Quantitative Proteomic Analysis of Escherichia coli Heat-Labile Toxin B Subunit (LTB) with Enterovirus 71 (EV71) Subunit VP1.

The nontoxic heat-labile toxin (LT) B subunit (LTB) was used as mucosal adjuvant experimentally. However, the mechanism of LTB adjuvant was still unclear. The LTB and enterovirus 71 (EV71) VP1 subunit (EVP1) were constructed in pET32 and expressed in E. coli BL21, respectively. The immunogenicity of purified EVP1 and the adjuvanticity of LTB were evaluated via intranasal immunization EVP1 plus LTB in Balb/c mice. In order to elucidate the proteome change triggered by the adjuvant of LTB, the proteomic profiles of LTB, EVP1, and LTB plus EVP1 were quantitatively analyzed by iTRAQ-LC-MS/MS (isobaric tags for relative and absolute quantitation; liquid chromatography-tandem mass spectrometry) in murine macrophage RAW264.7. The proteomic data were analyzed by bioinformatics and validated by western blot analysis. The predicted protein interactions were confirmed using LTB pull-down and the LTB processing pathway was validated by confocal microscopy. The results showed that LTB significantly boosted EVP1 specific systematic and mucosal antibodies. A total of 3666 differential proteins were identified in the three groups. Pathway enrichment of proteomic data predicted that LTB upregulated the specific and dominant MAPK (mitogen-activated protein kinase) signaling pathway and the protein processing in endoplasmic reticulum (PPER) pathway, whereas LTB or EVP1 did not significantly upregulate these two signaling pathways. Confocal microscopy and LTB pull-down assays confirmed that the LTB adjuvant was endocytosed and processed through endocytosis (ENS)-lysosomal-endoplasmic reticulum (ER) system.

Intravenous Administration Is an Effective and Safe Route for Cancer Gene Therapy Using the Bifidobacterium-Mediated Recombinant HSV-1 Thymidine Kinase and Ganciclovir.

The herpes simplex virus thymidine kinase/ganciclovir (HSV TK/GCV) system is one of the best studied cancer suicide gene therapy systems. Our previous study showed that caspase 3 expression was upregulated and bladder tumor growth was significantly reduced in rats treated with a combination of Bifidobacterium (BF) and HSV TK/GCV (BF-rTK/GCV). However, it was raised whether the BF-mediated recombinant thymidine kinase combined with ganciclovir (BF-rTK/GCV) was safe to administer via venous for cancer gene therapy. To answer this question, the antitumor effects of BF-rTK/GCV were mainly evaluated in a xenograft nude mouse model bearing MKN-45 gastric tumor cells. The immune response, including analysis of cytokine profiles, was analyzed to evaluate the safety of intramuscular and intravenous injection of BF-rTK in BALB/c mice. The results suggested that gastric tumor growth was significantly inhibited in vivo by BF-rTK/GCV. However, the BF-rTK/GCV had no effect on mouse body weight, indicating that the treatment was safe for the host. The results of cytokine profile analysis indicated that intravenous injection of a low dose of BF-rTK resulted in a weaker cytokine response than that obtained with intramuscular injection. Furthermore, immunohistochemical analysis showed that intravenous administration did not affect the expression of immune-associated TLR2 and TLR4. Finally, the BF-rTK/GCV inhibited vascular endothelial growth factor (VEGF) expression in mouse model, which is helpful for inhibiting of tumor angiogenesis. That meant intravenous administration of BF-rTK/GCV was an effective and safe way for cancer gene therapy.

[Effect of silencing AEG-1 with small interfering RNA on the proliferation and cell cycle of gastric carcinoma SGC-7901 cells].

OBJECTIVE: To explore the effect of down-regulation of astrocyte elevated gene-1 (AEG-1) expression on cell proliferation and cell cycle of gastric carcinoma cells, and its possible molecular mechanism. METHODS: Control siRNA and AEG-1 siRNA were transfected into gastric carcinoma SGC-7901 cells. 48 h after transfection, the cells were divided into 3 groups including untransfected, siRNA control and AEG-1 siRNA transfection groups. Expressions of AEG-1 mRNA and protein in the 3 group cells were detected by real-time quantitative PCR and Western blot. The changes of cell proliferation were examined using CCK-8 kit, and the cell cycle distribution was detected by flow cytometry. Finally, expressions of cell proliferation and cell cycle related proteins were detected by Western blot. RESULTS: Real-time quantitative PCR and Western blot demonstrated that compared with the untransfected and siRNA control groups, expressions of AEG-1 mRNA and protein were significantly down-regulated in the AEG-1 siRNA transfection group (P < 0.05), but there was no significant difference between the untransfected and siRNA control groups (P > 0.05). Furthermore, in vivo experiment confirmed a significant down-regulation of AEG-1 protein in the AEG-1 siRNA transfection group (P < 0.05). In addition, AEG-1 siRNA obviously inhibited the proliferation of SGC-7901 cells at different time points after transfection with AEG-1 siRNA. The percentage of cells in G0/G1 phase in the AEG-1 siRNA transfection group [(61.26 ± 1.25)%] was significantly higher than those in the untransfected group [(46.17 ± 1.91)%] and siRNA control group [(46.46 ± 1.96)%], and there was a significant difference between them (all P < 0.001). Furthermore, the result of Western blotting revealed that down-regulation of AEG-1 expression evoked the down-regulation of cdk2 and cyclin D1 expressions and elevation of p21 expression in vitro and in vivo. CONCLUSIONS: The inhibition of cell proliferation and cell cycle arrest mediated by down-regulation of AEG-1 expression may be closely associated with the changes of expression of cell cycle related proteins including cdk2, cyclin D1 and p21.

Development of stimuli responsive polymeric nanomedicines modulating tumor microenvironment for improved cancer therapy.

The complexity of the tumor microenvironment (TME) severely hinders the therapeutic effects of various cancer treatment modalities. The TME differs from normal tissues owing to the presence of hypoxia, low pH, and immune-suppressive characteristics. Modulation of the TME to reverse tumor growth equilibrium is considered an effective way to treat tumors. Recently, polymeric nanomedicines have been widely used in cancer therapy, because their synthesis can be controlled and they are highly modifiable, and have demonstrated great potential to remodel the TME. In this review, we outline the application of various stimuli responsive polymeric nanomedicines to modulate the TME, aiming to provide insights for the design of the next generation of polymeric nanomedicines and promote the development of polymeric nanomedicines for cancer therapy.

Stem cell-derived hepatocyte therapy using versatile biomimetic nanozyme incorporated nanofiber-reinforced decellularized extracellular matrix hydrogels for the treatment of acute liver failure.

Reactive oxygen species (ROS)-associated oxidative stress, inflammation storm, and massive hepatocyte necrosis are the typical manifestations of acute liver failure (ALF), therefore specific therapeutic interventions are essential for the devastating disease. Here, we developed a platform consisting of versatile biomimetic copper oxide nanozymes (Cu NZs)-loaded PLGA nanofibers (Cu NZs@PLGA nanofibers) and decellularized extracellular matrix (dECM) hydrogels for delivery of human adipose-derived mesenchymal stem/stromal cells-derived hepatocyte-like cells (hADMSCs-derived HLCs) (HLCs/Cu NZs@fiber/dECM). Cu NZs@PLGA nanofibers could conspicuously scavenge excessive ROS at the early stage of ALF, and reduce the massive accumulation of pro-inflammatory cytokines, herein efficiently preventing the deterioration of hepatocytes necrosis. Moreover, Cu NZs@PLGA nanofibers also exhibited a cytoprotection effect on the transplanted HLCs. Meanwhile, HLCs with hepatic-specific biofunctions and anti-inflammatory activity acted as a promising alternative cell source for ALF therapy. The dECM hydrogels further provided the desirable 3D environment and favorably improved the hepatic functions of HLCs. In addition, the pro-angiogenesis activity of Cu NZs@PLGA nanofibers also facilitated the integration of the whole implant with the host liver. Hence, HLCs/Cu NZs@fiber/dECM performed excellent synergistic therapeutic efficacy on ALF mice. This strategy using Cu NZs@PLGA nanofiber-reinforced dECM hydrogels for HLCs in situ delivery is a promising approach for ALF therapy and shows great potential for clinical translation.

[Effects of KIAA0101 expression on proliferation and invasion of gastric carcinoma MKN-45 cells].

OBJECTIVE: To investigate the expression of KIAA0101 protein in gastric carcinoma cells, and to explore the effects of its down-regulation on the cell proliferation, cell cycle and invasion. METHODS: Western blot was used to detect KIAA0101 protein expression in three gastric carcinoma cell lines including MKN-28, SGC-7901 and MKN-45. KIAA0101 siRNA and control siRNA were utilized to transfect MKN-45 cells, respectively. CCK-8 was used to analyze the changes of cell proliferation, and flow cytometry to examine the changes of cell cycle distribution. Finally, Boyden chamber was used to detect the ability of cell invasion. RESULTS: Relative level of KIAA0101 protein in MKN-45 cells was significantly higher than those in MKN-28 and SGC-7901 cells, and there was significant difference among the three cell lines (P < 0.05). The result of CCK-8 study demonstrated that, compared with untreated group and control siRNA group, the proliferation of MKN-45 cells in KIAA0101 siRNA group was significantly inhibited (P < 0.05). Additionally, the result of cell cycle analysis revealed that the percentage of cell number in G(0)/G(1) phase in KIAA0101 siRNA group [(61.47 ± 0.89)%] was significantly higher than those in untreated group [(47.43 ± 0.85)%] and control siRNA group [(48.43 ± 0.73)%; F = 271.653, P = 0.000]. Further, Boyden chamber assay showed that the cell numbers migrated to Matrigel in KIAA0101 siRNA group (61.51 ± 4.76) were significantly lower than those in untreated group (138.74 ± 10.16) and control siRNA group (132.93 ± 11.25; F = 65.949, P = 0.000). CONCLUSIONS: Down-regulation of KIAA0101 expression leads to an inhibition of cell proliferation, cell cycle and cell invasion. It may provide a novel target for the treatment of patients with gastric carcinoma.

Membrane-fusogenic biomimetic particles: a new bioengineering tool learned from nature.

Membrane fusion, a fundamental biological process of the fusion of the membrane composition between cells, is vital for cell-cell communication and cargo transport between living cells. This fusion interaction achieves the transportation of the inner content to the cellular cytosol as well as the simultaneous blending of foreign substances with the cell membrane. Inspired by this biological process, emerging membrane-fusogenic particles have been developed, opening a new area for bioengineering and biomedical applications. Especially, membrane-fusion-mediated transfer of inner cargoes can bypass endosomal entrapment to maximize the transportation efficiency, emerging as a unique cytoplasmic delivery platform distinct from those depending on conventional endocytosis-based pathways. In addition, the membrane fusion enables cell surface modification through lipid diffusion and mixing, providing a tool for direct cell membrane engineering. In this review, we focus on the development of membrane-fusogenic particles and their up-to-date progress. We briefly introduce the concept of membrane fusion, elaborate inspiring strategies of membrane-fusogenic particles, and highlight the recent advances and the promising applications of membrane-fusogenic particles as a next-generation bioengineering tool. In the end, we conclude with the present challenges and opportunities, providing insights in the future research of membrane-fusogenic particles.

Bovine serum albumin-gold nanoclusters protein corona stabilized polystyrene nanoparticles as dual-color fluorescent nanoprobes for breast cancer detection.

Breast cancer is the most prevalent malignancy and the first leading cause of cancer-related mortality among the female population worldwide. Approaches for precise and reliable detection of breast cancer cells, particularly in the nascent state, are desperately needed for elevating the survival rate of patients bearing the breast tumor. In this work, we successfully performed the sensitive, precise, and reliable breast cancer cell detection using facilely fabricated bovine serum albumin-gold nanocluster (BSA-AuNCs) protein corona stabilized, epithelial cell adhesion molecule (EpCAM) aptamer linked fluorescent polystyrene nanoparticle (PS NP), termed as PS-BSA-AuNCs-Apt. The rapidly adsorbed BSA-AuNCs hard protein corona without complicated covalent conjugation not only imparted excellent colloidal stability to the PS nanoparticles, but also offered numerous active anchors for the targeted EpCAM aptamers to locate. With the remarkable aid of the aptamers specifically targeting the EpCAM-positive breast cancer cells, the PS-BSA-AuNCs-Apt emitted strong and photostable dual-color fluorescent signals for precise and reliable cancer cell detection by overcoming the false signals. The specific identification potency of the PS-BSA-AuNCs-Apt system was further verified by successfully detecting the xenografted breast tumor tissue. Notably, to the best of our knowledge, the protein corona formed nanoprobes was exploited for direct tumor cell and tissue detection with high efficacy for the first time, demonstrating their promising potential in clinical tumor detection.

Betulinic acid enhanced the chemical sensitivity of esophageal cancer cells to cisplatin by inducing cell pyroptosis and reducing cell stemness.

BACKGROUND: Betulinic acid (BA) is a lupine pentacyclic triterpene compound derived from the bark of the white mulberry tree, which has a variety of pharmacological properties. The purpose of this study was to investigate the effects of BA combined with cisplatin on the proliferation, stemness, pyroptosis, and xenograft growth of esophageal carcinoma cells in a nude mouse xenograft model. METHODS: The cell survival rate was detected by CCK-8 method. TE-11 cells were treated with 3µM of BA and 15 µM of cisplatin. The cells were randomly divided into four groups: the control group, the BA group, the cisplatin group, and the BA + Cisplatin group. Western blotting was used to detect the expression levels of Ki67, PCNA, SOX2, OCT4, ASC, and Caspase-1. The xenograft model of nude mice was constructed to detect tumor volume, and the positive expression rates of Ki67 and Caspase-1 were detected by immunohistochemistry. RESULTS: Compared with the control group, Ki67, PCNA, SOX2, and OCT4 levels in the BA and cisplatin groups were significantly lower (P<0.05), while ASC and Caspase-1 levels were significantly higher (P<0.05). Compared with the BA group, Ki67, PCNA, SOX2, and OCT4 levels in the BA + cisplatin group were significantly lower (P<0.05), while ASC and Caspase-1 levels were significantly higher (P<0.05). In the nude mouse xenograft model, compared with the control group, the tumor volume of the BA and cisplatin groups was significantly decreased (P<0.05), the expression rate of Ki67 was significantly decreased (P<0.05), and the expression rate of Caspase-1 was significantly increased (P<0.05). Compared with the BA group, the levels of ASC and Caspase-1 in the BA + cisplatin group were significantly lower (P<0.05), the positive expression rate of Ki67 was significantly lower (P<0.05), and the positive expression rate of Caspase-1 was significantly higher (P<0.05). CONCLUSIONS: BA enhances the chemical sensitivity of esophageal cancer cells to cisplatin by inhibiting cell proliferation, reducing cell stemness, and inducing pyroptosis.

A chalcone inhibits the growth and metastasis of KYSE-4 esophageal cancer cells.

OBJECTIVE: To investigate the in vitro and in vivo anticancer effects of a chalcone against KYSE-4 esophageal cancer cells. METHODS: A chalcone was synthesized via the molecular hybridization strategy based on the anticancer activity of chalcone and dithiocarbamate scaffolds. The anticancer effects of different concentrations of the chalcone derivative were compared in esophageal cancer cells. RESULTS: This chalcone displayed strong inhibitory effects on esophageal cancer cell growth with an IC50 of 1.06 µM in KYSE-4 cells. Analysis of the mechanism revealed that the derivative obviously inhibited KYSE-4 cell growth, migration, and invasion in a concentration-dependent manner. Furthermore, the compound regulated migration-related biomarkers (E-cadherin, N-cadherin, and Slug) and inhibited the Wnt/ß-catenin pathway. According to western blotting, this chalcone suppressed the expression of proline-rich protein 11 (PRR11) in a concentration- and time-dependent manner. CONCLUSIONS: This chalcone might be a leading candidate for suppressing the growth and metastasis of esophageal cancer by downregulating PRR11 expression and inhibiting Wnt/ß-catenin signaling.

A polypeptide based podophyllotoxin conjugate for the treatment of multi drug resistant breast cancer with enhanced efficiency and minimal toxicity.

Podophyllotoxin (PPT) is a chemotherapeutic agent which has shown significant activity against P-glycoprotein (P-gp) mediated multi drug resistant cancer cells. However, because of the poor aqueous solubility and high toxicity, PPT cannot be used in clinical cancer therapy. In order to enhance the efficiency and reduce side effect of PPT, a polypeptide based PPT conjugate PLG-g-mPEG-PPT was developed and used for the treatment of multi drug resistant breast cancer. The PLG-g-mPEG-PPT was prepared by conjugating PPT to poly(l-glutamic acid)-g-methoxy poly(ethylene glycol) (PLG-g-mPEG) via ester bonds. The PPT conjugates self-assembled into nanoparticles with average sizes about 100 nm in aqueous solution. Western blotting assay showed that the PLG-g-mPEG-PPT could effectively inhibit the expression of P-gp in the multiple drug resistant MCF-7/ADR cells. In vitro cytotoxicity assay indicated that the resistance index (RI) values of PLG-g-mPEG-PPT on different drug-resistant cancer cell lines exhibited 57-270 folds reduction than of traditional microtubule inhibitor chemotherapeutic drug PTX or DTX. Hemolysis assay demonstrated that the conjugation greatly decreased the hemolytic activity of free PPT. Maximum tolerated dose (MTD) of PLG-g-mPEG-PPT increased greatly (13.3 folds) as compared to that of free PPT. In vivo study showed that the PLG-g-mPEG-PPT conjugate remarkably enhanced the antitumor efficacy against MCF-7/ADR xenograft tumors with a tumor suppression rate (TSR) of 82.5%, displayed significantly improved anticancer efficacy as compared to free PPT (TSR = 37.1%) with minimal toxicity when both of the two formulations were used in MTD. STATEMENT OF SIGNIFICANCE: The development of multiple drug resistance (MDR) of cancer cells is the main cause of chemotherapy failure. The over-expression of P-glycoprotein (P-gp) has been recognized to be the most important cause of MDR in cancer. Podophyllotoxin (PPT) is a chemotherapeutic agent which has shown strong activity against P-gp mediated multidrug resistant cancer cells by simultaneously inhibiting the over-expression of P-gp and the growth of cancer cells. However, PPT can not be used in clinical cancer treatment due to its poor aqueous solubility and high toxicity. Herein, we developed a polypeptide based PPT conjugate PLG-g-mPEG-PPT by conjugating PPT to poly(l-glutamic acid)-g-methoxy poly(ethylene glycol). The PLG-g-mPEG-PPT shows significantly decreased hemolytic activity, greatly improved maximum tolerated dose and remarkably enhanced antitumor efficacy against MCF-7/ADR xenograft tumors as compared to free PPT.

Legumain-cleavable 4-arm poly(ethylene glycol)-doxorubicin conjugate for tumor specific delivery and release.

Traditional chemotherapy strategy exists undesirable toxic side-effects to normal tissues due to the low selectively to cancer cells of micromolecule cytotoxic drugs. One considered method to realizing the targeted delivery and increasing the specificity to tumor tissues of the cytotoxic drug is to transporting and discharging it through an environment-sensitive mechanism. In this study, a novel enzyme-sensitive polymer-doxorubicin conjugate was designed to delivery chemotherapeutic drug in a tumor-specific behavior and selectively activated in tumor tissue. Briefly, doxorubicin (DOX) was conjugated to carboxyl-terminated 4-arm poly(ethylene glycol) through a tetrapeptide linker, alanine-alanine-asparagine-leucine (AANL), which was one of the substrates of legumain, an asparaginyl endopeptidase that was found presented in plants, mammals and also highly expressed in human tumor tissues. Hereinafter, the polymer-DOX conjugate was termed as 4-arm PEG-AANL-DOX. Dynamic laser scattering (DLS) and transmission electron microscopy (TEM) measurements indicated that the 4-arm PEG-AANL-DOX could self-assemble into micelles in aqueous solution. Drug release and in vitro cytotoxicity studies revealed that the 4-arm PEG-AANL-DOX could be cleaved by legumain. Ex vivo DOX fluorescence imaging measurements demonstrated that the 4-arm PEG-AANL-DOX had an improved tumor-targeting delivery as compared with the free DOX·HCl. In vivo studies on nude mice bearing MDA-MB-435 tumors revealed that the 4-arm PEG-AANL-DOX had a comparable anticancer efficacy with the free DOX·HCl but without DOX-related toxicities to normal tissues as measured by body weight change and histological assessments, indicating that the 4-arm PEG-AANL-DOX had an improved therapeutic index for cancer therapy. STATEMENT OF SIGNIFICANCE: Herein we describe the construction of a novel tumor environment-sensitive delivery system through the instruction of a legumain-cleavable linkage to a polymer-DOX conjugate (4-arm PEG-AANL-DOX). This particular design strategy allows for polymer-DOX conjugates to be delivered in a tumor-specific manner and selectively activable in tumor microenvironment so that it can combine the advantages of tumor-specific delivery and tumor intracellular microenvironment-triggered release systems.

Expression of proline rich protein 11 in esophageal cancer tissues and its effect on malignant biological behaviors of TE-2 cells / 中国肿瘤生物治疗杂志

@# Objective: To investigate the expressionof proline-rich protein 11 (PRR11) in esophageal carcinoma (EC) tissues and to study it’s effect on the proliferation and metastasis of human EC TE-2 cells in vitro. Methods: Eighty patients were pathologically diagnosed with EC the Department of Thoracic Surgery of the Second Affiliated Hospital of Zhengzhou University from October 2016 to October 2018, and their surgically resected cancer tissues and corresponding para-cancerous tissues were collected for this study. qPCR was used to detect the expression of PRR11 mRNAin tissues or cells. Log-rank Test was used to analyzethe relationship between the expression of PRR11 in EC tissues and general data, histological type, lymphatic metastasis, depth of invasion and TNM stageof the EC patients. Kaplan-Meierplot was used to analyze the association between PRR11 mRNA and patients’prognosis. TE-2 cells were transfected with lentivirus shRNA to construct cell line with PRR11 knockout and corresponding control cell lines, as shPRR11#1, shPRR11#2 and control group. qPCR and WB assays were used to verify the mRNA and protein expressions of PRR11 in cell lines respectively. MTT was used to examine the proliferation of transfected cells, and Transwell experiments were used to detect cell invasion and migration. Results: The expression of PRR11 mRNA in EC was higher than that in para-cancer tissues (P<0.05). There was significant correlation between PRR11 over-expression and histological type, lymphatic metastasis, depth of invasion and TNM stage(all P <0.05), and high PRR11 expression was significantly related with the poor prognosis of EC patients (P<0.05). The mRNA and protein expressions of PRR11 in cells of shPRR11#1 and shPRR11#2 groups were significantly lower than those in control group (all P <0.05). MTT assay showed that the proliferation of cells in shPRR11#1 and shPRR11#2 groups was significantly lower than that in the control group (P<0.05 or P<0.01). The results of Transwell invasion and migration assays showed that the average number of cells with in each field of viewin shPRR11#1 and shPRR11#2 groups was significantly lower than that in the control group (P<0.01). Conclusion: PRR11 is over-expressed in EC tissues and PRR11 over-expression is closely related to the occurrence, progression and prognosis of esophageal cancer. In vitro experiments have also demonstrated that knockdown of PRR11 can inhibit the proliferation, invasion and migration of EC. PRR11 can be used as a potential molecule marker and drug targets for EC. ··