Anti-Inflammatory Effects of New Naphthyridine from Sponge Aaptos suberitoides in LPS-Stimulated RAW 264.7 Macrophages via Regulation of MAPK and Nrf2 Signaling Pathways.

Two new naphthyridine compounds, 4-methoxycarbonyl-5-oxo-1,6-naphthyridine (1) and 5-methoxycarbonyl-4-oxo-1,6-naphthyridine (2) were obtained from the MeOH extracts of sponge Aaptos suberitoides. Their structures were determined by spectroscopic methods, including HR-ESI-MS, 1D-NMR (1 H-NMR, 13 C-NMR), 2D-NMR (COSY, HSQC, HMBC). The structure of compound 1 was further confirmed via single crystal X-ray diffraction analysis. Compound 1 was found to reduce NO production in LPS-induced RAW 264.7 macrophages with IC50 value of 0.15 mM. In addition, it decreased the mRNA expression levels of pro-inflammatory mediators, such as the tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2) in LPS-induced macrophages. It also decreased the protein expression of iNOS and COX-2 in LPS-induced macrophages. Mechanistic studies further revealed that compound 1 inhibited the mitogen-activated protein kinase (MAPK), and activated the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) signaling pathways in LPS-induced RAW 264.7 macrophages.

Chemical constituents from the seeds of Cullen corylifolium and their inhibitory activity on diacylglycerol acyltransferase.

A large number of extracts of medicinal plants or natural products shows beneficial to combat obesity. In the present work, a new flavonoid named (2S,1″R,2″R)-4'-hydroxy-7-methoxy-6-(1,2,3-trihydroxy-3-methyl-butyl)-flavanone (1), along with seven known compounds (2-8) were isolated from the seeds of Cullen corylifolium. Their structures, including the absolute configurations, were determined by the analysis of comprehensive spectroscopic data and computational calculation methods. All isolates were evaluated for their diacylglycerol acyltransferase (DGAT) inhibitory activity. Compounds 1-4 exhibited different level of DGAT1 inhibitory activity with IC50 values ranging from 28.2 ± 1.1 to 127.3 ± 1.9 µM. In addition, 45 flavonoids which be evaluated for DGAT inhibitory activity were summarised and potential structure-activity relationships were discussed.

A Combination of Genome Mining with an OSMAC Approach Facilitates the Discovery of and Contributions to the Biosynthesis of Melleolides from the Basidiomycete Armillaria tabescens.

Genome mining revealed that the genomes of basidiomycetes may include a considerable number of biosynthetic gene clusters (BGCs), yet numerous clusters remain unidentified. Herein, we report a combination of genome mining with an OSMAC (one strain, many compounds) approach to characterize the spectrum of melleolides produced by Armillaria tabescens CPCC 401429. Using F1 fermentation medium, the metabolic pathway of the gene cluster mel was successfully upregulated. From the extracts of the wild-type strain, two new melleolides (1 and 2), along with five new orsellinic acid-derived lactams (10-14), were isolated, and their structures were elucidated by LC-HR-ESIMS/MS and 2D-NMR. Several melleolides exhibited moderate anti-carcinoma (A549, NCI-H520, and H1299) effects with IC50 values of 4.0-48.8 µM. RNA-sequencing based transcriptomic profiling broadened our knowledge of the genetic background, regulation, and mechanisms of melleolide biosynthesis. These results may promote downstream metabolic engineering studies of melleolides. Our study demonstrates the approach is effective for discovering new secondary metabolites from Armillaria sp. and will facilitate the mining of the unexploited biosynthetic potential in other basidiomycetes.

Aaptamine - a dual acetyl - and butyrylcholinesterase inhibitor as potential anti-Alzheimer's disease agent.

CONTEXT: Alzheimer's disease (AD) is a neurodegenerative disorder that affects millions of people worldwide. Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are promising therapeutic targets for AD. OBJECTIVE: To evaluate the inhibitory effects of aaptamine on two cholinesterases and investigate the in vivo therapeutic effect on AD in a zebrafish model. MATERIALS AND METHODS: Aaptamine was isolated from the sponge Aaptos suberitoides Brøndsted (Suberitidae). Enzyme inhibition, kinetic analysis, surface plasmon resonance (SPR) and molecular docking assays were used to determine its inhibitory effect on AChE and BuChE in vitro. Zebrafish were divided into six groups: control, model, 8 µM donepezil, 5 , 10 and 20 µM aaptamine. After three days of drug treatment, the behaviour assay was performed. RESULTS: The IC50 values of aaptamine towards AChE and BuChE were 16.0 and 4.6 µM. And aaptamine directly inhibited the two cholinesterases in the mixed inhibition type, with Ki values of 6.96 ± 0.04 and 6.35 ± 0.02 µM, with Kd values of 87.6 and 10.7 µM. Besides, aaptamine interacts with the crucial anionic sites of AChE and BuChE. In vivo studies indicated that the dyskinesia recovery rates of 5 , 10 and 20 µM aaptamine group were 34.8, 58.8 and 60.0%, respectively, and that of donepezil was 63.7%. DISCUSSION AND CONCLUSIONS: Aaptamine showed great potential to exert its anti-AD effects by directly inhibiting the activities of AChE and BuChE. Therefore, this study identified a novel medicinal application of aaptamine and provided a new structural scaffold for the development of anti-AD drugs.

Cytochalasins from coastal saline soil-derived fungus Aspergillus flavipes RD-13 and their cytotoxicities.

Chemical investigation of coastal saline soil-derived fungus Aspergillus flavipes RD-13 led to the isolation of two new seco-cytochalasins (1) and (2) along with nine known analogs. Their structures were elucidated by comprehensive spectral analysis, and the absolute configurations of these two new ones were determined through Rh2(OCOCF3)4-induced CD experiment and chemical interconversions. Moreover, the absolute configuration of a known compound named cytochalasins Z18 (3) was also determined for the first time. Structurally, compounds 1, 2 and 3 were the open ring derivatives of compounds 5, 8, and 4, respectively. All compounds were evaluated for their cytotoxic activities on A549, H1299 and H520 cells and 4 exhibited the strongest inhibitory activities towards the above cell lines with IC50 values of 0.15, 0.23 and 0.43 µg/mL, respectively. Preliminary structure-activity relationship analysis suggested the importance of macrocyclic ring in cytochalasins to confer cytotoxicity.

Aaptamine derivatives with CDK2 inhibitory activities from the South China Sea sponge Aaptos suberitoides.

Three new aaptamines (1-3) together with two known derivatives (4-5) were isolated from the South China Sea sponge Aaptos suberitoides. The structures of all compounds were unambiguously elucidated by spectroscopic analyses as well as the comparison with literature data. All the compounds were evaluated for their cytotoxic activities against five human cancer cell lines including H1299, H520, SCG7901, CNE-2 and SW680 cells. As a result, compounds 3-5 showed moderate cytotoxicities against H1299 and H520 cells with IC50 values ranging from 12.9 to 20.6 µg/mL. Besides, compounds 3-5 also showed potent inhibitory activities toward cyclin-dependent kinase-2 (CDK2) with IC50 values of 14.3, 3.0 and 6.0 µg/mL, respectively. In addition, compounds 3-5 significantly induced G1 arrests of H1299 cells at low concentrations. Drug affinity responsive target stability (DARTS) experiments were carried out and further demonstrated that compound 3 could effectively bind with CDK2 protein and protect it from the degradation by pronase.

LncRNA MALAT1 Regulating Lung Carcinoma Progression via the miR-491-5p/UBE2C Axis.

Long noncoding RNAs (lncRNAs) play a critical role in the development of lung carcinoma. The mechanism of MALAT1 in lung carcinoma development is not understood very well. This study aimed to investigate the role of MALAT1 in lung carcinoma progression and the mechanism underlying the role of miR-491-5p in the MALAT1 mediated regulation of UBE2C expression. The results indicated that the expression of MALAT1 was often augmented in lung carcinoma cells. Suppression of MALAT1 blocked the proliferation, invasion and migration ability of cancer cells and inhibited the expression of UBE2C. UBE2C restoration attenuated the MALAT1 knockdown-induced anti-cancer effects. Moreover, UBE2C and MALAT1 were indicated as targets of miR-491-5p and inhibition of miR-491-5p restored the MALAT1 knockdown-induced inhibition of the progression of lung carcinoma. Furthermore, MALAT1 sponged miR-491-5p to upregulate UBE2C expression, causing it to act as a competing endogenous RNA. Collectively, MALAT1 downregulation suppressed lung carcinoma progression by regulating the miR-491-5p/UBE2C axis. These results indicate that MALAT1 could be a molecular target for lung carcinoma treatment and prognosis.

Scutellariabarbata D. Don extraction selectively targets stemness-prone NSCLC cells by attenuating SOX2/SMO/GLI1 network loop.

ETHNOPHARMACOLOGICAL RELEVANCE: Scutellariabarbata D. Don extraction (SBE), a traditional Chinese medicine, has been proved effective against various malignant disorders in clinics with tolerable side-effects when administered alone or in combination with conventional chemotherapeutic regimens. AIM OF THIS STUDY: Multi-drug resistance of cancer is attributed to existence of cancer stemness-prone cells that harbor aberrantly high activation of Sonic Hedgehog (SHH) cascade. Our previous study has demonstrated that SBE sensitized non-small cell lung cancer (NSCLC) cells to Cisplatin (DDP) treatment by downregulating SHH pathway. Yet, whether SBE could prohibit proliferation of cancer stemness-prone cells and its underlying molecular mechanisms remain to be investigated. In this article, we further investigated intervention of SBE on NSCLC cell stemness-associated phenotypes and its potential mode of action. MATERIALS AND METHODS: CCK-8 and clonal formation detection were used to measure the anti-proliferative potency of SBE against NSCLC and normal epithelial cells. Sphere formation assay and RQ-PCR were used to detect proliferation of cancer stemness cells and associated marker expression upon SBE incubation. Mechanistically, DARTS-WB and SPR were used to unveil binding target of SBE. Immunodeficient mice were implanted with patient derived tumor bulk for in vivo validation of anti-cancer effect of SBE. RESULTS: SBE selectively attenuated proliferation and stemness-like phenotypes of NSCLC cells rather than bronchial normal epithelial cells. Drug-protein interaction analysis revealed that SBE could directly bind with stem cell-specific transcription factor sex determining region Y-box 2 (SOX2) and interfere with the SOX2/SMO/GLI1 positive loop. In vivo assay using patient-derived xenografts (PDXs) model further proved that SBE diminished tumor growth and SOX2 expression in vivo. CONCLUSION: Our data indicate that SBE represses stemness-related features of NSCLC cells via targeting SOX2 and may serve as an alternative therapeutic option for clinic treatment.

Author Correction: Disruption of SHH signaling cascade by SBE attenuates lung cancer progression and sensitizes DDP treatment.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Aaptamine attenuates the proliferation and progression of non-small cell lung carcinoma.

CONTEXT: Aaptamine is a potent ocean-derived non-traditional drug candidate against human cancers. However, the underlying molecular mechanisms governing aaptamine-mediated repression of lung cancer cells remain largely undefined. OBJECTIVE: To examine the inhibitory effect of aaptamine on proliferation and progression of non-small cell lung carcinoma (NSCLC) and dissect the potential mechanisms involved in its anticancer functions. MATERIALS AND METHODS: In vitro assays of cell proliferation, cell cycle analysis, clonal formation, apoptosis and migration were performed to examine the inhibitory effects of aaptamine (8, 16 and 32 µg/mL) on NSCLC cells. The expression levels of proteins were analysed using western blotting analysis when cells were treated with a single drug or a combination treatment for 48 h. RESULTS: Aaptamine significantly inhibited A549 and H1299 cells proliferation with IC50 values of 13.91 and 10.47 µg/mL. At the concentrations of 16 and 32 µg/mL, aaptamine significantly reduced capacities in clonogenicity, enhanced cellular apoptosis and decreased the motile and invasive cellular phenotype. In addition, aaptamine arrested cell cycle at G1 phase via selectively abating cell cycle regulation drivers (CDK2/4 and Cyclin D1/E). Western blotting results showed that aaptamine attenuated the protein expression of MMP-7, MMP-9 and upregulated the expression of cleaved-PARP and cleaved-caspase 3. Moreover, aaptamine inhibited PI3K/AKT/GSK3ß signalling cascades through specifically degrading the phosphorylated AKT and GSK3ß. DISCUSSION AND CONCLUSIONS: Aaptamine retarded the proliferation and invasion of NSCLC cells by selectively targeting the pathway PI3K/AKT/GSK3ß suggesting it as a potential chemotherapeutic agent for repressing tumorigenesis and progression of NSCLC in humans.

m6A demethylase ALKBH5 inhibits tumor growth and metastasis by reducing YTHDFs-mediated YAP expression and inhibiting miR-107/LATS2-mediated YAP activity in NSCLC.

BACKGROUND: The importance of mRNA methylation erased by ALKBH5 in mRNA biogenesis, decay, and translation control is an emerging research focus. Ectopically activated YAP is associated with the development of many human cancers. However, the mechanism whereby ALKBH5 regulates YAP expression and activity to inhibit NSCLC tumor growth and metastasis is not clear. METHODS: Protein and transcript interactions were analyzed in normal lung cell and NSCLC cells. Gene expression was evaluated by qPCR and reporter assays. Protein levels were determined by immunochemical approaches. Nucleic acid interactions and status were analyzed by immunoprecipitation. Cell behavior was analyzed by standard biochemical tests. The m6A modification was analyzed by MeRIP. RESULTS: Our results show that YAP expression is negatively correlated with ALKBH5 expression and plays an opposite role in the regulation of cellular proliferation, invasion, migration, and EMT of NSCLC cells. ALKBH5 reduced m6A modification of YAP. YTHDF3 combined YAP pre-mRNA depending on m6A modification. YTHDF1 and YTHDF2 competitively interacted with YTHDF3 in an m6A-independent manner to regulate YAP expression. YTHDF2 facilitated YAP mRNA decay via the AGO2 system, whereas YTHDF1 promoted YAP mRNA translation by interacting with eIF3a; both these activities are regulated by m6A modification. Furthermore, ALKBH5 decreased YAP activity by regulating miR-107/LATS2 axis in an HuR-dependent manner. Further, ALKBH5 inhibited tumor growth and metastasis in vivo by reducing the expression and activity of YAP. CONCLUSIONS: The presented findings suggest m6A demethylase ALKBH5 inhibits tumor growth and metastasis by reducing YTHDFs-mediated YAP expression and inhibiting miR-107/LATS2-mediated YAP activity in NSCLC. Moreover, effective inhibition of m6A modification of ALKBH5 might constitute a potential treatment strategy for lung cancer.

Metformin-repressed miR-381-YAP-snail axis activity disrupts NSCLC growth and metastasis.

BACKGROUND: Recent evidence indicates that metformin inhibits mammalian cancer growth and metastasis through the regulation of microRNAs. Metformin regulates miR-381 stability, which plays a vital role in tumor progression. Moreover, increased YAP expression and activity induce non-small cell lung cancer (NSCLC) tumor growth and metastasis. However, the molecular mechanism underpinning how metformin-induced upregulation of miR-381 directly targets YAP or its interactions with the epithelial-mesenchymal transition (EMT) marker protein Snail in NSCLC is still unknown. METHODS: Levels of RNA and protein were analyzed using qPCR, western blotting and immunofluorescence staining. Cellular proliferation was detected using a CCK8 assay. Cell migration and invasion were analyzed using wound healing and transwell assays. Promoter activity and transcription were investigated using the luciferase reporter assay. Chromatin immunoprecipitation was used to detect the binding of YAP to the promoter of Snail. The interaction between miR-381 and the 3'UTR of YAP mRNA was analyzed using the MS2 expression system and co-immunoprecipitation with biotin. RESULTS: We observed that miR-381 expression is negatively correlated with YAP expression and plays an opposite role to YAP in the regulation of cellular proliferation, invasion, migration, and EMT of NSCLC cells. The miR-381 function as a tumor suppressor was significantly downregulated in lung cancer tissue specimens and cell lines, which decreased the expression of its direct target YAP. In addition, metformin decreased cell growth, migration, invasion, and EMT via up-regulation of miR-381. Moreover, YAP, which functions as a co-transcription factor, enhanced NSCLC progression and metastasis by upregulation of Snail. Snail knockdown downregulated the mesenchymal marker vimentin and upregulated the epithelial marker E-cadherin in lung cancer cells. Furthermore, miR-381, YAP, and Snail constitute the miR-381-YAP-Snail signal axis, which is repressed by metformin, and enhances cancer cell invasiveness by directly regulating EMT. CONCLUSIONS: Metformin-induced repression of miR-381-YAP-Snail axis activity disrupts NSCLC growth and metastasis. Thus, we believe that the miR-381-YAP-Snail signal axis may be a suitable diagnostic marker and a potential therapeutic target for lung cancer.

Triazole derivatives and their antiplasmodial and antimalarial activities.

Malaria, caused by protozoan parasites of the genus Plasmodium especially by the most prevalent parasite Plasmodium falciparum, represents one of the most devastating and common infectious disease globally. Nearly half of the world population is under the risk of being infected, and more than 200 million new clinical cases with around half a million deaths occur annually. Drug therapy is the mainstay of antimalarial therapy, yet current drugs are threatened by the development of resistance, so it's imperative to develop new antimalarials with great potency against both drug-susceptible and drug-resistant malaria. Triazoles, bearing a five-membered heterocyclic ring with three nitrogen atoms, exhibit promising in vitro antiplasmodial and in vivo antimalarial activities. Moreover, several triazole-based drugs have already used in clinics for the treatment of various diseases, demonstrating the excellent pharmaceutical profiles. Therefore, triazole derivatives have the potential for clinical deployment in the control and eradication of malaria. This review covers the recent advances of triazole derivatives especially triazole hybrids as potential antimalarials. The structure-activity relationship is also discussed to provide an insight for rational designs of more efficient antimalarial candidates.

Quinoline and quinolone dimers and their biological activities: An overview.

Quinoline and quinolone motifs which act as structural subunits of more complex natural products are ubiquitous in nature, and they are useful pharmacophores which play a pivotal role in drug development. Compared with the corresponding monomeric compounds, the dimers usually exhibited some unique properties, so dimers have caused great interests in recent years. Quinline and quinolone dimers possess various biological properties such as antibacterial, anticancer, antimalarial and antitubercular activities, and some of them which are exemplified by piperaquine have already used in clinical practice. Numerous quinline and quinolone dimers have been synthesized and screened for their in vitro and in vivo biological activities, and some of them exhibited promising potency. Therefore, quinline and quinolone dimers have the potential for clinical deployment in the control and eradication of various diseases. This review covers the recent advances of quinline and quinolone dimers as bioactive substances. The structure-activity relationship was also discussed to provide an insight for rational designs of more active quinline and quinolone dimers.

The miR 495-UBE2C-ABCG2/ERCC1 axis reverses cisplatin resistance by downregulating drug resistance genes in cisplatin-resistant non-small cell lung cancer cells.

Cisplatin (DDP) resistance has become the leading cause of mortality in non-small cell lung cancer (NSCLC). miRNA dysregulation significantly contributes to tumor progression. In this study, we found that miR-495 was significantly downregulated in lung cancer tissue specimens. This study aimed to elucidate the functions, direct target genes, and molecular mechanisms of miR-495 in lung cancer. miR-495 downregulated its substrate UBE2C through direct interaction with UBE2C 3'- untranslated region. UBE2C is a proto-oncogene activated in lung cancer; however, its role in chemotherapeutic resistance is unclear. Herein, UBE2C expression levels were higher in DDP-resistant NSCLC cells; this was associated with the proliferation, invasion, and DDP resistance in induced cisplatin-resistant NSCLC cells. Furthermore, epithelial-mesenchymal transitions (EMT) contributed to DDP resistance. Moreover, UBE2C knockdown downregulated vimentin. In contrast, E-cadherin was upregulated. Importantly, miR-495 and UBE2C were associated with cisplatin resistance. We attempted to evaluate their effects on cell proliferation and cisplatin resistance. We also performed EMT, cell migration, and invasion assays in DDP-resistant NSCLC cells overexpressing miR-495 and under-expressing UBE2C. Furthermore, in silico assays coupled with western blotting and luciferase assays revealed that UBE2C directly binds to the 5'-UTR of the drug-resistance genes ABCG2 and ERCC1. Furthermore, miR-495 downregulated ABCG2 and ERCC1 via regulation of UBE2C. Together, the present results indicate that the miR495-UBE2C-ABCG2/ERCC1 axis reverses DDP resistance via downregulation of anti-drug genes and reducing EMT in DDP-resistant NSCLC cells.

Deregulation of UBE2C-mediated autophagy repression aggravates NSCLC progression.

The roles of aberrantly regulated autophagy in human malignancy and the mechanisms that initiate and sustain the repression of autophagy in carcinogenesis are less well defined. Activation of the oncogene UBE2C and repression of autophagy are concurrently underlying the initiation, progression, and metastasis of lung cancer and exploration of essential association of UBE2C with autophagy will confer more options in searching novel molecular therapeutic targets in lung cancer. Here we report that aberrant activation of UBE2C in lung tumors from patients associates with adverse prognosis and enhances cell proliferation, clonogenicity, and invasive growth of NSCLC. UBE2C selectively represses autophagy in NSCLC and disruption of UBE2C-mediated autophagy repression attenuates cell proliferation, clonogenicity, and invasive growth of NSCLC. Autophagy repression is essentially involved in UBE2C-induced cell proliferation, clonogenicity, and invasive growth of NSCLC. Interference of UBE2C-autophagy repression axis by Norcantharidin arrests NSCLC progression. UBE2C is repressed post-transcriptionally via tumor suppressor miR-381 and epitranscriptionally stabilized with maintenance of lower m6A level within its mature RNAs due to the upregulation of m6A demethylase ALKBH5 in NSCLC. Collectively, our results indicated that deregulated UBE2C-autophagy repression axis drives NSCLC progression which renders varieties of potential molecular targets in cancer therapy of NSCLC.