Improving combination cancer immunotherapy by manipulating dual immunomodulatory signals with enzyme-triggered, cell-penetrating peptide-mediated biomodulators.

Immunosuppressive tumor microenvironments challenge the effectiveness of protein-based biopharmaceuticals in cancer immunotherapy. Reestablishing tumor cell immunogenicity by enhancing calreticulin (CRT) exposure is expected to improve tumor immunotherapy. Given that CRT translocation is inherently modulated by phosphorylated eIF2α, the selective inhibition of protein phosphatase 1 (PP1) emerges as an effective strategy to augment tumor immunogenicity. To harness the PP1-disrupting potential of GADD34-derived motifs and address their limited intracellular delivery, we integrated these sequences into an enzyme-triggered, cell-penetrating peptide-mediated chimeric protein scaffold. This design not only facilitates efficient cytoplasmic delivery of these immunostimulatory motifs to induce "eat-me" signaling, but also provides a versatile platform for combination immunotherapy. Fabrication of biomodulators with cytotoxic BLF1 provides additional "eat-me" signaling through phosphatidylserine exposure or that with an immunomodulatory designed ankyrin repeat protein disables "don't-find-me" signaling by antagonizing PD-L1. Notably, these bifunctional biomodulators exhibit remarkable ability to induce macrophage phagocytosis, dendritic cell maturation, and CD8+ T activation, ultimately substantially inhibiting tumor growth. This study presents a modular genetic coding strategy for PP1-centered therapies that enables seamless integration of immunostimulatory sequences into protein-based anti-tumor cocktail therapies, thereby offering novel alternatives for improving antitumor efficacy.

Improving nanochemoimmunotherapy efficacy by boosting "eat-me" signaling and downregulating "don't-eat-me" signaling with Ganoderma lucidum polysaccharide-based drug delivery.

To address the challenges posed by low immunogenicity and immune checkpoints during cancer treatment, we propose an alternative strategy that combines immunogenic cell death (ICD) effects with CD47/SIRPα blockade to reactivate phagocytosis of tumor cells by macrophages with polysaccharide-based drug delivery. In this study, the EGFR inhibitor gefitinib was identified as a novel CD47 modulator, which promoted the translocation of CD47 molecules from the cell membrane to endosomes through the EGFR-Rab5 pathway, leading to reduced cell surface CD47 levels and limiting interaction with SIRPα. Based on this finding, we developed prophagocytic mixed nanodrugs to enhance macrophage phagocytosis by encapsulating ICD inducer doxorubicin and CD47 inhibitor gefitinib with immunostimulatory polysaccharides from Ganoderma lucidum. This approach downregulated cell surface CD47 expression to attenuate "don't-eat-me" signaling, while increasing doxorubicin accumulation in tumors by inhibiting drug-resistance proteins, leading to more exposure of calreticulin and amplifying the "eat-me" signaling. In vivo experiments demonstrated that this approach significantly suppressed intraperitoneal tumor dissemination, reversed doxorubicin-induced weight loss, and effectively induced macrophage polarization, dendritic cell maturation, and CD8+ T cell activation. These findings highlighted the significant potential of our macrophage-centered therapeutic strategy using polysaccharide-based nanocarriers and provided new perspectives for chemoimmunotherapy.

Design and characterization of a novel tumor-homing cell-penetrating peptide for drug delivery in TGFBR3 high-expressing tumors.

Targeted therapy has attracted more and more attention in cancer treatment in recent years. However, due to the diversity of tumor types and the mutation of target sites on the tumor surface, some existing targets are no longer suitable for tumor therapy. In addition, the long-term administration of a single targeted drug can also lead to drug resistance and attenuate drug potency, so it is important to develop new targets for tumor therapy. The expression of Type III transforming growth factor ß receptor (TGFBR3) is upregulated in colon, breast, and prostate cancer cells, and plays an important role in the occurrence and development of these cancers, so TGFBR3 may be developed as a novel target for tumor therapy, but so far there is no report on this research. In this study, the structure of bone morphogenetic protein 4 (BMP4), one of the ligands of TGFBR3 was analyzed through the docking analysis with TGFBR3 and sequence charge characteristic analysis, and a functional tumor-targeting penetrating peptide T3BP was identified. The results of fluorescent labeling experiments showed that T3BP could target and efficiently enter tumor cells with high expression of TGFBR3, especially A549 cells. When the expression of TGFBR3 on the surface of tumor cells (HeLa) was knocked down by RNA interference, the high delivery efficiency of T3BP was correspondingly reduced by 40%, indicating that the delivery was TGFBR3-dependent. Trichosanthin (TCS, a plant-derived ribosome inactivating protein) fused with T3BP can enhance the inhibitory activity of the fusion protein on A549 cells by more than 200 times that of TCS alone. These results indicated that T3BP, as a novel targeting peptide that can efficiently bind TGFBR3 and be used for targeted therapy of tumors with high expression of TGFBR3. This study enriches the supply of tumor-targeting peptides and provides a new potential application option for the treatment of tumors with high expression of TGFBR3.

Cytotoxic effects of recombinant proteins enhanced by momordin Ic are dependent on cholesterol and ganglioside GM1.

Plant-derived triterpenoid saponins have been shown to play a powerful role in enhancing the cytotoxic activity of protein therapeutics. However, the mechanism of how saponins are acting is not clearly understood. In this study, momordin Ic (MIC), a triterpenoid saponin derived from Kochia scoparia (L.) Schrad., specifically enhance the antiproliferative effect of recombinant MAP30 (a type I ribosome inactivating protein, RIP) in breast cancer cells. Subsequently, the possible mechanism of how MIC enhanced the cytotoxicity of MAP30 was analyzed in detail. We observed the level of intracellular labeled MAP30 using fluorescence microscopy and flow cytometry. And a reporter protein, GAL9, was used to monitor the role of MIC in promoting endosomal escape. We found endosomal escape does not play a role for the enhancer effect of MIC while the effect of MIC on MAP30 is cholesterol dependent and that ganglioside GM1, a lipid raft marker, can competitively inhibit cytotoxicity of MAP30 enhanced by MIC. Finally, we provided some insights into the correlation between the sugar side chain of MIC and its role in enhancing of RIP cytotoxicity and altering of drug cell tropism.

Expression level of serum miR-374a-5p in patients with acute pancreatitis and its effect on viability, apoptosis, and inflammatory factors of pancreatic acinar cells induced by cerulein.

Acute pancreatitis (AP) is one of the life-threatening diseases of the digestive system. MicroRNA has been asserted to be a regulator of AP. This paper explored the miR-374a-5p expression in AP patients and investigated the efficacy of AR42J cells. In this study, 60 healthy people, 58 MAP patients and 58 SAP patients were included, and the serum miR-374a-5p levels of the subjects were detected by RT-qPCR technology. The pancreatitis cell model was structured by stimulating AR42J cells with cerulein. Next, cell viability and apoptosis were detected by CCK-8 assay and flow cytometry. ELISA was used to measure the concentration of cytokines, such as TNF-α, IL-6, and IL-1ß. The data showed that miR-374a-5p was downregulated in samples from AP patients, while showing discriminative power for AP populations. Attenuated miR-374a-5p were negatively bound up with patients' Ranson score and APACHE II score. Besides, miR-374a-5p was declined in cerulein-treated AR42J cells and forced elevation of miR-374a-5p was beneficial to increase cell viability, and inhibit cell apoptosis and inflammation. The present study found that miR-374a-5p was reduced in AP serum samples, and up-regulated expression level of miR-374a-5p in cell models had a protective effect on cerulein-induced inhibition of cell function and inflammatory response.

Screening and characterisation of a novel efficient tumour cell-targeting peptide derived from insulin-like growth factor binding proteins.

Targeted delivery of antitumor drugs is particularly important in tumour treatment. Tumour-targeted peptide is a very effective drug carrier for tumour therapy. Here, we screened and characterised a highly efficient targeted peptide named IHP5, which was derived from insulin-like growth factor binding proteins (IGFBPs). IHP5 exhibited preferential binding to the tested tumour cell lines. The delivery efficiency of IHP5 was higher in various tested tumour cells than in normal cells, especially in the human cervical cancer cell line HeLa, which was 11.7-fold higher than in normal human embryonic kidney cells HEK293. Moreover, the penetration efficiency of IHP5 was 13 times higher than that of the classical cell penetrating peptide TAT in HeLa cells. Detail analysis revealed that IHP5 endocytosis was possibly correlated with acetylated heparan sulphate proteoglycans including phosphatidylinositol proteoglycan 3 (GPC3), phosphatidylinositol proteoglycan 5 (GPC5) and syndecan 2 (SDC2). Subsequently, the introduction of IHP5 enhanced the inhibitory effect of trichosanthin (TCS) on tumour cells, resulting in at least 19-fold increase in tumour cells without enhanced cytotoxicity in normal cells HEK293. These results suggested that IHP5, as a novel tumour cell-targeting penetrating peptide with the ability to target tumour cells, has great potential in drug delivery applications.

In addition to its endosomal escape effect, platycodin D also synergizes with ribosomal inactivation protein to induce apoptosis in hepatoma cells through AKT and MAPK signaling pathways.

Efficient endosomal escape after cellular uptake is a major challenge for the clinical application of therapeutic proteins. To overcome this obstacle, several strategies have been used to help protein drugs escape from endosomes without affecting the integrity of the cell membrane. Among them, some triterpenoid saponins with special structures were used to greatly enhance the anti-tumor therapeutic effect of protein toxins. Herein, we demonstrated that platycodin D (PD), polygalacin D (PGD) and platycodin D2 (PD2) from Platycodonis Radix significantly enhanced the ability of MHBP (a type I ribosome-inactivating protein toxin MAP30 fused with a cell-penetrating peptide HBP) to induce apoptosis in hepatoma cells. Based on the results of co-localization of endocytosed EGFP-HBP with a lysosomal probe and Galectin-9 vesicle membrane damage sensor, we demonstrated that PD, PGD and PD2 have the ability to promote endosomal escape of endocytic proteins without affecting the integrity of the plasma membrane. Meanwhile, we observed that cholesterol metabolism plays an important role in the activity of PD by RNA-seq analysis and KEGG pathway enrichment analysis, and confirm that PD, PGD and PD2 enhance the anti-tumor activity of MHBP by inducing the redistribution of free cholesterol and inhibiting the activity of cathepsin B and cathepsin D. Finally, we found that PD synergized with MHBP to induce caspase-dependent apoptosis through inhibiting Akt and ERK1/2 signaling pathways and activating JNK and p38 MAPK signaling pathways. This study provides new insights into the application of PD in cancer therapy and provides efficient and promising strategies for the cytosolic delivery of therapeutic proteins.

Raddeanin A synergistically enhances the anti-tumor effect of MAP30 in multiple ways, more than promoting endosomal escape.

Biomacromolecules such as proteins and nucleic acids are very attractive due to their high efficiency and specificity as cancer therapeutics. In fact, the endocytosed macromolecules are often trapped in the endosomes and cannot exhibit pharmacological effects well. Many strategies have been used to address this bottleneck, and one promising approach is to exploit the endosomal escape-promoting effect of triterpenoid saponins to aid in the release of biomacromolecules. Here, Raddeanin A (RA, an oleanane-type triterpenoid saponin) was proved to significantly promote endosomal escape as it recruited Galectin-9, an endosomal escape event reporter. As expected, RA effectively enhanced the anti-tumor effect of MAP30 (a type I ribosome-inactivating protein derived from Momordica charantia). However, based on the results of fluorescent colocalization, RA did not significantly promote MAP30 release from endosomes, suggesting that RA enhances MAP30 activity not only by promoting endosomal escape. Furthermore, it was found that the inhibitors of micropinocytosis and caveolae could almost completely inhibit the cytotoxicity of MAP30 combined with RA without affecting the cytotoxicity of MAP30 alone, indicating that RA may regulate the endocytic pathway of MAP30. Meanwhile, the effect of RA is related to the intra vesicular pH and cholesterol content on cell membrane, and is also cell-type dependent. Therefore, RA enhanced the anti-tumor effect of MAP30 in multiple ways, not just by promoting endosomal escape. Our findings will help to further decipher the possible mechanisms by which triterpenoid saponins enhance drug activity, and provide a new perspective for improving the activity of endocytosed drugs.

Liraglutide Attenuates Restenosis After Vascular Injury in Rabbits With Diabetes Via the TGF-ß/Smad3 Signaling Pathway.

Background: Lower limb ischemia due to arterial stenosis is a major complication in patients with diabetes mellitus (DM). Liraglutide is a long-acting analogue of a glucagon-like peptide 1 (GLP-1) receptor agonist used for lowering blood glucose in patients with DM, and is believed to possess cardiovascular protective effects. The aim of this study was to investigate whether liraglutide has a protective effect on blood vessels and alleviates vascular intimal hyperplasia in streptozotocin (STZ)-induced rabbits with DM and its molecular mechanism. Methods: Rabbits with DM were induced by STZ, and a lower limb ischemia model was established. The animals were divided into a control group, DM-injury group and liraglutide treatment group. Pathological staining was used to observe the intimal growth, analyze the oxidation levels of malondialdehyde (MDA), superoxide dismutase (SOD) and plasma glutathione peroxidase (GSH-Px), and analyze the changes in expression of marker proteins and signaling pathway proteins by Western blotting. A hyperglycemia (HG)-injured vascular smooth muscle cells (VSMCs) model was established to analyze reactive oxygen species (ROS) levels, Cell-Counting Kit-8 (CCK-8) was used to analyze cell proliferation, scratch assay and Transwell Migration Assay to analyze cell migration, flow cytometry to analyze apoptosis and Western blotting was used to analyze changes in the expression of marker and signaling pathway proteins. Results: The results of pathological staining showed that intimal hyperplasia was severe after diabetes-induced lower limb ischemia in rabbits at 4 weeks, and liraglutide treatment reduced symptoms. Liraglutide treatment significantly decreased MDA content, increased SOD, GSH-Px content, and augmented total antioxidant capacity levels in tissues. The results of Western blotting analysis showed that E-cadherin, mitochondrial membrane potential 9 (MMP-9), proliferating cell nuclear antigen (PCNA), and type I collagen protein expression levels were significantly decreased after liraglutide treatment compared with the DM injury group. The results indicated that liraglutide inhibited epithelial-mesenchymal transition (EMT) progression, vascular cell proliferation and migration and collagen production. Liraglutide inhibits transforming growth factor beta 1 (TGF-ß1)/Smad3 signaling pathway protein expression. In vitro assays have shown that liraglutide reduces cellular ROS levels, inhibits cell proliferation and migration and promotes apoptosis. Liraglutide down-regulated the expression of E-cadherin, MMP-9, PCNA, type I collagen protein as well as the TGF-ß1/Smad3 signaling pathway, but this effect could be reversed by tumor necrosis factor alpha (TNF-α). Conclusion: Liraglutide can significantly improve tissue antioxidant capacity, reduce vascular cell proliferation and migration via the TGF-ß1/Smad3 signaling pathway, inhibit the EMT and collagen production processes, and alleviate hyperglycemia(HG)-induced lower limb ischemia and intimal hyperplasia.

Influence of Microcirculatory Dysfunction on Myocardial Injury after Cardiopulmonary Resuscitation.

Objective: This study aimed to examine the effects of microcirculatory dysfunction and 654-1 intervention after cardiopulmonary resuscitation on myocardial injury. Methods: Landrace pigs were divided into a sham operation group (S group, n= 6), ventricular fibrillation control group (VF-C group, n= 8) and 654-1 intervention group (VF-I group, n= 8). Hemodynamics was recorded at baseline, at recovery of spontaneous circulation (ROSC), and 1 h, 2 h, 4 h and 6 h thereafter. Sidestream dark field (SDF) technology was used to evaluate and monitor the microcirculation flow index, total vessel density, perfusion vessel ratio, De-Backer score, and perfusion vessel density in animal viscera at various time points. Results: After administration of 654-1 at 1.5 h post-ROSC, the hemodynamics in the VF-I group, as compared with the VF-C group, was significantly improved. The visceral microcirculation detected by SDF was also significantly improved in the VF-I group. As observed through electron microscopy, significantly less myocardial tissue injury was present in the VF-I group than the VF-C group. Conclusion: Administration of 654-1 inhibited excessive inflammatory by improving the state of visceral microcirculation.

Effect of umbilical cord blood stem cell transplantation on restenosis after endovascular interventional therapy for diabetic hindlimb vascular disease.

This study aimed to investigate the mechanism of human umbilical cord blood stem cell (HUCBSC) transplantation on restenosis after percutaneous transluminal angioplasty (PTA) for diabetic hindlimb vascular disease in rabbits. After successfully preparing a rabbit model of diabetic hindlimb vascular disease, 16 rabbits were randomly assigned to two groups. Of these, 8 rabbits received PTA surgery alone (PTA group), and the other 8 rabbits received PTA and HUCBSC (PTA+HUCBSC group) treatments. Five more healthy rabbits were set as healthy control (HC group). Samples were collected after 4 weeks of treatment. The expressions of regulator of calcineurin 1 (RCAN1) and calcineurin A (CnA) in the diseased artery were detected by immunofluorescence staining. The distribution of HUCBSCs was observed by pathological examination in transplanted artery, distal artery, and liver. Cytology experiments were applied to assess the levels of JAK and STAT3, and the migration and proliferation of human aortic vascular smooth muscle cells (HA-VSMC). In the rabbit model of diabetic vascular lesions in the hindlimbs, we found the stenosis of the femoral artery became more and more serious with time, and the expression level of PCNA positive cells was also gradually increased. The expression levels of RCAN1 and CnA in the PTA+HUCBSC group were significantly lower than those in PTA group. HUCBSC inhibited the migration and proliferation of HA-VSMC via JAK/STAT3 pathway. After HUCBSC local transplantation, HUCBSC had no distal tissue distribution. HUCBSC transplantation may prevent restenosis after PTA of diabetic hindlimb vascular disease through JAK/STAT3 pathway.

Five-year follow-up observation of interventional therapy for lower extremity vascular disease in type 2 diabetes and analysis of risk factors for restenosis.

BACKGROUND: The high incidence of type 2 diabetes, the low rate of compliance, and the complex mechanism of vascular disease caused by diabetes make its complications increase year by year. Our study aimed to investigate the clinical characteristics of lower extremity vascular diseases in type 2 diabetes and evaluate the long-term efficacy of vascular intervention for these diseases. METHODS: From 2007 to 2014, 362 patients who underwent vascular intervention in our hospital due to lower extremity vascular diseases in type 2 diabetes were followed up for 5 years and their clinical characteristics were analyzed in this retrospective study. RESULTS: Compared with those before treatment, the values of blood pressure, fasting blood glucose, glycated hemoglobin (HbA1c), total cholesterol (TC), triglyceride Ester (TG), and low density lipoprotein-cholesterol (LDL-C) of patients were significantly lower 5 years after intervention (P < 0.01). We found that the levels of fibrinogen, blood glucose, HbA1c, TC, TG, LDL-C, and small dense low-density lipoprotein (sdLDL) in the vascular restenosis group were significantly higher than those in the vascular patency group (P < 0.001), whereas the level of HDL-C in the vascular restenosis group was significantly lower compared with the vascular patency group. CONCLUSIONS: Vascular intervention can significantly improve a series of biochemical indicators in patients with lower extremity vascular diseases caused by type 2 diabetes. Postoperative restenosis may be related to hypertension, duration of diabetes, rate of inferior knee disease, fibrinogen, and sdLDL. Good survival and limb salvage were achieved in the patients in this series with interventions and medical treatment provided by endocrinologists.

Constructing a better binding peptide for drug delivery targeting the interleukin-4 receptor.

Targeted delivery of antitumor drugs is especially important for tumour therapy. Tumour targeting peptides have been shown to be very effective drug carriers for tumour therapy. Interleukin-4 receptor (IL-4R) is overexpressed on the surface of various human solid tumours. To obtain a better targeting peptide, we first designed a novel targeting peptide derived from interleukin-4 (IL-4), ILBP-b. ILBP-b contains the key high-affinity binding residue E9 of IL-4 to IL-4R. Compared with a reported targeting peptide ILBP-a (containing another key high affinity residue R88), ILBP-b was proved to be a better targeting peptide by the fluorescence experiments. Then, we further fused ILBP-b and ILBP-a to increase the multisite-binding ability of ILBP-b and got a better targeting peptide ILBP-ba. ILBP-ba showed a stronger preferential binding ability to IL-4R high-expressing cells than ILBP-a and ILBP-b. Competitive binding experiments demonstrated ILBP-ba specifically targets IL-4R. By fusing ILBP-ba with drug protein trichosanthin (TCS), in vitro drug carrying experiments showed that ILBP-ba could specifically enhance the killing effect of TCS on IL-4R high-expressing tumour cells (more than 10 folds). These results indicated that ILBP-ba has great potential for drug delivery applications targeting IL-4R and will be beneficial for the development of tumour therapeutic agents.

Effective Therapeutic Drug Delivery by GALA3, an Endosomal Escape Peptide with Reduced Hydrophobicity.

Endosomal escape is a rate-limiting step in the cytosolic delivery of therapeutic drugs. Overcoming this barrier is crucial to achieve an effective biological based therapy. In this work, we evaluated the ability of a synthetic biomimetic peptide derived from the GALA to facilitate endosomal escape of protein drugs. Our results showed that the cytoplasmic distribution of GALA fusion proteins changed according to the hydrophobicity of GALA. One of the synthetic peptides, GALA3, significantly enhanced the endosomal escape efficiency of protein drugs. The cytosolic delivery capacity of GALA3 was significantly higher than that of several previously reported endosomal escape peptides, including hemagglutinin 2 (HA2). Moreover, when GALA3 was fused to BLF1-HBP, a ribosome-inactivating protein with cell-penetrating peptide HBP, the cytotoxicity of the fusion protein was significantly increased in various cell lines, including H460, HeLa, A549, and SMCC-7721. The growth inhibition effect of GALA3-BLF1-HBP was at least 20 times greater than that of BLF1-HBP alone in different tumor cell lines. GALA3 effectively promoted the endosomal escape of BLF1-HBP in a pH-dependent manner and greatly enhanced the apoptotic activity of BLF1-HBP. Taken together, our data show that by adjusting the hydrophobicity of GALA we obtained a more effective endosomal escape peptide. Therefore, GALA3-fusions can improve the efficiency of therapeutic protein drugs.

Analysis of Triterpenoid Saponins Reveals Insights into Structural Features Associated with Potent Protein Drug Enhancement Effects.

Plant-based saponins are amphipathic glycosides composed of a hydrophobic aglycone backbone covalently bound to one or more hydrophilic sugar moieties. Recently, the endosomal escape activity of triterpenoid saponins has been investigated as a potentially powerful tool for improved cytosolic penetration of protein drugs internalized by endocytic uptake, thereby greatly enhancing their pharmacological effects. However, only a few saponins have been studied, and the paucity in understanding the structure-activity relationship of saponins imposes significant limitations on their applications. To address this knowledge gap, 12 triterpenoid saponins with diverse structural side chains were screened for their utility as endosomolytic agents. These compounds were used in combination with a toxin (MAP30-HBP) comprising a type I ribosome-inactivating protein fused to a cell-penetrating peptide. Suitability of saponins as endosomolytic agents was assessed on the basis of cytotoxicity, endosomal escape promotion, and synergistic effects on toxins. Five saponins showed strong endosomal escape activity, enhancing MAP30-HBP cytotoxicity by more than 106 to 109 folds. These saponins also enhanced the apoptotic effect of MAP30-HBP in a pH-dependent manner. Additionally, growth inhibition of MAP30-HBP-treated SMMC-7721 cells was greater than that of similarly treated HeLa cells, suggesting that saponin-mediated endosomolytic effect is likely to be cell-specific. Furthermore, the structural features and hydrophobicity of the sugar side chains were analyzed to draw correlations with endosomal escape activity and derive predictive rules, thus providing new insights into structure-activity relationships of saponins. This study revealed new saponins that can potentially be exploited as efficient cytosolic delivery reagents for improved therapeutic drug effects.

Bioactive Polysaccharide Nanoparticles Improve Radiation-Induced Abscopal Effect through Manipulation of Dendritic Cells.

Radiotherapy was considered to induce an abscopal effect initiated through antigen release and presented by dendritic cells (DC), while the immunosuppressive tumor microenvironment (TEM) attenuated the effects. Herein, we utilized bioactive polysaccharides extracted from the natural herb Astragalus membranaceus and developed polysaccharide nanoparticles (ANPs) that can reverse TEM and, accordingly, enhance the radiation-induced abscopal effect. ANP showed ability to prolong the survival rate of tumor-bearing mice. In addition, ANP dramatically inhibited the growth of the primary tumor subjected to radiation as well as the secondary tumor distant from the primary lesion. Mechanistic study demonstrated that an ANP-induced immune response was mainly reflected by DC activation, represented by phenotypic maturation and enhanced antigen presentation through the TLR4 signaling pathway. Mature DC induced by ANP migrated to the tumor-draining lymph node and initiated T-cell expansion. Specifically, DC activation was successfully translated into an increase in CD4+ T/Treg and CD8+ T/Treg ratios within both primary (irradiated) and secondary (unirradiated) tumors. Our results also indicated that the systemic antitumor immune response and immune memory were enhanced with the increase in IFN-γ production and effector memory T-cell population. Our work provided a novel strategy to facilitate the incorporation of immunoactive macromolecules purified from natural herbs into modern nanotechnology in the era of immunotherapy.

Screening and characterization of a novel high-efficiency tumor-homing cell-penetrating peptide from the buffalo cathelicidin family.

Targeted delivery of antitumor drugs is especially important for tumor therapy. Cell-penetrating peptides (CPPs) have been shown to be very effective drug carriers for tumor therapy. However, most CPPs lack tumor cell specificity. Here, we identified a highly efficient CPP, CAT, from the newly identified buffalo-derived cathelicidin family, which exhibits a preferential binding capacity for multiple tumor cell lines and delivers carried drug molecules into cells. CAT showed an approximately threefold to sixfold higher translocation efficiency than some reported cell-penetrating antimicrobial peptides, including the well-known classical CPP TAT. Moreover, the delivery efficiency of CAT was greater in a variety of tested tumor cells than in normal cells, especially for the human hepatoma cell line SMMC-7721, for which delivery was 7 times more efficient than the normal human embryonic lung cell line MRC-5, according to fluorescent labeling experiment results. CAT was conjugated to the Momordica charantia-derived type-I ribosome-inactivating protein MAP 30, and the cytotoxicity of the MAP 30-CAT fusion protein in the tumor cell line SMMC-7721 was significantly enhanced compared with that of the unconjugated MAP 30. The IC50 value of MAP 30-CAT was approximately 83 times lower than the IC50 value of the original MAP 30. Interestingly, the IC50 value of MAP 30 alone for MRC-5 was approximately twofold higher than the value for SMMC-7721, showing a small difference. However, when MAP 30 was conjugated to CAT, the difference in IC50 values between the two cell lines was significantly increased by 38-fold. The results of the flow cytometric detection of apoptosis revealed that the increase in cytotoxicity after CAT conjugation was mainly caused by the increased induction of apoptosis by the fusion protein. These results suggest that CAT, as a novel tumor-homing CPP, has great potential in drug delivery applications in vivo and will be beneficial to the development of tumor therapeutics.

Real-Time Quantitative PCR Analysis of the Expression Pattern of the Hypoglycemic Polypeptide-P Gene in Momordica charantia.

This study was designed to establish a real-time quantitative polymerase chain reaction (qPCR) method to rapidly and reliably analyze the hypoglycemic polypeptide-P gene expression pattern in Momordica charantia (MC) and to examine its expression changes in different MC accessions, harvesting seasons, and tissue types. The qPCR results were further verified by using Western blotting (WB). A total of 10 MCs with different accessions were collected and tested in this study. Among the tested accessions, RU5H showed the highest expression level of the polypeptide-P gene. The expression level of the polypeptide-P gene was not only season-related (with the highest in early July) but also tissue-related (with the highest in the seed tissue). In addition, the expression characteristic of the polypeptide-P gene was maturity-related, with the highest expression level in the tender MC. The WB results show that the transcription level of this gene shows an almost similar trend to the corresponding protein expression level. In conclusion, the established qPCR method can rapidly and effectively detect the expression levels of the polypeptide-P gene in MCs with different accessions; furthermore, various factors, including the accessions, harvesting seasons, and tissue types can affect the expression level.

Enhanced anticancer effect of MAP30-S3 by cyclosproin A through endosomal escape.

Cyclosporin A (CsA) is a calcium antagonist and can enhance the efficacy of some protein drugs, but its mechanism remains unknown. In this study, MAP30, a ribosome-inactivating protein reported to have apoptotic effects on cancer cells, was fused with S3, an epidermal growth factor receptor (EGFR)-targeting peptide. In addition, CsA was used to investigate whether it can further promote the apoptotic effects of S3 fused MAP30 (MAP30-S3). Our result showed that the internalization of FITC-labeled MAP30-S3 was increased significantly by S3 in HeLa cells. Unexpectedly, MAP30-S3 only showed a minor decrease in the viability of EGFR-overexpressing cancer cells, including HeLa, SMMC-7721, and MGC803 (IC50>5 µmol/l). However, 2 µmol/l CsA significantly increased the cytotoxicity of MAP30-S3, especially for HeLa cells (IC50=40.3 nmol/l). In comparison, CsA did not further decrease the cytotoxicity of MAP30-S3 on MRC-5, an EGFR low-expressing cell line from normal lung tissue, indicating that CsA did not affect the cancer-targeting specificity of MAP30-S3. Our results also showed that CsA further increased the apoptotic activity of MAP30-S3 in HeLa cells. CsA could promote the endosomal escape of FITC-MAP30-S3 with a diffused pattern in the cytoplasm. Five endocytic inhibitors were used to investigate the cellular uptake mechanism of MAP30-S3, and the results showed that the endosomal escape-enhancing effect of CsA on MAP30-S3 may be associated with the clathrin-dependent endocytic pathways. Our study suggested that CsA could be a novel endosomal escape enhancer to potentiate the intracellular release of anticancer protein drugs, resulting in their improved therapeutic efficacy.