Notch Pathway: A Journey from Notching Phenotypes to Cancer Immunotherapy

Kidney Renin Release under Hypoxia and Its Potential Link with Nitric Oxide: A Narrative Review

The renin-angiotensin system (RAS) and hypoxia have a complex interaction: RAS is activated under hypoxia and activated RAS aggravates hypoxia in reverse. Renin is an aspartyl protease that catalyzes the first step of RAS and tightly regulates RAS activation. Here, we outline kidney renin expression and release under hypoxia and discuss the putative mechanisms involved. It is important that renin generally increases in response to acute hypoxemic hypoxia and intermittent hypoxemic hypoxia, but not under chronic hypoxemic hypoxia. The increase in renin activity can also be observed in anemic hypoxia and carbon monoxide-induced histotoxic hypoxia. The increased renin is contributed to by juxtaglomerular cells and the recruitment of renin lineage cells. Potential mechanisms regulating hypoxic renin expression involve hypoxia-inducible factor signaling, natriuretic peptides, nitric oxide, and Notch signaling-induced renin transcription.

Spotlights on ubiquitin-specific protease 12 (USP12) in diseases: from multifaceted roles to pathophysiological mechanisms

Ubiquitination is one of the most significant post-translational modifications that regulate almost all physiological processes like cell proliferation, autophagy, apoptosis, and cell cycle progression. Contrary to ubiquitination, deubiquitination removes ubiquitin from targeted protein to maintain its stability and thus regulate cellular homeostasis. Ubiquitin-Specific Protease 12 (USP12) belongs to the biggest family of deubiquitinases named ubiquitin-specific proteases and has been reported to be correlated with various pathophysiological processes. In this review, we initially introduce the structure and biological functions of USP12 briefly and summarize multiple substrates of USP12 as well as the underlying mechanisms. Moreover, we discuss the influence of USP12 on tumorigenesis, tumor immune microenvironment (TME), disease, and related signaling pathways. This study also provides updated information on the roles and functions of USP12 in different types of cancers and other diseases, including prostate cancer, breast cancer, lung cancer, liver cancer, cardiac hypertrophy, multiple myeloma, and Huntington's disease. Generally, this review sums up the research advances of USP12 and discusses its potential clinical application value which deserves more exploration in the future.

Identification of necroptosis-related long non-coding RNAs prognostic signature and the crucial lncRNA in bladder cancer

BACKGROUND

Research on the relationships between long non-coding RNAs (lncRNAs) and cancer is attractive and has progressed very rapidly. Necroptosis-related biomarkers can potentially be used for predicting the prognosis of cancer patients. This study aimed to establish a necroptosis-related lncRNA (NPlncRNA) signature to predict the prognosis of patients with bladder cancer (BCa).

METHODS

First, NPlncRNAs were identified using Pearson correlation analysis and machine learning algorithms, including SVM-RFE, least absolute shrinkage and selection operator (LASSO) regression, and random forest. The prognostic NPlncRNA signature was constructed using univariate and multivariate Cox regression analyses and the diagnostic efficacy and clinically predictive efficiency were evaluated and validated. The biological functions of the signature were analysed using gene set enrichment analysis (GSEA) and functional enrichment analysis. We further integrated the RNA-seq dataset (GSE133624) with our outcomes to reveal the crucial NPlncRNA that was functionally verified by assessing cell viability, proliferation, and apoptosis in BCa cells.

RESULTS

The prognostic NPlncRNAs signature was composed of PTOV1-AS2, AC083862.2, MAFG-DT, AC074117.1, AL049840.3, and AC078778.1, and a risk score based on this signature was proven to be an independent prognostic factor for the BCa patients, indicated by poor overall survival (OS) of patients in the high-risk group. Additionally, the NPlncRNAs signature had a higher diagnostic validity than that of other clinicopathological variables, with a greater area under the receptor operating characteristic and concordance index curves. A nomogram established by integrating clinical variables and risk score confirmed that the signature can accurately predict the OS of patients and has high clinical practicability. Functional enrichment analysis and GSEA revealed that some cancer-related and necroptosis-related pathways were enriched in high-risk groups. The crucial NPlncRNA MAFG-DT was associated with poor prognosis and was highly expressed in BCa cells. MAFG-DT silencing notably inhibited proliferation and enhanced apoptosis of BCa cells.

CONCLUSIONS

A novel prognostic NPlncRNAs signature was identified in BCa in this study, which provides potential therapeutic targets among which MAFG-DT plays critical roles in the tumorigenesis of BCa.

The expression of ASAP3 and NOTCH3 and the clinicopathological characteristics of adult glioma patients

ASAP3 is involved in a variety of biological activities, including cancer progression in humans. In adult glioma, we explore the effects of ASAP3 and NOTCH3 and their relationships on prognosis. The Oncomine, TIMER, and Gene Expression Profiling Interactive Analysis databases were used to investigate ASAP3 expression. Immunohistochemistry was used to assess the levels of ASAP3 and NOTCH3 expressions. The effects of ASAP3 and NOTCH3 on prognosis were assessed using survival analysis. The results revealed that the amount of ASAP3 mRNA in gliomas was much higher than in normal tissue (P < 0.01). Glioma patients with high ASAP3 mRNA expression had a worse overall survival and progression-free survival. ASAP3 overexpression is directly associated with the NOTCH signaling system. Immunohistochemistry revealed that ASAP3 and NOTCH3 were overexpressed in glioblastomas (GBMs). ASAP3 expression was associated with age, recurrence, tumor resection, postoperative chemoradiotherapy, World Health Organization (WHO) grade, and Ki-67 expression. ASAP3 expression was related to the isocitrate dehydrogenase-1 mutation in low-grade glioma. Gender, local recurrence, tumor resection, postoperative radio-chemotherapy, WHO grade, recurrence, and ATRX expression were all associated with NOTCH3 expression. ASAP3 was shown to be positively associated with NOTCH3 (r = 0.337, P = 0.000). Therefore, ASAP3 and NOTCH3 as oncogene factors have the potential to be prognostic biomarkers and therapeutic targets in adult glioma.

Targeting the Cbl-b-Notch1 axis as a novel immunotherapeutic strategy to boost CD8+ T-cell responses

A critical feature of cancer is the ability to induce immunosuppression and evade immune responses. Tumor-induced immunosuppression diminishes the effectiveness of endogenous immune responses and decreases the efficacy of cancer immunotherapy. In this study, we describe a new immunosuppressive pathway in which adenosine promotes Casitas B-lineage lymphoma b (Cbl-b)-mediated Notch1 degradation, causing suppression of CD8+ T-cells effector functions. Genetic knockout and pharmacological inhibition of Cbl-b prevents Notch1 degradation in response to adenosine and reactivates its signaling. Reactivation of Notch1 results in enhanced CD8+ T-cell effector functions, anti-cancer response and resistance to immunosuppression. Our work provides evidence that targeting the Cbl-b-Notch1 axis is a novel promising strategy for cancer immunotherapy.

Modulation of Notch Signaling Pathway by Bioactive Dietary Agents

Notch signaling is often aberrantly activated in solid and hematological cancers and regulates cell fate decisions and the maintenance of cancer stem cells. In addition, increased expression of Notch pathway components is clinically associated with poorer prognosis in several types of cancer. Targeting Notch may have chemopreventive and anti-cancer effects, leading to reduced disease incidence and improved survival. While therapeutic agents are currently in development to achieve this goal, several researchers have turned their attention to dietary and natural agents for targeting Notch signaling. Given their natural abundance from food sources, the use of diet-derived agents to target Notch signaling offers the potential advantage of low toxicity to normal tissue. In this review, we discuss several dietary agents including curcumin, EGCG, resveratrol, and isothiocyanates, which modulate Notch pathway components in a context-dependent manner. Dietary agents modulate Notch signaling in several types of cancer and concurrently decrease in vitro cell viability and in vivo tumor growth, suggesting a potential role for their clinical use to target Notch pathway components, either alone or in combination with current therapeutic agents.

In vivo Evaluation of Non-viral NICD Plasmid-Loaded PLGA Nanoparticles in Developing Zebrafish to Improve Cardiac Functions

In the era of the advanced nanomaterials, use of nanoparticles has been highlighted in biomedical research. However, the demonstration of DNA plasmid delivery with nanoparticles for in vivo gene delivery experiments must be carefully tested due to many possible issues, including toxicity. The purpose of the current study was to deliver a Notch Intracellular Domain (NICD)-encoded plasmid via poly(lactic-co-glycolic acid) (PLGA) nanoparticles and to investigate the toxic environmental side effects for an in vivo experiment. In addition, we demonstrated the target delivery to the endothelium, including the endocardial layer, which is challenging to manipulate gene expression for cardiac functions due to the beating heart and rapid blood pumping. For this study, we used a zebrafish animal model and exposed it to nanoparticles at varying concentrations to observe for specific malformations over time for toxic effects of PLGA nanoparticles as a delivery vehicle. Our nanoparticles caused significantly less malformations than the positive control, ZnO nanoparticles. Additionally, the NICD plasmid was successfully delivered by PLGA nanoparticles and significantly increased Notch signaling related genes. Furthermore, our image based deep-learning analysis approach evaluated that the antibody conjugated nanoparticles were successfully bound to the endocardium to overexpress Notch related genes and improve cardiac function such as ejection fraction, fractional shortening, and cardiac output. This research demonstrates that PLGA nanoparticle-mediated target delivery to upregulate Notch related genes which can be a potential therapeutic approach with minimum toxic effects.

Intrinsically disordered proteins play diverse roles in cell signaling

Signaling pathways allow cells to detect and respond to a wide variety of chemical (e.g. Ca2+ or chemokine proteins) and physical stimuli (e.g., sheer stress, light). Together, these pathways form an extensive communication network that regulates basic cell activities and coordinates the function of multiple cells or tissues. The process of cell signaling imposes many demands on the proteins that comprise these pathways, including the abilities to form active and inactive states, and to engage in multiple protein interactions. Furthermore, successful signaling often requires amplifying the signal, regulating or tuning the response to the signal, combining information sourced from multiple pathways, all while ensuring fidelity of the process. This sensitivity, adaptability, and tunability are possible, in part, due to the inclusion of intrinsically disordered regions in many proteins involved in cell signaling. The goal of this collection is to highlight the many roles of intrinsic disorder in cell signaling. Following an overview of resources that can be used to study intrinsically disordered proteins, this review highlights the critical role of intrinsically disordered proteins for signaling in widely diverse organisms (animals, plants, bacteria, fungi), in every category of cell signaling pathway (autocrine, juxtacrine, intracrine, paracrine, and endocrine) and at each stage (ligand, receptor, transducer, effector, terminator) in the cell signaling process. Thus, a cell signaling pathway cannot be fully described without understanding how intrinsically disordered protein regions contribute to its function. The ubiquitous presence of intrinsic disorder in different stages of diverse cell signaling pathways suggest that more mechanisms by which disorder modulates intra- and inter-cell signals remain to be discovered.

A Phase Ib Dose Escalation Trial of RO4929097 (a γ-secretase inhibitor) in Combination with Exemestane in Patients with ER + Metastatic Breast Cancer (MBC)

PRECLINICAL STUDIES: have demonstrated a complex cross-talk between Notch and estrogen signaling in ERα-positive breast cancer. Gamma-secretase inhibitors (GSIs) are investigational agents that block the cleavage and activation of Notch receptors. In animal models of endocrine-resistant breast cancer, combinations of tamoxifen and GSIs produce additive or synergistic efficacy, while decreasing the intestinal toxicity of GSIs. However, results of a clinical trial of a GSI-endocrine therapy combination in the metastatic setting have not been published to date, nor had the safety of such combinations been investigated with longer term treatment. We conducted a phase 1b dose escalation trial (NCT01149356) of GSI RO4929097 with exemestane in patients with ERα+, metastatic breast cancer (MBC) STUDY OBJECTIVES: To determine the safety, tolerability and maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) of RO4929097 when administered in combination with exemestane in patients with estrogen receptor positive metastatic breast cancer RESULTS: We enrolled 15 patients with MBC. Of 14 evaluable patients, one had a partial response, 6 had stable disease and 7 progressive disease. Twenty % of patients had stable disease for ≥ 6 months. Common toxicities included nausea (73.3%), anorexia (60%), hyperglycemia (53.3%), hypophosphatemia (46.7%), fatigue (66.7%) and cough (33.0%). Grade 3 toxicities were uncommon, and included hypophosphatemia (13%) and rash (6.3%). Rash was the only DLT observed at 140 mg/d. Results suggest a possible recommended phase 2 dose of 90 mg/d. Ten patients with evaluable archival tissue showed expression of PKCα, which correlated with expression of Notch4. Mammospheres from a PKCα-expressing, endocrine-resistant T47D cell line were inhibited by a GSI-fulvestrant combination CONCLUSIONS: Our data indicate that combinations including endocrine therapy and Notch inhibitors deserve further investigation in endocrine-resistant ERα-positive breast cancer.

[Inhibition of the Notch1/Jagged1 pathway promotes homing of bone mesenchymal stem cells to improve asthma in rats]

OBJECTIVE

To explore the association of the Notch1/Jagged1 pathway with the homing of mesenchymal stem cells (BMSCs) to regulate Th1/Th2 drift in asthma.

METHODS

Twenty SD rats were randomly divided into normal control group, model group, BMSC transplantation group, and BMSC+Notch inhibitor group. Ovalbumin sensitization was used to establish rat models of asthma, and BMSCs were transplanted via the tail vein. The pathology of the lung tissue was examined with HE staining, and the contents of interleukin (IL)-5, IL-13, and interferon-γ (IFN-γ) in lung tissue homogenate were determined with enzyme-linked immunosorbent assay. The expressions of Notch1 and Jagged1 mRNA were detected with RT-PCR, and CXCR4 expression in the bronchial epithelial cells was examined using immunofluorescence staining; Western blotting was used to detect the protein expressions of T-bet, GATA-3, Notch1, and Jagged1 in the lung tissue.

RESULTS

Compared with those in the control group, the expressions of IFN-γ and T-bet proteins decreased significantly and the pulmonary expressions of IL-5, IL-13, and GATA-3 proteins as well as Notch1 and Jagged1 mRNA and protein expressions all increased significantly in the model group (P < 0.05 or 0.01). Compared with those in the model group, CXCR4, IFN-γ, and T-bet protein expressions in BMSC group and BMSCs+Notch inhibitor group all increased significantly, and Notch1 and Jagged1 protein expressions in BMSCs group and IL-5, IL-13, Notch1, and Jagged1 mRNA and protein expressions in BMSCs + Notch inhibitor group all decreased significantly (P < 0.05 or 0.01). The expressions of CXCR4 and IFN-γ were significantly higher and the expressions of IL-13 and Notch1 mRNA were significantly lower in BMSCs+Notch inhibitor group than in BMSC group (P < 0.05).

CONCLUSION

In asthmatic rats, the homing of the BMSCs to the lung tissue has a regulatory effect on Th1/Th2 drift, and the Notch1/Jagged1 pathway may participate in the homing of the BMSCs.

The conserved C2 phospholipid-binding domain in Delta contributes to robust Notch signalling

Accurate Notch signalling is critical for development and homeostasis. Fine‐tuning of Notch–ligand interactions has substantial impact on signalling outputs. Recent structural studies have identified a conserved N‐terminal C2 domain in human Notch ligands which confers phospholipid binding in vitro. Here, we show that Drosophila ligands Delta and Serrate adopt the same C2 domain structure with analogous variations in the loop regions, including the so‐called β1‐2 loop that is involved in phospholipid binding. Mutations in the β1‐2 loop of the Delta C2 domain retain Notch binding but have impaired ability to interact with phospholipids in vitro. To investigate its role in vivo, we deleted five residues within the β1‐2 loop of endogenous Delta. Strikingly, this change compromises ligand function. The modified Delta enhances phenotypes produced by Delta loss‐of‐function alleles and suppresses that of Notch alleles. As the modified protein is present on the cell surface in normal amounts, these results argue that C2 domain phospholipid binding is necessary for robust signalling in vivo fine‐tuning the balance of trans and cis ligand–receptor interactions.

Myelin and lymphocyte protein 2 regulates cell proliferation and metastasis through the Notch pathway in prostate adenocarcinoma

Background

Myelin and lymphocyte protein 2 (MAL2) is a proven oncogene in some human tumors. However, currently, little is known about the function of MAL2 in prostate adenocarcinoma (PRAD). This study sought to investigate the role of MAL2 on PRAD progression.

Methods

MAL2 expression in PRAD was first analyzed by the Gene Expression Profiling Interactive Analysis (GEPIA) database. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay and Western blot assay were used to detect the expression of MAL2 in PRAD tissues and cell lines. Additionally, immunohistochemistry (IHC) straining was used to detect the expression of MAL2 in PRAD pathological tissues. The Cell Counting Kit-8 (CCK-8) assay, clone formation assay and Flow cytometry were performed to investigate the effect of MAL2 on PRAD cell proliferation and cell apoptosis. Cell migration and invasion were measured by Transwell assay. The effect of MAL2 on epithelial-mesenchymal transition (EMT) progression and the Notch signaling pathway in PRAD was also investigated.

Results

MAL2 was discovered to be obviously upregulated in PRAD tissues and cell lines. The upregulation of MAL2 was closely associated with tumor, nodes and metastases (TNM) stage, the Gleason score and metastasis of PRAD patients, and affected the prognosis of PRAD patients. Functionally, the depletion of MAL2 suppressed cell proliferation, migration, invasion, and EMT progression, and promoted cell apoptosis of PRAD cells. In an in vivo experiment, MAL2 knockdown significantly suppressed tumor growth in mice. Further, inhibiting the Notch pathway reversed the effect of MAL2 knockdown on PRAD progression.

Conclusions

In sum, MAL2 was found to be upregulated in PRAD, and appears to act as a carcinogen in PRAD. Additionally, MAL2 appears to regulate PRAD progression through the Notch signaling pathway.

ZFPM2-AS1 facilitates cell proliferation and migration in cutaneous malignant melanoma through modulating miR-650/NOTCH1 signaling

Aberrant expression of long non-coding RNA (lncRNA) zinc finger protein, FOG family member 2 antisense RNA 1 (ZFPM2-AS1) has been identified in many tumors, but its role in cutaneous malignant melanoma remains largely obscure. Our present study was intended to unveil the role and potential mechanism of ZFPM2-AS1 in cutaneous malignant melanoma. RT-qPCR was utilized to analyze ZFPM2-AS1 expression in cutaneous malignant melanoma cells. Cell counting kit-8 (CCK-8), colony formation, flow cytometry, and transwell analyses were utilized to assess ZFPM2-AS1 function on cell proliferation, apoptosis, and migration. Luciferase reporter, RNA immunoprecipitation, and RNA-pull down assays were applied to probe the regulatory mechanism of ZFPM2-AS1 in cutaneous malignant melanoma cells. Up-regulation of ZFPM2-AS1 was discovered in cutaneous malignant melanoma cells. ZFPM2-AS1 deletion restrained cell proliferation, migration, and elevated cell apoptosis in cutaneous malignant melanoma. ZFPM2-AS1 regulated notch receptor 1 (NOTCH1) to activate the NOTCH pathway. ZFPM2-AS1 acted as a competing endogenous RNA (ceRNA) to affect NOTCH1 expression via sponging miR-650. Collectively, ZFPM2-AS1 exerted an oncogenic role in cutaneous malignant melanoma progression via targeting miR-650/NOTCH1 signaling. Our study might offer a novel sight for cutaneous malignant melanoma treatment.

Notch Signaling in Prevention And Therapy: Fighting Cancer with a Two-Sided Sword

The evolutionary conserved Notch pathway that first developed in metazoans and that was first discovered in fruit flies (Drosophila melanogaster) governs fundamental cell fate decisions and many other cellular key processes not only in embryonic development but also during initiation, promotion, and progression of cancer. On a first look, the Notch pathway appears remarkably simple, with its key feature representing a direct connection between an extracellular signal and transcriptional output without the need of a long chain of protein intermediaries as known from many other signaling pathways. However, on a second, closer look, this obvious simplicity exerts surprising complexity. There is no doubt that the enormous scientific progress in unraveling the functional mechanisms that underlie this complexity has recently greatly increased our knowledge about the role of Notch signaling for pathogenesis and progression of many types of cancer. Moreover, these new scientific findings have shown promise in opening new avenues for cancer prevention and therapy, although this goal is still challenging. Vol. III of the second edition of the book Notch Signaling in Embryology and Cancer, entitled Notch Signaling in Cancer, summarizes important recent developments in this fast-moving and fascinating field. Here, we give an introduction to this book and a short summary of the individual chapters that are written by leading scientists, covering the latest developments in this intriguing research area.