Bioinspired Surface Ligand Engineering Regulates Electron Transfers in Gold Clusterzymes to Enhance the Catalytic Activity for Improving Sensing Performance.

Metal nanoclusters feature a hierarchical structure, facilitating their ability to mimic enzyme-catalyzed reactions. However, the lack of true catalytic centers, compounded by tightly bound surface ligands hindering electron transfers to substrates, underscores the need for universal rational design methodologies to emulate the structure and mechanisms of natural enzymes. Motivated by the electron transfer in active centers with specific chemical structures, by integrating the peroxidase cofactor Fe-TCPP onto the surface of glutathione-stabilized gold nanoclusters (AuSG), we engineered AuSG-Fe-TCPP clusterzymes with a remarkable 39.6-fold enhancement in peroxidase-like activity compared to AuSG. Fe-TCPP not only mimics the active center structure, enhancing affinity to H2O2, but also facilitates the electron transfer process, enabling efficient H2O2 activation. By exemplifying the establishment of a detecting platform for trace H2O2 produced by ultrasonic cleaners, we substantiate that the bioinspired surface-ligand-engineered electron transfer can improve sensing performance with a wider linear range and lower detection limit.

A fatty acid photodecarboxylase-mimicking photonanozyme with defect-induced enzymatic substrate-binding pockets.

Hydrocarbon synthesis hints at the significance of in-depth investigations and detailed explanations of mimicking fatty acid photodecarboxylase (FAP). Considering the importance of photodecarboxylases in hydrocarbon synthesis, we present the potential of defective semiconductor nanomaterials as a novel type of photonanozymes (PNZs) that mimic enzyme-like performance, serving as alternatives to FAP. Ferrum-doped titanium dioxide (Fe-TiO2) was synthesized to introduce appropriate amounts of surface defects including reduced Ti3+ sites and oxygen vacancies, which reduce the band gap of TiO2 and enhance the visible-light absorption, thereby facilitating efficient charge trapping. Notably, the surface defects of Fe-TiO2 PNZs singularly act as enzymatic substrate-binding pockets that enable efficient carboxylic acid adsorption during the dark process, conversely facilitating the formation of more defects and boosting the FAP-like activity for photocatalytic decarboxylation reactions. This work provides a creative strategy for designing substrate-dependent higher-concentration defects as enzyme-like binding sites on promising PNZs that mimic natural photoenzymes.

Silver Ion-Facilitated Singular Poulos-Kraut Mechanism of O-O Heterolysis to Enhance the Light Activation of H2O2 over Peroxidase-Mimicking Photonanozymes.

The Poulos-Kraut heterolytic O-O cleavage mechanism is essential for natural peroxidases to activate H2O2. Current existing peroxidase-mimicking nanozymes, including photonanozymes (PNZs), however, are generally believed to prefer the Fenton-type mechanism of O-O homolysis, which produces •OH radicals. Here, Ag+ ions are introduced into TiO2 PNZs to boost the hot hole-driven O-O heterolysis for the expedited H2O2 activation in the peroxidase-like photonanozymatic reaction while inhibiting the Fenton-type O-O homolysis. The Ag+-facilitated Poulos-Kraut heterolytic O-O cleavage mechanism for H2O2 activation is explicated in terms of the speedy capture and exhaustion of photogenerated electrons by Ag+ and the dissociation of the peroxo-oxygen bridge in Ti-O-OH promoted by accumulated hot holes. Moreover, the enhanced photonanozymatic activity of TiO2 PNZs enables the construction of a rapid colorimetric sensing platform for Ag+ determination. This work provides valuable insights into the mechanism of H2O2 activation and exemplifies a novel photoregulation strategy for controlling reaction pathways in nanozymes.

Methyl orange as a novel colorimetric iodide indicator with in situ generation of H2O2 by etching uncoated Ag-Ti3C2 nanohybrids.

Iodine intake remains a major public health concern, as both iodine excess and deficiency are related to adverse effects on health. Therefore, developing simple and economical methods to detect I- is still in great demand. Herein, we constructed a visual I- sensing platform based on the uncoated Ag-Ti3C2 nanohybrids using methyl orange (MO) as a colorimetric indicator. Plasmonic nanostructures are frequently employed in colorimetric analysis, but uncoated Ag nanoparticles (NPs) are unstable because their surface energies are usually high. Considering that Ag NPs can be etched by I- via forming Ag-I bond, we introduce Ag-Ti3C2 nanohybrids because uncoated Ag NPs with immaculate surfaces are more conducive to binding with I- and being etched. Dissolved O2 molecules adsorbed on Ti3+ of Ti3C2 MXenes enable the in situ generation of H2O2 by iodine-etching of uncoated Ag-Ti3C2 nanohybrids. ∙OH radicals promote the degradation of MO through a self-driven Fenton-like process, exhibiting the color variation from orange to transparent. Under optimal conditions, the absorbance of MO at 465 nm decreases linearly with the concentration of I- in the range of 0.5-300 µM, with a limit of detection as low as 0.31 µM. This work opens the feasibility of iodine-etching of Ag in developing novel probes for facile colorimetric determination of I-.

Bioinspired Coassembly of Copper Ions and Nicotinamide Adenine Dinucleotides for Single-Site Nanozyme with Dual Catalytic Functions.

Nanozymes can imitate the catalytic properties of natural enzymes while overcoming the limitations of natural enzymes such as high cost, poor robustness, and difficulty in recycling. However, rational design and facile preparation of nanozymes are still in demand. Inspired by the chemical structure of laccase, we report an amorphous metal-organic coordination nanocomposite named CuNAD, which is composed of copper ions and nicotinamide adenine dinucleotide (NAD+) via a simple coordinating coassembly process. As a single-site nanozyme, CuNAD exhibits excellent robustness under extreme conditions, significantly stronger catalytic activity for phenolic compounds, and 4.02-fold higher sensitivity for epinephrine detection than laccase. Furthermore, by breaking through the functional constraints of laccase, CuNAD is also able to activate H2O2 at neutral pH, benefiting a one-step chromogenic detection platform for cholesterol. This facile approach demonstrates the potential to develop single-site nanozymes by biomimicking natural enzymes and may boost more insights into the structure-function relationship of nanozymes.

Exosome Transplantation From Patients With Schizophrenia Causes Schizophrenia-Relevant Behaviors in Mice: An Integrative Multi-omics Data Analysis.

Exosomes are involved in the pathophysiology of neuropsychiatric diseases, but the role of exosomes in schizophrenia (SCZ) is unclear. Here, we demonstrate that transplantation of serum exosomes from SCZ patients into mice caused behavioral abnormalities such as deficits in prepulse inhibition and sociability, hyperactivity, and anxiogenesis. A comparative bioinformatics analysis suggested shared and distinct differentially expressed genes (DEGs) and enriched molecular pathways in the brains of SCZ exosome-recipient mice, methylazoxymethanol acetate-treated rats, and SCZ patients, which correlates evidence of altered prefrontal-hippocampal functional coherence in SCZ. A large proportion of SCZ-relevant DEGs in the exosome-recipient mice were targets of DE exosomal miRNAs in SCZ patients. Furthermore, we identified 20 hub genes for SCZ risk genes, including BDNF and NRG1, which were DE miRNA targets in SCZ. Collectively, our study suggests that SCZ exosome transplantation caused SCZ-relevant behaviors in mice, and epigenetic regulation may contribute to the phenotypes in the SCZ exosome-recipient mice. Our results may provide a potential animal model and novel therapeutic targets for SCZ.

An integrated bioinformatics analysis to investigate the targets of miR-133a-1 in breast cancer.

BACKGROUND: The microRNA (miRNA) miR-133a-1 has been identified as a tumor suppressor in breast cancer. However, the underlying mechanisms of miR-133a-1 in breast cancer have not been fully elucidated. This study aimed to explore the targets of miR-133a-1 in breast cancer using an integrated bioinformatics approach. METHODS: Human SKBR3 breast cancer cells were transfected with miR-133a-1 or a miRNA negative control (miRNA-NC) for 48 hours. The RNA-seq sequencing technique was performed to identify the differential expression of genes induced by miR-133a-1 overexpression. Functional enrichment analysis was conducted to determine the target genes and pathways involved in breast cancer. RESULTS: Breast cancer patients with high levels of miR-133a-1 expression commonly showed longer overall survival compared to patients with a low level of miR-133a-1 expression. Using Cuffdiff, we identified 1,216 differentially expressed genes induced by miR-133a-1 overexpression, including 653 upregulated and 563 downregulated genes. MOCS3 was the most upregulated gene and KRT14 was the most downregulated gene. The top 10 pathways related to the differentially expressed genes were identified through Gene Ontology (GO) enrichment analysis. Sex-determining region Y-box 9 (SOX9) demonstrated the highest semantic similarities among the differentially expressed genes. Since SOX9 and CD44 were hub nodes in the protein-protein interaction network, the SOX9 gene may be a target of miR-133a-1 in breast cancer. CONCLUSIONS: This report provides useful insights for understanding the underlying mechanisms in the pathogenesis of breast cancer.

Electrostatic Interaction-Induced Formation of Enzyme-on-MOF as Chemo-Biocatalyst for Cascade Reaction with Unexpectedly Acid-Stable Catalytic Performance.

Combining biocatalytic and chemocatalytic reactions in a one-pot reaction not only avoids the tedious isolation of intermediates during the reactions but also provides a desirable alternative to extend the range of catalytic reactions. Here, we report a facile strategy to immobilize an enzyme, glucose oxidase (GOx), on PCN-222(Fe) induced by electrostatic interaction in which PCN-222(Fe) serves as both a support and chemocatalyst. The immobilization was confirmed through ζ potential measurement, confocal laser scanning microscopy, Fourier transform infrared spectrometry, and UV-vis spectroscopy. This chemo-biocatalyst was applied to a cascade reaction to catalyze glucose oxidation and ABTS (ABTS = 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (or pyrogallol) oxidation. The catalytic kinetics studies show that these chemo-biocatalytic cascade reactions obey the Michaelis-Menten equation, which indicates that the cascade reactions follow the typical enzymatic dynamic regulation process. Interestingly, GOx/PCN-222(Fe) exhibits an exceptional acid-stable catalytic performance as evidenced by circular dichroism spectroscopy where no significant structure change was observed toward acidic solutions with different pH values. GOx/PCN-222(Fe) also displays desirable recyclability since no significant loss of conversion rates was found after six repeated reactions. This work presents a convenient strategy to construct metal-organic framework based chemo-biocatalysts, which may find potential applications in sensing and nanomachines.

Azoreductase-Responsive Metal-Organic Framework-Based Nanodrug for Enhanced Cancer Therapy via Breaking Hypoxia-induced Chemoresistance.

The insufficient oxygen supply may cause hypoxia in a solid tumor, which can lead to drug resistance and unsatisfactory chemotherapy effect. To address this issue, a new nanodrug has been developed with azoreductase-responsive functional metal-organic frameworks (AMOFs), where chemotherapeutic drugs were encapsulated in the AMOFs and small interfering RNAs (siRNAs) were absorbed on the surface of AMOFs. The siRNA was designed to contain hypoxia-inducible factor (HIF)-1α against RX-0047, which can induce significant downregulation of HIF-1α protein. The azobenzene units within the frameworks of AMOFs could be reduced to amines by the highly expressed azoreductase under the oxygen-deficient environment, which results in azoreductase-responsive release of the encapsulated drugs and siRNAs under the hypoxic condition. Therefore, once the drug-loaded AMOF entered the hypoxic cancer cells, the azoreductase-responsive release of siRNA could decrease the efflux of chemotherapeutic drugs via inhibiting the expressions of HIF-1α, multidrug resistance gene 1, and P-glycoprotein. This nanodrug can thus efficiently break hypoxia-induced chemoresistance and result in high-efficient cancer therapy in hypoxic tumors. As far as we know, this is the first attempt to construct an AMOF-based nanodrug with hypoxic harvesting behaviors. This proof-of-concept research provides a simple strategy for the construction of hypoxic-responsive AMOFs and also offers a unique on-command drug delivery platform, which can effectively break hypoxia-induced chemoresistance.

miR­96 inhibits EMT by targeting AEG­1 in glioblastoma cancer cells.

The induction of epithelial to mesenchymal transition (EMT) is important for carcinogenesis and cancer progression. Previous studies have estimated that microRNA (miRNA/miR) expression is associated with EMT via the regulation of the expression of target genes. miR­96 has been reported to exhibit a correlation with the EMT process. However, the functional role of miR­96 and its mechanism in glioblastoma multiforme (GBM) remains to be completely elucidated. The objective of the present study was to investigate the functional role and mechanism of miR­96 in the migration and invasion, in addition to proliferation, apoptosis and cell cycle distribution, of GBM. In the present study, the results suggested that the introduction of miR­96 significantly inhibited the migration and invasion, in addition to proliferation and cell cycle progression, of GBM cells and promoted their apoptosis in vitro, leading to the hypothesis that miR­96 may be a potential tumor suppressor. It was subsequently confirmed that astrocyte elevated gene­1 (AEG­1) was a direct target gene of miR­96, using a luciferase assay and reverse transcription­quantitative polymerase chain reaction analysis, in addition to western blotting. miR­96 was observed to downregulate the expression of AEG­1 at the mRNA and protein levels. Notably, AEG­1 may suppress EMT by increasing the expression levels of E­cadherin, an epithelial marker, and decreasing the expression levels of vimentin, a mesenchymal marker. Therefore, it was concluded that miR­96 may impede the EMT process by downregulating AEG­1 in GBM. Additionally, it was observed that inhibition of AEG­1 led to a similar effect compared with overexpression of miR­96 in GBM. In conclusion, the results of the present study demonstrated that miR­96 may act as a tumor suppressor by regulating EMT via targeting of AEG­1, suggesting that miR­96 may be a potential biomarker and anticancer therapeutic target for GBM in the future.

Up-Regulated Expression of SPRY4-IT1 Predicts Poor Prognosis in Colorectal Cancer.

BACKGROUND Long non-coding RNA SPRY4 intronic transcript 1 (lncRNA SPRY4-IT1) has been reported to be associated with the progression of several cancers, but its expression level in colorectal cancer (CRC) has rarely been reported. The purpose of this study was to estimate the clinical significance of SPRY4-IT1 in CRC. MATERIAL AND METHODS The relative expression levels of SPRY4-IT1 were detected by quantitative real-time polymerase chain reaction (qRT-PCR) in diseased tissues and the adjacent normal tissues of 106 CRC patients. Chi-square method was used to evaluate the association between SPRY4-IT1 expression and the clinical features. Additionally, we assessed the overall survival at different expression levels of SPRY4-IT1 using Kaplan-Meier method. The prognostic significance of SPRY4-IT1 was estimated by Cox regression analysis. RESULTS Up-regulated level of SPRY4-IT1 was detected in pathologic tissues of CRC patients compared with adjacent normal tissues (P=0.000). The relative expression of SPRY4-IT1 was associated with the tumor size, the depth of invasion, lymph node invasion, distant invasion, and tumor stage (P<0.05). Patients with high expression of SPRY4-IT1 had poor overall survival compared with those with high level (39.3 vs. 49.3 months, log-rank test, P=0.016). Cox regression analysis showed that SPRY4-IT1 could act as an independent prognostic factor in CRC (HR=2.341, 95% CI=1.136-4.826, P=0.021). CONCLUSIONS SPRY4-IT1 might be associated with tumorigenesis and progression of CRC, and it may be a promising biomarker for prognosis in patients with CRC.

A bispecific antibody effectively neutralizes all four serotypes of dengue virus by simultaneous blocking virus attachment and fusion.

Although dengue virus (DENV) infection severely threatens the health of humans, no specific antiviral drugs are currently approved for clinical use against DENV infection. Attachment and fusion are 2 critical steps for the flavivirus infection, and the corresponding functional epitopes are located at E protein domain III (E-DIII) and domain II (E-DII), respectively. Here, we constructed a bispecific antibody (DVD-1A1D-2A10) based on the 2 well-characterized anti-DENV monoclonal antibodies 1A1D-2 (1A1D) and 2A10G6 (2A10). The 1A1D antibody binds E-DIII and can block the virus attaching to the cell surface, while the 2A10 antibody binds E-DII and is able to prevent the virus from fusing with the endosomal membrane. Our data showed that DVD-1A1D-2A10 retained the antigen-binding activity of both parental antibodies. Importantly, it was demonstrated to be significantly more effective at neutralizing DENV than its parental antibodies both in vitro and in vivo, even better than the combination of them. To eliminate the potential antibody-dependent enhancement (ADE) effect, this bispecific antibody was successfully engineered to prevent Fc-γ-R interaction. Overall, we generated a bispecific anti-DENV antibody targeting both attachment and fusion stages, and this bispecific antibody broadly neutralized all 4 serotypes of DENV without risk of ADE, suggesting that it has great potential as a novel antiviral strategy against DENV.

Facile synthesis of NiCo2O4@Polyaniline core-shell nanocomposite for sensitive determination of glucose.

In this work, the core-shell structure of NiCo2O4@Polyaniline (NiCo2O4@PANI) nanocomposite is fabricated via a facile hydrothermal treatment followed by a post-Polyaniline (PANI) coating process. The synthesized materials are characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectrometer. The biosensing properties of NiCo2O4@PANI composite and NiCo2O4 nanoparticles toward glucose are studied based on glassy carbon electrode. Electrochemical studies indicate that the obtained core-shell NiCo2O4@PANI composite shows higher electrocatalytic activity toward the oxidation of glucose, compared with NiCo2O4 nanoparticles. The enhanced performance is related to the core-shell structure of NiCo2O4@PANI composite and the outstanding conductivity of the polyaniline shell. At a potential of +0.5V, the NiCo2O4@PANI nanocomposite modified glass carbon electrode demonstrates a wide linear range up to 4.7350mM with sensitivity of 4.55mAmM(-1)cm(-2) and detection limit of 0.3833µM. It also shows significant electrochemical stability, good reproducibility and excellent selectivity. The results suggest that the NiCo2O4@PANI nanocomposite is a promising electrode material for electrochemical biosensor.

Association of pSTAT3-VEGF signaling pathway with peritumoral edema in newly diagnosed glioblastoma: an immunohistochemical study.

It is well recognized that peritumoral edema is vasogenic cerebral edema in malignant glioma, and vascular endothelial growth factor (VEGF) induced by phosphorylated signal transducer and activator of transcription factor 3 (pSTAT3) strongly contributes to tumor angiogenesis in glioblastoma. However, there is no study with regard to the correlation between pSTAT3 or VEGF and peritumoral edema. Such evidence may contribute to providing new targets for the management of peritumoral cerebral. In this study, newly diagnosed glioblastoma tissues from 84 patients were collected to investigate pSTAT3 and VEGF expression by immunohistochemistry, and peritumoral edema was detected by preoperative magnetic resonance imaging. We found that a significantly positive correlation emerged between VEGF and pSTAT3 expression (P = 0.000) in glioblastoma tissues, but they were not related to patient gender and age (P > 0.05); the expression of pSTAT3 and VEGF were associated with peritumoral edema extent (P = 0.005), but not with edema shape (P > 0.05). Therefore, the pSTAT3-VEGF signaling pathway, which is correlated with peritumoral edema extent, might be a regulatory mechanism in the course of peritumoral edema formation during glioblastoma tumorigenesis and progression, thereby suggesting that STAT3 inhibition might be helpful for alleviation of peritumoral cerebral edema.

Insights into HER2 signaling from step-by-step optimization of anti-HER2 antibodies.

HER2, a ligand-free tyrosine kinase receptor of the HER family, is frequently overexpressed in breast cancer. The anti-HER2 antibody trastuzumab has shown significant clinical benefits in metastatic breast cancer; however, resistance to trastuzumab is common. The development of monoclonal antibodies that have complementary mechanisms of action results in a more comprehensive blockade of ErbB2 signaling, especially HER2/HER3 signaling. Use of such antibodies may have clinical benefits if these antibodies can become widely accepted. Here, we describe a novel anti-HER2 antibody, hHERmAb-F0178C1, which was isolated from a screen of a phage display library. A step-by-step optimization method was employed to maximize the inhibitory effect of this anti-HER2 antibody. Crystallographic analysis was used to determine the three-dimensional structure to 3.5 Å resolution, confirming that the epitope of this antibody is in domain III of HER2. Moreover, this novel anti-HER2 antibody exhibits superior efficacy in blocking HER2/HER3 heterodimerization and signaling, and its use in combination with pertuzumab has a synergistic effect. Characterization of this antibody revealed the important role of a ligand binding site within domain III of HER2. The results of this study clearly indicate the unique potential of hHERmAb-F0178C1, and its complementary inhibition effect on HER2/HER3 signaling warrants its consideration as a promising clinical treatment.

Combining trastuzumab and cetuximab combats trastuzumab-resistant gastric cancer by effective inhibition of EGFR/ErbB2 heterodimerization and signaling.

The anti-ErbB2 antibody trastuzumab has currently been approved for ErbB2-positive gastric cancer. Despite the effectiveness of trastuzumab, resistance is common. Thus, there is an urgent need to overcome trastuzumab resistance. Here, we obtain a trastuzumab-resistant cell line, which is derived from the human gastric cancer NCI-N87 cell line, by modeling the development of acquired resistance in patients. Our data show that combining trastuzumab and cetuximab leads to a significant decrease in EGFR/ErbB2 heterodimers and signaling compared with either antibody alone, and the combination results in greater antitumor activity against the trastuzumab-resistant NCI-N87 cell line, both in vitro and in vivo, suggesting that a combined EGFR/ErbB2 inhibition may overcome trastuzumab resistance.

The ErbB2-targeting antibody trastuzumab and the small-molecule SRC inhibitor saracatinib synergistically inhibit ErbB2-overexpressing gastric cancer.

The anti-ErbB2 antibody trastuzumab has shown significant clinical benefits in ErbB2-overexpressing breast and gastric cancer, but resistance to the drug is common. Here, we investigated the antitumor activity of the combination of trastuzumab and the SRC inhibitor saracatinib in ErbB2-overexpressing trastuzumab-resistant gastric cancer. The ErbB2-overexpressing human gastric cancer cell line NCI-N87 was treated with trastuzumab to obtain the trastuzumab-resistant cell line NCI-N87R. The NCI-N87R cell line showed a marked increase in SRC activity and ErbB signaling compared with the NCI-N87 cell line. Our data demonstrated that trastuzumab plus saracatinib was much more potent than either agent alone in reducing the phosphorylation of ErbB3 and AKT in both NCI-N87 and NCI-N87R gastric cancer cell lines. Trastuzumab and saracatinib synergistically inhibited the in vitro growth of NCI-N87 and NCI-N87R cell lines. Further data showed that combination therapy of trastuzumab with saracatinib resulted in a significant benefit over either agent alone in both NCI-N87 and NCI-N87R xenograft models, suggesting its potential use for treating ErbB2-overexpressing gastric cancer.

Risk of severe diarrhea with dual anti-HER2 therapies: a meta-analysis.

Although promising progress has been made with dual HER2 blockade in patients with HER2-positive breast cancer, whether the strategy of combined HER2 blockade increases the risk of severe diarrhea remains inclusive. In the present study, we investigated the overall incidence and risk of severe diarrhea when patients were treated with a combination of anti-HER2 therapies compared to anti-HER2 monotherapy. Studies that evaluated the administration of an anti-HER2 monotherapy (lapatinib or trastuzumab or pertuzumab) versus anti-HER2 combination therapy (pertuzumab plus trastuzumab or trastuzumab plus lapatinib) in breast cancer were identified from the PubMed database (1966-2013), the Cochrane library, abstracts presented at the American Society of Clinical Oncology annual conference (2004-2013), and the Web of Science database (1998-2013). Eligible studies were those in which the only systematic difference between the study arms was the type of anti-HER2 therapy used. Incidence, relative risk (RR), and 95% confidence intervals (CIs) were calculated using random effects or fixed-effects models based on the heterogeneity of the included studies. Seven trials were considered eligible. The overall incidence results for severe diarrhea in the combined anti-HER2 therapy and the anti-HER2 monotherapy were 3.48% (95% CI: 11.60-15.37%) and 8.68% (9 % CI: 7.33-10.03%), respectively. The odds ratio (OR) of severe diarrhea between anti-HER2 combination therapy and monotherapy was 1.67 (95% CI: 1.38 -5.57, p = 0.00001). This meta-analysis provides evidence that the incidence rates of severe diarrhea are comparable between anti-HER2 combination therapy and anti-HER2 monotherapy.

Bispecific antibody to ErbB2 overcomes trastuzumab resistance through comprehensive blockade of ErbB2 heterodimerization.

The anti-ErbB2 antibody trastuzumab has shown significant clinical benefits in metastatic breast cancer. However, resistance to trastuzumab is common. Heterodimerization between ErbB2 and other ErbBs may redundantly trigger cell proliferation signals and confer trastuzumab resistance. Here, we developed a bispecific anti-ErbB2 antibody using trastuzumab and pertuzumab, another ErbB2-specific humanized antibody that binds to a distinct epitope from trastuzumab. This bispecific antibody, denoted as TPL, retained the full binding activities of both parental antibodies and exhibited pharmacokinetic properties similar to those of a conventional immunoglobulin G molecule. Unexpectedly, TPL showed superior ErbB2 heterodimerization-blocking activity over the combination of both parental monoclonal antibodies, possibly through steric hindrance and/or inducing ErbB2 conformational change. Further data indicated that TPL potently abrogated ErbB2 signaling in trastuzumab-resistant breast cancer cell lines. In addition, we showed that TPL was far more effective than trastuzumab plus pertuzumab in inhibiting the growth of trastuzumab-resistant breast cancer cell lines, both in vitro and in vivo. Importantly, TPL treatment eradicated established trastuzumab-resistant tumors in tumor-bearing nude mice. Our results suggest that trastuzumab-resistant breast tumors remain dependent on ErbB2 signaling and that comprehensive blockade of ErbB2 heterodimerization may be an effective therapeutic avenue. The unique potential of TPL to overcome trastuzumab resistance warrants its consideration as a promising treatment in the clinic.

A bispecific antibody against two different epitopes on hepatitis B surface antigen has potent hepatitis B virus neutralizing activity.

Treatment of chronic hepatitis B virus (HBV) infection with interferon and viral reverse transcriptase inhibitor regimens results in poor viral clearance, loss of response, and emergence of drug-resistant mutant virus strains. These problems continue to drive the development of new therapeutic approaches to combat HBV. Here, we engineered a bispecific antibody using two monoclonal antibodies cloned from hepatitis B surface antigen (HBsAg)-specific memory B cells from recombinant HBsAg-vaccinated healthy volunteers. Next, we evaluated its efficacy in neutralizing HBV in HepaRG cells. This bispecific antibody, denoted as C4D2-BsAb, had superior HBV-neutralizing activity compared with the combination of both parental monoclonal antibodies, possibly through steric hindrance or induction of HBsAg conformational changes. Moreover, C4D2-BsAb has superior endocytotic characteristics into hepatocytes, which inhibits the secretion of HBsAg. These results suggest that the anti-HBsAg bispecific antibody may be an effective treatment method against HBV infection.