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Maytansinoids, the chemical derivatives of Maytansine, are commonly used as potent cytotoxic payloads in antibody-drug conjugates (ADC). Structure-activity-relationship studies had identified the C3 ester side chain as a critical element for antitumor activity of maytansinoids. The maytansinoids bearing the methyl group at C3 position with D configuration were about 100 to 400-fold less cytotoxic than their corresponding L-epimers toward various cell lines. The detailed mechanism of how chirality affects the anticancer activity remains elusive. In this study, we determined the high-resolution crystal structure of tubulin in complex with maytansinol, L-DM1-SMe and D-DM1-SMe. And we found the carbonyl oxygen atom of the ester moiety and the tail thiomethyl group at C3 side chain of L-DM1-SMe form strong intramolecular interaction with the hydroxyl at position 9 and the benzene ring, respectively, fixing the bioactive conformation and enhancing the binding affinity. Additionally, ligand-based and structure-based virtually screening methods were used to screen the commercially macrocyclic compounds library, and 15 macrocyclic structures were picketed out as putatively new maytansine-site inhibitors. Our study provides a possible strategy for the rational discovery of next-generation maytansine site inhibitors.

The DNA repair enzyme 8-oxoguanine DNA glycosylase 1 (OGG1), which excises 8-oxo-7,8-dihydroguanine lesions induced in DNA by reactive oxygen species, has been linked to the pathogenesis of lung diseases associated with bacterial infections. A recently developed small molecule, SU0268, has demonstrated selective inhibition of OGG1 activity; however, its role in attenuating inflammatory responses has not been tested. In this study, we report that SU0268 has a favorable effect on bacterial infection both in mouse alveolar macrophages (MH-S cells) and in C57BL/6 wild-type mice by suppressing inflammatory responses, particularly promoting type I IFN responses. SU0268 inhibited proinflammatory responses during Pseudomonas aeruginosa (PA14) infection, which is mediated by the KRAS–ERK1–NF-κB signaling pathway. Furthermore, SU0268 induces the release of type I IFN by the mitochondrial DNA–cGAS–STING–IRF3–IFN-β axis, which decreases bacterial loads and halts disease progression. Collectively, our results demonstrate that the small-molecule inhibitor of OGG1 (SU0268) can attenuate excessive inflammation and improve mouse survival rates during PA14 infection. This strong anti-inflammatory feature may render the inhibitor as an alternative treatment for controlling severe inflammatory responses to bacterial infection.

Angiokinases, such as vascular endothelial-, fibroblast- and platelet-derived growth factor receptors (VEGFRs, FGFRs and PDGFRs) play crucial roles in tumor angiogenesis. Anti-angiogenesis therapy using multi-angiokinase inhibitor has achieved great success in recent years. In this study, we presented the design, synthesis, target identification, molecular mechanism, pharmacodynamics (PD) and pharmacokinetics (PK) research of a novel triple-angiokinase inhibitor WXFL-152. WXFL-152, identified from a series of 4-oxyquinoline derivatives based on a structure–activity relationship study, inhibited the proliferation of vascular endothelial cells (ECs) and pericytes by blocking the angiokinase signals VEGF/VEGFR2, FGF/FGFRs and PDGF/PDGFRβ simultaneously in vitro. Significant anticancer effects of WXFL-152 were confirmed in multiple preclinical tumor xenograft models, including a patient-derived tumor xenograft (PDX) model. Pharmacokinetic studies of WXFL-152 demonstrated high favourable bioavailability with single-dose and continuous multi-dose by oral administration in rats and beagles. In conclusion, WXFL-152, which is currently in phase Ib clinical trials, is a novel and effective triple-angiokinase inhibitor with clear PD and PK in tumor therapy., Graphical abstract WXFL-152 is a novel and effective triple-angiokinase inhibitor with clear pharmacodynamics and pharmacokinetics in tumour therapy. Recently, WXFL-152 as a novel clinical candidate is being tested in phase Ib clinical trials. Further clinical trials will focus on the treatment of solid tumors and pulmonary fibrosis.Image 1

BACKGROUND Anastomotic leakage (AL) is one of the most dreadful complications after rectal cancer surgery. Indocyanine green fluorescence angiography (ICG FA) is now being used to evaluate blood supply at the anastomotic site. The aim of this study is to conduct a meta-analysis of the available literature to evaluate whether ICG FA could prevent AL after low anterior resection (LAR) for rectal cancer. METHODS Databases including PubMed, Web of Science, Google Scholar databases, Cochrane Library and China National Knowledge Infrastructure were searched to find out potential comparative studies comparing AL rates after LAR between intraoperative use and non-use of ICG FA. RESULTS A total of 1499 patients undergoing LAR in six studies were included. Intraoperative use of ICG FA was associated with lower AL rate (odds ratio (OR) 0.30; 95% confidence interval (CI) 0.19-0.49; P

Immune checkpoint inhibitors have achieved unprecedented success in cancer immunotherapy. However, the overall response rate to immune checkpoint inhibitor therapy for many cancers is only between 20 and 40%, and even less for colorectal cancer (CRC) patients. Thus, there is an urgent need to develop an efficient immunotherapeutic strategy for CRC. Here, we developed a novel CRC combination therapy consisting of a multiple receptor tyrosine kinase inhibitor (Foretinib) and anti-PD-1 antibody. The combination therapy significantly inhibited tumor growth in mice, led to improved tumor regression without relapse (83% for CT26 tumors and 50% for MC38 tumors) and prolonged overall survival. Mechanistically, Foretinib caused increased levels of PD-L1 via activating the JAK2-STAT1 pathway, which could improve the effectiveness of the immune checkpoint inhibitor. Moreover, the combination therapy remodeled the tumor microenvironment and enhanced anti-tumor immunity by further increasing the infiltration and improving the function of T cells, decreasing the percentage of tumor-associated macrophages (TAMs) and inhibiting their polarization toward the M2 phenotype. Furthermore, the combination therapy inhibited the metastasis of CT26-Luc tumors to the lung in BALB/c mouse by reducing proportions of regulatory T-cells, TAMs and M2 phenotype TAMs in their lungs. This study suggests that a novel combination therapy utilizing both Foretinib and anti-PD-1 antibody could be an effective combination strategy for CRC immunotherapy.

Background: Drugs that interfere with microtubule dynamics are used widely in cancer chemotherapy. Microtubules are composed of αβ-tubulin heterodimers, and the colchicine binding site of tubulin is an important pocket for designing tubulin polymerization inhibitors. We have previously designed and synthesized a series of colchicine binding site inhibitors (CBSIs). However, these compounds showed no anticancer activity in vivo. Then, we have used a deconstruction approach to obtain a new derivative MT189, which showed in vivo anticancer activity. Methods: We crystallized a protein complex including two tubulins, one stathmin-like domain of RB3 and one tubulin tyrosine ligase, and soaked MT189 into the crystals. We collected the diffraction data and determined the tubulin-MT189 structure to 2.8 Å. Results: Here, we report the crystal structure of tubulin complexed with MT189, elucidate how the small-molecular agent binds to tubulin and inhibits microtubule assembly, and explain previous results of the structure-activity-relationship studies. Conclusion: The tubulin-MT189 complex structure reveals the interactions between this agent and tubulin and provides insights into the design of new derivatives targeting the colchicine binding site.

5T4, a membrane protein, is overexpressed in many tumor tissues but rarely expressed in normal tissues. Here, CHO-5T4+ cells were generated and served as the antigen to immunize mice. Hybridoma techniques were employed to produce monoclonal antibodies (mAbs). The recombinant protein of human IgG Fc-fused extracellular domain of 5T4 (5T4 ECD-Fc) was obtained from transient expression in HEK293F cells. The fusion protein 5T4 ECD-Fc and CHO-5T4+ cells were respectively utilized to screen anti-5T4 antibodies that could bind to the native antigen. In preliminary screening, three hundred and fifty mAbs were obtained. Via surface plasmon resonance and flow cytometry screening, seven anti-5T4 mAbs stood out. Among them, H6 showed a high affinity (KD = 1.6 × 10−11 M) and internalization percentage (36% for 1 h and 80% for 4 h). The molecular weight and isoelectric point of H6 were determined by LC-MS and iCIEF. Moreover, the specific reactivity of H6 was demonstrated by western blotting, flow cytometry, and immunohistochemistry, respectively. In conclusion, we produced human recombinant protein of 5T4 extracellular domain and developed high-affinity internalizing monoclonal antibodies which may be applied in the 5T4-targeting ADC therapy and basic research.

MBRI-001, a deuterium-substituted plinabulin derivative, has been reported to have better pharmacokinetic and similar antitumor effects in comparison with plinabulin. In this approach, we further carried out its polymorphs, co-crystal structure of MBRI-001-tubulin and tubulin inhibition study. Among the different polymorphs, Form F (MBRI-001/H2O) was prepared and evaluated, which had better physical stability and suitable process for scale-up production. Co-crystal structure of MBRI-001-tubulin (PDB:5XI5) was prepared and analyzed. The result of tubulin polymerization assay demonstrated that MBRI-001 could inhibit tubulin polymerization which was similar as plinabulin. Subsequently, the anti-proliferative activities of plinabulin and MBRI-001 were evaluated against two different human lung cancer cell lines. In vivo study, MBRI-001 revealed similar antitumor inhibition in comparison with plinabulin in A549 xenograft tumor model. Therefore, we suggested that MBRI-001 could be developed as a promising anti-cancer agent in near future.

Microtubules (MTs) is one of the most important proteins in eukaryotic cells and plays a key role in the maintenance of cell morphology and cell division. The discovery and development of small molecule drugs targeting MTs has always been an important direction of anti-cancer research. Nowadays 4-Aryl-4H-chromenes have emerged as potent microtubule-targeting agents (MTAs) for various cancers. Crolibulin, a derivative of 4-Aryl-4H-chromenes, which has been progressed to Phase I/II clinical testing's for anaplastic thyroid cancer with the National Cancer Institute. However, the design and development of 4-Aryl-4H-chromenes family drugs have been hindered for a long time by the lack of structural information of the tubulin-agent complex. Here we report a 2.5 A crystal structure of tubulin complexed with crolibulin. This complex structure reveals the interactions between crolibulin and tubulin, helps explain the results of the structure-activity-relationship (SAR) studies and provides a solid structural basis for the design and development of new 4-Aryl-4H-chromenes derivatives as MTAs.

AlgW, a membrane-bound periplasmic serine protease belonging to the HtrA protein family, is a key regulator of the regulated intramembrane proteolysis (RIP) pathway and is responsible for transmitting the envelope stress signals in Pseudomonas aeruginosa The AlgW PDZ domain senses and binds the C-terminal of mis-localized outer membrane proteins (OMPs) or periplasmic protein MucE, leading to catalytic activation of the protease domain. While AlgW is functionally well studied, its exact activation mechanism remains to be elucidated. Here, we show that AlgW is a novel HtrA protease that can be biochemically activated by both peptide and lipid signals. Compared with the corresponding homologue DegS in Escherichia coli, AlgW exhibits a distinct substrate specificity and regulation mechanism. Structural, biochemical, and mutagenic analyses revealed that, by specifically binding to the C-terminal decapeptide of MucE, AlgW could adopt more relaxed conformation and obtain higher activity than with tripeptide activation. We also investigated the regulatory mechanism of the LA loop in AlgW and proved that the unique structural feature of this region was responsible for the distinct enzymatic property of AlgW. These results demonstrate the unique and diverse activation mechanism of AlgW, which P. aeruginosa may utilize to enhance its adaptability to environmental stress.IMPORTANCE HtrA-family proteases are commonly employed to sense the protein folding stress and activate the regulated intramembrane proteolysis (RIP) cascade in Gram-negative bacteria. Here, we reveal the unique dual-signal activation and dynamic regulation properties of AlgW, an HtrA-type protease triggering the AlgU stress-response pathway, which controls alginate production and mucoid conversion in Pseudomonas aeruginosa The structural and functional data offer insights into the molecular basis underlying the transition of different activation states of AlgW in response to different effectors. Probing these unique features provides an opportunity to correlate the diverse regulation mechanism of AlgW with the high adaptability of P. aeruginosa to environmental changes during infection.

According to numerous epidemiological studies, aspirin is a non-steroidal anti-inflammatory drug (NSAID) that reduces the occurrence and mortality of colorectal cancer (CRC). However, the underlying mechanisms are not well identified. In an effort to fill these gaps, we administered aspirin on mice one day before induction in an azoxymethane (AOM)/dextran sulfate sodium (DSS) induced CRC model. In this study, we assessed the effects of aspirin on tumorigenesis and tumor cell proliferation. Multi-layer analyses were carried out to identify changes in cytokines, metabolites, level of gene expressions, and proteins associated with tumorigenesis and aspirin treatment. The results showed that aspirin-treated mice developed fewer colon tumors in response to AOM/DSS, and aspirin can actively block cyclooxygenase (COX) metabolism and reduce levels of pro-inflammatory cytokines. In addition, the transcriptomic and proteomic analyses both indicated that aspirin has an inhibitory effect on the Wnt pathway. The in vitro results further indicated that aspirin inhibits WNT6 production, possibly by suppressing its transcription factor NR4A2, which in turn is regulated by prostaglandin E2, thereby ultimately inhibiting the Wnt pathway. These findings improve our understanding of the mechanisms behind aspirin's chemoprevention effect on CRC.

MucA and MucB are critical negative modulators of sigma factor AlgU and regulate the mucoid conversion of Pseudomonas aeruginosa. Previous studies have revealed that lipid signals antagonize MucA-MucB binding. Here we report the crystal structure of MucB in complex with the periplasmic domain of MucA and polyethylene glycol (PEG), which unveiled an intermediate state preceding the MucA-MucB dissociation. Based on the biochemical experiments, the aliphatic side chain with a polar group was found to be of primary importance for inducing MucA cleavage. These results provide evidence that the hydrophobic cavity of MucB is a primary site for sensing lipid molecules and illustrates the detailed control of conformational switching within MucA-MucB in response to lipophilic effectors., Tao Li et al. report crystal structure of MucA-MucB complex and identify a cavity region of MucB that binds PEG molecule. They further show that this hydrophobic cavity of MucB is a primary site for sensing lipid molecules and that lipid A stimulates MucB to release MucA for AlgW cleavage, helping to understand the regulation mechanism of alginate biosynthesis.

Peroxisome proliferator-activated receptor α/δ (PPAR α/δ), regulating glucolipid metabolism and immune inflammation, has been identified as an effective therapeutic target in non-alcoholic steatohepatitis (NASH). Dual PPAR α/δ agonist, such as GFT505 (also known as elafibranor), demonstrated potential therapeutic effect for NASH in clinical trials. To profile the regulatory network of PPAR α/δ agonist in NASH, the choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) induced NASH model was used to test the pharmacodynamics and transcriptome regulation of GFT505 in this study. The results showed that GFT505 ameliorated hepatic steatosis, inflammation and fibrosis in CDAHFD mice model. RNA-sequencing yielded 3995 up-regulated and 3576 down-regulated genes with GFT505 treatment. And the most significant differentialy expressed genes involved in glucolipid metabolism (Pparα, Acox1, Cpt1b, Fabp4, Ehhadh, Fabp3), inflammation (Ccl6, Ccl9, Cxcl14) and fibrosis (Timp1, Lamc3, Timp2, Col3a1, Col1a2, Col1a1, Hapln4, Timp3, Pik3r5, Pdgfα, Pdgfβ, Tgfβ1, Tgfβ2) were confirmed by RT-qPCR. The down-regulated genes were enriched in cytokine-cytokine receptor interaction pathway and ECM-receptor interaction pathway, while the up-regulated genes were enriched in PPAR signaling pathway and fatty acid degradation pathway. This study provides clues and basis for further understanding on the mechanism of PPAR α/δ agonist on NASH.

Cryptophycin-52 (CR52), a tubulin inhibitor, exhibits promising antitumor activity in vitro (picomolar level) and in mouse xenograft models. However, the narrow therapeutic window in clinical trials limits its further development. Antibody-drug conjugate (ADC), formed by coupling cytotoxic compound (payload) to an antibody via a linker, can deliver drug to tumor locations in a targeted manner by antibody, enhancing the therapeutic effects and reducing toxic and side effects. In this study, we aim to explore the possibility of CR52-based ADC for tumor targeted therapy. Due to the lack of a coupling site in CR52, its prodrug cryptophycin-55 (CR55) containing a free hydroxyl was synthesized and conjugated to the model antibody trastuzumab (anti-HER2 antibody drug approved by FDA for breast cancer therapy) via the linkers based on Mc-NHS and Mc-Val-Cit-PAB-PNP. The average drug-to-antibody ratios (DARs) of trastuzumab-CR55 conjugates (named T-L1-CR55, T-L2-CR55, and T-L3-CR55) were 3.50, 3.29, and 3.35, respectively. These conjugates exhibited potent cytotoxicity in HER2-positive tumor cell lines with IC50 values at low nanomolar levels (0.58–1.19 nM). Further, they displayed significant antitumor activities at the doses of 10 mg/kg in established ovarian cancer (SKOV3) and gastric cancer (NCI–N87) xenograft models without overt toxicities. Finally, the drug releases were analyzed and the results indicated that T-L3-CR55 was able to effectively release CR55 and further epoxidized to CR52, which may be responsible for its best performance in antitumor activities. In conclusion, our results demonstrated that these conjugates have the potential for tumor targeted therapy, which provides insights to further research the CR55/CR52-based ADC for tumor therapy.

Colchicine binding site inhibitors (CBSIs) hold great potential in developing new generations of antimitotic drugs. Unlike existing tubulin inhibitors such as paclitaxel, they are generally much less susceptible to resistance caused by the overexpression of drug efflux pumps. The 3,4,5-trimethoxyphenyl (TMP) moiety is a critical component present in many CBSIs, playing an important role in maintaining suitable molecular conformations of CBSIs and contributing to their high binding affinities to tubulin. Previously reported modifications to the TMP moiety in a variety of scaffolds of CBSIs have usually resulted in reduced antiproliferative potency. We previously reported a potent CBSI, VERU-111, that also contains the TMP moiety. Herein, we report the discovery of a VERU-111 analogue 13f that is significantly more potent than VERU-111. The X-ray crystal structure of 13f in complex with tubulin confirms its direct binding to the colchicine site. In addition, 13f exhibited a strong inhibitory effect on tumor growth in vivo.

A newly proposed method for detecting content of adriamycin in pectin–adriamycin conjugate has been developed and evaluated. The content of adriamycin was detected by selective degradation of adram...

Neovascular age-related macular degeneration (AMD) is a leading cause of vision loss worldwide. Although intravitreal injection of anti-VEGF antibodies and VEGF Trap have significant clinical benefits, the complications of intravitreal injection, drug resistance and patient compliance still need to be concerned. In this study, the effects of an orally administered multi-targeted tyrosine kinase inhibitor (Lenvatinib, E7080) were evaluated in vitro and in vivo on neovascular AMD mouse model. The results showed that E7080 effectively inhibited the proliferation, migration and tubule formation of human choroidal microvascular endothelial cells (HCMECs), and suppressed the angiogenesis of zebrafish subintestinal vessels without causing malformation. The anti-angiogenic effect of E7080 on the laser-induced choroidal neovascularization (CNV) mouse model by oral administration of 10 mg/kg/day was observed. The fluorescein angiography showed CNV leakage area in treatment group vs control group was 3.407 ± 0.2939 vs 5.202 ± 0.9001 (P = .0133) at day 7th post laser-induced CNV, 1.138 ± 0.4334 vs 3.122 ± 0.3466 (P = .0064) at day 14th, 1.401 ± 0.6577 vs 2.781 ± 0.9815 (P = .00262) at day 21th respectively. Moreover, pharmacokinetics analysis in rat retina showed that E7080 rapidly penetrated the blood-retina barrier to retina through oral administration. The T1/2 in retina was 3.81 ± 0.77 h, the Tmax was 4.60 ± 0.73 h, the AUC0-∞ was 110448.51 ± 18532.51 h*ng/g after a single dose administration analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). In conclusion, our study suggested that orally administered E7080 can be a novel therapeutic strategy for neovascular AMD.

We report the design, synthesis, and biological evaluation of heterocyclic-fused pyrimidines as tubulin polymerization inhibitors targeting the colchicine binding site with significantly improved therapeutic index. Additionally, for the first time, we report high-resolution X-ray crystal structures for the best compounds in this scaffold, 4a, 4b, 6a, and 8b. These structures not only confirm their direct binding to the colchicine site in tubulin and reveal their detailed molecular interactions but also contrast the previously published proposed binding mode. Compounds 4a and 6a significantly inhibited tumor growth in an A375 melanoma xenograft model and were accompanied by elevated levels of apoptosis and disruption of tumor vasculature. Finally, we demonstrated that compound 4a significantly overcame clinically relevant multidrug resistance in a paclitaxel resistant PC-3/TxR prostate cancer xenograft model. Collectively, these studies provide preclinical and structural proof of concept to support the continued development of this scaffold as a new generation of tubulin inhibitors.

In molecular biology, protein synthesis is an essential biological process of generating specific proteins in living systems. Many mathematical models are designed to characterize the process of the flow of genetic information from deoxyribonucleic acid (DNA) to protein; however, most of them cannot provide detailed and observed steps to describe and analyze this fundamental biological process. Colored Petri Net (CPN), as a mathematical method widely applied in the process analysis of discrete event dynamic systems, has increasingly become an innovative and efficient theoretical approach for exploring the biological processes. Aiming at describing the entire process of protein synthesis, a CPN-based model has been designed that successfully and intuitively represents the flow of genetic information involving transcription and translation. DNA mutations are permanent alterations in the nucleotide sequence of the DNA strand, while different types of mutations have various effects on the synthesized proteins. Based on the proposed protein synthesis model, we put forward a new CPN model to identify the type of mutation, which is beneficial for analyzing whether the mutation has impacts on the structure or function of the produced protein. The mutation position and bases mutated rate are obtained by contrasting the nucleobases on DNA sequences, while the mutation type is determined via the alignment of the amino acids in the polypeptide chain. The model’s effectiveness and accuracy are illustrated by biological mutation examples, indicating this method offers great superiority in modeling and analyzing the complex biological processes.

Breast cancer is the most common female cancer with considerable metastatic potential, explaining the need for new candidates that inhibit tumor metastasis. In our study, betulinic acid (BA), a kind of pentacyclic triterpenoid compound derived from birch trees, was evaluated for its anti-metastasis activity in vitro and in vivo. BA decreased the viability of three breast cancer cell lines and markedly impaired cell migration and invasion. In addition, BA could inhibit the activation of stat3 and FAK which resulted in a reduction of matrix metalloproteinases (MMPs), and increase of the MMPs inhibitor (TIMP-2) expression. Moreover, in our animal experiment, intraperitoneal administration of 10 mg/kg/day BA suppressed 4T1 tumor growth and blocked formation of pulmonary metastases without obvious side effects. Furthermore, histological and immunohistochemical analyses showed a decrease in MMP-9 positive cells, MMP-2 positive cells and Ki-67 positive cells and an increase in cleaved caspase-3 positive cells upon BA administration. Notably, BA reduced the number of myeloid-derived suppressor cells (MDSCs) in the lungs and tumors. Interestingly, in our caudal vein model, BA also obviously suppressed 4T1 tumor pulmonary metastases. These findings suggested that BA might be a potential agent for inhibiting the growth and metastasis of breast cancer.

Small cell lung cancer (SCLC) is of a highly invasive and metastatic lung cancer subtype and there had not been effective targeted therapies. CD56, a cell surface marker highly expressed on most SCLC, is a promising therapeutic target for treatment of this aggressive cancer. In this study, we generated a novel anti-CD56 antibody named promiximab, characterized by high affinity, internalization and tumor specificity. Then, the promiximab was conjugated with a potent DNA alkylating agent duocarmycin via reduced interchain disulfides to yield the promiximab-Duocarmycin (promiximab-DUBA) conjugates. Mass spectrometry analysis showed promiximab-DUBA had an average DAR (Drug-to-Antibody Ratio) of about 2.04. In vitro, promiximab-DUBA exerted strong inhibitory effects on SCLC cell lines NCI-H526, NCI-H524 and NCI-H69, with IC50 values of 0.07 nmol/L, 0.18 nmol/L and 0.29 nmol/L, respectively. In vivo antitumor activity, promiximab-DUBA at the dose of 5 mg/kg and 10 mg/kg every three days with a total of three times were sufficient to induce sustained regression of NCI-H526 tumors over control treatment with promiximab. Mostly, no recurrence was observed until 65 days post treatment with promiximab-DUBA. In the NCI-H69 subcutaneous xenograft model, significant inhibition of tumor growth was also observed following administration of promiximab-DUBA at the dose of 5 mg/kg or 10 mg/kg. Moreover, body weight and histopathology of major organs (liver, spleen, heart, lung and kidney) showed no significant changes after treatment of promiximab-DUBA. In conclusion, promiximab-DUBA is highly efficacious in small cell lung cancer xenograft models, and provides a new immunotherapy approach for SCLC.

Zoledronate is a bisphosphonate that is widely used in the treatment of metabolic bone diseases. However, zoledronate induces significant nephrotoxicity associated with acute tubular necrosis and renal fibrosis when administered intravenously. There is speculation that zoledronate-induced nephrotoxicity may result from its pharmacological activity as an inhibitor of the mevalonate pathway but the molecular mechanisms are not fully understood. In this report, human proximal tubular HK-2 cells and mouse models were combined to dissect the molecular pathways underlying nephropathy caused by zoledronate treatments. Metabolomic and proteomic assays revealed that multiple cellular processes were significantly disrupted, including the TGFβ pathway, fatty acid metabolism and small GTPase signaling in zoledronate-treated HK-2 cells (50 μM) as compared with those in controls. Zoledronate treatments in cells (50 μM) and mice (3 mg/kg) increased TGFβ/Smad3 pathway activation to induce fibrosis and kidney injury, and specifically elevated lipid accumulation and expression of fibrotic proteins. Conversely, fatty acid transport protein Slc27a2 deficiency or co-administration of PPARA agonist fenofibrate (20 mg/kg) prevented zoledronate-induced lipid accumulation and kidney fibrosis in mice, indicating that over-expression of fatty acid transporter SLC27A2 and defective fatty acid β-oxidation following zoledronate treatments were significant factors contributing to its nephrotoxicity. These pharmacological and genetic studies provide an important mechanistic insight into zoledronate-associated kidney toxicity that will aid in development of therapeutic prevention and treatment options for this nephropathy. Electronic supplementary material The online version of this article (doi:10.1007/s00204-017-2048-0) contains supplementary material, which is available to authorized users.

In this research, the cationic photopolymerization of 1,4-butanediol diglycidyl ether was found to have an infinitely long induction period due to the sustained stability of the secondary oxonium ions species at low temperature. Based on this, the system could be separated into two steps: photolysis of the photoinitiator without polymerization under irradiation and polymerization in the dark. Under irradiation, only the secondary oxonium ion species was generated at low temperature, whereas the polymerization could proceed and auto-accelerate at room temperature without irradiation. The two steps could be monitored by a significant change of the temperature. The temperature controlled cationic mechanism resolved the issue of light penetration in colored thick composites. Through temperature control, the infinitely thick and dark material could be prepared by cationic photopolymerization.

The co-crystal structure of Compound 6b with tubulin was prepared and solved for indicating the binding mode and for further optimization. Based on the co-crystal structures of tubulin with plinabulin and Compound 6b, a total of 27 novel A/B/C-rings plinabulin derivatives were designed and synthesized. Their biological activities were evaluated against human lung cancer NCI-H460 cell line. The optimum phenoxy-diketopiperazine-type Compound 6o exhibited high potent cytotoxicity (IC50 = 4.0 nM) through SAR study of three series of derivatives, which was more potent than plinabulin (IC50 = 26.2 nM) and similar to Compound 6b (IC50 = 3.8 nM) against human lung cancer NCI-H460 cell line. Subsequently, the Compound 6o was evaluated against other four human cancer cell lines. Both tubulin polymerization assay and immunofluorescence assay showed that Compound 6o could inhibit microtubule polymerization efficiently. Furthermore, theoretical calculation of the physical properties and molecular docking were elucidated for these plinabulin derivatives. The binding mode of Compound 6o was similar to Compound 6b based on the result of molecular docking. The theoretical calculated LogPo/w and PCaco of Compound 6o were better than Compound 6b, which could enhance its cytostatic activity. Therefore, Compound 6o might be developed as a novel potent anti-microtubule agent.

Interfering with microtubule dynamics is a well-established strategy in cancer treatment; however, many microtubule-targeting agents are associated with drug resistance and adverse effects. Substantial evidence points to ATP-binding cassette (ABC) transporters as critical players in the development of resistance. Herein, we demonstrate the efficacy of DJ95 (2-(1H-indol-6-yl)-4-(3,4,5-trimethoxyphenyl)-1H-imidazo[4,5-c]pyridine), a novel tubulin inhibitor, in a variety of cancer cell lines, including malignant melanomas, drug-selected resistant cell lines, specific ABC transporter-overexpressing cell lines, and the National Cancer Institute 60 cell line panel. DJ95 treatment inhibited cancer cell migration, caused morphologic changes to the microtubule network foundation, and severely disrupted mitotic spindle formation of mitotic cells. The high-resolution crystal structure of DJ95 in complex with tubulin protein and the detailed molecular interactions confirmed its direct binding to the colchicine site. In vitro pharmacological screening of DJ95 using SafetyScreen44 (Eurofins Cerep-Panlabs) revealed no significant off-target interactions, and pharmacokinetic analysis showed that DJ95 was maintained at therapeutically relevant plasma concentrations for up to 24 hours in mice. In an A375 xenograft model in nude mice, DJ95 inhibited tumor growth and disrupted tumor vasculature in xenograft tumors. These results demonstrate that DJ95 is potent against a variety of cell lines, demonstrated greater potency to ABC transporter-overexpressing cell lines than existing tubulin inhibitors, directly targets the colchicine binding domain, exhibits significant antitumor efficacy, and demonstrates vascular-disrupting properties. Collectively, these data suggest that DJ95 has great potential as a cancer therapeutic, particularly for multidrug resistance phenotypes, and warrants further development. SIGNIFICANCE STATEMENT: Paclitaxel is a widely used tubulin inhibitor for cancer therapy, but its clinical efficacy is often limited by the development of multidrug resistance. In this study, we reported the preclinical characterization of a new tubulin inhibitor DJ95, and demonstrated its abilities to overcome paclitaxel resistance, disrupt tumor vasculature, and exhibit significant antitumor efficacy.

Photopolymerization is extensively used in today's industrial field due to its advantages of rapid reaction, environmental friendly, energy saving and economical. Benzophenone is a most common photoinitiator (PI) using in photopolymerization because of its superior ability to initiate acrylate monomers. However, the intrinsic nature of initiator molecules is that they migrate out of polymer network, which limits its application, especially in the domain of food packaging materials. A polymerizable PI 4-methylbenzophenone acrylate (MBPAc) was synthesized by a facile procedure and characterized by 1H NMR, 13C NMR, and MS analyses. A systematic study of the photopolymerization kinetics of MBPAc was explored by the Real-Time Fourier Transform Infrared Spectrometer. The results show that the final conversion and photopolymerization rate of acrylate monomers are closely related to the factors of their chemical structure, viscosity, functionality and light intensity, which means MBPAc is an efficient PI. Ultraviolet-visible Spectrophotometer and vitro cytotoxicity measurement results indicate that the noncytotoxic MBPAc shows significantly lower migration than its analogue. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016

The cationic photopolymerization of 3-benzyloxymethyl-3-ethyl-oxetane (MOX104) initiated by triphenylsulfonium hexafluoroantimonate under UV light was conducted. The kinetics were investigated by real-time Fourier transform IR spectroscopy and the mechanical and thermal properties of poly(MOX104) were examined by dynamic mechanical analysis and TGA. To adjust the properties of the polymer, different initiator concentrations and comonomer composition were applied. The results showed that the conversion of MOX104 was improved significantly from 17% to almost 90% by adding a certain amount of 3,4-epoxycyclohexane carboxylate or diglycidyl ether of bisphenol A epoxy resin, while not much effect was observed by adding 1,4-butanediol diglycidyl ether. Moreover, the glass transition temperature, decomposition temperature and Young's modulus of poly(MOX104) were improved by adding different amounts of diglycidyl ether of bisphenol A epoxy resin. © 2016 Society of Chemical Industry

Fluorinated polysiloxane urethane acrylates were synthesized by 1H,1H,2H,2H-Perfluorooctanol (F13), polysiloxane (PSi), isophorone diisocyanate (IPDI) and 2-hydroxyethyl acrylate (HEA). The molecular structure was characterized by FTIR, GPC, and XPS. The yellowing resistance was measured by sphere Spectrophotometer and ultraviolet-visible spectrophotometer. The volume shrinkage was measured by laser displacement sensor (LDS). The glass-transition temperature (Tg) and storage modulus (E′) were measured by dynamic mechanical analysis (DMA). Real time infrared (RTIR) spectroscopy was used to investigate the reaction kinetics of photopolymerization of synthesized fluorinated polysiloxane urethane acrylate (PSi-IPDI-HEA-F13). It was proved that the introduced of 1H,1H,2H,2H-Perfluorooctanol into the system of polysiloxane urethane acrylates (PSi-IPDI-HEA) could increase the yellowing resistance and decrease the volume shrinkage. Thermal stability was reduced by a small amount.

Background Cachexia has a devastating impact on survival and quality of life for many cancer patients and contributes to nearly one-third of all cancer deaths; also, it is associated with poor responses to chemotherapy and survival. A better understanding of the underlying mechanisms of cancer-associated cachexia (CAC), coupled with effective therapeutic approaches, will improve management of progressive functional impairment in cancer patients. Salidroside, a phenylpropanoid glycoside in Rhodiola rosea L, has been reported to possess potential anti-fatigue, anti-ageing, and anti-Alzheimer's disease properties. It is widely consumed as a nutritional supplement, but its effects on CAC and the possible mechanism remain a mystery. Methods In the murine models of cachexia induced by CT-26 and Lewis lung carcinoma (LLC) tumour, respectively, main features of CAC were determined after treatment of salidroside or chemotherapy. In vitro experiments were performed using murine C2C12 myotubes, which were treated by tumour necrosis factor-α. Levels of several critical muscle-related signal proteins such as mammalian target of rapamycin (mTOR), p-mTOR, and myosin heavy chain (MyHC) were examined using western blot both in vitro and in vivo. Results In the present study, we showed the exciting effect of salidroside on the treatment of CAC. In CT-26 and LLC models, respectively, salidroside treatment could effectively preserve the tumour-free body weight, decrease loss of adipose and gastrocnemius muscles, alleviate tumour burden, and prolong their survival time. Additionally, in combined chemotherapy, salidroside could synergistically enhance the anti-tumour activity of cisplatin, especially decreased or eliminated chemotherapy-induced cachexia. Further analysis demonstrated that salidroside could significantly increase expression of mTOR, p-mTOR, and MyHC in gastrocnemius muscle. Also, results in vitro showed that salidroside could not only obviously increase mTOR, p-mTOR, and MyHC expression in C2C12 myotubes but also effectively rescue their down-regulation induced by tumour necrosis factor-α. Conclusions In the current study, the exciting effect of salidroside on CAC suggested that salidroside supplementation might be a promising approach for a multi-targeted therapy for the treatment of CAC.

Antibody-drug conjugates (ADCs) have achieved great success in cancer therapy in recent years. Some peptidyl microtubule inhibitors consisting of natural and unnatural amino acids, such as monomethyl auristatin E (MMAE) and F (MMAF), are extremely cytotoxic and have been used as a payload in ADCs. However, their precise molecular interaction with tubulin and microtubules remains unclear. We determined the crystal structures of tubulin in complex with three ultra-potent peptidyl microtubule inhibitors [MMAE, taltobulin (HTI- 286), and tubulysin M] at 2.5 Å. Our data showed that the three peptides bound to the vinca domain and shared a common and key pharmacophore containing two consecutive hydrophobic groups (Val, Ile-like side chain). These groups protruded in opposite directions into hydrophobic pockets on the tubulin β and α subunits. Nitrogen and oxygen atoms from the same backbone formed hydrogen bonds with Asn329 from the α subunit and Asp179 from the β subunit in a direction normal to the surface formed by the aforementioned hydrophobic groups. In addition, our crystal structure data indicated that tubulysin M bound to the β subunit alone, providing a structural explanation for its higher affinity. We also compared the conformations of two representative structurally different vinca domain compounds, ustiloxin D and vinblastine, with those of the aforementioned peptidyl ligands, and found that they shared a similar pharmacophore. Our findings lay a foundation for the rational design of novel vinca domain ligands and may facilitate the development of microtubule inhibitors with high specificity, affinity, and efficiency as payloads for ADCs in cancer therapy.

Background Non-alcoholic steatohepatitis (NASH) is a progressive liver disease characterized by hepatic steatosis, lobular inflammation and fibrosis. Acetyl-CoA carboxylase (ACC) isoform 1 and 2 involved in de novo lipogenesis (DNL) and fatty acid oxidation have been identified as a therapeutic target in NASH. GS-0976, the inhibitor of ACC1 and ACC2, has achieved favorable therapeutic effects in clinical trials with NASH. The purpose of this study was to explore the transcriptional alterations regulated by GS-0976 in NASH. Methods C57BL/6 mice were fed on a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) or normal diet for 12 weeks. Mice were treated with or without GS-0976 (3 mg/kg per day) in the last 8 weeks. Oil Red O, Haematoxylin-eosin (H & E), and Sirius Red were used to evaluate hepatic steatosis, inflammation and fibrosis. The comparative RNA-sequencing was conducted to analyse the hepatic gene expression profiles in mice. Reverse transcription–polymerase chain reaction analysis was performed to validate the differential expression of representative genes. Results GS-0976 attenuated the steatosis, inflammation, and fibrosis of NASH in CDAHFD mouse model. High-throughput sequencing and differential gene expression analysis showed that there were 516 up-regulated genes and 525 down-regulated genes after GS-0976 treatment. Genes involved in the metabolic process, extracellular matrix formation, immune response, and angiogenesis were significantly enriched. The “Metabolic pathways” and “ECM-receptor interaction” pathways were the most significantly enriched KEGG pathways in the up-regulated and down-regulated differentially expressed genes (DEGs), respectively. Conclusions Transcriptome analysis showed that GS-0976 could regulate the expression of genes related to metabolism, inflammation and fibrosis in NASH. The global transcriptomic changes in gene expression promote the further understanding for the inhibition mechanisms of GS-0976 in NASH.

Antibody-drug conjugates (ADCs) have been successfully applied clinically as target drugs for cancer. In this study, anti-neural cell adhesion molecule also called CD56 antibody-monomethyl auristatin E (MMAE) conjugate named Promiximab-MMAE was prepared by conjugation of microtubule inhibitor MMAE with Promiximab. The average drug-to-antibody ratio (DAR) of Promiximab-MMAE was 3.13 as analysed by liquid chromatography-mass spectrometry/ mass spectrometry (LC-MS/MS). The targeting capacity and affinity kinetics of Promiximab-MMAE were similar to that of Promiximab after being conjugated with MMAE as tested by flow cytometry and biolayer interferometry analysis. Promiximab-MMAE showed effective anti-proliferation on CD56-positive cell lines (NCI-H524, NCI-H526, and NCI-H69), with the half maximal inhibitory concentration (IC50) values of 19.24, 5.23, and 0.32 nmol/L in vitro, respectively. Promiximab-MMAE of 10 mg/kg every three days with a total of three times was administered in vivo. Results showed that the tumour regression was not recrudesced in NCI-H69 and NCI-H526 xenograft mice models till 52 and 56 days. Moreover, body weight and histopathology of the major organs (liver, spleen, heart, lung, and kidney) showed no significant changes after treatment with Promiximab-MMAE. In conclusion, Promiximab-MMAE is a potential candidate for the treatment of CD56 positive small cell lung cancer.

Nitric oxide (NO) is an important bioactive molecule that functions in regulating diverse abiotic stresses in plants, whereas its molecular mechanism remains obscure. In this study, treatment with 0.1 mM NO donor (sodium nitroprusside, SNP) significantly alleviated the inhibited growth induced by 15% polyethyleneglycol (PEG)-stimulated water deficiency (WD) for 3 days in maize seedlings, manifested by less decreased plant total fresh weight and dry weight. Comprehensive proteome analysis was further used to measure the expression profiles of leaf proteins of SNP-pretreated maize seedlings under WD conditions to explore the molecular mechanisms of NO-induced WD tolerance. Using 2-DE method, 135 protein spots showed significantly enhanced or reduced abundance, of which 102 spots were successfully identified MALDI-TOF/TOF MS. The identified protein species were associated with diverse functions, and most (52/83, 62.7%) of known protein species were related to photosynthetic processes. Compared to alone PEG treatment, the abundance of 25 identified protein species in SNP + PEG treatment were enhanced among the identified photosynthesis-related protein species. In addition, exogenous SNP application dramatically regulated chlorophyll α fluorescence kinetics e.g. the increase of maximum quantum yield of PSII (Fv/Fm), photosynthetic performance index (PI), and IP phase, whereas it remarkably reduced the polyphasic OJIP fluorescence transient, the accumulation of reactive oxygen species (H2O2 and O2•-) and malondialdehyde (MDA). These findings suggest that the NO-induced WD tolerance could be associated with improved photosynthetic capability in higher plants.

Tubulin inhibitors that target the colchicine binding site continue to emerge as promising anticancer agents. In this study, based on the anti-proliferative activities, a novel tubulin inhibitor 7a3 targeting the colchicine binding site was designed, synthesized, and optimized from a series of novel cis-restricted pyrazole analogues of combretastatin A-4. The structure-activity relationships (SARs) of these newly synthesized compounds are summarized indicating that the methyl substituent at the N1 position and deamination were significantly important for the anti-proliferative efficacy. The optimized compound 7a3 exhibited the ability to arrest the cell cycle in the G2/M phase, induce cell apoptosis, and inhibit cell migration in tumour cells. The results of the immunofluorescence analysis using confocal microscopy and the tubulin polymerization assay revealed that tubulin assembly was disrupted by 7a3 in vitro. Furthermore, the targeting identification of 7a3 was illuminated by solving the crystal structure of 7a3 in complex with tubulin at a resolution of 3.2 A (PDB code 5Z4U ), which confirmed the result of molecular docking and further demonstrated that 7a3 binds to the site of colchicine. Moreover, the pharmacokinetic analysis in mouse plasma showed that 7a3 rapidly reached a peak concentration at 0.25 h after intraperitoneal administration, and the T1/2, Cmax, and AUC0-inf were 1.67 ± 0.28 h, 882 ± 71 ng mL-1, and 1166 ± 129 h ng·mL-1, respectively, after a single-dose administration analysed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). In addition, the in vivo study indicated that 7a3 significantly inhibited the tumour growth of the SK-OV-3 xenograft in a nude mouse model. In conclusion, our study proved 7a3 to be a potential microtubule-targeting drug for cancer therapy. The SARs and mechanism of action studies of 7a3 based on the X-ray co-crystal structure provided insights into the next-generation tubulin inhibitors for cancer therapy.

Isoliquiritigenin (ISL) is an important flavonoid component of licorice and has been reported to possess anti-inflammatory and antioxidant properties, but its exact mechanism of action remains poorly understood. Previously, we demonstrated that ISL could suppress IL-6 expression in multiple myeloma. Here, we further characterized the anti-inflammatory effects of ISL in several psoriasis models, including the keratin 14/vascular endothelial growth factor (VEGF) transgenic mouse, the imiquimod (IMQ)-induced psoriasis-like mouse, and the human keratinocytes HaCaT and NHEK in vitro. We found that ISL ameliorated the inflammatory process in psoriasis models but not in their respective controls. Moreover, the anti-inflammatory effects of ISL were attributed to the suppression of nuclear factor-κB (NF-κB) activity, which consequently resulted in the reduction of pro-inflammation cytokines IL-6 and IL-8 expression. In conclusion, ISL exhibited anti-inflammatory effects in psoriasis models, by downregulating IL-6 and IL-8 via suppression of NF-κB activity, suggesting that ISL might serve as a potential candidate for treatment of psoriasis and other autoimmune inflammatory diseases.ISL could ameliorate the inflammatory process of psoriasis. ISL could suppress NF-κB and subsequent production of a series of pro-inflammatory cytokines. Dual-inhibitory activity against IL-6 and IL-8 of ISL is implemented via inhibiting NF-κB. ISL exerts no inhibitory effects on normal human keratinocytes or wild-type Balb/c mice, implying its low toxicity and safety.

A fluorinated photoinitiator, namely perfluorooctanoyl acid 2- [4-(2-hydroxy-2-methyl-propionyl)-phenoxy]-ethyl ester (F-2959) was synthesized and characterized. To increase the polymerization rate, fluorine groups were connected to the benzene ring rather than the hydroxyalkyl. Real time FTIR analysis was taken to study the ability of F-2959 to overcome oxygen inhibition. UV–vis absorption spectroscopy, XPS, SEM, and multi-channel thermo detector were used to prove the migration of F-2959 in the formulations. During photopolymerization, the oxygen inhibition could be obviously decreased as the large amount of photoinitiator at the surface could consume oxygen in the air atmosphere. The fluorine compounds gathering on the surface also reduced the surface energy. By using this strategy, the film surface develops a wrinkled pattern with a low surface energy. And the wrinkled pattern may prove very useful in photopolymerization.

Based on a D–π-A–π-D structural strategy, six novel dyes (Cz–SO, Cz–SO2, TA–SO, TA–SO2, PTZ–SO, and PTZ–SO2) containing triphenylamine/phenothiazine/carbazole as electron donors and sulfone/sulfoxide as electron acceptors are prepared and incorporated into a photoinitiating system, together with iodonium salt (ONI). The one- and two-photon photophysical properties of these dyes were studied. The UV-vis spectra showed red-shifts of 51 and 75 nm from N-ethyl carbazole (CZ) to Cz–SO and Cz–SO2. Similar red-shifts were found in the other dyes. The two-photon excited fluorescence (TPEF) spectra in the range 700–880 nm were recorded and it was found that these dyes present a clear two-photon absorption (TPA). Among them, PTZ–SO2 possesses the maximum TPA cross-section, which is 2465.5 GM. Ring-opening cationic polymerization of epoxides and free radical polymerization of acrylates upon exposure to very soft irradiation of laser diodes at 405 nm and 455 nm were performed using ONI/dyes initiating systems. Compared with the well-known camphorquinone-based systems, the combinations of the obtained dyes with iodonium salt exhibit higher polymerization efficiency. The results from photobleaching and electrochemical experiments show that these dyes could photosensitize ONI through photoinduced charge transfers. Owing to their higher polymerization efficiency and large TPA cross-section, these dyes would have extensive application prospects in the fields of photopolymerization by soft visible light irradiation sources and two-photon polymerization (TPP).

The benzophenone (BP)/1,3-benzodioxole (BDO) bimolecular photoinitiating system was developed in recent years. However, the obvious yellowness of the samples cured by the BP–BDO photoinitiating system would limit its wide application in the photocuring field. To study the reasons for the yellowness of the cured samples, the photoreaction products of the mixture of BP and BDO were analyzed by infrared spectroscopy (IR) and GC-MS. Electron spin resonance (ESR) spectroscopy was also used to gain insight into the formation of the initiating radicals with 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) as a spin trap. The results of IR and GC-MS indicated that after the UV exposure of the BP–BDO mixture, four other main photoreaction products (ingredient 1–4) were generated via the interaction of excited BP and BDO. From the ESR hyperfine spectrum, only phenyl radical could be observed in the absence of air, which was significant to initiate the photopolymerization of HDDA and to form the three dimensional network. However, a minor amount of hydroxyl radical could also be generated besides the phenyl radical in the presence of air. The generation of hydroxyl radical in the photoreaction system is attributed to the formation of the phenol compound ingredient 1, which greatly contributed to the obvious yellowness of cured samples photoinduced by BP–BDO in practical applications.

A linear ABA type diacrylic macromer containing an amphiphilic backbone composed of a siloxane block (SiO) and two polyoxyethylene blocks (EO) was synthesized and subsequently photopolymerized and copolymerized with a polyoxyethylene diacrylate. The kinetics of the photopolymerization was monitored by rt-FTIR, confirming the reactivity of the acrylic functionalities. The obtained polymers were then characterized by DMTA analyses and showed interesting biphasic morphology with two Tgs attributable to the EO domains and to the SiO domains. Swelling in different solvents was also tested: compared to siloxane acrylates, the introduction of EO enhanced the chemical resistance of the polymer to most solvents, excluding water. Surface analyses showed that the incorporation of both hydrophobic siloxane groups and hydrophilic polyoxyethylene groups into the networks is a successful method for controlling their surface; due to the preferential segregation of the SiO blocks at the air interface, the wettability of the polymers with water is very low, but can change depending on the environment. Compatibility toward DNA amplification reaction was successfully tested. As the possibility of fast, accurate, and cheap reproducibility of microdevices by liquid phase photopolymerization increases the attractiveness of the polymer, this material is a good alternative to polydimethylsiloxane for the fabrication of microfluidic chips for biological analysis purposes.

DNA mutation is a permanent change in the order of bases along the DNA strand such that the sequence differs from the normal genetic information. Different type of mutations may cause various effects on the produced proteins. Colored Petri Net (CPN), as a powerful tool for modeling and analysing the discrete event systems, provides an innovative and effective theoretical method for studying the biological systems. In this paper, CPN is employed for modeling and determining the classification of the mutations type. The proposed model first contrasts the bases of DNA strands to obtain the mutation position and calculate the mutation rate, and then makes a comparative analysis of the codons of amino acids along the polypeptide chain to determine the mutation type. The model is helpful for analyzing whether the changes affect the protein structures and functions. Biological examples illustrate the effectiveness and accuracy of the proposed model.

As a major component of the cytoskeleton, microtubules consist of αβ-tubulin heterodimers and have been recognized as attractive targets for cancer chemotherapy. Microtubule-stabilizing agents (MSAs) promote polymerization of tubulin and stabilize the polymer, preventing depolymerization. The molecular mechanisms by which MSAs stabilize microtubules remain elusive. Here we report a 2.05 Å crystal structure of tubulin complexed with taccalonolide AJ, a newly identified taxane-site MSA. Taccalonolide AJ covalently binds to β-tubulin D226. On AJ binding, the M-loop undergoes a conformational shift to facilitate tubulin polymerization. In this tubulin–AJ complex, the E-site of tubulin is occupied by GTP rather than GDP. Biochemical analyses confirm that AJ inhibits the hydrolysis of the E-site GTP. Thus, we propose that the β-tubulin E-site is locked into a GTP-preferred status by AJ binding. Our results provide experimental evidence for the connection between MSA binding and tubulin nucleotide state, and will help design new MSAs to overcome taxane resistance., Microtubule-stabilizing agents (MSAs) promote the polymerization of tubulin and are of great interest as anticancer drugs. Here the authors present the crystal structure of the MSA taccalonolide AJ bound to tubulin and give insights into its mode of action, which might help in the design of novel MSAs.

Antibody–drug conjugates (ADCs) take the advantage of monoclonal antibodies to selectively deliver highly potent cytotoxic drugs to tumor cells, which have become a powerful measure for cancer treatment in recent years. To develop a more effective therapy for human epidermal growth factor receptor 2 (HER2)-positive cancer, we explored a novel ADCs composed of anti-HER2 scFv–HSA fusion antibodies conjugates with a potent cytotoxic drug DM1. The resulting ADCs, T-SA1–DM1 and T-SA2–DM1 (drug-to-antibody ratio in the range of 3.2–3.5) displayed efficient inhibition in the growth of HER2-positive tumor cell lines and the half-maximal inhibitory concentration on SKBR-3 and SKOV3 cells were both at the nanomolar levels in vitro. In HER2-positive human ovarian cancer xenograft models, T-SA1–DM1 and T-SA2–DM1 also showed remarkable antitumor activity. Importantly, three out of six mice exhibited complete remission without regrowth in the high-dose group of T-SA1–DM1. On the basis of the analysis of luminescence imaging, anti-HER2 scFv–HSA fusion antibodies, especially T-SA1, showed strong and rapid tumor tissue penetrability and distribution compared with trastuzumab. Collectively, the novel type of ADCs is effective and selective targeting to HER2-positive cancer, and may be a promising antitumor drug candidate for further studies.

Antimitotics that target tubulin are among the most useful chemotherapeutic drugs, but their clinical activity is often limited by the development of multidrug resistance. We recently discovered the novel small-molecule DJ101 as a potent and metabolically stable tubulin inhibitor that can circumvent the drug efflux pumps responsible for multidrug resistance of existing tubulin inhibitors. In this study, we determined the mechanism of action of this drug. The basis for its activity was illuminated by solving the crystal structure of DJ101 in complex with tubulin at a resolution of 2.8Å. Investigations of the potency of DJ101 in a panel of human metastatic melanoma cell lines harboring major clinically relevant mutations defined IC50 values of 7–10 nmol/L. In cells, DJ101 disrupted microtubule networks, suppressed anchorage-dependent melanoma colony formation, and impaired cancer cell migration. In melanoma-bearing mice, DJ101 administration inhibited tumor growth and reduced lung metastasis in the absence of observable toxicity. DJ101 also completely inhibited tumor growth in a paclitaxel-resistant xenograft mouse model of human prostate cancer (PC-3/TxR), where paclitaxel was minimally effective. Our findings offer preclinical proof of concept for the continued development of DJ101 as a next-generation tubulin inhibitor for cancer therapy. Significance: These findings offer preclinical proof of concept for the continued development of DJ101 as a next-generation antitubulin drug for cancer therapy. Cancer Res; 78(1); 265–77. ©2017 AACR.

In this paper, a new photocoinitiator for free radical photopolymerization, belonging to the benzodioxole (BDO) derivatives, was synthesized and characterized, and the effect of phenyl at the 2-position of BDO was estimated. The structure of PhBDO was characterized by elemental analysis, (1)H NMR and (13)C NMR. Laser flash photolysis (LFP) and an electron spin resonance spin trapping technique (ESR-ST) were used to study the photochemical mechanisms. The rate of decomposition (Rd) of PhBDO in acetonitrile was studied by UV-Vis spectroscopy and the photopolymerization kinetics were monitored by real time Fourier Transform near-IR (FT-IR). The FT-IR results showed that the concentration of PhBDO and BP functionalities of the acrylates and the light intensity affected the polymerization rate and the final conversion. The results showed that the BP/PhBDO system had the same hydrogen abstraction mechanism and reactivity as the BP/BDO system. Consequently, PhBDO could also be an effective coinitiator.

This paper contains a kind of ultraviolet-cured antifogging and antibacterial coating. A quaternary ammonium salt (14QAS), which was synthesized in this paper, has been implemented as a monomer. The chemical structure of 14QAS has been confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The nitrogen atom on the surface of the coatings with 14QAS was observed by X-ray photoelectron spectroscopy. The Surface wettability of the polymer film was studied by contact angle analysis, which confirmed the hydrophilicity of the coatings with low water contact angle (~25°). The antifog properties were evaluated under different conditions. The antibacterial activity of coatings with 14QAS reached 99.9% against S. aureus and E. coli. Copyright © 2014 John Wiley & Sons, Ltd.

This work presents the electrochemically-induced polymerization of vinyl ether monomers by using potassium hexafluoroantimonate (KSbF6) as the initiating species. Static characterization of the resulting polymers was investigated by ATR-FT-IR. Real-time FT-NIR was used to study the kinetics of the electro-initiated polymerizations. Under certain conditions, rapid cationic polymerization kinetic profiles and high final conversion of monomer to polymer could be obtained. The reaction rate could be readily adjusted based on the applied voltage or by the introduction of an alkaline additive, which along with the observation of extended post curing clearly demonstrated the cationic nature of the electrochemical process. The thermo-stability of the polymerized product was investigated by TGA.

International audience; Microtubules are dynamic assemblies of αβ-tubulin heterodimers and have been recognized as highly attractive targets for cancer chemotherapy. A broad range of agents bind to tubulin and interfere with microtubule assembly. Despite having a long history of characterization, colchicine binding site inhibitors (CBSIs) have not yet reached the commercial phase as anti-cancer drugs to date. We determined the structures of tubulin complexed with a set of structurally diverse CBSIs (lexibulin, nocodazole, plinabulin and tivantinib), among which nocodazole and tivantinib are both binary-function inhibitors targeting cancer-related kinases and microtubules simultaneously. High resolution structures revealed the detailed interactions between these ligands and tubulin. Our results showed that the binding modes of the CBSIs were different from previous docking models, highlighting the importance of crystal structure information in structure-based drug design. A real structure-based pharmacophore was proposed to rationalize key common interactions of the CBSIs at the colchicine domain. Our studies provide a solid structural basis for developing new anti-cancer agents for the colchicine binding site.; The atomic coordinates and structure factors for tubulin complexed with lexibulin, nocodazole, plinabulin and tivantinib have been deposited in the Protein Data Bank under accession codes 5CA0, 5CA1, 5C8Y and 5CB4, respectively.