Advances in the Regulatory Effects of Bioactive Peptides on Metabolic Signaling Pathways in Tumor Cells

Screening and separation of natural anticancer active ingredients related to phospholipase C

Based on the specific binding of drug molecules to cell membrane receptors, a screening and separation method for active compounds of natural products was established by combining phospholipase C (PLC) sensitized hollow fiber microscreening by a solvent seal with high-performance liquid chromatography technology. In the process, the factors affecting the screening were optimized. Under the optimal screening conditions, we screened honokiol (HK), magnolol (MG), negative control drug carbamazepine, and positive control drug amentoflavone, the repeatability of the method was tested. The PLC activity was determined before and after the screening. Experimental results showed that the sensitization factors of PLC of HK and MG were 61.0 and 48.5, respectively, and amentoflavone was 15.0, carbamazepine could not bind to PLC. Moreover, the molecular docking results were consistent with this measurement, indicating that HK and MG could be combined with PLC, and they were potential interacting components with PLC. This method used organic solvent to seal the PLC greatly ensuring the activity, so this method had the advantage of integrating separation, and purification with screening, it not only exhibited good reproducibility and high sensitivity but was also suitable for screening the active components in natural products by various targets in vitro.

Effects of Low Molecular Weight Peptides from Red Shrimp (Solenocera crassicornis) Head on Immune Response in Immunosuppressed Mice

This study aimed to investigate the immunoenhancement effects of low molecular weight peptides (SCHPs-F1) from red shrimp (Solenocera crassicornis) head against cyclophosphamide (CTX)-induced immunosuppressed mice. ICR mice were intraperitoneally injected with 80 mg/kg CTX for 5 consecutive days to establish the immunosuppressive model and then intragastrically administered with SCHPs-F1 (100 mg/kg, 200 mg/kg, and 400 mg/kg) to investigate its improving effect on immunosuppressed mice and explore its potential mechanism using Western blot. SCHPs-F1 could effectively improve the spleen and thymus index, promoting serum cytokines and immunoglobulins production and upregulating the proliferative activity of splenic lymphocytes and peritoneal macrophages of the CTX-treated mice. Moreover, SCHPs-F1 could significantly promote the expression levels of related proteins in the NF-κB and MAPK pathways in the spleen tissues. Overall, the results suggested that SCHPs-F1 could effectively ameliorate the immune deficiency caused by CTX and had the potential to explore as an immunomodulator in functional foods or dietary supplements.

Atractylenolide-1 affects glycolysis/gluconeogenesis by downregulating the expression of TPI1 and GPI to inhibit the proliferation and invasion of human triple-negative breast cancer cells

Atractylenolide-1 (AT-1) is a major octanol alkaloid isolated from Atractylodes Rhizoma and is widely used to treat various diseases. However, few reports have addressed the anticancer potential of AT-1, and the underlying molecular mechanisms of its anticancer effects are unclear. This study aimed to assess the effect of AT-1 on triple-negative breast cancer (TNBC) cell proliferation and migration and explore its potential molecular mechanisms. Cell invasion assays confirmed that the number of migrating cells decreased after AT-1 treatment. Colony formation assays showed that AT-1 treatment impaired the ability of MDA-MB-231 cells to form colonies. AT-1 inhibited the expression of p-p38, p-ERK, and p-AKT in MDA-MB-231 cells, significantly downregulated the proliferation of anti-apoptosis-related proteins CDK1, CCND1, and Bcl2, and up-regulated pro-apoptotic proteins Bak, caspase 3, and caspase 9. The gas chromatography-mass spectroscopy results showed that AT-1 downregulated the metabolism-related genes TPI1 and GPI through the glycolysis/gluconeogenesis pathway and inhibited tumor growth in vivo. AT-1 affected glycolysis/gluconeogenesis by downregulating the expression of TPI1 and GPI, inhibiting the proliferation, migration, and invasion of (TNBC) MDA-MB-231 cells and suppressing tumor growth in vivo.

Cocktail strategy based on a dual function nanoparticle and immune activator for effective tumor suppressive

Background

Immune checkpoint inhibitor-mediated immunotherapy cannot be carried out on a large scale clinically due to its low universality. In recent years, cyclic guanosine monophosphate synthase/interferon gene stimulating factor (cGAS/STING)-mediated innate immune signaling pathway-mediated immunotherapy has attracted more and more attention. In addition, metabolic inhibitors also show good effects on tumor treatment, but their application is often limited because of their large first pass effect or difficult administration.

Methods

The particle size and potential parameters were measured by DLS. In order to determine the optimal ratio of the two drugs, we calculated the CI value of different nanoparticles through MTT experiment, and simulated their synergistic effect through Gaussian software. Then the morphology and crystal form of the best proportion of drugs were studied by TEM and XRD. The anti-tumor mechanism of composite nanoparticles was confirmed by the determination of metabolic related indexes, Q-PCR and WB. The antitumor effect and immune activation effect were comprehensively evaluated by in vivo and in vitro experiments.

Results

Here, we found and synthesized BCP nanoparticles ((BPA + CPI) @ PLGA NPs) which can effectively reduce the metabolism of tumor cells and inhibit cell proliferation. At the same time, the release of mitochondrial DNA (mtDNA) caused by mitochondrial metabolism disorder further activated the cGAS/STING signal pathway in Hepa1–6 cells. We found that the drug-treated Hepa1–6 cells had obvious TBK1 phosphorylation and STING dimerization. Combined with STING agonist, it could effectively promote the activation of CD8 T cells and enhanced the therapeutic effect on liver cancer.

Conclusion

Our results showed that PLGA nanocarrier can successfully improve the dosage forms of two metabolic inhibitors and show the effect of synergistic therapy. BCP nanoparticles can also activate the innate immunity of tumor cells and significantly enhance tumor inhibition after combined with STING agonists. This study has high reference and transformation value for the combined treatment of immunosuppression and metabolic inhibition.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01241-y.

Tumor microenvironment-responsive size-switchable drug delivery nanosystems

INTRODUCTION

Compared with ordinary chemotherapeutic drugs, the variable-size nanoparticles (NPs) have better therapeutic effects and fewer side effects.

AREAS COVERED

This review mainly summarizes the strategies used to construct smart, size-tunable nanocarriers based on characteristic factors of tumor microenvironment (TME) to dramatically increase the penetration and retention of drugs within tumors.

EXPERT OPINION

Nanosystems with changeable sizes based on the TME have been extensively studied in the past decade, and their permeability and retention have been greatly improved, making them a very promising treatment for tumors.

LncRNA-mediated posttranslational modifications and reprogramming of energy metabolism in cancer

Altered metabolism is a hallmark of cancer, and the reprogramming of energy metabolism has historically been considered a general phenomenon of tumors. It is well recognized that long noncoding RNAs (lncRNAs) regulate energy metabolism in cancer. However, lncRNA‐mediated posttranslational modifications and metabolic reprogramming are unclear at present. In this review, we summarized the current understanding of the interactions between the alterations in cancer‐associated energy metabolism and the lncRNA‐mediated posttranslational modifications of metabolic enzymes, transcription factors, and other proteins involved in metabolic pathways. In addition, we discuss the mechanisms through which these interactions contribute to tumor initiation and progression, and the key roles and clinical significance of functional lncRNAs. We believe that an in‐depth understanding of lncRNA‐mediated cancer metabolic reprogramming can help to identify cellular vulnerabilities that can be exploited for cancer diagnosis and therapy.

Targeted delivery of β-glucosidase-loaded magnetic nanoparticles: effect of external magnetic field duration and intensity

Aim: The effect of applied magnetic field duration and intensity on the delivery of β-glucosidase-loaded magnetic nanoparticles was evaluated. Materials & methods: The prepared β-glucosidase-loaded magnetic nanoparticles were targeted to subcutaneous tumors with an external magnetic field. Iron concentration and enzyme activity in tumor tissue were analyzed via electron spin resonance detection, Prussian blue staining and enzyme activity measurement. Results: The increase in magnetic nanoparticles quantity and enzyme activity in tumor tissue was not synchronous with the magnetic targeting duration. In addition, accumulation of magnetic nanoparticles and the increase in enzyme activity were not synchronous with the magnetic field intensity. Conclusion: The results suggested that appropriate magnetic field conditions should be considered for targeted delivery of bioactivity proteins based on magnetic nanoparticles.

MicroRNA-31 weakens cisplatin resistance of medulloblastoma cells via NF-κB and PI3K/AKT pathways

BACKGROUND

Medulloblastoma (MB) is a malignant intracranial tumor. Cisplatin is a broad-spectrum antitumor drug. It is important to study the cisplatin resistance of MB cells for the treatment of MB. In this article, we preliminarily studied the cisplatin resistance of microRNA (miR)-31 and the possible mechanism in DAOY and UW228 cells, laying a theoretical foundation for clinical treatment of MB.

METHODS

Following anti-miR-31 and pre-miR-31 transfections, cell viability, BrdU, CyclinD1, and apoptosis levels of DAOY and UW228 cell were detected by CCK8, BrdU, and western blot. Meanwhile, migration, invasion, and western blot assay were respectively used to detect the functions of miR-31 migration and invasion. miR-31 levels were changed by cell transfection and detected by RT-qPCR. Furthermore, the related-proteins of pathways were also detected by western blot.

RESULTS

Anti-miR-31 increased DAOY and UW228 cells viability, BrdU⁺ numbers, and expression of CyclinD1. The migration/invasion rate and expression levels of MMP-9 and vimentin after anti-miR-31 transfection were increased. Furthermore, anti-miR-31 enhanced cells' cisplatin resistance and triggered PI3K/AKT and NF-κB pathways. Pre-miR-31 played opposite roles and promoted the apoptosis.

CONCLUSION

miR-31 regulated cell growth, migration, invasion and cisplatin resistance of MB cells via PI3K/AKT and NF-κB pathways.

Effect of bioactive peptide on ram semen cryopreservation

This present study investigated the effect of bioactive peptide (BAPT) (BAPT) on the quality of ram semen during cryopreservation. Ram ejaculates were extended with Tris buffer supplemented with no antioxidants (as control group), 20 μg/mL BAPT (as BAPT20 group), 40 μg/mL BAPT (as BAPT40 group) and 60 μg/mL BAPT (as BAPT60 group). After cryopreservation, sperm quality including motility, vitality, the percentage of hypoosmotic swelling test (HOST)-positive spermatozoa and the percentage of intact acrosomes was assessed. Furthermore, the malondialdehyde (MDA) in seminal plasma and spermatozoa were analyzed, followed by the measurement of superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GSH-Px) levels in seminal plasma. After in vitro fertilization, the embryonic cleavage rates and development rates of different groups were analyzed to compare the developmental abilities of spermatozoa. The results showed that the post-thaw sperm motility was significantly higher in the BAPT60 group compared to those in the BAPT20, BAPT40 and control groups (P < 0.05). The percentage of live sperms significantly increased from 48.12 ± 2.35% for the BAPT20 group, 55.43 ± 2.16% for the BAPT40 group to 57.53 ± 3.15% for the BAPT60 group. The percentage of HOST-positive spermatozoa was significantly higher in the BAPT60 group than those in BAPT20, BAPT40 and control groups (P < 0.05). The MDA levels in seminal plasma and spermatozoa were significantly reduced with BAPT supplement (P < 0.05). Additionally, the SOD, CAT and GSH-Px levels in the BAPT experimental groups were significantly higher than those of the control group, which further indicated that BAPT significantly inhibit the reactive oxygen species (ROS) production during the cryopreservation of ram semen. Furthermore, the embryonic cleavage rates and development rates of the BAPT40 and BAPT60 groups were significantly increased in comparison with the BAPT20 and control groups (P < 0.05). In conclusion, BAPT improved the ram sperm quality via inhibiting the ROS production during cryopreservation, and could be applied as a promising supplement for ram semen cryopreservation.

Hydrolysates from bee pollen could induced apoptosis in human bronchogenic carcinoma cells (ChaGo-K-1)

In order to examine bee pollen hydrolysates to assess their anticancer and antioxidant properties, hydrolysis of bee pollen was first performed using three different commercially available enzymes: Alcalase^®, Neutrase^®, and Flavourzyme^®. The study used DPPH and ABTS assay to evaluate the antioxidant properties of the hydrolysates obtained from bee pollen. All of the tested hydrolysates demonstrated antioxidant activity, while hydrolysate based on Alcalase^® offered a high value for IC₅₀ and was therefore chosen for further separation into five sub-fractions via ultrafiltration. The greatest antioxidant activity was presented by the MW < 0.65 kDa fraction, which achieved an IC₅₀ value of 0.39 ± 0.01 µg/mL in the DPPH assay and 1.52 ± 0.01 µg/mL for ABTS. Purification of the MW < 0.65 kDa fraction was completed using RP-HPLC, whereupon the three fractions from the original six which had the highest antioxidant activity underwent further examination through ESI-Q-TOF-MS/MS. These particular peptides had between 7 and 11 amino acid residues. In the case of the MW < 0.65 kDa fraction, testing was also carried out to determine the viability of lung cancer cell lines, represented by ChaGo-K1 cells. Analysis of the antiproliferative properties allowed in vitro assessment of the ChaGo-K1 cells' viability following treatment using the MW < 0.65 kDa fraction. Flow-cytometry generated date which revealed that it was possible for the MW < 0.65 kDa fraction to induce apoptosis in the ChaGo-K1 cells in comparison to the results with cells which had not been treated.

PEG modification enhances the in vivo stability of bioactive proteins immobilized on magnetic nanoparticles

OBJECTIVE

To increase the in vivo stability of bioactive proteins via optimized loading methods.

RESULTS

β-Glucosidase (β-Glu), as a model protein, was immobilized on magnetic nanoparticles(denoted as MNP-β-Glu) by chemical coupling methods and was further modified by poly(ethylene glycol) (PEG) molecules (denoted as MNP-β-Glu-PEG) to increase its stability. The physicochemical properties of the as-prepared nanohybrids, including the particle size, zeta potential, and enzyme activity, were well characterized. The proper MNP/β-Glu feed ratio was important for optimizing the particle size. Analysis of enzyme activity showed that the stability of immobilized β-Glu compared with free β-Glu was lower in deionized water and higher in blood serum at 37 °C. MNP-β-Glu-PEG retained 77.9% of the initial activity within 30 days at 4 °C, whereas the free enzyme retained only 58.2%. Pharmacokinetic studies of Sprague-Dawley (SD) rats showed that the MNP-β-Glu-PEG group retained a higher enzyme activity in vivo (41.46% after 50 min) than the MNP-β-Glu group (0.03% after 50 min) and the β-Glu group (0.37% after 50 min). Moreover, in contrast to the MNP-β-Glu group, the enzyme activity was not fully synchronous with the decrease in the Fe concentration in the MNP-β-Glu-PEG group.

CONCLUSIONS

All findings indicated that the method of immobilization on magnetic nanoparticles and PEG modification is promising for the application of bioactive proteins in vivo.