Prenylated indole diketopiperazine alkaloids as phosphatase inhibitors from the marine-derived fungus Talaromyces purpureogenus.

Six previously undescribed prenylated indole diketopiperazine alkaloids, talaromyines A-F (1-6), were isolated from the marine-derived fungus Talaromyces purpureogenus SCSIO 41517. Their structures including absolute configurations were elucidated on the basis of comprehensive spectroscopic data including NMR, HR-ESI-MS, and electronic circular dichroism calculations, together with chemical analysis of hydrolysates. Compounds 1-5 represent the first example of spirocyclic indole diketopiperazines biosynthesized from the condensation of L-tryptophan and L-alanine. Compounds 2 and 4-5 showed selective inhibitory activities against phosphatases TCPTP and MEG2 with IC50 value of 17.9-29.7 µM, respectively. Compounds 4-5 exhibited mild cytotoxic activities against two human cancer cell lines H1975 and HepG-2.

Alternaphenol B2, a new IDH1 inhibitor from the coral-derived fungus Parengyodontium album SCSIO SX7W11.

A new aromatic polyketide, alternaphenol B2 (1), and four known compounds (2-5) were isolated from the coral-derived fungus Parengyodontium album SCSIO SX7W11. Their structures were elucidated by high-resolution mass spectrometry, 1D and 2D NMR spectroscopy and comparison with reported literatures. Compounds 1 and 2 exhibited selective inhibitory activity against isocitrate dehydrogenase mutant R132H (IDH1m), with IC50 values of 41.9 and 27.7 µM, respectively. Our findings thus provide a fresh incentive for investigation on IDH1m inhibitors as lead compounds for cancer treatment.

Carotane sesquiterpenoids A-G from the desert endophytic fungus Fusarium sp. HM 166.

Seven undescribed carotane sesquiterpenoids named fusanoids A-G (1-7), along with one known analog (8) and two known sesterterpenes (9 and 10), were isolated from the fermentation broth of the desert endophytic fungi Fusarium sp. HM166. The structures of the compounds, including their absolute configurations, were determined by spectroscopic data, single-crystal X-ray diffraction analysis, and ECD calculations. Compound 10 showed cytotoxic activities against human hepatoma carcinoma cell line (Huh-7) and human breast cell lines (MCF-7 and MDA-MB-231), and compound 2 showed cytotoxic activity against MCF-7, while compounds 4-9 were inactive against all the tested cell lines. Compounds 4 and 10 showed potent inhibitory activities against the IDH1R132h mutant.

Structure-based discovery of a specific SHP2 inhibitor with enhanced blood-brain barrier penetration from PubChem database.

The thiophene [2,3-d]pyrimidine structure-like small molecules were discovered from structure-based virtual screening of 1 billion compounds. Base on enzyme activity assay results, a SHP2-specific molecule inhibitor Comp#2 with IC50 of 1.174 µM, 85-fold more selective for SHP2 than the highly related SHP1 (IC50 > 100 µM). The compound can effectively inhibit SHP2-mediated cell signaling and cancer cell proliferation, including cervix cancer, human pancreatic cancer, large cell lung cancer, and mouse glioma cell. Moreover, the in vivo assay indicated that Comp#2 could inhibit cervix cancer tumors growth in BABL/c mice. This work has shown the specific SHP2 inhibitor can inhibit glioblastoma growth in vivo.

Isoquinoline Alkaloids as Protein Tyrosine Phosphatase Inhibitors from a Deep-Sea-Derived Fungus Aspergillus puniceus.

Puniceusines A-N (1-14), 14 new isoquinoline alkaloids, were isolated from the extracts of a deep-sea-derived fungus, Aspergillus puniceus SCSIO z021. Their structures were elucidated by spectroscopic analyses. The absolute configuration of 9 was determined by ECD calculations, and the structures of 6 and 12 were further confirmed by a single-crystal X-ray diffraction analysis. Compounds 3-5 and 8-13 unprecedentedly contained an isoquinolinyl, a polysubstituted benzyl or a pyronyl at position C-7 of isoquinoline nucleus. Compounds 3 and 4 showed selective inhibitory activity against protein tyrosine phosphatase CD45 with IC50 values of 8.4 and 5.6 µM, respectively, 4 also had a moderate cytotoxicity towards human lung adenocarcinoma cell line H1975 with an IC50 value of 11.0 µM, and 14, which contained an active center, -C=N+, exhibited antibacterial activity. An analysis of the relationship between the structures, enzyme inhibitory activity and cytotoxicity of 1-14 revealed that the substituents at C-7 of the isoquinoline nucleus could greatly affect their bioactivity.

Piperlongumine inhibits the growth of non-small cell lung cancer cells via the miR-34b-3p/TGFBR1 pathway.

BACKGROUND: Non-small cell lung cancer is a common type of lung cancer. Piperlongumine (PL), which is extracted from the roots of piperaceae plant, long pepper, and peppercorn, is an alkaloid amide that inhibits tumor growth and metastasis. However, whether it affects lung cancer cells remains unclear. METHODS: We assessed the effects of PL on the proliferation and apoptosis of A549 and H1299 NSCLC cell lines. RESULTS: PL was mildly toxic to normal human bronchial epithelial cells and significantly suppressed growth and facilitated apoptosis of A549 and H1299 cells. It also upregulated microRNA (miR)-34b-3p and downregulated the transforming growth factor beta type I receptor (TGFBR1). The dual-luciferase reporter assay showed that TGFBR1 is a target gene of miR-34b-3p. Silencing of miR-34b-3p or overexpression of TGFBR1 partially attenuated the effects of PL on A549 and H1299 cells. CONCLUSIONS: PL inhibits proliferation and induces apoptosis of A549 and H1299 cells by upregulating miR-34b-3p and modulating TGFBR1 signaling pathway.

Exploring the dynamic mechanism of allosteric drug SHP099 inhibiting SHP2E69K.

The E69K mutation is one of the most frequent protein tyrosine phosphatase-2 (SHP2) mutations in leukemia, and it can cause the increase in the protein activity. Recent studies have shown that the E69K mutation was fairly sensitive to the allosteric inhibitor of SHP2 (SHP099). However, the molecular mechanism of the allosteric drug SHP099 inhibiting SHP2E69K remains unclear. Thus, the molecular dynamic simulations and the post-dynamics analyses (RMSF, PCA, DCCM, RIN and the binding free energies) for SHP2WT, SHP2WT-SHP099, SHP2E69K and SHP2E69K-SHP099 were carried out, respectively. Owing to the strong binding affinity of SHP099 to residues Thr219 and Arg220, the flexibility of linker region (residues Val209-Arg231) was reduced. Moreover, the presence of SHP099 kept the autoinhibition state of the SHP2 protein through enhancing the interactions between the linker region and Q loop in PTP domain, such as Thr219/Val490, Thr219/Asn491, Arg220/Ile488 and Leu254/Asn491. In addition, it was found that the residues (Thr219, Arg220, Leu254 and Asn491) might be the key residues responsible for the conformational changes of protein. Overall, this study may provide an important basis for understanding how the SHP099 effectively inhibited the SHP2E69K activity at the molecular level.

Exploring the mechanism of the potent allosteric inhibitor compound2 on SHP2 WT and SHP2F285S by molecular dynamics study.

Abnormal activation of Ras/MAPK signaling pathway could trigger excessive cell division. Src-homology 2 (SH2) domain-containing protein tyrosine phosphatase (SHP2) could promote Ras/MAPK activation by integrating growth factor signals. Thus, SHP2 inhibitors had become a hot topic in the treatment of cancer. SHP2F285S, mutation in SHP2, was detected in leukemia variants. The compound 2 (3-benzyl-8-chloro-2-hydroxy-4H-benzo[4,5]thiazolo[3,2-a]pyrimidin-4-one) had been reported that it was a potent allosteric inhibitor of both SHP2 wild type (SHP2WT) and the F285S mutant (SHP2F285S). However, the mechanism of inhibition remained to be further discovered. Herein, molecular docking and molecular dynamic (MD) simulation were performed to explain the inhibition mechanism of compound 2 on SHP2WT and SHP2F285S. Overall, the molecular docking analysis revealed that compound 2 maintained the "close" structure of SHP2 protein probably by locking the C-SH2 and PTP domain. Next, post-analysis demonstrated that compound 2 might make TYR66-GLU76 of D'E-loop in N-SH2 and GLU258-LYS266 of B'C-loop, HIS458-ARG465 of P-loop, VAL497-THR507 of Q-loop in PTP domain regions tightly connect and much easier maintain "self-inhibited" conformation of SHP2F285S-compound2 than that of SHP2WT-compound2. Importantly, GLU76 of D'E-loop could play a vital role in inhibition of SHP2WT-compound2 and SHP2F285S-compound2. This work provided a reliable clue to develop novel inhibitors for leukemia related to SHP2F285S.

Design, synthesis, biological evaluation, common feature pharmacophore model and molecular dynamics simulation studies of ethyl 4-(phenoxymethyl)-2-phenylthiazole-5-carboxylate as Src homology-2 domain containing protein tyrosine phosphatase-2 (SHP2) inhibitors.

SHP2 is a non-receptor protein tyrosine phosphatase (PTP) encoded by the PTPN11 gene involved in cell death pathway (PD-1/PD-L1) and cell growth and differentiation pathway (MAPK). Moreover, mutations in SHP2 have been implicated in Leopard syndrome (LS), Noonan syndrome (NS), juvenile myelomonocytic leukemia (JMML) and several types of cancer and solid tumors. Thus, SHP2 inhibitors are much needed reagents for evaluation of SHP2 as a therapeutic target. A series of novel ethyl 4-(phenoxymethyl)-2-phenylthiazole-5-carboxylate derivatives were designed and synthesized, and their SHP2 inhibitory activities (IC50) were determined. Among the desired compounds, 1d shares the highest inhibitory activity (IC50 = 0.99 µM) against SHP2. Additionally, a common feature pharmacophore model was established to explain the structure activity relationship of the desired compounds. Finally, molecular dynamics simulation was carried out to explore the most likely binding mode of compound 1d with SHP2. In brief, the findings reported here may at least provide a new strategy or useful insights in discovering novel effective SHP2 inhibitors.Communicated by Ramaswamy H. Sarma.

New protein tyrosine phosphatase inhibitors from fungus Aspergillus gorakhpurensis F07ZB1707.

Twelve new compounds, aspergorakhins A-L (1-12) coupled with one known xanthone leptosphaerin D (13), were isolated from the extract of soil-derived fungus Aspergillus gorakhpurensis F07ZB1707. Their structures were elucidated by spectroscopic data analysis including UV, IR, NMR, and HRESIMS. The absolute configurations of 5 and 8-11 were identified using ECD and OR calculations. All compounds were tested by enzyme inhibitory activity assay in vitro. Aspergorakhin A (1) showed selective activities against PTP1B and SHP1 over TCPTP with IC50 values 0.57, 1.19, and 22.97 µM, respectively. Compounds 1 and 2 exhibited modest cytotoxicity against tumor cell lines A549, HeLa, Bel-7402, and SMMC-7721 with IC50 values in the range of 6.75-83.4 µM.

Scaffold-based selective SHP2 inhibitors design using core hopping, molecular docking, biological evaluation and molecular simulation.

PTPN11 (coding the gene of SHP2), a classic non-receptor protein tyrosine phosphatase, is implicated in multiple cell signaling pathway. Abnormal activation of SHP2 has been shown to contribute to a variety of human diseases, including Juvenile myelomonocytic leukemia (JMML), Noonan syndrome and tumors. Thus, the SHP2 inhibitors have important therapeutic value. Here, based on the compound PubChem CID 8,478,960 (IC50 = 45.01 µM), a series of thiophene [2,3-d] pyrimidine derivatives (IC50 = 0.4-37.87 µM) were discovered as novel and efficient inhibitors of SHP2 through powerful "core hopping" and CDOCKER technology. Furthermore, the SHP2-PTP phosphatase activity assay indicated that Comp#5 (IC50 = 0.4 µM) was the most active SHP2 inhibitor. Subsequently, the effects of Comp#5 on the structure and function of SHP2 were investigated through molecular dynamics (MD) simulation and post-kinetic analysis. The result indicated that Comp#5 enhanced the interaction of residues THR357, ARG362, LYS366, PRO424, CYS459, SER460, ALA461, ILE463, ARG465, THR507 and GLN510 with the surrounding residues, improving the stability of the catalytic active region and the entrance of catalytic active region. In particular, the Comp#5 conjugated with residue ARG362, elevating the efficient and selectivity of SHP2 protein. The study here may pave the way for discovering the novel SHP2 inhibitors for suffering cancer patients.

SNHG11 contributes to NSCLC cell growth and migration by targeting miR-485-5p/BSG axis.

Accumulating studies implied that long noncoding RNAs (lncRNAs) act as essential factors in regulating diverse biological behaviors of cancers. Small nucleolar RNA host gene 11 (SNHG11) has been reported as for its oncogenic properties in several cancer types. However, it is unclear whether SNHG11 exerts functions in non-small cell lung cancer (NSCLC) remains unclear. The aim of this study was to inspect the role and regulatory mechanism of SNHG11 in NSCLC. The expression of SNHG11 in NSCLC cells was analyzed by qRT-PCR. Functional experiments were carried out to determine the effects of SNHG11 silence on the biological behaviors of NSCLC cells, including growth, migration and epithelial-mesenchymal transition. The inhibition of above functions was observed after SNHG11 was silenced. Subcellular fractionation and FISH assays were performed to detect the cellular distribution of SNHG11. Moreover, SNHG11 was found to be a sponge of miR-485-5p that could directly target to Basigin (BSG) mRNA. The interaction between SNHG11 and miR-485-5p as well as between miR-485-5p and BSG was proven by RNA pull down and luciferase reporter assays. Restoration assay confirmed the involvement of miR-485-5p and BSG in SNHG11-mediated NSCLC cellular functions. Conclusively, SNHG11 was overexpressed in NSCLC and functioned as a miR-485-5p sponge to up-regulate BSG.

Exploring the effect of aplidin on low molecular weight protein tyrosine phosphatase by molecular docking and molecular dynamic simulation study.

The low molecular weight protein tyrosine phosphatase (LMW-PTP) could regulate many signaling pathways, and it had drawn attention as a potential target for cancer. As previous report has indicated that the aplidin could inhibit the LMW-PTP, and thus, the relevant cancer caused by the abnormal regulation of the LMW-PTP could be remission. However, the molecular mechanism of inhibition of the LMW-PTP by the aplidin had not been fully understood. In this study, various computational approaches, namely molecular docking, MDs and post-dynamic analyses were utilized to explore the effect of the aplidin on the LMW-PTP. The results suggested that the intramolecular interactions of the residues in the two sides of the active site (Ser43-Ala55 and Pro121-Asn134) and the P-loop region (Leu13-Ser19) in the LMW-PTP was disturbed owing to the aplidin, meanwhile, the π-π interaction between Tyr131 and Tyr132 might be broken. The Asn15 might be the key residue to break the residues interactions. In a word, this study may provide more information for understanding the effect of inhibition of the aplidin on the LMW-PTP.

Discovery of naphthacemycins as a novel class of PARP1 inhibitors.

Poly (ADP-ribose) polymerase-1 (PARP-1) is an abundant nuclear protein that plays important roles in a variety of nuclear processes, and it has been proved a prominent target in oncology for its key function in DNA damage repair. In this study, we discovered a series of naphthacemycins as a new class of PARP1 inhibitors from a microbial metabolites library via high-throughput screening. Compound I, one of this series of compounds, could reduce cellular poly (ADP-ribose) level, trap PARP1 on the damaged DNA and elevate the level of γ-H2AX, and showed the selective cytotoxicity against BRCA1-deficient cell line. Our study provided a potential scaffold for the development of new PARP1 inhibitors in cancer therapy.

Aberrant expression of hsa_circ_0025036 in lung adenocarcinoma and its potential roles in regulating cell proliferation and apoptosis.

As the most common histological subtype of lung cancer, lung adenocarcinoma remains a tremendous risk to public health, which requires ceaseless efforts to elucidate the potential diagnostic and therapeutic strategies. Circular RNAs (circRNAs) have been identified with emerging roles in tumorigenesis and development. Our preliminary work noticed that hsa_circ_0025036 was significantly upregulated in lung adenocarcinoma tissues. However, its specific roles in lung adenocarcinoma remain unclear. The results in this study revealed that hsa_circ_0025036 existed as a circular form and was aberrantly upregulated in lung adenocarcinoma tissues via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Its expression level exhibited a close link with aggressive clinicopathological parameters including cancer differentiation, TNM stage and lymph node metastasis. hsa_circ_0025036 knockdown significantly suppressed cell proliferation and promoted cell apoptosis in A549 and Calu-3 cells. Moreover, hsa_circ_0025036/miR-198/SHMT1&TGF-α axis was identified via bioinformatics analysis and Dual-Luciferase Reporter assays. miR-198 inhibitors reversed the function of hsa_circ_0025036 knockdown. hsa_circ_0025036 knockdown exerted similar effects with miR-198 upregulation on cell proliferation and apoptosis. In conclusion, we demonstrate that hsa_circ_0025036 regulates cell proliferation and apoptosis in lung adenocarcinoma cells probably via hsa_circ_0025036/miR-198/SHMT1&TGF-α axis. hsa_circ_0025036 may serve as a potential prognostic biomarker and a therapeutic target for lung adenocarcinoma.

Cervical Cancer HeLa Cell Autocrine Apoptosis Induced by Coimmobilized IFN-γ plus TNF-α Biomaterials.

Using external methods to induce the death of cancer cells is recognized as one of the main strategies for cancer treatment. Research indicated that TNF-α is frequently used in tumor biotherapy while IFN-γ can directly inhibit tumor cell proliferation. In our study, TNF-α and IFN-γ were coimmobilized on polystyrene material (PSt) or Fe3O4-oleic acid nanoparticles (NPs). Then the structural change of these two proteins can be observed. Meanwhile, the expressions of both TNF-α and IFN-α increased significantly, as determined by gene microarray analysis; however, in the presence of TNF-α plus IFN-α inhibitors, TNF-α and IFN-α did not increase in HeLa cells induced by coimmobilized IFN-γ plus TNF-α. Our results indicate that such change can stimilate HeLa cells to secrete more TNF-α and IFN-α, by which the apoptosis of HeLa cells could be further induced. This study is the first report of autocrine-induced apoptosis of HeLa cells. In addition, we performed ELISA, RT-PCR, flow cytometry, and Western blot analyses, as well as a series of analytical tests at the animal level. our data also indicate that the PSt-coimmobilized IFN-γ plus TNF-α has apparent effects for cancer treatment in vivo, which is of great significance for translation into clinical medicine.

Long-term G1 cell cycle arrest in cervical cancer cells induced by co-immobilized TNF-α plus IFN-γ polymeric drugs.

A realistic control of cell cycle arrest is an attractive goal for the development of new effective anti-cancer drugs. Any clinical application of an effective anti-cancer drug necessarily relies on the understanding of cellular interaction mechanisms. In the present study, we prepared a co-immobilized TNF-α plus IFN-γ biomaterial, which showed a significant inhibition effect on cervical cancer cell growth, as demonstrated by a series of structural and cellular characterizations. We found that co-immobilized TNF-α plus IFN-α induced a long-term G1 phase cell cycle arrest in HeLa, SiHa, and CaSki cells, respectively. More surprisingly, the expression level of the p27 protein decreased, even when p27 mRNA was highly expressed. In addition, gene-chip results and microarray analysis showed that p57 may be downstream from p27, which acts as a direct regulator of the long-term G1 cell cycle arrest in these cells, leaving no escape for cervical cancer cells. Finally, we also investigated the anti-tumor mechanism of co-immobilized TNF-α plus IFN-γin vivo, using a nude mice animal model. To sum up, our findings suggested that the co-immobilized TNF-α plus IFN-γ can induce a long-term cell cycle arrest in cancer, thus serving as a very efficient tool for treating cervical cancer.

Trivaric acid, a new inhibitor of PTP1b with potent beneficial effect on diabetes.

AIM: To screen a potential PTP1b inhibitor from the microbial origin-based compound library and to investigate the potential anti-diabetic effects of the inhibitor in vivo and determine its primary anti-diabetic mechanism in vitro and in silico. METHODS: PTP1b inhibitory activity was measured using recombination protein as the enzyme and p-NPP as the substrate. The binding of the inhibitor to PTP1b was analysed by docking in silico and confirmed by ITC experiments. The intracellular signalling pathway was detected by Western blot analysis in HepG2 cells. The anti-diabetic effects were evaluated using a diabetic mice model in vivo. RESULTS: Among 545 microbial origin-based pure compounds tested, trivaric acid, a tridepside, was selected as a PTP1B inhibitor exhibiting strong inhibitory activity with an IC50 of 173nM. Docking and ITC studies showed that trivaric acid was able to spontaneously bind to PTP1b and may inhibit PTP1b by blocking the catalytic domain of the phosphatase. Trivaric acid also enhanced the ability of insulin to stimulate the IR/IRS/Akt/GLUT2 pathway and increase the glucose consumption in HepG2 cells. In diabetic mice, trivaric acid that had been encapsulated into Eudrgit L100-5.5 showed significant anti-diabetic effects, improving insulin resistance, leptin resistance and lipid profile and weight control at doses of 5mg/kg and 50mg/kg. SIGNIFICANCE: Trivaric acid is a potential lead compound in the search for anti-diabetic agents targeting PTP1b.

Wortmannilactones I-L, new NADH-fumarate reductase inhibitors, induced by adding suberoylanilide hydroxamic acid to the culture medium of Talaromyces wortmannii.

With the aim of finding more potential inhibitors against NADH-fumarate reductase (specific target for treating helminthiasis and cancer) from natural resources, Talaromyces wortmannii was treated with the epigenome regulatory agent suberoylanilide hydroxamic acid, which resulted in the isolation of four new wortmannilactones derivatives (wortmannilactones I-L, 1-4). The structures of these new compounds were elucidated based on IR, HRESIMS and NMR spectroscopic data analyses. These four new compounds showed potent inhibitory activity against NADH-fumarate reductase with the IC50 values ranging from 0.84 to 1.35µM.