Purification and identification of novel antioxidant peptides derived from Bombyx mori pupae hydrolysates

The biological importance of antioxidant peptides was the focus of new natural sources of food preservatives. Bombyx mori pupae are considered a valuable by-product of the silk-reeling industry due to their high-quality protein content. This study aimed to purify and identify the antioxidant peptides obtained from enzymatically hydrolyzed B. mori pupae, which could be used as new sources of natural food preservatives. Among the prepared hydrolysates, pepsin hydrolysate with the highest antioxidant activities was purified sequentially using ultrafiltration and reversed-phase high-performance liquid chromatography (RP-HPLC). The DPPH radical scavenging and ferrous ion chelating activity were used to evaluate antioxidant activity. Fractions with high activity were further analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Three peptides were identified as Glu-Asn-Ile-Ile-Leu-Phe-Arg (ENIILFR), Leu-Asn-Lys-Asp-Leu-Met-Arg (LNKDLMR), and Met-Leu-Ile-Ile-Ile-Met-Arg (MLIIIMR), respectively. All three novel identified peptides exhibited significantly stronger antioxidant capacity than synthetic antioxidants used in the food industry, including butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT). ENIILFR showed the best antioxidant activity. These findings indicate that the three peptides have potential applications as natural antioxidants in the food industry.

Distinct cholangiocarcinoma cell migration in 2D monolayer and 3D spheroid culture based on galectin-3 expression and localization

Introduction

Cholangiocarcinoma (CCA) is difficult to cure due to its ineffective treatment and advanced stage diagnosis. Thoroughly mechanistic understandings of CCA pathogenesis crucially help improving the treatment success rates. Using three-dimensional (3D) cell culture platform offers several advantages over a traditional two-dimensional (2D) culture as it resembles more closely to in vivo tumor.

Methods

Here, we aimed to establish the 3D CCA spheroids with lowly (KKU-100) and highly (KKU-213A) metastatic potentials to investigate the CCA migratory process and its EMT-associated galectin-3 in the 3D setting.

Results and discussion

Firstly, the growth of lowly metastatic KKU-100 cells was slower than highly metastatic KKU-213A cells in both 2D and 3D systems. Hollow formation was observed exclusively inside the KKU-213A spheroids, not in KKU-100. Additionally, the migration activity of KKU-213A cells was higher than that of KKU-100 cells in both 2D and 3D systems. Besides, altered expression of galectin-3 were observed across all CCA culture conditions with substantial relocalization from inside the 2D cells to the border of spheroids in the 3D system. Notably, the CCA migration was inversely proportional to the galectin-3 expression in the 3D culture, but not in the 2D setting. This suggests the contribution of culture platforms to the alternation of the CCA cell migration process.

Conclusions

Thus, our data revealed that 3D culture of CCA cells was phenotypically distinct from 2D culture and pointed to the superiority of using the 3D culture model for examining the CCA cellular mechanisms, providing knowledges that are better correlated with CCA phenotypes in vivo.

Comparative Proteomic Profiling of Cisplatin-resistant Nasopharyngeal Carcinoma Cell Lines: Novel Biomarkers for Improving Chemotherapy of NPC

BACKGROUND/AIM

Nasopharyngeal carcinoma (NPC) originates in the hidden nasopharynx, causing NPC patients to be diagnosed at a late stage and develop drug resistance. Therefore, the identification of drug-resistance biomarkers is indispensable to improve NPC detection and treatment. Hence, this study aimed to identify novel cisplatinresistance biomarkers using comparative proteomic profiles of cisplatin-resistant (CDDP/NPC) cell lines.

MATERIALS AND METHODS

Two cisplatin-resistant NPC cell lines (CDDP/5-8F and CDDP/6-10B) were established by a continuous cisplatin treatment. Then, morphology, proliferation, and migration of all NPC cells were evaluated, followed by the examination of protein profiles using 1D in-gel digestion coupled with mass spectrometry. The potential drugresistance biomarkers were transcriptionally and translationally validated by qPCR and western blotting, respectively.

RESULTS

CDDP/5-8F and CDDP/6-10B cells were successfully developed with a resistance index of 8.42 and 2.46, respectively. Furthermore, both CDDP/NPC cells demonstrated relatively altered morphology, retarded growth, and decreased migration. Additionally, the comparative proteomic analysis of CDDP/NPC revealed 92 differentially expressed proteins (DEPs). Specifically, up-regulated DEPs were notably enriched in cellular metabolic processes, while down-regulated DEPs were predominantly enriched in actin filament-based movement, methylation, and programmed cell death. Six up-regulated, namely ALPI, CKB, HMGB1, KHSRP, PDIA4, and STMN1, and three down-regulated proteins, FUBP1, YWHAZ, and PLEC, were validated at the transcriptional level. CKB and FUBP1 were further validated at the translational level and demonstrated corresponding expression levels at both protein and gene levels.

CONCLUSION

Our findings suggest novel biomarkers to indicate cisplatin resistance in NPC, expanding the drug resistance knowledge and paving the way for in-depth mechanism studies in NPC.

Cell-penetrable nanobodies (transbodies) that inhibit the tyrosine kinase activity of EGFR leading to the impediment of human lung adenocarcinoma cell motility and survival

Most patients suffering from non-small cell lung cancer (NSCLC) have epidermal growth factor receptor (EGFR) overexpression. Currently, EGFR tyrosine kinase inhibitors (TKIs) that act as the ATP-analogs and monoclonal antibodies (MAbs) to EGFR-ectodomain that block intracellular signaling are used for the treatment of advanced NSCLC. Unfortunately, adverse effects due to the TKI off-target and drug resistance occur in a significant number of the treated patients while some NSCLC genotypes do not respond to the therapeutic MAbs. Thus, a more effective remedy for the treatment of EGFR-overexpressed cancers is deemed necessary. In this study, VH/V_H H displayed-phage clones that are bound to recombinant EGFR-TK were fished-out from a humanized-camel VH/V_H H phage display library. VH/V_H H of three phage-infected Escherichia coli clones (VH18, V_H H35, and VH36) were linked molecularly to nonaarginine (R9) for making them cell penetrable. R9-VH18, R9-V_H H35, and R9-VH36 were cytotoxic to human adenocarcinomic alveolar basal epithelial cells (A549) at the fifty percent inhibitory concentration (IC₅₀ ) 0.181 ± 0.132, 0.00961 ± 0.00516, and 0.00996 ± 0.00752 μM, respectively, which were approximately 1000-fold more effective than small molecular TKIs. R9-VH18 and R9-VH36 also delayed cancer cell migration in a scratch-wound assay. Computerized homology modeling and intermolecular docking revealed that VH18 and V_H H35 used CDR3 to interact with EGFR-TK residues close to the catalytic site, which might sterically hinder the ATP-binding of the TK; VH36 used CDR2 to bind at the asymmetric dimerization surface, which might disrupt EGFR dimerization leading to inhibition of intracellular signaling. The humanized-cell penetrable nanobodies have a high potential for developing further towards a clinical application.

Engineering Nanocarriers for siRNA Delivery

The discovery of RNA interference has revitalized the long ongoing pursuit of gene therapy for the treatment of diseases. Nevertheless, despite promising results from experimental studies, there remains a pressing need for the development of nanocarriers that are clinically-relevant, biocompatible, efficient, and that can be tailored to specific disease targets. This review surveys the broad spectrum of nanomaterials and their functional add-ons, and aims to provide a guide towards engineering nanocarriers for effective siRNA delivery.

Multifunctional nanoarchitectures from DNA-based ABC monomers

The ability to attach different functional moieties to a molecular building block could lead to applications in nanoelectronics, nanophotonics, intelligent sensing and drug delivery. The building unit needs to be both multivalent and anisotropic, and although many anisotropic building blocks have been created, these have not been universally applicable. Recently, DNA has been used to generate various nanostructures or hybrid systems, and as a generic building block for various applications. Here, we report the creation of anisotropic, branched and crosslinkable building blocks (ABC monomers) from which multifunctional nanoarchitectures have been assembled. In particular, we demonstrate a target-driven polymerization process in which polymers are generated only in the presence of a specific DNA molecule, leading to highly sensitive pathogen detection. Using this monomer system, we have also designed a biocompatible nanovector that delivers both drugs and tracers simultaneously. Our approach provides a general yet versatile route towards the creation of a range of multifunctional nanoarchitectures.