An autocatalytic CRISPR-Cas amplification effect propelled by the LNA-modified split activators for DNA sensing.

CRISPR-Cas systems with dual functions offer precise sequence-based recognition and efficient catalytic cleavage of nucleic acids, making them highly promising in biosensing and diagnostic technologies. However, current methods encounter challenges of complexity, low turnover efficiency, and the necessity for sophisticated probe design. To better integrate the dual functions of Cas proteins, we proposed a novel approach called CRISPR-Cas Autocatalysis Amplification driven by LNA-modified Split Activators (CALSA) for the highly efficient detection of single-stranded DNA (ssDNA) and genomic DNA. By introducing split ssDNA activators and the site-directed trans-cleavage mediated by LNA modifications, an autocatalysis-driven positive feedback loop of nucleic acids based on the LbCas12a system was constructed. Consequently, CALSA enabled one-pot and real-time detection of genomic DNA and cell-free DNA (cfDNA) from different tumor cell lines. Notably, CALSA achieved high sensitivity, single-base specificity, and remarkably short reaction times. Due to the high programmability of nucleic acid circuits, these results highlighted the immense potential of CALSA as a powerful tool for cascade signal amplification. Moreover, the sensitivity and specificity further emphasized the value of CALSA in biosensing and diagnostics, opening avenues for future clinical applications.

Sm(â ¢), Gd(â ¢), and Eu(â ¢) complexes with 8-hydroxyquinoline derivatives as potential anticancer agents via inhibiting cell proliferation, blocking cell cycle, and inducing apoptosis in NCI-H460 cells.

Four lanthanide complexes with 8-hydroxyquinoline-2-aldehyde-2-hydrazinopyridine (H-L1), 8-hydroxyquinoline-2-aldehyde-2-hydrazimidazole (H-L2): [Sm(L1)2][Sm(L1)(NO3)3]·CHCl3·2CH3OH (1), [Gd(L1)2][Gd(L1)(NO3)3]·CHCl3·2CH3OH (2), [Sm(L2)(NO3)2]2·CH3OH (3), and [Eu(L2)(NO3)2]2·CH3OH (4) were synthesized and characterized. In vitro cytotoxicity evaluation showed that the ligands and four lanthanide complexes exhibited cytotoxicity to the five tested tumor cell lines. Among them, complex 1 showed the best antiproliferative activity against NCI-H460 tumor cells. Mechanistic studies demonstrated that complex 1 arrested the cell cycle of NCI-H460 cells in G1 phase and induced mitochondria-mediated apoptosis, which resulted in the loss of mitochondrial membrane potential, enhanced intracellular Ca2+ levels and reactive oxygen species generation. In addition, complex 1 affected the expression levels of intracellular apoptosis-related proteins and activated the caspase-3/9 in NCI-H460 cells. Therefore, complex 1 is a potential anticancer agent.

Oxysulfonylation of Alkynes with Sodium Sulfinates to Access ß-Keto Sulfones Catalyzed by BF3·OEt2.

An efficient and operationally simple method for the synthesis of ß-keto sulfones through the BF3·OEt2-promoted reaction of alkynes and sodium sulfinates is developed. With its facile and selective access to the targets, it features good functional group compatibility, mild conditions, easily available starting materials, and good yields. Notably, the reaction does not require metal catalysts or chemical reagents with pungent odors.

In vitro and in vivo anticancer activity of novel Rh(III) and Pd(II) complexes with pyrazolopyrimidine derivatives.

Six pyrazolopyrimidine rhodium(III) or palladium(II) complexes, [Rh(L1)(H2O)Cl3] (1), [Rh(L2)(CH3OH)Cl3] (2), [Rh(L3)(H2O)Cl3] (3), [Rh2(L4)Cl6]·CH3OH (4), [Rh(L5)(CH3CN)Cl3]·0.5CH3CN (5), and [Pd(L5)Cl2] (6), were synthesized and characterized. These complexes showed high cytotoxicity against six tested cancer cell lines. Most of the complexes showed higher cytotoxicity to T-24 cells in vitro than cisplatin. Mechanism studies indicated that complexes 5 and 6 induced G2/M phase cell cycle arrest through DNA damage, and induced apoptosis via endoplasmic reticulum stress response. In addition, complex 5 also induced cell apoptosis via mitochondrial dysfunction. Complexes 5 and 6 showed low in vivo toxicity and high tumor growth inhibitory activity in mouse tumor models. The inhibitory effect of rhodium complex 5 on tumor growth in vivo was more pronounced than that of palladium complex 6.

DBDMH-Promoted Methylthiolation in DMSO: A Metal-Free Protocol to Methyl Sulfur Compounds with Multifunctional Groups.

Organic thioethers play an important role in the discovery of drugs and natural products. However, the green synthesis of organic sulfide compounds remains a challenging task. The convenient and efficient synthesis of 5-alkoxy-3-halo-4-methylthio-2(5H)-furanones from DMSO is performed via the mediation of 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), affording a facile route for the sulfur-functionalization of 3,4-dihalo-2(5H)-furanones under transition metal-free conditions. This new approach has demonstrated the functionalization of non-aromatic Csp2-X-type halides with unique structures containing C-X, C-O, C=O and C=C bonds. Compared with traditional synthesis methods using transition metal catalysts with ligands, this reaction has many advantages, such as the lower temperature, the shorter reaction time, the wide substrate range and good functional group tolerance. Notably, DMSO plays multiple roles, and is simultaneously used as an odorless methylthiolating reagent and safe solvent.

[Construction and Expression of Eukaryotic and Prokaryotic Recombinant Vectors of Pepck and Gp63 Dominant Epitopes of Leishmania infantum].

OBJECTIVE: To construct eukaryotic and prokaryotic recombinant vectors containing Pepck- Gp63 and to achieve protein expression by selecting the dominant epitope genes of Pepck and Gp63 of Leishmania infantum. METHODS: The secondary structure and HLA epitopes of phosphoenolpyruvate carboxylase (PEPCK) were predicted by in silico analysis, and the dominant epitopes were picked out. According to the analysis results of glycoprotein of 63×10 3(GP63) epitopes identified by the same method in our laboratory, the dominant epitope genes of Pepck and Gp63 were used to construct pET32a- Pepck- Gp63 and pVAX1- Pepck- Gp63 by overlapping PCR and enzyme reaction. Then, for protein expression, the prokaryotic vectors were transfected into E.coil while the eukaryotic vectors were transfected into NIH3T3 cells by liposome transfection. RESULTS: There were multiple dominant epitopes in Pepckand there were Pepck-Gp63 sequences in the polyclonal site of expression vector. The expression of Pepck-Gp63 in E.coil appeared in inclusion form and led to 74 kDa band in SDS-PAGE. The immunofluorescence results of NIH3T3 cells transfected by pVAX1- Pepck-Gp63 were positive. CONCLUSION: The recombinant prokaryotic expression plasmids pET32a- Pepck-Gp63 and eukaryotic expression plasmids pVAX1- P epck -Gp63 were successfully constructed, and it was shown that the recombinant plasmids were able to express the corresponding target proteins in E. coli and NIH3T3 cells, respectively, providing a preliminary experimental basis for the subsequent study of immunization strategies.

Antinociceptive Effect of Ghrelin in a Rat Model of Irritable Bowel Syndrome Involves TRPV1/Opioid Systems.

BACKGROUND/AIMS: Irritable bowel syndrome (IBS), defined as recurrent abdominal pain and changes in bowel habits, seriously affects quality of life and ability to work. Ghrelin is a brain-gut hormone, which has been reported to show antinociceptive effects in peripheral pain. We investigated the effect of ghrelin on visceral hypersensitivity and pain in a rat model of IBS. METHODS: Maternal deprivation (MD) was used to provide a stress-induced model of IBS in Wistar rats. Colorectal distension (CRD) was used to detect visceral sensitivity, which was evaluated by abdominal withdrawal reflex (AWR) scores. Rats that were confirmed to have visceral hypersensitivity after MD were injected with ghrelin (10 µg/kg) subcutaneously twice a week from weeks 7 to 8. [D-Lys3]-GHRP-6 (100 nmol/L) and naloxone (100 nmol/L) were administered subcutaneously to block growth hormone secretagogue receptor 1α (GHS-R1α) and opioid receptors, respectively. Expression of transient receptor potential vanilloid type 1 (TRPV1) and µ and κ opioid receptors (MOR and KOR) in colon, dorsal root ganglion (DRG) and cerebral cortex tissues were detected by western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemical analyses and immunofluorescence. RESULTS: Ghrelin treatment increased expression of opioid receptors and inhibited expression of TRPV1 in colon, dorsal root ganglion (DRG) and cerebral cortex. The antinociceptive effect of ghrelin in the rat model of IBS was partly blocked by both the ghrelin antagonist [D-Lys3]-GHRP-6 and the opioid receptor antagonist naloxone. CONCLUSION: The results indicate that ghrelin exerted an antinociceptive effect, which was mediated via TRPV1/opioid systems, in IBS-induced visceral hypersensitivity. Ghrelin might potentially be used as a new treatment for IBS.

Anti-myocardial Ischemia Effect and Components of Litchi Pericarp Extracts.

Litchi (Litchi chinensis Sonn.) is a famous fruit in south China, and it is also effective for chest tightness or chest pain, irritability, flatulence, epigastric pain and neuralgic pain, hernia pain and testicular swelling, cough, etc. It is valued because a great amount of polyphenol was found in litchi pericarp. In this paper, we got litchi pericarp pure extract by a simple purification method, then evaluated its activity to clear oxygen free radicals in vitro, and evaluated its myocardial protection effect in vivo through acute myocardial ischemia rat model. The results showed that the pure extract had protective effect on myocardial ischemia injury in a certain dose-effect relationship, which reflected in the electrocardiogram, myocardial pathological morphology and other indicators such as cardiac function enzymes, serum and myocardial antioxidant capacity, and eNOS, Bcl-2 and Bax gene expression. Furthermore, we analyzed the components of pure extract by UPLC-MS, ESI-MS and NMR. The main components of PLPE were procyanidin which were identified as procyanidin B2(1), (-)-epicatechin(2), epicatechin-(4ߠ→ 8,2ߠ→ O â†’ 7)-epicatechin-(4ߠ→ 8)-epicatechin(3), A-type procyanidin trimer(4), B-type procyanidin dimer(5) and procyanidin A2(6).This study proved that litchi pericarp extract may have antioxidant activity and cardioprotection effect. It suggested that litchi pericarp may be good for cardiovascular disease. Copyright © 2017 John Wiley & Sons, Ltd.

The anti-inflammatory effect of Sonchus oleraceus aqueous extract on lipopolysaccharide stimulated RAW 264.7 cells and mice.

CONTEXT: Sonchus oleraceus L. (Asteraceae) (SO) is a dietary and traditional medicinal plant in China. However, its underlying mechanism of action as an anti-inflammatory agent is not known. OBJECTIVE: This study evaluates the anti-inflammatory activity of aqueous extract of SO. MATERIALS AND METHODS: The extract of SO was used to treat RAW 264.7 cells (in the working concentrations of 500, 250, 125, 62.5, 31.3 and 15.6 µg/mL) for 24 h. Pro-inflammatory cytokines and mediators produced in LPS-stimulated RAW 264.7 cells were assessed. Meanwhile, the expression level of TLR-4, COX-2, pSTATs and NF-κB was tested. Moreover, the anti-inflammatory activity of the extract in vivo was assessed using xylene-induced mouse ear oedema model and the anti-inflammatory compounds in the extracts were analyzed by HPLC-MS. RESULTS: SO extract significantly inhibited the production of pro-inflammatory cytokines and mediators at gene and protein levels with the concentration of 31.3 µg/mL, and suppressed the expression of TLR-4, COX-2, NF-κB and pSTAT in RAW 264.7 cells. The anti-inflammatory activity of SO in vivo has significant anti-inflammatory effects with the concentration of 250 and 125 mg/kg, and less side effect on the weights of the mice at the concentration of 250 mg/kg. Moreover, HPLC-MS analysis revealed that the anti-inflammatory compounds in the extract were identified as villosol, ferulaic acid, ß-sitosterol, ursolic acid and rutin. DISCUSSION AND CONCLUSION: This study indicated that SO extract has anti-inflammatory effects in vitro and in vivo, which will be further developed as novel pharmacological strategies in order to defeat inflammatory diseases.

Ghrelin Attenuated Lipotoxicity via Autophagy Induction and Nuclear Factor-κB Inhibition.

BACKGROUND/AIMS: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Autophagy is associated with NAFLD. Ghrelin is a gut hormone with various functions including energy metabolism and inflammation inhibition. We investigated the therapeutic effect of ghrelin on NAFLD and its association with autophagy. METHODS: C57bl/6 mice were fed a high-fat diet for 8 weeks to induce a model of chronic NAFLD, with ghrelin (10 µg/kg) administrated subcutaneously twice weekly from weeks 6 to 8. LO2 cells were pretreated with ghrelin (10(-8) M) before stimulation with free fatty acid (palmitic and oleic acids; 1 mM). Lipid droplets were identified by hematoxylin and eosin and Red O staining and quantified by triglyceride test kits. LC3I/II, an important biomarker protein of autophagy was detected by western blotting, real-time polymerase chain reaction, immunohistochemistry and immunofluorescence. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 were detected by ELISA and immunohistochemistry. Nuclear factor (NF)-κB p65 was detected by western blotting and immunofluorescence. AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) were detected by western blotting. RESULTS: Ghrelin reduced the triglyceride content in high fat diet (HFD) group in vivo and free fatty acid (FFA) group in vitro. TNF-α and IL-6 were significantly reduced in the ghrelin-treated mice compared with the control group. Autophagy induction was accompanied with intracellular lipid reduction in ghrelin-treated mice. Ghrelin upregulated autophagy via AMPK/mTOR restoration and inhibited translocation of NF-κB into the nucleus. CONCLUSIONS: The results indicate that ghrelin attenuates lipotoxicity by autophagy stimulation and NF-κB inhibition.

Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis by inhibiting the activation of nuclear factor-kappa B.

AIM: This study aimed to investigate the effect and underlying mechanism of ghrelin on intestinal barrier dysfunction in dextran sulfate sodium (DSS)-induced colitis. METHODS AND RESULTS: Acute colitis was induced in C57BL/6J mice by administering 2.5% DSS. Saline or 25, 125, 250 µg/kg ghrelin was administrated intraperitoneally (IP) to mice 1 day before colitis induction and on days 4, 5, and 6 after DSS administration. IP injection of a ghrelin receptor antagonist, [D-lys(3)]-GHRP-6, was performed immediately prior to ghrelin injection. Ghrelin (125 or 250 µg/kg) could reduce the disease activity index, histological score, and myeloperoxidase activities in experimental colitis, and also prevented shortening of the colon. Ghrelin could prevent the reduction of transepithelial electrical resistance and tight junction expression, and bolstered tight junction structural integrity and regulated cytokine secretion. Ultimately, ghrelin inhibited nuclear factor kappa B (NF-κB), inhibitory κB-α, myosin light chain kinase, and phosphorylated myosin light chain 2 activation. CONCLUSIONS: Ghrelin prevented the breakdown of intestinal barrier function in DSS-induced colitis. The protective effects of ghrelin on intestinal barrier function were mediated by its receptor GHSR-1a. The inhibition of NF-κB activation might be part of the mechanism underlying the effects of ghrelin that protect against barrier dysfunction.

Ghrelin Attenuates Liver Fibrosis through Regulation of TGF-ß1 Expression and Autophagy.

Ghrelin is a stomach-derived growth hormone secretagogue that promotes various physiological effects, including energy metabolism and amelioration of inflammation. The purpose of this study was to investigate the protective mechanism of ghrelin against liver fibrosis. Liver fibrosis was induced in C57BL/6 mice by intraperitoneal injection of CCl4 (2.0 mL/kg of 10% CCl4 v/v solution in peanut oil) two times per week for eight weeks. Ghrelin (10 µg/kg) was intraperitoneally injected two times per week for eight weeks. A second murine liver fibrosis model was induced by bile duct ligation (BDL) and concurrent ghrelin administration for four weeks. Hematoxylin eosin (H&E), and Masson's trichrome were used to detect pathological changes to liver tissue. Western blotting was used to detect protein levels of transforming growth factor (TGF)-ß1, phosphorylated Smad3 (p-Smad3), I-collage, α-smooth muscle actin (α-SMA), matrix metalloproteinases (MMPs) 2, tissue inhibitor of matrix metalloproteinases (TIMPs) 1, phosphorylated NF-κB (p-NF-κB), and microtubule-associated protein light chain 3 (LC3). In addition, qRT-PCR was used to detect mRNA levels of TGF-ß1, I-collage, α-SMA, MMP2, TIMP1 and LC3, while levels of TGF-ß1, p-Smad3, I-collage, α-SMA, and LC3 were detected immunohistochemically. Levels of aspartate aminotransferase and alanine aminotransferase were significantly decreased by ghrelin treatment. Ghrelin administration also significantly reduced the extent of pathological changes in both murine liver fibrosis models. Expression levels of I-collage and α-SMA in both models were clearly reduced by ghrelin administration. Furthermore, ghrelin treatment decreased protein expression of TGF-ß1 and p-Smad3. The protein levels of NF-κB and LC3 were increased in the CCl4- and BDL-treatment groups but were significantly reduced following ghrelin treatment. In addition, ghrelin inhibited extracellular matrix formation by decreasing NF-κB expression and maintaining the balance between MMP2 and TIMP1. Our results demonstrated that ghrelin attenuates liver fibrosis via inhibition of the TGF-ß1/Smad3 and NF-κB signaling pathways, as well as autophagy suppression.

Fluorinated benzothiadiazole fluorescent probe based on ICT mechanism for highly selectivity and sensitive detection of fluoride ion.

Excessive fluoride ion (F-) in the environment can affect health and even endanger life when ingested by the human body. However, most fluoride probes have the disadvantages of low sensitivity and long detection time. Herein, fluorescent probe 3a is successfully synthesized by linking two acetylenyltrimethylsilyl groups at both ends of the fluorinated benzothiadiazole core. After the addition of F- to 3a, the emission at 436 nm is significantly quenched and slightly blue-shifted. It is confirmed by electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and density functional theory calculations (DFT) that these changes are due to the F- triggered Si-C bond cleavage and the subsequent inactivation of intramolecular charge transfer (ICT). The detection limit and response time of probe 3a for F- are 10-8 mol/L and 25 s, respectively. Importantly, fluorescent material 3a can be processed into portable test tools for the visual detection of fluoride ion.

3,4-Dimethoxystilbene, a resveratrol derivative with anti-angiogenic effect, induces both macroautophagy and apoptosis in endothelial cells.

Angiogenesis plays an important role in many pathological processes. Identification of novel anti-angiogenic agents will provide new insights into the mechanisms for angiogenesis as well as potential lead compounds for developing new drugs. In the present study, a series of resveratrol methylated derivatives have been synthesized and screened. We found trans-3,4-dimethoxystilbene (3,4-DMS) with the fullest potential to develop as an anti-angiogenic agent. In vitro and in vivo analyses suggested that 3,4-DMS could effectively inhibit endothelial cell proliferation, migration, tube formation, and endogenous neovascularization. Our results showed that 3,4-DMS exerted its anti-angiogenic effect likely through induction of endothelial cell apoptosis via a pathway involving p53, Bax, cytochrome c, and caspase proteases. Moreover, 3,4-DMS also induced macroautophagy in endothelial cells through activation of AMPK and the downstream inhibition of mTOR signaling pathway. Further studies indicated that intracellular calcium ([Ca(2+)](i)) might bridge the 3,4-DMS-induced apoptosis and macroautophagy through modulating reactive oxygen species (ROS) levels in endothelial cells. Combination of 3,4-DMS with inhibitor of autophagy, such as 3-methyladenine (3-MA) and autophagy-related gene (ATG) 5 small interfering RNA (siRNA), potentiated the pro-apoptotic and anti-angiogenic effects of 3,4-DMS. Our study provides a novel angiogenic inhibitor and a useful tool in exploring the molecular mechanisms for the crosstalk between apoptosis and macroautophagy in endothelial cells. 3,4-DMS could be served as a potential lead compound for developing a class of new drugs targeting angiogenesis-related diseases.

Rhodium(III)-Picolinamide Complexes Act as Anticancer and Antimetastasis Agents via Inducing Apoptosis and Autophagy.

As a continuation of our endeavors in discovering metal-based drugs with cytotoxic and antimetastatic activities, herein, we reported the syntheses of 11 new rhodium(III)-picolinamide complexes and the exploration of their potential anticancer activities. These Rh(III) complexes showed high antiproliferative activity against the tested cancer cell lines in vitro. The mechanism study indicated that Rh1 ([Rh(3a)(CH3CN)Cl2]) and Rh2 ([Rh(3b)(CH3CN)Cl2]) inhibited cell proliferation by multiple modes of action via cell cycle arrest, apoptosis, and autophagy and inhibited cell metastasis via FAK-regulated integrin ß1-mediated suppression of EGFR expression. Furthermore, Rh1 and Rh2 significantly inhibited bladder cancer growth and breast cancer metastasis in a xenograft model. These rhodium(III) complexes could be developed as potential anticancer agents with antitumor growth and antimetastasis activity.

Disruption of Wnt/ß-catenin Pathway Elevates the Sensitivity of Gastric Cancer Cells to PD-1 Antibody.

BACKGROUND: Gastric Cancer (GC) is the fifth most common malignancy tumor and the third cause of cancer-related death around the world. Immune checkpoint inhibitors (ICIs) such as programmed cell death-1 (PD-1) antibodies play an active role in tumor therapy. A recent study reveals that Wnt/ß-catenin signaling pathway is negatively correlated with T-cell infiltration in tumor microenvironment (TME), thereby influencing the therapeutic efficacy of PD-1 antibody. OBJECTIVE: In this study, we aimed to uncover the relationship of Wnt/ß-catenin pathway to CD8+ T cell activity as well as its effect on anti-PD-1 therapeutic efficacy in GC. METHODS AND RESULTS: We first collected clinical samples and went through an immunohistochemical analysis and found that a high ß-catenin expression in GC tissues was often associated with a significant absence of CD8+ T-cell infiltration. In addition, our data further indicated that disruption of the Wnt/ß-catenin pathway in GC cells inhibited their migratory and invasive ability. Meanwhile, enhanced sensitivity of GC cells to PD-1 blockade therapy was evident by decreased Jurkat cell apoptosis rate and increased GC cell apoptosis rate in a tumor and Jurkat cells co-culture system with the presence of Wnt/ß-catenin pathway inhibition. CONCLUSION: Collectively, these findings indicated Wnt/ß-catenin pathway may play a significant role in modulating the activity of Jurkat cells and downregulation of Wnt/ß-catenin may enhance the sensitivity of GC cells to PD-1 antibody in vitro. This result further indicated that ß-catenin and PD-1 targeted inhibition might become a potential and effective therapy for GC patients.

Terpyridine copper(II) complexes as potential anticancer agents by inhibiting cell proliferation, blocking the cell cycle and inducing apoptosis in BEL-7402 cells.

Four mononuclear terpyridine complexes [Cu(H-La)Cl2]·CH3OH (1), [Cu(H-La)Cl]ClO4 (2), [Cu(H-Lb)Cl2]·CH3OH (3), and [Cu(H-Lb)(CH3OH)(DMSO)](ClO4)2 (4) were prepared and fully characterized. Complexes 1-4 exhibited higher cytotoxic activity against several tested cancer cell lines especially BEL-7402 cells compared to cisplatin, and they showed low toxicity towards normal human liver cells. ICP-MS detection indicated that the copper complexes were accumulated in mitochondria. Mechanistic studies demonstrated that the copper complexes induced G0/G1 arrest and altered the expression of the related proteins of the cell cycle. All copper complexes reduced the mitochondrial membrane potential while increasing the intracellular ROS levels and the release of Ca2+. They also up-regulated Bax and down-regulated Bcl-2 expression levels, caused cytochrome c release and the activation of the caspase cascade, and induced mitochondrion-mediated apoptosis. Animal studies demonstrated that complex 1 suppressed tumor growth in a mouse xenograft model bearing BEL-7402 tumor cells.

Ghrelin Regulates Cyclooxygenase-2 Expression and Promotes Gastric Cancer Cell Progression.

AIM: To research the molecular mechanism of ghrelin in apoptosis, migratory, and invasion of gastric cancer (GC) cells. METHODS: After GC AGS cells were handled with ghrelin (10-8 M), cyclooxygenase-2 inhibitor NS398 (100 µM), and Akt inhibitor perifosine (10uM), the rates of apoptosis were detected by TUNEL assay and flow cytometry assay. We assessed the expressions of PI3K, p-Akt, and COX-2 proteins by making use of Western blot analysis. The cell migratory and invasion were detected by using wound-healing and transwell analysis. RESULTS: The migratory and invasion were increased in ghrelin-treated cells, while the rates of apoptosis were decreased. GC AGS cells treated with ghrelin showed an increase in protein expression of p-Akt, PI3K, and COX-2. After cells were treated with Akt inhibitor perifosine, the protein expression of p-Akt, PI3K, and COX-2 and the cell migratory, invasion, and apoptosis were partly recovered. After cells were treated with cyclooxygenase-2 inhibitor NS398, the protein expression of COX-2 and the cell migratory and invasion were decreased, while the rates of apoptosis were increased. CONCLUSION: Ghrelin regulates cell migration, invasion, and apoptosis in GC cells through targeting PI3K/Akt/COX-2. Ghrelin increases the expression of COX-2 in GC cells by targeting PI3K/Akt. Ghrelin is suggested to be one of the molecular targets in GC.

Identification and Validation of the Immune Regulator CXCR4 as a Novel Promising Target for Gastric Cancer.

Immune checkpoint blockade has attracted a lot of attention in the treatment of human malignant tumors. We are trying to establish a prognostic model of gastric cancer (GC) based on the expression profile of immunoregulatory factor-related genes. Based on the TCGA database, we identified 234 differentially expressed immunoregulatory factors. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) conducted enrichment analysis to clarify the biological functions of differential expression of immunoregulatory factors. STRING database predicted the interaction network between 234 differently expressed immune regulatory factors. The expression of 11 immunoregulatory factors was significantly related to the overall survival of gastric cancer patients. Univariate Cox regression analysis, Kaplan-Meier analysis and multivariate Cox regression analysis found that immunomodulatory factors were involved in the progression of gastric cancer and promising biomarkers for predicting prognosis. Among them, CXCR4 was related to the low survival of GC patients and a key immunomodulatory factor in GC. Based on TCGA data, the high expression of CXCR4 in GC was positively correlated with the advanced stage and grade of gastric cancer and related to poor prognosis. Univariate analysis and multivariate analysis indicated that CXCR4 was an independent prognostic indicator for TCGA gastric cancer patients. In vitro functional studies had shown that CXCR4 promoted the proliferation, migration, and invasion of gastric cancer cells. In summary, this study has determined the prognostic value of 11 immunomodulatory factors in gastric cancer. CXCR4 is an independent prognostic indicator for gastric cancer patients, which may help to improve the individualized prognostic prediction of GC and provide candidates for the diagnosis and treatment of GC.

LMX1A inhibits C-Myc expression through ANGPTL4 to exert tumor suppressive role in gastric cancer.

Our research group has showed that the LIM homeobox transcription factor 1 alpha (LMX1A) is inactivated in gastric cancers. Overexpression of LMX1A inhibits tumor growth. However, the mechanisms remains unclear. Considering LMX1A as a transcription factor, a comparison of RNA-seq between gastric cancer cells (GCCs) and GCCs with LMX1A overexpressed was performed to identify genes transcriptionally activated by LMX1A. Among the potential LMX1A target genes, angiopoietin-like 4 (ANGPTL4) has been reported to be an important tumor suppressor and thus was selected for further validation and research. Both LMX1A and ANGPTL4 showed downregulated expression in gastric cancer samples. More importantly, the expression of LMX1A is positively correlated with ANGPTL4, without including other family members in gastric cancer cell lines. What's more, knockdown of ANGPTL4 rescued the tumor suppressive phenotype of LMX1A overexpression, which indicated that LMX1A upregulates ANGPTL4 to exert its role. Mechanistically, we found that LMX1A inhibited the expression of the oncogene C-Myc, which is alleviated by ANGPTL4 knockdown. In general, our results showed that LMX1A exerts its tumor suppressive role by activating ANGPTL4 to inhibit C-Myc.