with different ratios to promote bone tissue regeneration. First, we quantified the level of transforming growth factor-ß1 (TGF-ß1), vascular endothelial growth factor (VEGF), and platelet-derived growth factor-AB (PDGF-AB) in vitro and analyzed their release kinetics from F-PRF, L-PRF, and the fresh/lyophilized PRF in different weight ratios (F:L=1:1, 1:3, 1:5). The second experimental phase was to investigate the proliferation and differentiation of bone mesenchymal stem cells (BMSCs) as a functional response to the factors released. To further test the osteogenic potential in vivo, different scaffolds (F-PRF, or L-PRF, or F:L=1:1) were implanted in rabbit cranial bone defects. There was a statistically significant increase in proliferation and differentiation of BMSCs when the culture medium contained different PRF exudates collected at day 14 compared with the negative control group. The results showed that the new bone formation in the fresh/lyophilized PRF (1:1) was much more than that of other groups in defects at both 6 and 12 weeks. Our data suggested growth factor concentration and release kinetics as a consequence of fresh and lyophilized PRF combination, which is an effective way for promoting bone regeneration.

Loss of Fam20c causes defects in the acinar and duct structure of salivary glands in mice.

Family with sequence similarity 20­member C (FAM20C), a recently characterized Golgi kinase, performs numerous biological functions by phosphorylating more than 100 secreted proteins. However, the role of FAM20C in the salivary glands remains undefined. The present study demonstrated that FAM20C is mainly located in the cytoplasm of duct epithelial cells in the salivary glands. Fam20cf/f; Mmtv­Cre mice were created in which Fam20c was inactivated in the salivary gland cells and observed that the number of ducts and the ductal cross­sectional area increased significantly, while the number of acinar cells was reduced. The granular convoluted tubules (GCTs) exhibited an accumulation of aberrant secretory granules, along with a reduced expression and altered distribution patterns of ß nerve growth factor, α­amylase and bone morphogenetic protein (BMP) 4. This abnormality suggested that the GCT cells were immature and exhibited defects in developmental and secretory functions. In accordance with the morphological alterations and the reduced number of acinar cells, FAM20C deficiency in the salivary glands significantly decreased the salivary flow rate. The Na+, Cl- and K+ concentrations in the saliva were all significantly increased due to dysfunction of the ducts. Furthermore, Fam20c deficiency significantly increased BMP2 and BMP7 expression, decreased BMP4 expression, and attenuated the canonical and noncanonical BMP signaling pathways in the salivary glands. Collectively, the results of the present study demonstrate that FAM20C is a key regulator of acinar and duct structure and duct maturation and provide a novel avenue for investigating novel therapeutic targets for oral diseases including xerostomia.

Vasoactive intestinal polypeptide relaxes isolated rat pulmonary artery rings through two distinct mechanisms.

Vasoactive intestinal polypeptide (VIP), an endogenous neuropeptide normally present in lungs and other organs, relaxes pulmonary arteries (PAs) in different species, whereas the underlying mechanisms are still not fully understood. The aim of this study, therefore, is to investigate the signal transduction of VIP in the relaxation of isolated rat PA rings. The isometric tension of the rings was studied in vitro with force-electricity transducers. In endothelium-intact (EI) rings, VIP elicited concentration-dependent relaxation after the rings were pre-contracted by phenylephrine. A similar effect, though smaller, was observed in endothelium-denuded (ED) rings. Inhibition of the endothelial nitric oxide synthase (eNOS) by NG-nitro-L-arginine methyl ester diminished the VIP-induced vasodilatation of PA rings. The VIP-induced vasorelaxation was markedly reduced by the inhibition of the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway with wortmannin and LY294002, respectively, which was seen in EI rings, but not in ED rings. Western blot analysis revealed that VIP increased the phosphorylation of eNOS at Ser 1177, but did not affect the overall expression of eNOS. In ED rings, the PKA inhibitor H-89 and K(ATP) channel inhibitor glibenclamide almost totally abolished the vasodilatation effect of VIP. The results suggested that the vasodilatation effect of VIP on rat PAs is mediated by both vascular endothelium and smooth muscle, involving respectively the PI3K/Akt-eNOS pathway and the PKA-K(ATP) channel pathway.

Expression of 15-lipoxygenases in pulmonary arteries after hypoxia.

AIMS: We have previously reported that subacute hypoxia upregulates and activates the steady state expression of pulmonary artery 15-lipoxygenase (15-LOX). However, there are two 15-LOX isoenzymes, 15-LOX-1 and 15-LOX-2, which are expressed in pulmonary arteries that have not been previously studied. In the present study, we identified the differential expression of the two isoenzymes in normoxic or hypoxic intrapulmonary arteries of rats, pulmonary artery endothelial cells (PAECs) and pulmonary artery smooth muscle cells (PASMCs) from the main branches of pulmonary artery of neonatal bovines. METHODS: Immunohistochemistry, in situ hybridisation, RT-PCR, and Western blotting were employed to identify the differential expression of the two isoenzymes. RESULTS: 15-LOX-1 was expressed in both normoxic and hypoxic rat arteries. In contrast, 15-LOX-2 was hardly detectable in normoxic vessels by immunohistochemistry and Western blotting, but it was detected in hypoxic arteries. In cultured bovine pulmonary artery cells, 15-LOX-1 and 15-LOX-2 were found to be different in cellular distribution. The expression of 15-LOX-1 was stronger in PAECs than in PASMCs, whereas, 15-LOX-2 was weaker in PAECs than in PASMCs. Moreover, the expressions of both 15-LOX isoenzymes increased dramatically after hypoxia. CONCLUSIONS: These results suggest that both isoenzymes of 15-LOXs are upregulated after hypoxia.

PKA-dependent activation of the vascular smooth muscle isoform of KATP channels by vasoactive intestinal polypeptide and its effect on relaxation of the mesenteric resistance artery.

Vasoactive intestinal polypeptide (VIP) is a potent vasodilator and has been successfully used to alleviate hypertension. Consistently, disruption of VIP gene in mice leads to hypertension. However, its downstream targets in the vascular regulation are still not well demonstrated. To test the hypothesis that the vascular smooth muscle isoform of KATP channels is a downstream target of the VIP signaling, we performed the studies on the Kir6.1/SUR2B channel expressed in HEK293 cells. We found that the channel was strongly activated by VIP. Through endogenous VIP receptors, the channel activation was reversible and dependent on VIP concentrations with the midpoint-activation concentration approximately 10 nM. The channel activation was voltage-independent and could be blocked by KATP channel blocker glibenclamide. In cell-attached patches, VIP augmented the channel open-state probability with modest suppression of the single channel conductance. The VIP-induced Kir6.1/SUR2B channel activation was blocked by PKA inhibitor RP-cAMP. Forskolin, an adenylyl cyclase activator, activated the channel similarly as VIP. The effect of VIP was further evident in the native tissues. In acutely dissociated mesenteric vascular smooth myocytes, VIP activated the KATP currents in a similar manner as in HEK293 cells. In endothelium-free mesenteric artery rings, VIP produced concentration-dependent vasorelaxation that was attenuated by glibenclamide. These results therefore indicate that the vascular isoform (Kir6.1/SUR2B) of KATP channels is a target of VIP. The channel activation relies on the PKA pathway and produces mesenteric arterial relaxation.