The Neuropilin-1 Ligand, Sema3A, Acts as a Tumor Suppressor in the Pathogenesis of Acute Leukemia

Development of an in vitro genotoxicity assay to detect retroviral vector-induced lymphoid insertional mutants

Safety assessment in retroviral vector-mediated gene therapy remains challenging. In clinical trials for different blood and immune disorders, insertional mutagenesis led to myeloid and lymphoid leukemia. We previously developed the In Vitro Immortalization Assay (IVIM) and Surrogate Assay for Genotoxicity Assessment (SAGA) for pre-clinical genotoxicity prediction of integrating vectors. Murine hematopoietic stem and progenitor cells (mHSPCs) transduced with mutagenic vectors acquire a proliferation advantage under limiting dilution (IVIM) and activate stem cell- and cancer-related transcriptional programs (SAGA). However, both assays present an intrinsic myeloid bias due to culture conditions. To detect lymphoid mutants, we differentiated mHSPCs to mature T cells and analyzed their phenotype, insertion site pattern, and gene expression changes after transduction with retroviral vectors. Mutagenic vectors induced a block in differentiation at an early progenitor stage (double-negative 2) compared to fully differentiated untransduced mock cultures. Arrested samples harbored high-risk insertions close to Lmo2, frequently observed in clinical trials with severe adverse events. Lymphoid insertional mutants displayed a unique gene expression signature identified by SAGA. The gene expression-based highly sensitive molecular readout will broaden our understanding of vector-induced oncogenicity and help in pre-clinical prediction of retroviral genotoxicity.

mRNA-lncRNA gene expression signature for predicting pediatric AML relapse

Children with acute myeloid leukemia (AML) face a relapse of the disease in 30% of all cases. AML relapse is difficult to predict, and existing risk scales are often ineffective. Using data from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET-AML) project, we defined an expression signature based on matrix RNAs (mRNAs) and long non-coding RNAs (lncRNAs) that could predict relapse in pediatric AML patients. We used a comprehensive bioinformatics analysis that included the identification of functionally significant differentially expressed genes in AML relapse, several rounds of association with relapse-free survival (RFS) mRNAs and lncRNAs selection, and evaluation of the obtained expression signatures to predict recurrence at the primary tumor level. Two mRNAs (ENSG00000149289.11 (ZC3H12C) and ENSG00000075213.11 (SEMA3A)) and one lncRNA (ENSG00000287569.1) were associated with a decreased RFS. Models including changes in the expression of ZC3H12C and ENSG00000287569.1, as well as all three markers, demonstrated very good quality and could predict the recurrence of pediatric AML.

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.

Semaphorins as Potential Immune Therapeutic Targets for Cancer

Semaphorins are a large class of secreted or membrane-bound molecules. It has been reported that semaphorins play important roles in regulating several hallmarks of cancer, including angiogenesis, metastasis, and immune evasion. Semaphorins and their receptors are widely expressed on tumor cells and immune cells. However, the biological role of semaphorins in tumor immune microenvironment is intricate. The dysregulation of semaphorins influences the recruitment and infiltration of immune cells, leading to abnormal anti-tumor effect. Although the underlying mechanisms of semaphorins on regulating tumor-infiltrating immune cell activation and functions are not fully understood, semaphorins can notably be promising immunotherapy targets for cancer.

Covid-19-Induced Dysautonomia: A Menace of Sympathetic Storm

Among the plethora of debilitating neurological disorders of COVID-19 syndrome in survivors, the scope of SARS-CoV-2-induced dysautonomia (DNS) is yet to be understood, though the implications are enormous. Herein, we present an inclusive mini-review of SARS-CoV-2-induced DNS and its associated complications. Although, the direct link between Covid-19 and DSN is still speculative, the hypothetical links are thought to be either a direct neuronal injury of the autonomic pathway or a para/post-infectious immune-induced mechanism. SARS-CoV-2 infection-induced stress may activate the sympathetic nervous system (SNS) leading to neuro-hormonal stimulation and activation of pro-inflammatory cytokines with further development of sympathetic storm. Sympathetic over-activation in Covid-19 is correlated with increase in capillary pulmonary leakage, alveolar damage, and development of acute respiratory distress syndrome. Furthermore, SARS-CoV-2 can spread through pulmonary mechanoreceptors and chemoreceptors to medullary respiratory center in a retrograde manner resulting in sudden respiratory failure. Taken together, DSN in Covid-19 is developed due to sympathetic storm and inhibition of Parasympathetic nervous system-mediated anti-inflammatory effect with development of cytokine storm. Therefore, sympathetic and cytokine storms together with activation of Renin-Angiotensin-System are the chief final pathway involved in the development of DSN in Covid-19.

Targeting neuropilin-1 interactions is a promising anti-tumor strategy

ABSTRACT

Neuropilins (NRP1 and NRP2) are multifunctional receptor proteins that are involved in nerve, blood vessel, and tumor development. NRP1 was first found to be expressed in neurons, but subsequent studies have demonstrated its surface expression in cells from the endothelium and lymph nodes. NRP1 has been demonstrated to be involved in the occurrence and development of a variety of cancers. NRP1 interacts with various cytokines, such as vascular endothelial growth factor family and its receptor and transforming growth factor β1 and its receptor, to affect tumor angiogenesis, tumor proliferation, and migration. In addition, NRP1+ regulatory T cells (Tregs) play an inhibitory role in tumor immunity. High numbers of NRP1+ Tregs were associated with cancer prognosis. Targeting NRP1 has shown promise, and antagonists against NRP1 have had therapeutic efficacy in preliminary clinical studies. NRP1 treatment modalities using nanomaterials, targeted drugs, oncolytic viruses, and radio-chemotherapy have gradually been developed. Hence, we reviewed the use of NRP1 in the context of tumorigenesis, progression, and treatment.

Novel genes associated with folic acid-mediated metabolism in mouse: A bioinformatics study

Folic acid plays an essential role in the central nervous system and cancer. This study aimed to screen genes related to folic acid metabolism. Datasets (GSE80587, GSE65267 and GSE116299) correlated to folic acid were screened in the Gene Expression Omnibus. Weighed gene co-expression network analysis was performed to identify modules associated with sample traits of folic acid and organs (brain, prostate and kidney). Functional enrichment analysis was performed for the eigengenes in modules that were significantly correlated with sample traits. Accordingly, the hub genes and key nodes in the modules were identified using the protein interaction network. A total of 17,252 genes in three datasets were identified. One module, which included 97 genes that were highly correlated with sample traits (including folic acid treatment [cor = -0.57, P = 3e-04] and kidney [cor = -0.68, p = 4e-06]), was screened out. Hub genes, including tetratricopeptide repeat protein 38 (Ttc38) and miR-185, as well as those (including Sema3A, Insl3, Dll1, Msh4 and Snai1) associated with "neuropilin binding", "regulation of reproductive process" and "vitamin D metabolic process", were identified. Genes, including Ttc38, Sema3A, Insl3, Dll1, Msh4 and Snai1, were the novel factors that may be associated with the development of the kidneys and related to folic acid treatment.

Enhanced expression of TIGIT but not neuropilin-1 in patients with type 2 diabetes mellitus

BACKGROUND

The aggressive T helper cell responses and regulatory T (Treg) cells dysfunction exist in type 2 diabetes mellitus (T2DM). The co-inhibitory T cell immunoglobulin and ITIM-domain (TIGIT), neuropilin-1 (Nrp-1), and the co-stimulatory CD226 play a critical role in the inhibition or activation of immune responses. In this project, the expression of TIGIT, CD226, Nrp-1, and their ligands, CD155 and semaphorin 3A (Sema-3A) were investigated in T2DM.

METHODS

Peripheral blood mononuclear cells (PBMCs) were collected from 30 patients with T2DM, and 30 healthy controls (HCs). The frequencies of TIGIT and Nrp-1 on CD4⁺CD25^hi Treg cells, CD4⁺CD25^- responder T cells, total CD4⁺ T cells, and non-CD4⁺ cells were assessed using flow cytometry. The mRNA levels of TIGIT, CD226, Nrp-1, CD155, and Sema-3A were assessed by real-time PCR.

RESULTS

The percentage and MFI of TIGIT on CD4⁺CD25^hi T cells, CD4⁺CD25^- T cells, total CD4⁺ T cells, and non-CD4⁺ cells were higher in patients versus HCs (p < 0.05 for all). The mRNA level of TIGIT was increased in patients compared with HCs (p = 0.003). No differences were observed in the expression of CD226, CD155, Nrp-1, and Sema-3A between the groups.

CONCLUSIONS

The expression of TIGIT was enhanced in T2DM and the TIGIT axis could be considered as a new therapeutic purpose for the T2DM.

MicroRNA-19b-3p suppresses gastric cancer development by negatively regulating neuropilin-1

Background

Gastric cancer (GC) remains one of the most common digestive malignancies worldwide and ranked third causes of cancer-related death. Mounting evidence has revealed that miRNAs exert critical regulatory roles in GC development.

Methods

Immunohistochemistry (IHC) and western blot assay were performed to determine the protein expression levels of neuropilin-1 (NRP1) and mRNA levels were confirmed by quantitative RT-PCR (qRT-PCR) in GC tissues. Kaplan–Meier analysis was performed to evaluate the prognostic value of NRP1 in GC. Knockdown of NRP1 was conducted to analyse its function in vitro and vivo. Luciferase reporter assay, western blot and qRT-qPCR were employed to identify the miRNAs which directly targeted NRP1. Furthermore, Bioinformatics analysis and experimental verification were used to explore the potential molecular mechanism and signalling pathway.

Results

In the current study, we revealed that NRP1 was highly expressed in GC tumor tissues and was associated with poor prognosis in GC patients. NRP1 knockdown inhibited GC cell growth, migration and invasion in vitro, while suppressed GC xenograft tumor development in vivo. Bioinformatics analysis predicted that miR-19b-3p down-regulated NRP1 expression by targeting its 3′-UTR. Functional assay demonstrated that miR-19b-3p inhibited GC cell growth, migration and invasion via negatively regulating NRP1. Overexpression NRP1 partially reversed the regulatory effect of miR-19b-3p. Moreover, we showed that miR-19b-3p/NRP1 axis regulated the epithelial-to-mesenchymal transition and focal adhesion in GC, which might contribute the GC development and progression.

Conclusions

Taken together, our findings suggest a regulatory network of miR-19b-3p/NRP1 in GC development. The miR-19b-3p/NRP1 axis might be further explored as a potential diagnostic and therapeutic target in GC.

Semaphorins and Their Receptors in Hematological Malignancies

While semaphorins were initially identified as axonal guidance cues for wiring the neural network, it was then recognized their wide relevance in tissue development and homeostasis. Notably, semaphorin activities were also extensively studied in many types of solid tumors; however, their relevance in hematological malignancies is far from understood. In this mini-review, we surveyed the current knowledge about semaphorins and their receptors in leukemias, lymphomas, and multiple myeloma. Noteworthy, current data support a promoting role for Semaphorin 4D and Neuropilin-1 in these tumors, while Semaphorin 3A seems to consistently act as oncosuppressor in leukemias and multiple myeloma. The expression levels and functional activities of SEMA3B, SEMA3F, and Neuropilin-2 have furthermore been investigated in leukemias and lymphoma cells. Herein, we reviewed the state of the art and highlighted some of the open questions to be addressed in the field.

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.