Platelet-derived growth factor receptors form complexes with neuropilin-1 during megakaryocytic differentiation of thrombopoietin-dependent UT-7/TPO cells

Tumor cells-derived exosomal circVCP promoted the progression of colorectal cancer by regulating macrophage M1/M2 polarization

BACKGROUND

Colorectal cancer (CRC) is among the most frequent tumors of the digestive tract and the second leading cause of cancer death worldwide. Tumor-associated macrophages (TAMs) are one of the most critical immune cells in the tumor microenvironment, which closely interact with tumor cells to promote tumor incidence and progression. However, the precise mechanism of action between CRC cells and TAMs polarization is still being investigated.

METHODS

Transmission electronic microscopy (TEM), NanoSight and western blotting were used to characterize exosomes (Exo) isolated from the culture medium of CRC cells. The cellular uptake and internalization of Exo were detected by confocal laser scanning microscopy. M1/ M2 phenotype markers expression were examined by ELISA and flow cytometry. Cell migration, invasion and proliferation were determined by transwell and CCK-8 assay, respectively. A xenograft tumor model was established to explore the role of circVCP in vivo. The target genes of circVCP or miR-9-5p were predicted by StarBase2.0. The target association among miR-9-5p and circVCP or NRP1 was confirmed using the luciferase assay and RNA-pull down assay.

RESULTS

circVCP was highly accumulated in exosomes derived from plasma of CRC patients and CRC cells. Additionally, exosomal circVCP derived from CRC cells promoted cell proliferation, migration and invasion by regulating the miR-9-5p/NRP1 axis, and induced macrophage M2 polarization and inhibited macrophage M1 polarization.

CONCLUSIONS

Over-expressed exosomal circVCP promoted the progression of CRC by regulating macrophage M1/M2 polarization through miR-9-5p/NRP1 axis. CircVCP may be a diagnostic biomarker and potential target for CRC therapy.

Targeted Delivery of Sunitinib by MUC-1 Aptamer-Capped Magnetic Mesoporous Silica Nanoparticles

Magnetic mesoporous silica nanoparticles (MMSNPs) are being widely investigated as multifunctional novel drug delivery systems (DDSs) and play an important role in targeted therapy. Here, magnetic cores were synthesized using the thermal decomposition method. Further, to improve the biocompatibility and pharmacokinetic behavior, mesoporous silica was synthesized using the sol-gel process to coat the magnetic cores. Subsequently, sunitinib (SUN) was loaded into the MMSNPs, and the particles were armed with amine-modified mucin 1 (MUC-1) aptamers. The MMSNPs were characterized using FT-IR, TEM, SEM, electrophoresis gel, DLS, and EDX. MTT assay, flow cytometry analysis, ROS assessment, and mitochondrial membrane potential analysis evaluated the nanoparticles' biological impacts. The physicochemical analysis revealed that the engineered MMSNPs have a smooth surface and spherical shape with an average size of 97.6 nm. The biological in vitro analysis confirmed the highest impacts of the targeted MMSNPs in MUC-1 overexpressing cells (OVCAR-3) compared to the MUC-1 negative MDA-MB-231 cells. In conclusion, the synthesized MMSNP-SUN-MUC-1 nanosystem serves as a unique multifunctional targeted delivery system to combat the MUC-1 overexpressing ovarian cancer cells.

Neuropilin: Handyman and Power Broker in the Tumor Microenvironment

Neuropilin-1 and neuropilin-2 form a small family of transmembrane receptors, which, due to the lack of a cytosolic protein kinase domain, act primarily as co-receptors for various ligands. Performing at the molecular level both the executive and organizing functions of a handyman as well as of a power broker, they are instrumental in controlling the signaling of various receptor tyrosine kinases, integrins, and other molecules involved in the regulation of physiological and pathological angiogenic processes. In this setting, the various neuropilin ligands and interaction partners on various cells of the tumor microenvironment, such as cancer cells, endothelial cells, cancer-associated fibroblasts, and immune cells, are surveyed. The suitability of various neuropilin-targeting substances and the intervention in neuropilin-mediated interactions is considered as a possible building block of tumor therapy.

MiR-200c sensitizes Olaparib-resistant ovarian cancer cells by targeting Neuropilin 1

BACKGROUND

Ovarian cancer (OC) is the most lethal gynecological malignancy and the second leading cause of cancer-related death in women. Treatment with PARP inhibitors (PARPi), such as Olaparib, has been recently introduced for OC patients, but resistance may occur and underlying mechanisms are still poorly understood. The aim of this study is to identify target genes within the tumor cells that might cause resistance to Olaparib. We focused on Neuropilin 1 (NRP1), a transmembrane receptor expressed in OC and correlated with poor survival, which has been also proposed as a key molecule in OC multidrug resistance.

METHODS

Using three OC cell lines (UWB, UWB-BRCA and SKOV3) as model systems, we evaluated the biological and molecular effects of Olaparib on OC cell growth, cell cycle, DNA damage and apoptosis/autophagy induction, through MTT and colony forming assays, flow cytometry, immunofluorescence and Western blot analyses. We evaluated NRP1 expression in OC specimens and cell lines by Western blot and qRT-PCR, and used RNA interference to selectively inhibit NRP1. To identify miR-200c as a regulator of NRP1, we used miRNA target prediction algorithms and Pearsons' correlation analysis in biopsies from OC patients. Then, we used a stable transfection approach to overexpress miR-200c in Olaparib-resistant cells.

RESULTS

We observed that NRP1 is expressed at high levels in resistant cells (SKOV3) and is upmodulated in partially sensitive cells (UWB-BRCA) upon prolonged Olaparib treatment, leading to poor drug response. Our results show that the selective inhibition of NRP1 is able to overcome Olaparib resistance in SKOV3 cells. Moreover, we demonstrated that miR-200c can target NRP1 in OC cells, causing its downmodulation, and that miR-200c overexpression is a valid approach to restore Olaparib sensitivity in OC resistant cells.

CONCLUSIONS

These data demonstrate that miR-200c significantly enhanced the anti-cancer efficacy of Olaparib in drug-resistant OC cells. Thus, the combination of Olaparib with miRNA-based therapy may represent a promising treatment for drug resistant OC, and our data may help in designing novel precision medicine trials for optimizing the clinical use of PARPi.

Neuropilins in the Context of Tumor Vasculature

Neuropilin-1 and Neuropilin-2 form a small family of plasma membrane spanning receptors originally identified by the binding of semaphorin and vascular endothelial growth factor. Having no cytosolic protein kinase domain, they function predominantly as co-receptors of other receptors for various ligands. As such, they critically modulate the signaling of various receptor tyrosine kinases, integrins, and other molecules involved in the regulation of physiological and pathological angiogenic processes. This review highlights the diverse neuropilin ligands and interacting partners on endothelial cells, which are relevant in the context of the tumor vasculature and the tumor microenvironment. In addition to tumor cells, the latter contains cancer-associated fibroblasts, immune cells, and endothelial cells. Based on the prevalent neuropilin-mediated interactions, the suitability of various neuropilin-targeted substances for influencing tumor angiogenesis as a possible building block of a tumor therapy is discussed.

Class-3 Semaphorins and Their Receptors: Potent Multifunctional Modulators of Tumor Progression

Semaphorins are the products of a large gene family containing 28 genes of which 21 are found in vertebrates. Class-3 semaphorins constitute a subfamily of seven vertebrate semaphorins which differ from the other vertebrate semaphorins in that they are the only secreted semaphorins and are distinguished from other semaphorins by the presence of a basic domain at their C termini. Class-3 semaphorins were initially characterized as axon guidance factors, but have subsequently been found to regulate immune responses, angiogenesis, lymphangiogenesis, and a variety of additional physiological and developmental functions. Most class-3 semaphorins transduce their signals by binding to receptors belonging to the neuropilin family which subsequently associate with receptors of the plexin family to form functional class-3 semaphorin receptors. Recent evidence suggests that class-3 semaphorins also fulfill important regulatory roles in multiple forms of cancer. Several class-3 semaphorins function as endogenous inhibitors of tumor angiogenesis. Others were found to inhibit tumor metastasis by inhibition of tumor lymphangiogenesis, by direct effects on the behavior of tumor cells, or by modulation of immune responses. Notably, some semaphorins such as sema3C and sema3E have also been found to potentiate tumor progression using various mechanisms. This review focuses on the roles of the different class-3 semaphorins in tumor progression.

Hypomethylated gene NRP1 is co-expressed with PDGFRB and associated with poor overall survival in gastric cancer patients

Gastric cancer (GC) has been an increasingly serious problem in public health. However, there is still a lack of efficient approach to diagnosis and treatment in time, especially in the field of targeted therapy. Increasing evidences demonstrated that DNA methylation plays an essential role in tumorigenesis and progression of GC. Thus the present study aims to identify DNA methylation-based prognostic biomarkers in GC. Two methylation array datasets (GSE25869 and GSE30601) and RNA-seq based gene profiling dataset (TCGA-STAD) were employed for exploring candidate DNA methylation-based biomarkers. Univariate Cox regression analysis was used to select the most efficient prognostic genes in GC patients. Weighted gene correlation network analysis (WGCNA) was performed to screen the cluster of co-expressed genes. As a result, our data proved that NRP1 was a hypomethylated / upregulated gene in GC tissues, and PDGFRB was strongly co-expressed with it. Both of them were significantly associated with the overall survival of patients. More importantly, high expression levels of NRP1 and PDGFRB were associated with malignant phenotypes in GC patients, including Laurén histological diffuse type and higher histological grade. Patients carrying high expression level of NRP1 and PDGFRB had a nearly two-fold increased death risk than others. In summary, the hypomethylated gene, NRP1, and its co-expressed gene, PDGFRB, were significantly correlated with tumor malignant phenotypes, which might serve as potential prognostic biomarkers for GC patients.

Semaphorin 3C and Its Receptors in Cancer and Cancer Stem-Like Cells

Neurodevelopmental programs are frequently dysregulated in cancer. Semaphorins are a large family of guidance cues that direct neuronal network formation and are also implicated in cancer. Semaphorins have two kinds of receptors, neuropilins and plexins. Besides their role in development, semaphorin signaling may promote or suppress tumors depending on their context. Sema3C is a secreted semaphorin that plays an important role in the maintenance of cancer stem-like cells, promotes migration and invasion, and may facilitate angiogenesis. Therapeutic strategies that inhibit Sema3C signaling may improve cancer control. This review will summarize the current research on the Sema3C pathway and its potential as a therapeutic target.

Neuropilin 1 Mediates Keratinocyte Growth Factor Signaling in Adipose-Derived Stem Cells: Potential Involvement in Adipogenesis

Adipogenesis is regulated by a complex network of molecules, including fibroblast growth factors. Keratinocyte growth factor (KGF) has been previously reported to promote proliferation on rat preadipocytes, although the expression of its specific receptor, FGFR2-IIIb/KGFR, is not actually detected in mesenchymal cells. Here, we demonstrate that human adipose-derived stem cells (ASCs) show increased expression of KGF during adipogenic differentiation, especially in the early steps. Moreover, KGF is able to induce transient activation of ERK and p38 MAPK pathways in these cells. Furthermore, KGF promotes ASC differentiation and supports the activation of differentiation pathways, such as those of PI3K/Akt and the retinoblastoma protein (Rb). Notably, we observed only a low amount of FGFR2-IIIb in ASCs, which seems not to be responsible for KGF activity. Here, we demonstrate for the first time that Neuropilin 1 (NRP1), a transmembrane glycoprotein expressed in ASCs acting as a coreceptor for some growth factors, is responsible for KGF-dependent pathway activation in these cells. Our study contributes to clarify the molecular bases of human adipogenesis, demonstrating a role of KGF in the early steps of this process, and points out a role of NRP1 as a previously unknown mediator of KGF action in ASCs.

Glycosylation-dependent galectin-1/neuropilin-1 interactions promote liver fibrosis through activation of TGF-β- and PDGF-like signals in hepatic stellate cells

Concomitant expressions of glycan-binding proteins and their bound glycans regulate many pathophysiologic processes, but this issue has not been addressed in liver fibrosis. Activation of hepatic stellate cells (HSCs) is a rate-limiting step in liver fibrosis and is an important target for liver fibrosis therapy. We previously reported that galectin (Gal)-1, a β-galactoside-binding protein, regulates myofibroblast homeostasis in oral carcinoma and wound healing, but the role of Gal-1 in HSC migration and activation is unclear. Herein, we report that Gal-1 and its bound glycans were highly expressed in fibrotic livers and activated HSCs. The cell-surface glycome of activated HSCs facilitated Gal-1 binding, which upon recognition of the N-glycans on neuropilin (NRP)-1, activated platelet-derived growth factor (PDGF)- and transforming growth factor (TGF)-β-like signals to promote HSC migration and activation. In addition, blocking endogenous Gal-1 expression suppressed PDGF- and TGF-β1-induced signaling, migration, and gene expression in HSCs. Methionine and choline-deficient diet (MCD)-induced collagen deposition and HSC activation were attenuated in Gal-1-null mice compared to wild-type mice. In summary, we concluded that glycosylation-dependent Gal-1/NRP-1 interactions activate TGF-β and PDGF-like signaling to promote the migration and activation of HSCs. Therefore, targeting Gal-1/NRP-1 interactions could be developed into liver fibrosis therapy.