The Role of the Tumor Microenvironment in Neuropilin 1-Induced Radiation Resistance in Lung Cancer Cells

Exploration of Antimicrobial Peptides in the Treatment of Gentamicin-Resistant Klebsiella pneumoniae Infection

Introduction

The emergence of multidrug-resistant Klebsiella pneumoniae (K. pneumoniae) and the decline of effective antibiotics lead to the urgent need for new antibacterial agents. The aim of this study is to investigate the therapeutic effect of antimicrobial peptides against gentamicin-resistant (RT) K. pneumoniae and to screen effective antimicrobial peptides.

Methods

In this study, the RT strains were induced by gradient gentamicin, and the RT strains were selected by detecting the expression levels of efflux pump genes, porin genes, and biofilm formation genes of the strains combined with their effects on the cells. Then the effects of four antimicrobial peptides on the efflux pump activity, biofilm formation level and cell condition after infection were detected to explore the effects of antimicrobial peptides on RT strains. Finally, the RT strain was used to induce a mouse model of pneumonia, and the four antimicrobial peptides were used to treat pneumonia mice for in vivo experiments. The pathological changes in lung tissues in each group were detected to explore the antimicrobial peptide with the most significant effect on the RT strain in vivo.

Results

The results showed that the minimal inhibitory concentrations of the RT strains (strain C and strain I) were significantly higher than those of the wild-type strain, and the expression of efflux pump, porin and biofilm formation genes was significantly increased. The antimicrobial peptides could effectively inhibit the biofilm formation and efflux pump protein function of the RT strains. In addition, the antimicrobial peptides showed promising antibacterial effects both in vitro and in vivo.

Discussion

Our study provided a theoretical basis for the treatment of gentamicin resistant K. pneumoniae infection with antimicrobial peptides, and found that KLA was significantly superior to LL37, Magainin I, KLA and Dermaseptin (10 μg/mL in cells, 50 μg in mice).

Is neuropilin-1 the neuroimmune initiator of multi-system hyperinflammation in COVID-19?

A major immunopathological feature of Coronavirus disease-2019 (COVID-19) is excessive inflammation in the form of "cytokine storm". The storm is characterized by injurious levels of cytokines which form a complicated network damaging different organs, including the lungs and the brain. The main starter of "cytokine network" hyperactivation in COVID-19 has not been discovered yet. Neuropilins (NRPs) are transmembrane proteins that act as neuronal guidance and angiogenesis modulators. The crucial function of NRPs in forming the nervous and vascular systems has been well-studied. NRP1 and NRP2 are the two identified homologs of NRP. NRP1 has been shown as a viral entry pathway for SARS-CoV2, which facilitates neuroinvasion by the virus within the central or peripheral nervous systems. These molecules directly interact with various COVID-19-related molecules, such as specific regions of the spike protein (major immune element of SARS-CoV2), vascular endothelial growth factor (VEGF) receptors, VEGFR1/2, and ANGPTL4 (regulator of vessel permeability and integrity). NRPs mainly play a role in hyperinflammatory injury of the CNS and lungs, and also the liver, kidney, pancreas, and heart in COVID-19 patients. New findings have suggested NRPs good candidates for pharmacotherapy of COVID-19. However, therapeutic targeting of NRP1 in COVID-19 is still in the preclinical phase. This review presents the implications of NRP1 in multi-organ inflammation-induced injury by SARS-CoV2 and provides insights for NRP1-targeting treatments for COVID-19 patients.

Overexpression of NRP1 is Associated with Poor Prognosis via Accelerating Immunosuppression in Head and Neck Squamous Cell Carcinoma

Background

Neuropilin-1 (NRP1) is a significant molecular structure that participates in many diseases progress including malignant tumors. However, its role in head and neck squamous cell carcinoma (HNSCC) remains to be uncovered. In this study, we determined the function of NRP1 as a crucial biomarker in proliferation, metastasis and immunosuppression in HNSCC.

Methods

We collected samples of normal tissues (n = 18) and HNSCC tissues (n = 202) for immunohistochemical staining of NRP1 and evaluated its correlation to clinical prognostic characteristics. Furthermore, we enrolled 37 HNSCC patients received immune checkpoint blockade (ICB) treatment with defined therapeutic effects records. The biological process, signal pathways, and immune infiltration relevance to NRP1 were analyzed utilized transcriptome data from The Cancer Genome Atlas (TCGA).

Results

The NRP1 protein expression was significantly upregulated in HNSCC tissue and was associated with T stage, N stage, histological differentiation, recurrence and NRP1 expression. The high expression of NRP1 indicated poor survival rate and was found to be an independent prognosis factor. Enrichment analysis showed that NRP1 was associated with cell adhesion, extracellular matrix organization, homophilic cell adhesion via plasma membrane in biological process and neuroactive ligand-receptor interaction, protein digestion and absorption, calcium signal pathways. Moreover, NRP1 mRNA level was found positively correlated to cancer associated fibroblast cells, Treg cells and macrophage/monocyte cells.

Conclusion

NRP1 might be likely to develop into a potential immunoregulation target as well as a predictive biomarker in HNSCC immune treatment.

α2,6 Sialylation mediated by ST6GAL1 promotes glioblastoma growth

One of the least-investigated areas of brain pathology research is glycosylation, which is a critical regulator of cell surface protein structure and function. β-Galactoside α2,6-sialyltransferase (ST6GAL1) is the primary enzyme that α2,6 sialylates N-glycosylated proteins destined for the plasma membrane or secretion, thereby modulating cell signaling and behavior. We demonstrate a potentially novel, protumorigenic role for α2,6 sialylation and ST6GAL1 in the deadly brain tumor glioblastoma (GBM). GBM cells with high α2,6 sialylation exhibited increased in vitro growth and self-renewal capacity and decreased mouse survival when orthotopically injected. α2,6 Sialylation was regulated by ST6GAL1 in GBM, and ST6GAL1 was elevated in brain tumor-initiating cells (BTICs). Knockdown of ST6GAL1 in BTICs decreased in vitro growth, self-renewal capacity, and tumorigenic potential. ST6GAL1 regulates levels of the known BTIC regulators PDGF Receptor β (PDGFRB), Activated Leukocyte Cell Adhesion Molecule, and Neuropilin, which were confirmed to bind to a lectin-recognizing α2,6 sialic acid. Loss of ST6GAL1 was confirmed to decrease PDGFRB α2,6 sialylation, total protein levels, and the induction of phosphorylation by PDGF-BB. Thus, ST6GAL1-mediated α2,6 sialylation of a select subset of cell surface receptors, including PDGFRB, increases GBM growth.

Neuropilin (NRPs) Related Pathological Conditions and Their Modulators

Neuropilin 1 (NRP1) represents one of the two homologous neuropilins (NRP, splice variants of neuropilin 2 are the other) found in all vertebrates. It forms a transmembrane glycoprotein distributed in many human body tissues as a (co)receptor for a variety of different ligands. In addition to its physiological role, it is also associated with various pathological conditions. Recently, NRP1 has been discovered as a coreceptor for the SARS-CoV-2 viral entry, along with ACE2, and has thus become one of the COVID-19 research foci. However, in addition to COVID-19, the current review also summarises its other pathological roles and its involvement in clinical diseases like cancer and neuropathic pain. We also discuss the diversity of native NRP ligands and perform a joint analysis. Last but not least, we review the therapeutic roles of NRP1 and introduce a series of NRP1 modulators, which are typical peptidomimetics or other small molecule antagonists, to provide the medicinal chemistry community with a state-of-the-art overview of neuropilin modulator design and NRP1 druggability assessment.

Insight of a Metabolic Prognostic Model to Identify Tumor Environment and Drug Vulnerability for Lung Adenocarcinoma

Metabolic reprogramming is a novel method for the treatment of malignant tumors. The exploration of metabolism procedures between radiosensitive and radioresistant tumors may provide novel perspectives for lung adenocarcinoma (LUAD) patients after radiation therapy. In our study, metabolic reprogramming and immune response changes were found between radioresistant cell line (A549RR) and its parent cells (A549) using gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Nucleotide/amino acid, lipid, and glucose metabolic process, including Alanine, aspartate and glutamate metabolism, Tryptophan/Tyrosine metabolism, Butanoate metabolism, Purine/Pyrimidine metabolism, were screened out. Then molecular signatures database and The Cancer Genome Atlas Program (TCGA) lung adenocarcinoma datasets were used to identify metabolism-related genes (MRGs) between radiosensitive and radioresistant lung adenocarcinoma (LUAD) cells. A metabolism-based prognostic model, receiver operating characteristic (ROC) curve and nomogram were constructed using Metabolism Score calculated by 14 metabolism-related genes (MRGs). Three independent public datasets, (GSE72094, GSE3141, GSE8894) and one immunotherapy cohort (IMvigor210) were used as external validation cohorts. Expression of 14 hub genes in cells, normal and LUAD specimens were explored by Human Protein Atlas, TIMER2.0 and RT-qPCR. Patients with low-Metabolism Scores were correlated with longer survival times, higher response rates to immune checkpoint inhibitors (ICIs), different immune cell infiltrations and drug vulnerability. Our study demonstrated a comprehensive landscape between radiosensitive and radioresistant LUAD, and provide novel targets for NSCLC, especially those patients received radiation therapy. Moreover, this metabolism-based prognostic model may help to investigate connections between radiosensitivity, immune response, metabolic reprogramming, and patients’ prognosis.

MiR-145 modulates the radiosensitivity of non-small cell lung cancer cells by suppression of TMOD3

Radioresistance is a major problem encountered in the treatment of non-small cell lung cancer (NSCLC). Aberrant microRNA (miRNA) expression contributes to multiple cancer‑associated signaling pathways, and profoundly influences effects of radiotherapy (RT) in cancers. MicroRNA-145-5p (miR-145) is recognized as a tumor suppresser in NSCLC. However, the roles of miR-145 during radiotherapy of NSCLC are largely unknown. The present study aimed to investigate the function and underlying mechanism of miR-145 in modulation of radiosensitivity in NSCLC. We generated radioresistant H460 and A549 subclones, named H460R and A549R, respectively, and found that irradiation (IR) could suppress the expression levels of miR-145 in radioresistant NSCLC cells. Furthermore, overexpression of miR-145 could sensitize radioresistant NSCLC cells to IR, while knockdown of miR-145 in NSCLC cells acted the converse manner. Mechanically, miR-145 was able to directly target 3'UTR of tropomodulin 3 (TMOD3) mRNA and decrease the expression of TMOD3 at the levels of mRNA and protein. Additionally, we confirmed that miR-145 could enhance the radiosensitivity of radioresistant NSCLC cells by targeting TMOD3 in vitro and in vivo, and could be used as a target in clinical treatment of NSCLC. Collectively, restoration of miR-145 expression increases the radiosensitivity of radioresistant NSCLC cells by suppression of TMOD3, and miR-145 can act as a new radiosensitizer for NSCLC therapy.

Establishment of a Pre-vascularized 3D Lung Cancer Model in Fibrin Gel-Influence of Hypoxia and Cancer-Specific Therapeutics

Lung cancer is the most frequently diagnosed cancer worldwide and the one that causes the highest mortality. In order to understand the disease and to develop new treatments, in vitro human lung cancer model systems which imitate the physiological conditions is of high significance. In this study, a human 3D lung cancer model was established that features the organization of a tumor with focus on tumor angiogenesis. Vascular networks were formed by co-culture of human umbilical vein endothelial cells and adipose tissue-derived mesenchymal stem cells (ASC) for 14 days in fibrin. A part of the pre-vascularized fibrin gel was replaced by fibrin gel containing lung cancer cells (A549) to form tri-cultures. This 3D cancer model system was cultured under different culture conditions and its behaviour after treatment with different concentrations of tumor-specific therapeutics was evaluated. The evaluation was performed by measurement of metabolic activity, viability, quantification of two-photon laser scanning microscopy and measurement of the proangiogenic factor vascular endothelial growth factor in the supernatant. Hypoxic conditions promoted vascularization compared to normoxic cultured controls in co- and tri-cultures as shown by significantly increased vascular structures, longer structures with a higher area and volume, and secretion of vascular endothelial growth factor. Cancer cells also promoted vascularization. Treatment with 50 µM gefitinib or 50 nM paclitaxel decreased the vascularization significantly. VEGF secretion was only reduced after treatment with gefitinib, while in contrast secretion remained constant during medication with paclitaxel. The findings suggest that the herein described 3D lung cancer model provides a novel platform to investigate the angiogenic potential of cancer cells and its responses to therapeutics. Thus, it can serve as a promising approach for the development and patient-specific pre-selection of anticancer treatment.

Construction of Radiation Surviving/Resistant Lung Cancer Cell Lines with Equidifferent Gradient Dose Irradiation

Radiotherapy plays an increasingly crucial role in the treatment of non-small cell lung cancer (NSCLC). Local tumor recurrence and tumor progression caused by intratumoral heterogeneity induced radiotherapy resistance remain the primary causes of radiotherapy failure. However, the lack of a suitable cell line model has hampered the exploration of the dynamic mechanisms of radiation resistance. We established 3 groups of equidifferent gradient dose irradiation surviving/resistant human lung cancer cell lines based on A549, H520, and H460 cells with clinical conventional fractionated radiotherapy (CFRT) (2 Gy × 20 F, 2 Gy × 30 F, and 2 Gy × 40 F). The radiosensitivity of the cells was detected by clone formation assay, EDU cell proliferation assay, neutral comet assay, and γ-H2AX immunofluorescence staining. The radiosensitivity and proliferation viability were increased in a received dose-dependent manner. Compared with parental cells, DNA double-strand breaks (DSBs) in cell lines that received higher-dose irradiation were significantly reduced. We successfully constructed equidifferent gradient dose irradiation surviving/resistant NSCLC cell lines whose radiation surviving and resistant abilities were increased in a received dose-dependent manner. This preclinical cell model could be used to dynamically observe and detect the radiation surviving/resistant biomarkers during radiotherapy stress, elucidate the mechanism of radiation resistance.