Visual detection and discrimination of nerve and blood agents using a dual-site fluorescent probe in living cells and mice.

Of all chemical warfare agents (CWAs), only nerve and blood agents cause massive mortality at low concentrations. To better detect and discriminate nerve and blood agents, a reliable detection method is desirable. We report a series of fluorescent probes for nerve and blood agent detection. Among the tested probes, SR-Pip detected nerve and blood agents quickly (within 10 s for nerve agents and 1 min for blood agents). SR-Pip coupled with nerve agent produced a weak orange fluorescence with good sensitivity [limit of detection (LOD)= 5.5 µM]. Upon reaction with blood agent, the fluorescence of SR-Pip changed from orange fluorescence to blue fluorescence with detection limits as low as 9.6 nM. This probe effectively visualised different concentrations of nerve agents in living cells and mice. A portable test kit using SR-Pip instantly detected nerve and blood agents. To the best of our knowledge, SR-Pip is the first fluorescent probe for nerve and blood agent detection.

ZDHHC9 promotes colon tumor growth by inhibiting effector T cells.

Zinc finger DHHC-type palmitoyltransferase 9 (ZDHHC9) has been reported to play an important role in the occurrence and development of several types of cancer. However, its effects on colon cancer growth remain unclear. Using Gene Expression Profiling Interactive Analysis and Tumor Immune Estimation Resource, data obtained from The Cancer Genome Atlas were analyzed, and the results showed that ZDHHC9 was highly expressed in colon cancer and that patients with higher ZDHHC9 expression levels had a worse prognosis. Inhibition of ZDHHC9 expression promoted the proliferation of colon cancer cells in vitro but decreased their growth in vivo. Additionally, inhibition of ZDHHC9 expression in cancer cells enhanced CD8+ T cell-mediated cytotoxicity in vitro and increased CD8+ T infiltration and activation in vivo. Furthermore, ZDHHC9 promoted IFN-γ-induced JAK/STAT1 activation and upregulated programmed death-ligand 1 (PD-L1) expression in colon cancer cells. In conclusion, the present findings showed that ZDHHC9 promoted colon cancer growth by upregulating the expression of PD-L1 and inhibiting the function of CD8+ T cells.

PIK3CA mutations-mediated downregulation of circLHFPL2 inhibits colorectal cancer progression via upregulating PTEN.

BACKGROUND: PIK3CA mutation and PTEN suppression lead to tumorigenesis and drug resistance in colorectal cancer (CRC). There is no research on the role of circular RNAs (circRNAs) in regulating PIK3CA mutation and MEK inhibitor resistance in CRC. METHODS: The expression of circLHFPL2 in PIK3CA-mutant and wild-type cells and tissues was quantified by RNA-sequencing and qRT-PCR. CCK-8 assay and colony formation assay were used to evaluate cell viability. Annexin V/PI staining was implemented to assess cell apoptosis. Luciferase assay, biotin-coupled microRNA capture, and RIP assay were used to validate the interaction among potential targets. Western blotting and qRT-PCR assays were used to evaluate the expression of involved targets. Xenograft tumor in a nude mouse model was used to explore the role of circRNAs in vivo. RESULTS: RNA sequencing defined downregulated expression of circLHFPL2 in both PIK3CAH1047R (HCT116) and PIK3CAE545K (DLD1) cells. CircLHFPL2 was also downregulated in PIK3CA-mutant CRC primary cells and tissues, which was correlated with poor prognosis. CircLHFPL2 was mainly localized in the cytoplasm and its downregulation was attributed to the PI3K/AKT signaling pathway activated by phosphorylating Foxo3a. CircLHFPL2 inhibited PI3KCA-Mut CRC progression both in vitro and in vivo. Furthermore, our work indicated that circLHFPL2 acts as a ceRNA to sponge miR-556-5p and miR-1322 in CRC cells and in turn modulate the expression of PTEN. Importantly, circLHFPL2 was able to overcome PIK3CA-mediated MEK inhibitor resistance in CRC cells. CONCLUSIONS: Downregulation of circLHFPL2 sustains the activation of the PI3K/AKT signaling pathway via a positive feedback loop in PIK3CA-mutant CRC. In addition, downregulation of circLHFPL2 leads to MEK inhibitor resistance in CRC. Therefore, targeting circLHFPL2 could be an effective approach for the treatment of CRC patients harboring oncogenic PIK3CA mutations.

Integrating Hydrogen Production and Transfer Hydrogenation with Selenite Promoted Electrooxidation of α-Nitrotoluenes to E-Nitroethenes.

Developing an electrochemical carbon-added reaction with accelerated kinetics to replace the low-value and sluggish oxygen evolution reaction (OER) is markedly significant to pure hydrogen production. Regulating the critical steps to precisely design electrode materials to selectively synthesize targeted compounds is highly desirable. Here, inspired by the surfaced adsorbed SeOx 2- promoting OER, NiSe is demonstrated to be an efficient anode enabling α-nitrotoluene electrooxidation to E-nitroethene with up to 99 % E selectivity, 89 % Faradaic efficiency, and the reaction rate of 0.25 mmol cm-2 h-1 via inhibiting side reactions for energy-saving hydrogen generation. The high performance can be associated with its in situ formed NiOOH surface layer and absorbed SeOx 2- via Se leaching-oxidation during electrooxidation, and the preferential adsorption of two -NO2 groups of intermediate on NiOOH. A self-coupling of α-carbon radicals and subsequent elimination of a nitrite molecule pathway is proposed. Wide substrate scope, scale-up synthesis of E-nitroethene, and paired productions of E-nitroethene and hydrogen or N-protected aminoarenes over a bifunctional NiSe electrode highlight the promising potential. Gold also displays a similar promoting effect for α-nitrotoluene transformation like SeOx 2- , rationalizing the strategy of designing materials to suppress side reactions.

Electrocatalytic Deuteration of Halides with D2 O as the Deuterium Source over a Copper Nanowire Arrays Cathode.

Precise deuterium incorporation with controllable deuterated sites is extremely desirable. Here, a facile and efficient electrocatalytic deuterodehalogenation of halides using D2 O as the deuteration reagent and copper nanowire arrays (Cu NWAs) electrochemically formed in situ as the cathode was demonstrated. A cross-coupling of carbon and deuterium free radicals might be involved for this ipso-selective deuteration. This method exhibited excellent chemoselectivity and high compatibility with the easily reducible functional groups (C=C, C≡C, C=O, C=N, C≡N). The C-H to C-D transformations were achieved with high yields and deuterium ratios through a one-pot halogenation-deuterodehalogenation process. Efficient deuteration of less-active bromide substrates, specific deuterium incorporation into top-selling pharmaceuticals, and oxidant-free paired anodic synthesis of high-value chemicals with low energy input highlighted the potential practicality.

Potential-tuned selective electrosynthesis of azoxy-, azo- and amino-aromatics over a CoP nanosheet cathode.

Azoxy-, azo- and amino-aromatics are among the most widely used building blocks in materials science pharmaceuticals and synthetic chemistry, but their controllable and green synthesis has not yet been well established. Herein, a facile potential-tuned electrosynthesis of azoxy-, azo- and amino-aromatics via aqueous selective reduction of nitroarene feedstocks over a CoP nanosheet cathode is developed. A series of azoxy-, azo- and amino-compounds with excellent selectivity, good functional group tolerance and high yields are produced by applying different bias input. The synthetically significant and challenging asymmetric azoxy-aromatics can be controllably synthesized in moderate to good yields. The use of water as the hydrogen source makes this strategy remarkably fascinating and promising. In addition, deuterated aromatic amines with a high deuterium content can be readily obtained by using D2O. By pairing with anodic oxidation of aliphatic amines to nitriles, synthetically useful building blocks can be simultaneously produced in a CoP||Ni2P two-electrode electrolyzer. Only 1.25 V is required to achieve a current density of 20 mA cm-2, which is much lower than that of overall water splitting (1.70 V). The paired oxidation and reduction reactions can also be driven using a 1.5 V battery to synthesize nitrile and azoxybenzene with good yields and selectivity, further emphasizing the flexibility and controllability of our method. This work paves the way for a promising approach to the green synthesis of valuable chemicals through potential-controlled electrosynthesis.

Boosting Hydrogen Production by Anodic Oxidation of Primary Amines over a NiSe Nanorod Electrode.

For electrocatalytic water splitting, the sluggish anodic oxygen evolution reaction (OER) restricts the cathodic hydrogen evolution reaction (HER). Therefore, developing an alternative anodic reaction with accelerating kinetics to produce value-added chemicals, especially coupled with HER, is of great importance. Now, a thermodynamically more favorable primary amine (-CH2 -NH2 ) electrooxidation catalyzed by NiSe nanorod arrays in water is reported to replace OER for enhancing HER. The increased H2 production can be obtained at cathode; meanwhile, a variety of aromatic and aliphatic primary amines are selectively electrooxidized to nitriles with good yields at the anode. Mechanistic investigations suggest that NiII /NiIII may serve as the redox active species for the primary amines transformation. Hydrophobic nitrile products can readily escape from aqueous electrolyte/electrode interface, avoiding the deactivation of the catalyst and thus contributing to continuous gram-scale synthesis.

OxyR positively and directly regulates Vi polysaccharide capsular antigen in Salmonella enterica serovar Typhi.

Salmonella enterica serovar Typhi (S. Typhi) is a human enteropathogen that can overcome oxidative stress and survive in macrophages. OxyR is an important part of the antioxidant defense system. S. Typhi expresses a virulence (Vi) polysaccharide capsular antigen, which provides the bacterium with the ability to avoid host defenses and suppress detection by the innate immune system. This study investigated the effect of OxyR on Vi antigen in S. Typhi. In the oxyR mutant strain, microarray analysis, quantitative real time PCR and ß-galactosidase assay confirmed that the viaB operon was positively regulated by OxyR. The Vi enzyme-linked immunosorbent assay and flow cytometry results showed that Vi capsule level was decreased in the oxyR mutant strain. Also, the EMSA revealed that OxyR directly binds to the promoter region of tviA. Thus, we propose that S. Typhi OxyR positively regulates expression of Vi capsule antigen in a direct manner.

Kupffer cell-derived TNF-α promotes hepatocytes to produce CXCL1 and mobilize neutrophils in response to necrotic cells.

The damage-associated molecular pattern molecules (DAMPs) released by necrotic cells can trigger inflammatory response, which will facilitate the clearance of these dead cells. Neutrophil mobilization is a very important step for the dead cell clearance, however the detailed mechanisms for DAMPs induce neutrophil mobilization remains largely elusive. In this study, by using a necrotic cell-induced neutrophil mobilization mice model, we found that both neutrophil number and percentage rapidly (as early as 30 min) increased with necrotic cells but not live cell treatment. CXCL1 was rapidly increased in the serum and was responsible for the neutrophil mobilization when treated with necrotic cells. We further demonstrated that the hepatocytes in the liver were the main source of CXCL1 production in response to necrotic cells challenge. However, the hepatocytes did not express CXCL1 when incubating with necrotic cells alone. When Kupffer cells were ablated, the increased CXCL1 levels as well as neutrophil mobilization were abolished with necrotic cells challenge. Moreover, we clarified Kupffer cells-derived TNF-α activates the NF-κB pathway in hepatocytes and promote hepatocytes to express CXCL1. In summary, we showed that the liver is the main source for necrotic cell-induced CXCL1 production and neutrophil mobilization. Kupffer cells in the liver sense DAMPs and release TNF-α to activate the NF-κB pathway in hepatocytes. The interaction between Kupffer cells and hepatocytes is critical for CXCL1 production.

The anti-ErbB2 antibody H2-18 and the pan-PI3K inhibitor GDC-0941 effectively inhibit trastuzumab-resistant ErbB2-overexpressing breast cancer.

Trastuzumab, an anti-ErbB2 humanized antibody, brings benefit to patients with ErbB2-amplified metastatic breast cancers. However, the resistance to trastuzumab is common. Our previously reported H2-18, an anti-ErbB2 antibody, potently induced programmed cell death in trastuzumab-resistant breast cancer cells. Here, we aim to investigate the antitumor efficacy of H2-18 in combination with the pan-PI3K inhibitor GDC-0941 in trastuzumab-resistant breast cancer cell lines. The results showed that H2-18 and GDC-0941 synergistically inhibited the in vitro proliferation of BT-474, SKBR-3, HCC-1954 and HCC-1419 breast cancer cells. H2-18 plus GDC-0941 showed significantly enhanced programmed cell death-inducing activity compared with each drug used alone. The combination of H2-18 and GDC-0941 did not increase the effect of single agent on ROS production, cell cycle and ErbB2 signaling. Importantly, the in vivo antitumor efficacy of H2-18 plus GDC-0941 was superior to that of single agent. Thus, the enhanced in vivo antitumor efficacy of H2-18 plus GDC-0941 may mainly be attributable to its increased programmed cell death-inducing activity. Collectively, H2-18 plus GDC-0941 could effectively inhibit tumor growth, suggesting the potential to be translated into clinic as an efficient strategy for ErbB2-overexpressing breast cancers.

A Micelle Self-Assembled from Doxorubicin-Arabinoxylan Conjugates with pH-Cleavable Bond for Synergistic Antitumor Therapy.

Nanomedicine offers new hope to overcome the low solubility and high side toxicity to normal tissue appeared in traditional chemotherapy. The biocompatibility and intracellular drug accumulation is still a big challenge for the nano-based formulations. Herein, a medical-used biocompatible arabinoxylan (AX) is used to develop to delivery chemodrug doxorubicin (DOX). The solubility of DOX is obviously enhanced via the hydrogen bond formed with AX which results in an amphiphilic AX-DOX. A micelle with pH-cleavable bond is thus self-assembled from such AX-DOX with DOX core and AX shell. The inner DOX can be easily released out at low intracellular pH, which obviously enhanced its in vitro cytotoxicity against breast cancer cells (MCF-7). Interestingly, an unexpected apoptosis is evoked except for the proliferation inhibition. Moreover, the therapeutic effects are further synergistically promoted by the enhanced permeability and retention (EPR) and intracellular pH-triggered drug release. Consequently, the in vivo intratumor accumulation of DOX, the tumor inhibition was significantly promoted after intravenous administration to the Balb/c nude mice bearing MCF-7 tumors. These in vitro/vivo results indicated that the AX-DOX micellular formulation holds high potential in cancer therapy.

Aberrant expression of STYK1 and E-cadherin confer a poor prognosis for pancreatic cancer patients.

Previous studies showed that aberrant Serine/threonine/tyrosine kinase 1 (STYK1, also known as NOK) or/and E-cadherin were involved in the progression of some types of human cancers. However, whether they contributed to the development of pancreatic cancer was unknown. Here, we investigated the prognostic significance of aberrant STYK1 and E-cadherin in pancreatic cancer. Our results showed that STYK1 expression increased while E-cadherin decreased in pancreatic cancer tissues compared with normal pancreas tissues. STYK1 level was positively correlated with lymph node metastasis and clinical stage in pancreatic cancer patients. E-cadherin expression was inversely correlated with STYK1 expression in pancreatic cancer tissue samples. Patients with high STYK1 and low E-cadherin expression had the worst prognosis. In addition, STYK1 knockdown in pancreatic cancer cell lines inhibited cell proliferation, enhanced cell apoptosis, induced cell cycle arrest, and prohibited cell migration, while STYK1 over-expression showed the opposite effects. Silencing STYK1 also increased E-cadherin expression and inhibited epithelial-to-mesenchymal transition (EMT) and p-p38 expression in vitro. Over-expression had showed the opposite trends, and treatment with p38 inhibitor, SB203580, could reverse the trends. Thus, STYK1 repressed E-cadherin expression and promoted EMT, mediated by p38 MAPK signaling pathway, which was the possible mechanism for STYK1-mediated pancreatic cancer cell proliferation and migration. In summary, our results showed that STYK1 might be a prognostic marker for pancreatic cancer patients and might be a novel strategy for the treatment of pancreatic cancer.

An anti-ErbB2 fully human antibody circumvents trastuzumab resistance.

Trastuzumab, an anti-HER2/ErbB2 humanized antibody, has shown great clinical benefits in ErbB2-positive breast cancer treatment. Despite of its effectiveness, response rate to trastuzumab is limited and resistance is common. Here, we developed a new anti-ErbB2 antibody, denoted as H2-18, which was isolated from a phage display human antibody library. Previous studies have demonstrated that trastuzumab recognizes the juxtamembrane region of domain IV, and pertuzumab, another humanized ErbB2-specific antibody, binds to ErbB2 near the center of domain II. Our crystallographic analysis showed that the epitope recognized by H2-18 is within domain I of the ErbB2 molecule. H2-18 potently induced programmed cell death (PCD) in both trastuzumab-sensitive and -resistant breast cancer cell lines, while trastuzumab and pertuzumab, either used alone or in combination, only exhibits very weak PCD-inducing activity. More importantly, H2-18 could inhibit the growth of trastuzumab-resistant breast cancer cells far more effectively than trastuzumab plus pertuzumab, both in vitro and in vivo. In conclusion, H2-18 shows a unique ability to overcome trastuzumab resistance, suggesting that it has the great potential to be translated to the clinic.

A bispecific anti-ErbB2 antibody potently induces ErbB2 internalization and suppresses ErbB2-overexpressing tumor growth.

The anti-ErbB2 humanized antibody trastuzumab was approved for ErbB2-positive metastatic gastric and gastro-esophageal junction cancer in 2010. Despite the effectiveness of trastuzumab, its efficacy remains variable and often modest. Thus, there is an urgent need to improve ErbB2-targeting therapy. Down-regulation of surface receptors induced by monoclonal antibody (mAb) contributes to its antitumor efficacy. Previous studies have demonstrated that if two anti-ErbB2 mAbs did not compete with each other for binding to ErbB2, the combination of them can enhance ErbB2 internalization. In the present study, we investigated ErbB2 internalization-inducing ability of non-competitive anti-ErbB2 mAb combinations and surprisingly found that most of the mAb combinations tested did not down-regulate ErbB2. Only 4 of 18 non-competitive mAb pairs efficiently induced ErbB2 internalization. Interestingly, although the non-competitive anti-ErbB2 mAbs trastuzumab and pertuzumab, either alone or in combination, were ineffective at inducing ErbB2 internalization, TPL, a bispecific antibody engineered from trastuzumab and pertuzumab, potently down-regulated the ErbB2 molecule. Importantly, TPL exhibited a far greater antitumor effect on ErbB2-overexpressing gastric cancer cell line than trastuzumab plus pertuzumab, suggesting that it may be a promising agent for the treatment of gastric cancer.