Downregulation of nicotinamide N-methyltransferase inhibits migration and epithelial-mesenchymal transition of esophageal squamous cell carcinoma via Wnt/β-catenin pathway Abstract Nicotinamide N-methyltransferase (NNMT) is an important methyltransferase involved in the biotransformation of many drugs and exogenous compounds. Abnormal expression of NNMT protein is closely associated with the onset and progression of many malignancies, but little is known about its role in esophageal squamous cell carcinoma (ESCC). Therefore, we aimed to explore whether NNMT plays any roles in carcinogenesis and metastasis in ESCC. NNMT expression was determined by immunohistochemistry in ESCC and corresponding adjacent normal tissues. Functional experiments were performed to elucidate the effects of NNMT knockdown on the proliferation, apoptosis, cell cycle, migration, and epithelial-mesenchymal transition (EMT) in EC9706 and TE1 cells. NNMT expression was significantly elevated in ESCC tissues compared with corresponding adjacent normal tissues. Moreover, a significant association emerged between NNMT expression and lymph node metastasis. SiRNA-mediated knockdown of NNMT in ESCC cells can significantly suppress cell viability and migration, induce cell cycle arrest, and promote cell apoptosis. In addition, NNMT downregulation led to the reversal of EMT, as reflected by upregulation of the intercellular adhesion molecule E-cadherin and downregulation of the mesenchymal markers N-cadherin and Vimentin. Further study found that NNMT knockdown suppressed the Wnt/β-catenin signaling pathway. Taken together, these findings indicate that NNMT is a critical regulator of EMT in ESCC and may be a potential therapeutic target for ESCC metastasis.

l -Alpha-glycerylphosphorylcholine can be cytoprotective or cytotoxic in neonatal rat cardiac myocytes: a double-edged sword phenomenon Abstract l-Alpha-glycerylphosphorylcholine (GPC) is a widely used food supplement. GPC has been shown to exert beneficial effects in several organs; however, the cardiac effects of GPC have yet to be investigated. The aim of the present study was therefore to map out the effects of GPC on cardiac myocytes, with or without ischemia–reperfusion insult. Neonatal rat cardiac myocytes were treated with GPC at 1, 10, 80, and 100 µM concentrations for 15 min, 3 h, or 24 h, respectively. Cell viability by calcein assay and the degree of oxidative stress by DHE (superoxide level) and H2DCF (total ROS accumulation) staining were measured. In separate experiments, cardiomyocytes were pre-treated with the optimal concentration of GPC for 3 h and then cells were exposed to 4 h of simulated ischemia followed by 2 h of reperfusion (SI/R). Cell viability was measured at the end of the SI/R protocol. In normoxic conditions, the 15-min and the 3-h GPC treatment did not affect cell viability, total ROS, and superoxide levels. Under SI/R conditions, the 3-h GPC treatment protected the cardiac myocytes from SI/R-induced cell death and did not alter the level of oxidative stress. The 24-h GPC treatment in normoxic conditions resulted in significant cell death and increased oxidative stress at each concentration. Here we provide the first evidence for the cytoprotective effect of short-term GPC treatment. However, long-term administration of GPC may exert cytotoxicity in a wide concentration range in cardiac myocytes. These results may draw attention to a comprehensive cardiac safety protocol for the testing of GPC.

Acetyl-11-keto-β-boswellic acid modulates membrane dynamics in benzo(a)pyrene-induced lung carcinogenesis Abstract Membrane fluidity is the most important physiochemical property of cell membranes and governs its functional attributes. The current investigations were undertaken to understand the potential role of acetyl-11-keto-β-boswellic acid (AKBA), if any, on regulation of membrane dynamics under conditions of benzo(a)pyrene (BaP)-induced lung carcinogenesis in female rats. The animals were divided into five groups which included (I) Normal control, (II) Vehicle treated (olive oil), (III) BaP treated, (IV) AKBA treated and (V) BaP + AKBA treated. BaP was administered at a dose level of 50 mg/kg b.wt. in olive oil orally twice a week for 4 weeks. AKBA was given at a dose level of 50 mg/kg b.wt. in olive oil orally thrice a week for 24 weeks. In addition, AKBA was also administered at a similar dose to BaP-treated animals 4 weeks prior to BaP administration and continued for another 20 weeks. The lipid profile and membrane dynamics were analysed in lung tissue. Total lipids, phospholipids content, membrane fluidity, polarization and order of membrane were significantly (p ≤ 0.001) increased in BaP-exposed animals. However, significant decrease was observed in glycolipids, cholesterol, microviscosity and anisotropy levels compared with normal control animals. Appreciable improvements in above indices were recorded when AKBA was administered to BaP-treated animals. Moreover, the structural variations observed in Fourier-transform infrared spectroscopy spectrum were also normalized in BaP-treated rats with AKBA supplementation. This suggests that the AKBA has a potential role in improving membrane fluidity and associated lipid content in BaP-induced lung carcinogenesis.

LncRNA H19 promotes lung cancer proliferation and metastasis by inhibiting miR-200a function Abstract Lung cancer is the major cause leading to cancer mortality, and the 5-year survival rate for patients with lung cancer still remains low. It is urgent to fully understand the development and progression of lung cancer to discover new therapeutic targets and develop new therapeutic approaches. H19 was documented to be upregulated in lung cancer and related to cell proliferation. However, it is still unclear if H19 has other functions in lung cancer. The mRNA levels of genes were detected by qRT-PCR, and the cell proliferation rate and cell viability were measured through cell count assay and MTT assay. Transwell assays were applied to detect cell abilities to migration and invasion, while luciferase reporter assay and RNA pull-down assay were used to examine interaction between H19 and miR-200a. H19 expression was elevated in the lung cancer tissues and cell lines, while H19 overexpression promoted the lung cancer cell growth, cell migration and invasion, as well as the epithelial mesenchymal transition (EMT). Meantime, RNA pull-down assay showed that H19 interacted with miR-200a, and miR-200a inhibited the activity of H19-fused luciferase. Furthermore, H19 overexpression inhibited miR-200a function and thereby upregulated miR-200a target genes, ZEB1 and ZEB2.H19 sponged and inhibited miR-200a to de-repress expression of ZEB1 and ZEB2, and thereby enhanced lung cancer proliferation and metastasis.

MiR-26a promotes fracture healing of nonunion rats possibly by targeting SOSTDC1 and further activating Wnt/β-catenin signaling pathway Abstract Nonunion is a serious complication after fracture due to its difficulty of self-healing. MicroRNA-26a (miR-26a) has been known to play a crucial role in bone metabolism. In this study, we established a rat nonunion model by removing periosteum, and found that miR-26a was significantly upregulated. Osteogenic differentiation of mesenchymal stem cells (MSCs) isolated from bone marrow transfected with miR-26a mimics was significantly enhanced, evidenced by increased calcium deposition and expression levels of alkaline phosphatase (ALP) and osteocalcin. Bioinformatics analysis suggested that sclerostin domain-containing 1 (SOSTDC1) may be a target of miR-26a, which was confirmed by dual-luciferase assay and western blot. Besides, miR-26a was used for nonunion rats. Delightfully, radiographs of nonunion rats with miR-26a mimics administration showed obvious new bone formation compared with nonhealing control. Hematoxylin–eosin and Masson staining assays revealed that osteogenesis capacity was greatly enhanced by miR-26a mimics’ administration. In addition, miR-26a mimics could promote osteogenic differentiation in nonunion rats, evidenced by increased protein levels of ALP and osteocalcin, while SOSTDC1 was suppressed. The injection of miR-26a mimics also gave rise to phosphorylation of GSK3β and nuclear accumulation of β-catenin, which indicated the activation of canonical Wnt/β-catenin signaling. In conclusion, we demonstrated that miR-26a promoted fracture healing of rats with nonunion in vivo and osteogenic differentiation of MSCs in vitro, possibly by targeting SOSTDC1, and that Wnt/β-catenin signaling pathway was involved in this process.

Potential of C1QTNF1-AS1 regulation in human hepatocellular carcinoma Abstract The aim of our study is to explore the regulation of C1QTNF1-AS1 on its target miR-221-3p/SOCS3 in human hepatocellular carcinoma (HCC). To explore the underlying molecular regulation of non-coding RNA for HCC, differentially expressed patterns of lncRNAs and genes were examined by RNA-seq. GO and KEGG pathway analysis were done based on the function of mRNAs that mediated by differentially expressed lncRNAs. RT-qPCR and western blot were conducted to detect the mRNA and protein level expression of C1QTNF1-AS1, miR-221-3p, SOCS3 and key proteins in JAK/STAT signaling pathway in HCC tissues and cells. The target miRNA of differentially expressed C1QTNF1-AS1 and SOCS3 was miR-221-3p predicted by bioinformatics analysis. C1QTNF1-AS1 and SOCS3 was downregulated and miR-221-3p was upregulated in HCC tissues and cells. In HepG2 and Huh-7 cells, the overexpression of C1QTNF1-AS1 or SOCS3, and silencing of miR-221-3p inhibited proliferation, migration, invasion and JAK/STAT signaling pathway, while promoted cell apoptosis. The results of dual-luciferase assay indicated that C1QTNF1-AS1 regulated miR-221-3p and miR-221-3p targeted SOCS3 by directly binding. And the growth of HCC in vivo was impeded when C1QTNF1-AS1 was upregulated. Overexpression of C1QTNF1-AS1 could downregulate miR-221-3p thereby inhibited the proliferation, migration and invasion of HCC cells.

MicroRNA-32 targeting PTEN enhances M2 macrophage polarization in the glioma microenvironment and further promotes the progression of glioma Abstract This study was aimed to explore the molecular mechanism of macrophage polarization and its effect on glioma progression. THP1 cells were cocultured in conditioned medium from U87 human glioblastoma cells to simulate the glioma microenvironment. The expression of miR-32 and PTEN in THP1 cells was detected by real-time PCR. A luciferase reporter assay was conducted to confirm the target relation between miR-32 and PTEN. Western blot assays and ELISA were performed to detect PTEN, M2 macrophage-specific markers, PI3K/AKT signaling proteins, and apoptosis-related proteins. U87 cell proliferation was evaluated by CCK-8 and colony forming assays, and the migration ability of the cells was evaluated by Transwell and wound healing assays. The U87 culture supernatant promoted the M2 phenotype of THP1 cells. miR-32 was upregulated and PTEN was downregulated in THP1 cells with the M2 phenotype in the glioma microenvironment. Luciferase assays confirmed that PTEN expression was suppressed by miR-32 through interaction with the 3′UTR of PTEN. Overexpression of miR-32 suppressed PTEN expression in THP1 cells. Overexpression of miR-32 or downregulation of PTEN promoted the expression of M2 macrophage-specific markers, thereby enhancing M2 macrophage polarization. Additionally, miR-32 inhibited THP1 cell apoptosis via suppressing the PI3K/AKT signaling pathway. Most importantly, the proliferation and migration capacities of U87 cells treated with the THP1 culture supernatant after miR-32 overexpression were enhanced, and these effects could be reversed by cotransfection with pcDNA3.1-PTEN. miR-32 negatively modulates PTEN, thereby promoting M2 macrophage transformation through PI3K/AKT signaling, enhancing glioma proliferation and migration abilities.

Novel tetrahydroacridine derivatives with iodobenzoic moieties induce G0/G1 cell cycle arrest and apoptosis in A549 non-small lung cancer and HT-29 colorectal cancer cells Abstract A series of nine tetrahydroacridine derivatives with iodobenzoic moiety were synthesized and evaluated for their cytotoxic activity against cancer cell lines—A549 (human lung adenocarcinoma), HT-29 (human colorectal adenocarcinoma) and somatic cell line—EA.hy926 (human umbilical vein cell line). All compounds displayed high cytotoxicity activity against A549 (IC50 59.12–14.87 µM) and HT-29 (IC50 17.32–5.90 µM) cell lines, higher than control agents—etoposide and 5-fluorouracil. Structure–activity relationship showed that the position of iodine in the substituent in the para position and longer linker most strongly enhanced the cytotoxic effect. Among derivatives, 1i turned out to be the most cytotoxic and displayed IC50 values of 14.87 µM against A549 and 5.90 µM against HT-29 cell lines. In hyaluronidase inhibition assay, all compounds presented anti-inflammatory activity, however, slightly lower than reference compound. ADMET prediction showed that almost all compounds had good pharmacokinetic profiles. 1b, 1c and 1f compounds turned out to act against chemoresistance in cisplatin-resistant 253J B-V cells. Compounds intercalated into DNA and inhibited cell cycle in G0/G1 phase—the strongest inhibition was observed for 1i in A549 and 1c in HT-29. Among compounds, the highest apoptotic effect in both cell lines was observed after treatment with 1i. Compounds caused DNA damage and H2AX phosphorylation, which was detected in A549 and HT-29 cells. All research confirmed anticancer properties of novel tetrahydroacridine derivatives and explained a few pathways of their mechanism of cytotoxic action.

Apelin promotes hepatic fibrosis through ERK signaling in LX-2 cells Abstract Apelin participates in cardiovascular functions, metabolic disease, and homeostasis disorder. However, the biological function of apelin in liver diseases, especially liver fibrosis is still under investigation. The present study aimed to investigate the expression of apelin in nonalcoholic fatty liver disease (NAFLD) and the mechanism of apelin promoting hepatic fibrosis through ERK signaling in hepatic stellate LX-2 cells. The results showed that the ALT and AST levels in serum were increased in the mice fed HFC. The histological staining revealed that hepatocellular steatosis and ballooning degeneration was severe, and fibrogenesis appeared as increased pericellular collagen deposition along with pericentral (lobular) collagen deposition in the mice fed HFC. Immunochemistry and qRT-PCR results showed that the expression of apelin and profibrotic genes was higher as compared to the control group. The in vitro experiments demonstrated that apelin-13 upregulated the transcription and translation levels of collagen type I (collagen-I) and α-smooth muscle actin (α-SMA) in LX-2 cells. The immunofluorescent staining, qRT-PCR, and Western blot results showed that the overexpression of apelin markedly increased the expression of α-SMA and cyclinD1. The LX-2 cells treated with apelin-13 displayed an increased expression of pERK1/2 in a time-dependent manner, while the pretreatment with PD98059 abolished the apelin-induced expression of α-SMA and cyclinD1. Furthermore, the in vivo and in vitro assays suggested a key role of apelin in promoting liver fibrosis, and the underlying mechanism might be ascribed to the apelin expression of profibrotic genes via ERK signaling pathway.

Endothelial retinoblastoma protein reduces abdominal aortic aneurysm development via promoting DHFR/NO pathway-mediated vasoprotection Abstract Cardiovascular disease (CVD) is a major cause of global mortality. The proper functioning of the endothelial layer of arteries is crucial to cardiovascular health. Retinoblastoma protein (Rb), encoded by the Rb1 gene, has been shown to offer vasoprotective effects. Herein, we investigated endothelial Rb’s effects on arterial function using an endothelial-specific conditional Rb1 knockout (Rb cKO) mouse model. We found that Rb deficiency reduced dihydrofolate reductase (DHFR) activity and downstream NO production in mouse aortic endothelial cells and blocked arterial vasodilation in an endothelial DHFR-dependent manner. Rb deficiency also increased phenylephrine-triggered arterial vasoconstriction, BP levels, and pathological aortic remodeling without significantly affecting prostanoid synthesis. Employing an angiotensin II (AngII)-stimulated apolipoprotein E knockout (apoE −/−) mice fed a standard, non-atherogenic diet, Rb deficiency increased aortic diameter, stimulated abdominal aortic aneurysm (AAA) development, and reduced survival. These pathological responses to Rb deficiency in AngII-stimulated apoE−/− mice were rescued by DHFR overexpression. Cumulatively, our findings reveal that endothelial Rb positively impacts arterial function by supporting vasoprotective endothelial DHFR/NO pathway activity, leading to reduced AAA development.