From fly wings to targeted cancer therapies: a centennial for notch signaling

The role of circular RNA during the urological cancer metastasis: exploring regulatory mechanisms and potential therapeutic targets

Metastasis is a major contributor to treatment failure and death in urological cancers, representing an important biomedical challenge at present. Metastases form as a result of cancer cells leaving the primary site, entering the vasculature and lymphatic vessels, and colonizing clones elsewhere in the body. However, the specific regulatory mechanisms of action underlying the metastatic process of urological cancers remain incompletely elucidated. With the deepening of research, circular RNAs (circRNAs) have been found to not only play a significant role in tumor progression and prognosis but also show aberrant expression in various tumor metastases, consequently impacting tumor metastasis through multiple pathways. Therefore, circRNAs are emerging as potential tumor markers and treatment targets. This review summarizes the research progress on elucidating how circRNAs regulate the urological cancer invasion-metastasis cascade response and related processes, as well as their role in immune microenvironment remodeling and circRNA vaccines. This body of work highlights circRNA regulation as an emerging therapeutic target for urological cancers, which should motivate further specific research in this regard.

Molecular insights and clinical implications for the tumor suppressor role of SCFFBXW7 E3 ubiquitin ligase

FBXW7 is one of the most well-characterized F-box proteins, serving as substrate receptor subunit of SKP1-CUL1-F-box (SCF) E3 ligase complexes. SCFFBXW7 is responsible for the degradation of various oncogenic proteins such as cyclin E, c-MYC, c-JUN, NOTCH, and MCL1. Therefore, FBXW7 functions largely as a major tumor suppressor. In keeping with this notion, FBXW7 gene mutations or downregulations have been found and reported in many types of malignant tumors, such as endometrial, colorectal, lung, and breast cancers, which facilitate the proliferation, invasion, migration, and drug resistance of cancer cells. Therefore, it is critical to review newly identified FBXW7 regulation and tumor suppressor function under physiological and pathological conditions to develop effective strategies for the treatment of FBXW7-altered cancers. Since a growing body of evidence has revealed the tumor-suppressive activity and role of FBXW7, here, we updated FBXW7 upstream and downstream signaling including FBXW7 ubiquitin substrates, the multi-level FBXW7 regulatory mechanisms, and dysregulation of FBXW7 in cancer, and discussed promising cancer therapies targeting FBXW7 regulators and downstream effectors, to provide a comprehensive picture of FBXW7 and facilitate the study in this field.

Wnt/β-catenin signaling pathway in carcinogenesis and cancer therapy

The Wnt/β-catenin signaling pathway plays a crucial role in various physiological processes, encompassing development, tissue homeostasis, and cell proliferation. Under normal physiological conditions, the Wnt/β-catenin signaling pathway is meticulously regulated. However, aberrant activation of this pathway and downstream target genes can occur due to mutations in key components of the Wnt/β-catenin pathway, epigenetic modifications, and crosstalk with other signaling pathways. Consequently, these dysregulations contribute significantly to tumor initiation and progression. Therapies targeting the Wnt/β-catenin signaling transduction have exhibited promising prospects and potential for tumor treatment. An increasing number of medications targeting this pathway are continuously being developed and validated. This comprehensive review aims to summarize the latest advances in our understanding of the role played by the Wnt/β-catenin signaling pathway in carcinogenesis and targeted therapy, providing valuable insights into acknowledging current opportunities and challenges associated with targeting this signaling pathway in cancer research and treatment.

Endothelial cell Notch signaling programs cancer-associated fibroblasts to promote tumor immune evasion

Stromal cells within the tumor tissue promote immune evasion as a critical strategy for cancer development and progression, but the underlying mechanisms remain poorly understood. In this study, we explore the role of endothelial cells (ECs) in the regulation of the immunosuppressive tumor microenvironment. Using mouse pancreatic ductal adenocarcinoma (PDAC) models, we found that canonical Notch signaling in endothelial cells suppresses the recruitment of antitumor T cells and promotes tumor progression by inhibiting the pro-inflammatory functions of cancer-associated fibroblasts (CAFs). Abrogation of endothelial Notch signaling modulates EC-derived angiocrine factors to enhance the pro-inflammatory activities of CAFs, which drive CXCL9/10-CXCR3-mediated T cell recruitment to inhibit tumor growth. Additionally, abrogation of endothelial Notch unleashed interferon gamma responses in the tumor microenvironment, upregulated PDL1 expression on tumor cells, and sensitized PDAC to PD1-based immunotherapy. Collectively, these data uncover a pivotal role of endothelial cells in shaping the immunosuppressive microenvironment, and suggest the potential of targeting EC-CAF interaction as a novel therapeutic modality to boost antitumor immunity.

Notch signaling pathway in cancer: from mechanistic insights to targeted therapies

Notch signaling, renowned for its role in regulating cell fate, organ development, and tissue homeostasis across metazoans, is highly conserved throughout evolution. The Notch receptor and its ligands are transmembrane proteins containing epidermal growth factor-like repeat sequences, typically necessitating receptor-ligand interaction to initiate classical Notch signaling transduction. Accumulating evidence indicates that the Notch signaling pathway serves as both an oncogenic factor and a tumor suppressor in various cancer types. Dysregulation of this pathway promotes epithelial-mesenchymal transition and angiogenesis in malignancies, closely linked to cancer proliferation, invasion, and metastasis. Furthermore, the Notch signaling pathway contributes to maintaining stem-like properties in cancer cells, thereby enhancing cancer invasiveness. The regulatory role of the Notch signaling pathway in cancer metabolic reprogramming and the tumor microenvironment suggests its pivotal involvement in balancing oncogenic and tumor suppressive effects. Moreover, the Notch signaling pathway is implicated in conferring chemoresistance to tumor cells. Therefore, a comprehensive understanding of these biological processes is crucial for developing innovative therapeutic strategies targeting Notch signaling. This review focuses on the research progress of the Notch signaling pathway in cancers, providing in-depth insights into the potential mechanisms of Notch signaling regulation in the occurrence and progression of cancer. Additionally, the review summarizes pharmaceutical clinical trials targeting Notch signaling for cancer therapy, aiming to offer new insights into therapeutic strategies for human malignancies.

Notch-Targeted Therapeutic in Colorectal Cancer by Notch1 Attenuation Via Tumor Microenvironment-Responsive Cascade DNA Delivery

The Notch signaling is a key molecular pathway that regulates cell fate and development. Aberrant Notch signaling can lead to carcinogenesis and progression of malignant tumors. However, current therapies targeting Notch pathway lack specificity and induce high toxicity. In this report, a tumor microenvironment-responsive and injectable hydrogel is designed to load plasmid DNA complexes as a cascade gene delivery system to achieve precise Notch-targeted gene therapy of colorectal cancer (CRC). The hydrogels are prepared through cross-linking between phenylboric acid groups containing poly(oligo(ethylene glycol)methacrylate) (POEGMA) and epigallocatechin gallate (EGCG), used to load the complexes between plasmid DNA encoding short hairpin RNAs of Notch1 (shNotch1) and fluorinated polyamidoamine (PAMAM-F) (PAMAM-F/shNotch1). In response to low pH and H2O2 in tumor microenvironment, the hydrogel can be dissociated and release the complexes for precise delivery of shNotch1 into tumor cells and inhibit Notch1 activity to suppress malignant biological behaviors of CRC. In the subcutaneous tumor model of CRC, PAMAM-F/shNotch1-loaded hydrogels can accurately attenuate Notch1 activity and significantly inhibit tumor growth without affecting Notch signal in adjacent normal tissues. Therefore, this therapeutic system can precisely inhibit Notch1 signal in CRC with high responsiveness and low toxicity, providing a promising Notch-targeted gene therapeutic for human malignancy.

Functional role of lncRNAs in gastrointestinal malignancies: the peculiar case of small nucleolar RNA host gene family

Long noncoding RNAs (lncRNAs) play crucial roles in normal physiology and are often de-regulated in disease states such as cancer. Recently, a class of lncRNAs referred to as the small nucleolar RNA host gene (SNHG) family have emerged as important players in tumourigenesis. Here, we discuss new findings describing the role of SNHGs in gastrointestinal tumours and summarize the three main functions by which these lncRNAs promote carcinogenesis, namely: competing with endogenous RNAs, modulating protein function, and regulating epigenetic marking. Furthermore, we discuss how SNHGs participate in different hallmarks of cancer, and how this class of lncRNAs may serve as potential biomarkers in cancer diagnosis and therapy.

Notch signaling genes and CD8+ T-cell dynamics: Their contribution to immune-checkpoint inhibitor therapy in oral squamous cell carcinoma: A retrospective study

BACKGROUND

Aberrant Notch signaling pathway has been related with the tumorigenesis in head and neck region, involving oral cavity. Here, we report the correlation between mutations in the Notch signaling pathway and CD8+ T-cell infiltration via PD-L1, which lead to enhanced antitumor immunity and may target for immune-checkpoint inhibitors (ICIs) therapy.

METHODS

This retrospective study analyzed the results of immunohistochemical staining for PD-L1 and CD8+ T-cell infiltration in 10 patients and whole-exome sequencing (WES) was conducted on five of these patients to identify frequently mutated genes.

RESULTS

Four of 10 patients were positive for PD-L1 and CD8+ T. By analyzing WES in three of these four patients, we notably identified the mutations of NOTCH1, FBXW7, and noncoding RNA intronic mutation in NOTCH2NLR in two of these three patients. This study may enable better selection of ICI therapy with CD8+ T-cell infiltration via PD-L1 expression for oral squamous cell carcinoma patients with mutations in Notch signaling pathway.

Changes in searching behaviour of CSL transcription complexes in Notch active conditions

During development cells receive a variety of signals, which are of crucial importance to their fate determination. One such source of signal is the Notch signalling pathway, where Notch activity regulates expression of target genes through the core transcription factor CSL. To understand changes in transcription factor behaviour that lead to transcriptional changes in Notch active cells, we have probed CSL behaviours in real time, using in vivo Single Molecule Localisation Microscopy. Trajectory analysis reveals that Notch-On conditions increase the fraction of bound CSL molecules, but also the proportion of molecules with exploratory behaviours. These properties are shared by the co-activator Mastermind. Furthermore, both CSL and Mastermind, exhibit characteristics of local exploration near a Notch target locus. A similar behaviour is observed for CSL molecules diffusing in the vicinity of other bound CSL clusters. We suggest therefore that CSL acquires an exploratory behaviour when part of the activation complex, favouring local searching and retention close to its target enhancers. This change explains how CSL can efficiently increase its occupancy at target sites in Notch-On conditions.

The Drosophila tumour suppressor Lgl and Vap33 activate the Hippo pathway through a dual mechanism

The tumour suppressor, Lethal (2) giant larvae [Lgl; also known as L(2)gl], is an evolutionarily conserved protein that was discovered in the vinegar fly Drosophila, where its depletion results in tissue overgrowth and loss of cell polarity. Lgl links cell polarity and tissue growth through regulation of the Notch and the Hippo signalling pathways. Lgl regulates the Notch pathway by inhibiting V-ATPase activity via Vap33. How Lgl regulates the Hippo pathway was unclear. In this current study, we show that V-ATPase activity inhibits the Hippo pathway, whereas Vap33 acts to activate Hippo signalling. Vap33 physically and genetically interacts with the actin cytoskeletal regulators RtGEF (Pix) and Git, which also bind to the Hippo protein (Hpo) and are involved in the activation of the Hippo pathway. Additionally, we show that the ADP ribosylation factor Arf79F (Arf1), which is a Hpo interactor, is involved in the inhibition of the Hippo pathway. Altogether, our data suggest that Lgl acts via Vap33 to activate the Hippo pathway by a dual mechanism: (1) through interaction with RtGEF, Git and Arf79F, and (2) through interaction and inhibition of the V-ATPase, thereby controlling epithelial tissue growth.

Signaling Pathways in Trans-differentiation of Mesenchymal Stem Cells: Recent Advances

Mesenchymal stem cells are a group of multipotent cells that can be induced to differentiate into other cell types. The cells fate is decided by various signaling pathways, growth factors, and transcription factors in differentiation. The proper coordination of these factors will result in cell specification. MSCs are capable of being differentiated into osteogenic, chondrogenic, and adipogenic lineages. Different conditions induces the MSCs into particular phenotypes. The MSC trans-differentiation ensues as a response to environmental factors or due to circumstances that prove to favor trans-differentiation. Depending on the stage at which they are expressed, and the genetic alterations they undergo prior to their expression, transcription factors can accelerate the process of trans-differentiation. Further research has been conducted on the challenging aspect of MSCs being developed into non-mesenchymal lineage. The cells that are differentiated in this way maintain their stability even after being induced in animals. The recent advancements in the trans-differentiation capacities of MSCs on induction with chemicals, growth inducers, improved differentiation mediums, growth factors from plant extracts, and electrical stimulation are discussed in this paper. Signaling pathways have a great effect on MSCs trans-differentiation and they need to be better understood for their applications in therapeutic techniques. So, this paper tends to review the major signaling pathways that play a vital role in the trans-differentiation of MSC.

The epigenetics orchestra of Notch signaling: a symphony for cancer therapy

The aberrant regulation of the Notch signaling pathway, which is a fundamental developmental pathway, has been implicated in a wide range of human cancers. The Notch pathway can be activated by both canonical and noncanonical Notch ligands, and its role can switch between acting as an oncogene or a tumor suppressor depending on the context. Epigenetic modifications have the potential to modulate Notch and its ligands, thereby influencing Notch signal transduction. Consequently, the utilization of epigenetic regulatory mechanisms may present novel therapeutic opportunities for both single and combined therapeutics targeted at the Notch signaling pathway. This review offers insights into the mechanisms governing the regulation of Notch signaling and explores their therapeutic potential.

Notch receptor/ligand diversity: contribution to colorectal cancer stem cell heterogeneity

Cancer cell heterogeneity is a key contributor to therapeutic failure and post-treatment recurrence. Targeting cell subpopulations responsible for chemoresistance and recurrence seems to be an attractive approach to improve treatment outcome in cancer patients. However, this remains challenging due to the complexity and incomplete characterization of tumor cell subpopulations. The heterogeneity of cells exhibiting stemness-related features, such as self-renewal and chemoresistance, fuels this complexity. Notch signaling is a known regulator of cancer stem cell (CSC) features in colorectal cancer (CRC), though the effects of its heterogenous signaling on CRC cell stemness are only just emerging. In this review, we discuss how Notch ligand-receptor specificity contributes to regulating stemness, self-renewal, chemoresistance and cancer stem cells heterogeneity in CRC.

Increased NOTCH1 expression is associated with low survival in moderate/ poor differentiated human oral squamous cell carcinoma patients

Notch deregulation has been reported in various types of cancers, including Oral squamous cell carcinomas (OSCCs). The role of Notch1 signaling in oral squamous cell carcinoma (OSCC) remains poorly understood. In this study, NOTCH1 was aberrantly expressed in human oral cancer tissues compared with that in normal marginal tissues and was associated with poor prognosis. The positive Notch 1 expression was significantly associated with poor tumor differentiation status. Kaplan-Meier survival curves revealed that elevated cytoplasmic NOTCH1 expression levels in OSCC patients were associated with poor overall survival. Moreover, multivariate COX proportional hazard models revealed that T N status, AJCC stage histological grade were independent prognostic factors for survival. Our result clearly demonstrates the oncogenic role of Notch1 in oral cancer and Notch1 may be a useful biomarker to target oral cancer patients.

A microprotein N1DARP encoded by LINC00261 promotes Notch1 intracellular domain (N1ICD) degradation via disrupting USP10-N1ICD interaction to inhibit chemoresistance in Notch1-hyperactivated pancreatic cancer

The extensively activated Notch signaling pathway in pancreatic cancer cells is important in carcinogenesis, chemoresistance, and recurrence. Targeting this pathway is a promising therapeutic strategy for pancreatic cancer; however, few successful approaches have been reported, and currently used molecular inhibitors of this pathway exhibit limited clinical benefits. In this study, we identified a previously uncharacterized microprotein, Notch1 degradation-associated regulatory polypeptide (N1DARP), encoded by LINC00261. N1DARP knockout accelerated tumor progression and enhanced stem cell properties in pancreatic cancer organoids and LSL-Kras, LSL-Trp53, and Pdx1-Cre (KPC) mice. Mechanistically, N1DARP suppressed canonical and non-canonical Notch1 pathways by competitively disrupting the interaction between N1ICD and ubiquitin-specific peptidase 10 (USP10), thereby promoting K11- and K48-linked polyubiquitination of N1ICD. To evaluate the therapeutic potential of N1DARP, we designed a cell-penetrating stapled peptide, SAH-mAH2-5, with a helical structure similar to that of N1DARP that confers remarkable physicochemical stability. SAH-mAH2-5 interacted with and promoted the proteasome-mediated degradation of N1ICD. SAH-mAH2-5 injection provided substantial therapeutic benefits with limited off-target and systemic adverse effects in Notch1-activated pancreatic cancer models. Taken together, these findings confirm that N1DARP acts as a tumor suppressor and chemosensitizer by regulating USP10-Notch1 oncogenic signaling, and suggest a promising therapeutic strategy targeting the N1DARP-N1ICD interaction in Notch1-activated pancreatic cancer.

A Phase I Study of the Pan-Notch Inhibitor CB-103 for Patients with Advanced Adenoid Cystic Carcinoma and Other Tumors

PURPOSE

CB-103 selectively inhibits the CSL-NICD (Notch intracellular domain) interaction leading to transcriptional downregulation of oncogenic Notch pathway activation. This dose-escalation/expansion study aimed to determine safety, pharmacokinetics, and preliminary antitumor activity.

EXPERIMENTAL DESIGN

Patients ≥18 years of age with selected advanced solid tumors [namely, adenoid cystic carcinoma (ACC)] and hematologic malignancies were eligible. CB-103 was dosed orally in cycles of 28 days at escalating doses until disease progression. Notch-activating mutations were required in a dose confirmatory cohort. Endpoints included dose-limiting toxicities (DLT), safety, tumor response, pharmacokinetics, and pharmacodynamics. Exploratory analyses focused on correlates of Notch and target gene expression.

RESULTS

Seventy-nine patients (64, 12 dose-escalation cohorts; 15, confirmatory cohort) enrolled with 54% receiving two or more lines of prior therapy. ACC was the dominant tumor type (40, 51%). Two DLTs were observed [elevated gamma-glutamyl transferase (GGT), visual change]; recommended phase II dose was declared as 500 mg twice daily (5 days on, 2 days off weekly). Grade 3-4 treatment-related adverse events occurred in 15 patients (19%), including elevated liver function tests (LFTs), anemia, and visual changes. Five (6%) discontinued drug for toxicity; with no drug-related deaths. There were no objective responses, but 37 (49%) had stable disease; including 23 of 40 (58%) patients with ACC. In the ACC cohort, median progression-free survival was 2.5 months [95% confidence interval (CI), 1.5-3.7] and median overall survival was 18.4 months (95% CI, 6.3-not reached).

CONCLUSIONS

CB-103 had a manageable safety profile and biological activity but limited clinical antitumor activity as monotherapy in this first-in-human study.

SIGNIFICANCE

CB-103 is a novel oral pan-Notch inhibitor that selectively blocks the CSL-NICD interaction leading to transcriptional downregulation of oncogenic Notch pathway activation. This first-in-human dose-escalation and -confirmation study aimed to determine the safety, pharmacokinetics, and preliminary antitumor efficacy of CB-103. We observed a favorable safety profile with good tolerability and biological activity but limited clinical single-agent antitumor activity. Some disease stabilization was observed among an aggressive NOTCH-mutant ACC type-I subgroup where prognosis is poor and therapies are critically needed. Peripheral downregulation of select Notch target gene levels was observed with escalating doses. Future studies exploring CB-103 should enrich for patients with NOTCH-mutant ACC and investigate rational combinatorial approaches in tumors where there is limited success with investigational or approved drugs.

Notch Signaling in Insect Development: A Simple Pathway with Diverse Functions

Notch signaling is an evolutionarily conserved pathway which functions between adjacent cells to establish their distinct identities. Despite operating in a simple mechanism, Notch signaling plays remarkably diverse roles in development to regulate cell fate determination, organ growth and tissue patterning. While initially discovered and characterized in the model insect Drosophila melanogaster, recent studies across various insect species have revealed the broad involvement of Notch signaling in shaping insect tissues. This review focuses on providing a comprehensive picture regarding the roles of the Notch pathway in insect development. The roles of Notch in the formation and patterning of the insect embryo, wing, leg, ovary and several specific structures, as well as in physiological responses, are summarized. These results are discussed within the developmental context, aiming to deepen our understanding of the diversified functions of the Notch signaling pathway in different insect species.

Carcinogenic potential in regenerated mucosa after endoscopic resection of esophageal squamous cell carcinoma

BACKGROUND AND AIM

Little is known about genetic mutations in the regenerated mucosa (RM) after endoscopic resection (ER) of esophageal carcinoma. Thus, this study investigates the status of genetic variation in RM after ER of esophageal squamous cell carcinoma (ESCC).

METHODS

The study cohort included 19 patients with ESCC. We used an esophageal carcinoma panel to identify target sequences for squamous cell carcinoma (SCC), background mucosa (BM), and RM after ER of ESCC. We used OncoKB to check whether each mutation was a putative driver.

RESULTS

We identified 77 mutations of 32 genes in SCC, 133 mutations of 34 genes in BM, and 100 mutations of 29 genes in RM. Putative driver mutations were identified in 20 mutations in 14 cases in SCC, 16 mutations in 10 cases in BM, and 7 mutations in 11 cases in RM. The rate of putative driver mutations to total mutations was significantly lower in RM (26% in SCC vs 12% in BM vs 7% in RM, P = 0.009). Additionally, the rate of cases with TP53 putative driver mutations was significantly lower in RM (63% in SCC vs 37% in BM vs 16% in RM, P = 0.011). The percentage of putative driver mutations and the percentage of cases with a putative driver of TP53 were significantly lower in RM.

CONCLUSION

Esophageal RM after ER of ESCC could have a lower risk of carcinogenesis.

Novel insights on perils and promises of miRNA in understanding colon cancer metastasis and progression

Colorectal cancer (CRC) is the third highest frequent malignancy and ultimate critical source of cancer-associated mortality around the world. Regardless of latest advances in molecular and surgical targeted medicines that have increased remedial effects in CRC patients, the 5-year mortality rate for CRC patients remains dismally low. Evidence suggests that microRNAs (miRNAs) execute an essential part in the development and spread of CRC. The miRNAs are a type of short non-coding RNA that exhibited to control the appearance of tumor suppressor genes and oncogenes. miRNA expression profiling is already being utilized in clinical practice as analytical and prognostic biomarkers to evaluate cancer patients' tumor genesis, advancement, and counteraction to drugs. By modulating their target genes, dysregulated miRNAs are linked to malignant characteristics (e.g., improved proliferative and invasive capabilities, cell cycle aberration, evasion of apoptosis, and promotion of angiogenesis). This review presents an updated summary of circulatory miRNAs, tumor-suppressive and oncogenic miRNAs, and the potential reasons for dysregulated miRNAs in CRC. Further we will explore the critical role of miRNAs in CRC drug resistance.

Comprehensive bioinformatic analysis of mind bomb 1 gene in stomach adenocarcinoma

BACKGROUND

The carcinogenesis of stomach adenocarcinoma (STAD) involves many different molecules and multiple pathways, including the NOTCH signaling pathway. As a key factor that functions as a critical link in the NOTCH pathway, mind bomb 1 (MIB1) is upregulated in various tumors and has been reported to promote cell metastasis and invasion. However, studies on the role of MIB1 in STAD are limited. Here, we evaluated the prognostic value of MIB1 in STAD and its association with immune infiltration and copy number variation.

AIM

To elucidate the relationship between MIB1 gene and gastric cancer (GC) and provide a new idea for the treatment of GC.

METHODS

We identified mutations in the MIB1 gene by searching the cBioPortal database and then analyzed their relationship with the overall survival rate and disease-free survival rate using the Kaplan-Meier method. The Cancer Genome Atlas (TCGA) database provided transcript levels for MIB1 in STADs and normal tissues. As a method of distinguishing the STAD tissues from adjacent normal tissues, a receiver operating characteristic (ROC) curve was generated. Kaplan-Meier plotter was used to determine the effect of MIB1 expression on survival. Based on the LinkedOmics database, we were able to identify the coexpressed genes of the MIB1 gene, the top 50 positively correlated genes, and the top 50 negatively correlated genes. STRING was used to construct protein-protein interaction networks related to the MIB1 gene. An analysis of functional enrichment was carried out using the R package “Cluster Profiler”. The relationships between mRNA expression of MIB1 and immune infiltrates were assessed by Tumor IMmune Estimation Resource (TIMER) and the “GSVA package” in R.

RESULTS

According to the cBioPortal database, the MIB1 mutation rate in 287 patients in the TCGA dataset was approximately 6%. Kaplan-Meier survival analysis showed that patients with STAD in the mutated group had a worse prognosis than those in the unmutated group (P = 0.0156). There was a significant upregulation of MIB1 expression in STAD tissues compared to adjacent normal tissues. A high T stage was associated with increased MIB1 mRNA expression. The ROC curve analysis revealed 59.4% sensitivity and 85.6% specificity of MIB1 for differentiating STAD tissues from adjacent normal tissues at a truncation level of 2.248. Kaplan-Meier plotter indicated that patients with higher MIB1 levels had a worse prognosis than those with lower levels (26.4 mo vs 56.2 mo, P = 0.0330). A correlation analysis demonstrated an association between immune infiltrates and MIB1 mRNA expression.

CONCLUSION

Upregulation of MIB1 expression is significantly associated with poor survival rate and immune infiltration in gastric adenocarcinoma. MIB1 may be a biomarker for the poor prognosis of STAD patients and a potential immunotherapeutic target.

A Novel Notch-Related Gene Signature for Prognosis and Immune Response Prediction in Ovarian Cancer

Background and Objectives: Notch is a fascinating signaling pathway. It is extensively involved in tumor growth, cancer stem cells, metastasis, and treatment resistance and plays important roles in metabolic regulation, tumor microenvironment, and tumor immunity. However, the role of Notch in ovarian cancer (OC) has yet to be fully understood. Therefore, this study systematically described the expression, mutation, and copy number variation of genes in the Notch signaling pathway in OC and evaluated the relationship between gene mutation and Overall Survival (OS) prognosis. Materials and Methods: Notch risk score (NTRS) was established by univariate Cox regression analysis combined with Lasso regression analysis, and the efficacy of NTRS in predicting prognosis and immunotherapy response in patients with OC was verified. We further assessed the correlations of NTRS with clinical features, immune infiltration level, immune checkpoint expression, and immune characteristics. Additionally, differential expression and functions of the fourteen signature genes were confirmed via vitro assays. Results: The results showed that Notch genes (NTGs) were markedly differentiated between tumor and normal tissues, which may help to explain the high heterogeneity in the biological characteristics and therapeutic outcomes of human OC. A Notch risk (NTR) prognostic model based on 11 key NTGs was successfully constructed. Tumors with high Notch risk scores (NTRS) were independently associated with shorter overall survival and poorer immunotherapy outcomes. We further assessed the correlations of NTRS with immune characteristics. The results showed that NTGs play a key role in regulating the tumor immune microenvironment. Additionally, we validated the baseline and induced expressions of 14 prognosis-related NTGs in our own OC samples. In vitro assays confirmed that the knockdown of NCOR2 and APH1B and overexpression of HEY2 and SKP2 could inhibit the proliferation, invasion, and migration of OC cells. Conclusions: These findings emphasize that Notch multilayer changes are associated with the prognosis of patients with OC and the characteristics of immune cell infiltration. Our predictive signature may predict the prognosis and immunotherapy response of OC patients in an independent manner. NCOR2, APH1B, HEY2, and SKP2 may more prominently represent important indicators to improve patient prognosis.

The role of nelarabine in the treatment of T-cell acute lymphoblastic leukemia/lymphoma: challenges, opportunities, and future directions

INTRODUCTION

Nelarabine is a guanine nucleoside analog and functions to terminate DNA synthesis in dividing cells. Pre-clinical and clinical studies have shown that it preferentially accumulates in T-cells where it exerts its cytotoxic effects. After generations of treatment protocol advances, it has been incorporated into numerous treatment regimens against T-lineage acute lymphoblastic leukemia/lymphoma (T-ALL/LLy). On 8 March 2023, the FDA approved the use of nelarabine for its use in T-ALL due to clear evidence of clinical benefits. This announcement concludes a nearly 6-decade period of evaluation for nelarabine and its role in the management of high-grade, aggressive T-cell malignancies.

AREAS COVERED

We review the medicinal biology of nelarabine, its evaluation through decades of clinical studies, its dose-limited adverse effects, and its areas of highest impact in the treatment of T-ALL/LLy.

EXPERT OPINION

We provide a context of when nelarabine might be considered in treatments against T-ALL/LLy, and also alternative strategies when it has or has not been used in therapies prior to relapse. We anticipate that an increasing number of treatment regimens will include nelarabine as a part of front-line therapy.

γ-tocotrienol regulates gastric cancer by targeting notch signaling pathway

BACKGROUND

Gastric cancer is a common cause of death from cancer and an important global health care issue. Consequently, there is an urgent need to find new drugs and therapeutic targets for the treatment of gastric cancer. Recent studies have shown that tocotrienols (T3) have significant anticancer ability in cancer cell lines. Our previous study found that γ-tocotrienol (γ-T3) induced apoptosis in gastric cancer cells. We further explored the possible mechanisms of γ-T3 therapy for gastric cancer.

METHODS

In this study, we treated gastric cancer cells with γ-T3, collect and deposit the cells. γ-T3-treated gastric cancer cells group and untreated group were subjected to RNA-seq assay, and analysis of sequencing results.

RESULTS

Consistent with our previous findings, the results suggest that γ-T3 can inhibit mitochondrial complexes and oxidative phosphorylation. Analysis reveals that γ-T3 has altered mRNA and ncRNA in gastric cancer cells. Significantly altered signaling pathways after γ-T3 treatment were enriched for human papillomavirus infection (HPV) pathway and notch signaling pathway. The same significantly down-regulated genes notch1 and notch2 were present in both pathways in γ-T3-treated gastric cancer cells compared to controls.

CONCLUSIONS

It is indicated that γ-T3 may cure gastric cancer by inhibiting the notch signaling pathway. To provide a new and powerful basis for the clinical treatment of gastric cancer.

HES1-mediated down-regulation of miR-138 sustains NOTCH1 activation and promotes proliferation and invasion in renal cell carcinoma

BACKGROUND

Although the aberrant activation of NOTCH1 pathway causes a malignant progression of renal cell carcinoma (RCC), the precise molecular mechanisms behind the potential action of pro-oncogenic NOTCH1/HES1 axis remain elusive. Here, we examined the role of tumor suppressive miR-138-2 in the regulation of NOTCH1-HES1-mediated promotion of RCC.

METHODS

This study employed bioinformatics, xenotransplant mouse models, ChIP assay, luciferase reporter assay, functional experiments, real-time PCR and Western blot analysis to explore the mechanisms of miR-138-2 in the regulation of NOTCH1-HES1-mediated promotion of RCC, and further explored miR-138-2-containing combination treatment strategies.

RESULTS

There existed a positive correlation between down-regulation of miR-138 and the aberrant augmentation of NOTCH1/HES1 regulatory axis. Mechanistically, HES1 directly bound to miR-138-2 promoter region and thereby attenuated the transcription of miR-138-5p as well as miR-138-2-3p. Further analysis revealed that miR-138-5p as well as miR-138-2-3p synergistically impairs pro-oncogenic NOTCH1 pathway through the direct targeting of APH1A, MAML1 and NOTCH1.

CONCLUSIONS

Collectively, our current study strongly suggests that miR-138-2 acts as a novel epigenetic regulator of pro-oncogenic NOTCH1 pathway, and that the potential feedback regulatory loop composed of HES1, miR-138-2 and NOTCH1 contributes to the malignant development of RCC. From the clinical point of view, this feedback regulatory loop might be a promising therapeutic target to treat the patients with RCC.

Interplay between Signaling Pathways and Tumor Microenvironment Components: A Paradoxical Role in Colorectal Cancer

The study of the tumor microenvironment (TME) has become an important part of colorectal cancer (CRC) research. Indeed, it is now accepted that the invasive character of a primary CRC is determined not only by the genotype of the tumor cells, but also by their interactions with the extracellular environment, which thereby orchestrates the development of the tumor. In fact, the TME cells are a double-edged sword as they play both pro- and anti-tumor roles. The interaction of the tumor-infiltrating cells (TIC) with the cancer cells induces the polarization of the TIC, exhibiting an antagonist phenotype. This polarization is controlled by a plethora of interconnected pro- and anti-oncogenic signaling pathways. The complexity of this interaction and the dual function of these different actors contribute to the failure of CRC control. Thus, a better understanding of such mechanisms is of great interest and provides new opportunities for the development of personalized and efficient therapies for CRC. In this review, we summarize the signaling pathways linked to CRC and their implication in the development or inhibition of the tumor initiation and progression. In the second part, we enlist the major components of the TME and discuss the complexity of their cells functions.

The role of SF3B1 and NOTCH1 in the pathogenesis of leukemia

The discovery of new genes/pathways improves our knowledge of cancer pathogenesis and presents novel potential therapeutic options. For instance, splicing factor 3b subunit 1 (SF3B1) and NOTCH1 genetic alterations have been identified at a high frequency in hematological malignancies, such as leukemia, and may be related to the prognosis of involved patients because they change the nature of malignancies in different ways like mediating therapeutic resistance; therefore, studying these gene/pathways is essential. This review aims to discuss SF3B1 and NOTCH1 roles in the pathogenesis of various types of leukemia and the therapeutic potential of targeting these genes or their mutations to provide a foundation for leukemia treatment.

Activation of NOTCH signaling via DLL1 is mediated by APE1-redox-dependent NF-κB activation in oesophageal adenocarcinoma

OBJECTIVE

Oesophageal adenocarcinoma (EAC) arises in the setting of Barrett's oesophagus, an intestinal metaplastic precursor lesion that can develop in patients with chronic GERD. Here, we investigated the role of acidic bile salts, the mimicry of reflux, in activation of NOTCH signaling in EAC.

DESIGN

This study used public databases, EAC cell line models, L2-IL1β transgenic mouse model and human EAC tissue samples to identify mechanisms of NOTCH activation under reflux conditions.

RESULTS

Analysis of public databases demonstrated significant upregulation of NOTCH signaling components in EAC. In vitro studies demonstrated nuclear accumulation of active NOTCH1 cleaved fragment (NOTCH intracellular domain) and upregulation of NOTCH targets in EAC cells in response to reflux conditions. Additional investigations identified DLL1 as the predominant ligand contributing to NOTCH1 activation under reflux conditions. We discovered a novel crosstalk between APE1 redox function, reflux-induced inflammation and DLL1 upregulation where NF-κB can directly bind to and induce the expression of DLL1. The APE1 redox function was crucial for activation of the APE1-NF-κB-NOTCH axis and promoting cancer cell stem-like properties in response to reflux conditions. Overexpression of APE1 and DLL1 was detected in gastro-oesophageal junctions of the L2-IL1ß transgenic mouse model and human EAC tissue microarrays. DLL1 high levels were associated with poor overall survival in patients with EAC.

CONCLUSION

These findings underscore a unique mechanism that links redox balance, inflammation and embryonic development (NOTCH) into a common pro-tumorigenic pathway that is intrinsic to EAC cells.

Notch3 regulates Mybl2 via HeyL to limit proliferation and tumor initiation in breast cancer

Notch signaling is a conserved signaling pathway that participates in many aspects of mammary gland development and homeostasis, and has extensively been associated with breast tumorigenesis. Here, to unravel the as yet debated role of Notch3 in breast cancer development, we investigated its expression in human breast cancer samples and effects of its loss in mice. Notch3 expression was very weak in breast cancer cells and was associated with good patient prognosis. Interestingly, its expression was very strong in stromal cells of these patients, though this had no prognostic value. Mechanistically, we demonstrated that Notch3 prevents tumor initiation via HeyL-mediated inhibition of Mybl2, an important regulator of cell cycle. In the mammary glands of Notch3-deficient mice, we observed accelerated tumor initiation and proliferation in a MMTV-Neu model. Notch3-null tumors were enriched in Mybl2 mRNA signature and protein expression. Hence, our study reinforces the anti-tumoral role of Notch3 in breast tumorigenesis.

lncRNA BREA2 promotes metastasis by disrupting the WWP2-mediated ubiquitination of Notch1

Notch has been implicated in human cancers and is a putative therapeutic target. However, the regulation of Notch activation in the nucleus remains largely uncharacterized. Therefore, characterizing the detailed mechanisms governing Notch degradation will identify attractive strategies for treating Notch-activated cancers. Here, we report that the long noncoding RNA (lncRNA) BREA2 drives breast cancer metastasis by stabilizing the Notch1 intracellular domain (NICD1). Moreover, we reveal WW domain containing E3 ubiquitin protein ligase 2 (WWP2) as an E3 ligase for NICD1 at K1821 and a suppressor of breast cancer metastasis. Mechanistically, BREA2 impairs WWP2-NICD1 complex formation and in turn stabilizes NICD1, leading to Notch signaling activation and lung metastasis. BREA2 loss sensitizes breast cancer cells to inhibition of Notch signaling and suppresses the growth of breast cancer patient-derived xenograft tumors, highlighting its therapeutic potential in breast cancer. Taken together, these results reveal the lncRNA BREA2 as a putative regulator of Notch signaling and an oncogenic player driving breast cancer metastasis.

A potential requirement for Smad3 phosphorylation in Notch-mediated EMT in colon cancer

Colorectal cancer (CRC) remains a challenging disease to treat due to several factors including stemness and epithelial to mesenchymal transition (EMT). Dysfunctional signaling pathways such as Notch and TGF-β contribute to these phenomena. We previously found that cells expressing constitutively active Notch1 also had increased expression of Smad3, an important member of the TGF-β signaling pathway. We hypothesized that Smad3, mediates the Notch-induced stemness and EMT observed in CRC cells. The human colorectal carcinoma cell line HCT-116, stably transduced with constitutively active Notch-1 (ICN) or a GFP-vector control was treated with different combinations of TGF-β1, DAPT (a Notch inhibitor), or SIS3 (a Smad3 inhibitor). Western blot analysis was performed to determine the effects of Smad3 stimulation and inhibition on Notch and potential downstream EMT-related targets, CD44, Slug and Snail. Smad3 inhibition induced a decrease in Notch1 and Notch3 receptor expression and effectively inhibited CD44, Slug, and Snail expression. Colosphere forming ability was also reduced in cells with inhibited Smad3. These results indicate a key role of TGF-β signaling in Notch1-induced tumorigenesis, and suggest a potential use for Smad3 inhibitors in combination with Notch1 inhibitors that are already in use for CRC treatments.

Role of Notch2 pathway in mature B cell malignancies

In recent decades, the Notch pathway has been characterized as a key regulatory signaling of cell-fate decisions evolutionarily conserved in many organisms and different tissues during lifespan. At the same time, many studies suggest a link between alterations of this signaling and tumor genesis or progression. In lymphopoiesis, the Notch pathway plays a fundamental role in the correct differentiation of T and B cells, but its deregulated activity leads to leukemic onset and evolution. Notch and its ligands Delta/Jagged exhibit a pivotal role in the crosstalk between leukemic cells and their environment. This review is focused in particular on Notch2 receptor activity. Members of Notch2 pathway have been reported to be mutated in Chronic Lymphocytic Leukemia (CLL), Splenic Marginal Zone Lymphoma (SMZL) and Nodal Marginal Zone Lymphoma (NMZL). CLL is a B cell malignancy in which leukemic clones establish supportive crosstalk with non-malignant cells of the tumor microenvironment to grow, survive, and resist even the new generation of drugs. SMZL and NMZL are indolent B cell neoplasms distinguished by a distinct pattern of dissemination. In SMZL leukemic cells affect mainly the spleen, bone marrow, and peripheral blood, while NMZL has a leading nodal distribution. Since Notch2 is involved in the commitment of leukemic cells to the marginal zone as a major regulator of B cell physiological differentiation, it is predominantly affected by the molecular lesions found in both SMZL and NMZL. In light of these findings, a better understanding of the Notch receptor family pathogenic role, in particular Notch2, is desirable because it is still incomplete, not only in the physiological development of B lymphocytes but also in leukemia progression and resistance. Several therapeutic strategies capable of interfering with Notch signaling, such as monoclonal antibodies, enzyme or complex inhibitors, are being analyzed. To avoid the unwanted multiple "on target" toxicity encountered during the systemic inhibition of Notch signaling, the study of an appropriate pharmaceutical formulation is a pressing need. This is why, to date, there are still no Notch-targeted therapies approved. An accurate analysis of the Notch pathway could be useful to drive the discovery of new therapeutic targets and the development of more effective therapies.

Clinical significance of Notch receptors in triple negative breast cancer

BACKGROUND

The Notch signaling pathway is an evolutionary conserved cell signaling pathway that plays an indispensable role in essential developmental processes. Aberrant activation of Notch pathway is known to initiate wide array of diseases and cancers.

OBJECTIVE

To evaluate the clinical significance of Notch receptors in Triple Negative Breast Cancer.

METHODS

We evaluated the association between Notch receptors and clinicopathological parameters including disease-free survival and overall survival of one hundred TNBC patients by immunohistochemistry.

RESULTS

Positive expression of nuclear Notch1 receptor (18%) was found be significantly correlated with positive lymph node (p = 0.009), high BR score (p = 0.02) and necrosis (p = 0.004) while cytoplasmic expression of Notch2 receptor (26%) was significantly correlated with metastasis (p = 0.05), worse DFS (p = 0.05) and poor OS (p = 0.02) in TNBC patients. Membrane (18%) and cytonuclear (3%) Notch3 expression were significantly associated with poorly differentiated tumors (p = 0.007), high BR score (p = 0.002) and necrosis (p = 0.03) respectively. However, cytoplasmic Notch3 and Notch4 expression were negatively correlated with poor prognostic factors.

CONCLUSIONS

Our data indicated that Notch receptors play a key role in promoting TNBC and mainly, Notch2 may contribute to poor prognosis of the disease. Hence, it is implicated that Notch2 may serve as a potential biomarker and therapeutic target for TNBC.

Endometriosis Stem Cells as a Possible Main Target for Carcinogenesis of Endometriosis-Associated Ovarian Cancer (EAOC)

Endometriosis is a serious recurrent disease impairing the quality of life and fertility, and being a risk for some histologic types of ovarian cancer defined as endometriosis-associated ovarian cancers (EAOC). The presence of stem cells in the endometriotic foci could account for the proliferative, migrative and angiogenic activity of the lesions. Their phenotype and sources have been described. The similarly disturbed expression of several genes, miRNAs, galectins and chaperones has been observed both in endometriotic lesions and in ovarian or endometrial cancer. The importance of stem cells for nascence and sustain of malignant tumors is commonly appreciated. Although the proposed mechanisms promoting carcinogenesis leading from endometriosis into the EAOC are not completely known, they have been discussed in several articles. However, the role of endometriosis stem cells (ESCs) has not been discussed in this context. Here, we postulate that ESCs may be a main target for the carcinogenesis of EAOC and present the possible sequence of events resulting finally in the development of EAOC.

JAG1 is associated with the prognosis and metastasis in breast cancer

Jagged canonical Notch ligand 1 (JAG1) regulates the progression of many cancers by the Notch signaling pathway, but its role in breast cancer (BC) remains unclear. In this research, JAG1 protein expression in BC tissues was detected by immunohistochemistry. The association between JAG1 and clinical significance was analyzed. The effect of JAG1 on malignant behaviors of BC cells was demonstrated by in vitro experiments. JAG1 expression in BC tissues was higher than that in para-carcinoma tissues. High JAG1 expression was significantly linked to advanced lymph node metastasis, distant metastasis, and the TNM stage. JAG1 was an independent prognostic factor for BC patients. JAG1 knockdown inhibited the proliferation, motility, migration, and invasion of BC cells, and weakened adhesion and penetration abilities to the blood-brain barrier, whereas JAG1 overexpression had the opposite effects. JAG1 has the potential to be a prognostic marker and therapeutic target for BC patients.

The structure, binding and function of a Notch transcription complex involving RBPJ and the epigenetic reader protein L3MBTL3

The Notch pathway transmits signals between neighboring cells to elicit downstream transcriptional programs. Notch is a major regulator of cell fate specification, proliferation, and apoptosis, such that aberrant signaling leads to a pleiotropy of human diseases, including developmental disorders and cancers. The pathway signals through the transcription factor CSL (RBPJ in mammals), which forms an activation complex with the intracellular domain of the Notch receptor and the coactivator Mastermind. CSL can also function as a transcriptional repressor by forming complexes with one of several different corepressor proteins, such as FHL1 or SHARP in mammals and Hairless in Drosophila. Recently, we identified L3MBTL3 as a bona fide RBPJ-binding corepressor that recruits the repressive lysine demethylase LSD1/KDM1A to Notch target genes. Here, we define the RBPJ-interacting domain of L3MBTL3 and report the 2.06 Å crystal structure of the RBPJ-L3MBTL3-DNA complex. The structure reveals that L3MBTL3 interacts with RBPJ via an unusual binding motif compared to other RBPJ binding partners, which we comprehensively analyze with a series of structure-based mutants. We also show that these disruptive mutations affect RBPJ and L3MBTL3 function in cells, providing further insights into Notch mediated transcriptional regulation.

The Binding of CSL Proteins to Either Co-Activators or Co-Repressors Protects from Proteasomal Degradation Induced by MAPK-Dependent Phosphorylation

The primary role of Notch is to specify cellular identities, whereby the cells respond to amazingly small changes in Notch signalling activity. Hence, dosage of Notch components is crucial to regulation. Central to Notch signal transduction are CSL proteins: together with respective cofactors, they mediate the activation or the silencing of Notch target genes. CSL proteins are extremely similar amongst species regarding sequence and structure. We noticed that the fly homologue suppressor of hairless (Su(H)) is stabilised in transcription complexes. Using specific transgenic fly lines and HeLa RBPJ^KO cells we provide evidence that Su(H) is subjected to proteasomal degradation with a half-life of about two hours if not protected by binding to co-repressor hairless or co-activator Notch. Moreover, Su(H) stability is controlled by MAPK-dependent phosphorylation, matching earlier data for RBPJ in human cells. The homologous murine and human RBPJ proteins, however, are largely resistant to degradation in our system. Mutating presumptive protein contact sites, however, sensitised RBPJ for proteolysis. Overall, our data highlight the similarities in the regulation of CSL protein stability across species and imply that turnover of CSL proteins may be a conserved means of regulating Notch signalling output directly at the level of transcription.

SOX8 Knockdown Overcomes Enzalutamide Resistance in Castration-Resistant Prostate Cancer by Inhibiting the Notch Signaling Pathway

Castration-resistant prostate cancer (CRPC) is still challenging to treat. Dissatisfaction with androgen signal-targeted therapy forces people to look for other treatment strategies. Therefore, this study is aimed at exploring the role of SOX8/Notch signaling in CRPC. The upregulation of SOX8, Notch4, and Hes5 indicated a poor progression-free survival (PFS) in CRPC patients. The expression of these proteins was also upregulated in enzalutamide-resistant LNCaP cells (Enza-R). Moreover, knocking down SOX8 inhibited malignant biological behaviors and decreased the activation of Notch signaling in Enza-R cells. Importantly, knocking down SOX8 obviously reversed the enzalutamide resistance in Enza-R cells, while RO0429097 (a γ secretase inhibitor inactivates Notch signaling) exerted similar effects. At last, we found that both SOX8 knockdown and/or RO0429097 suppressed tumor growth and bone metastasis in vivo. Altogether, our study indicated that the SOX8/Notch signaling is involved in CRPC and that these enzymes are possible targets to develop novel treatment for CRPC.

Upregulation of EMID1 Accelerates to a Favorable Prognosis and Immune Infiltration in Lung Adenocarcinoma

Lung cancer is a difficult-to-treat cancer. Lung adenocarcinoma (LUAD) is the main subtype of lung cancer. Although there are many ways to treat lung cancer, the survival rate of patients is low. Therefore, novel molecules need to be identified to diagnose and treat LUAD. This study utilized The Cancer Genome Atlas (TCGA) LUAD data to analyze and validate the value of EMID1 as a LUAD diagnostic surface marker and overall survival prognostic marker. Differential expression analysis formally confirmed that decreased EMID1 expression was significantly associated with advanced stage and metastasis of lung cancer. Kaplan–Meier survival analysis showed that the patients with low EMID expression are dismal. The relationship between clinicopathological features and EMID1 was scored using Wilcoxon signed-rank test and R (v.3.5.1) logistic regression and suggested that patients with low EMID1 expression had a worse prognosis than patients with high EMID1 expression. (Gene Ontology) GO, Kyoto Encyclopedia of Genes and Genomes(KEGG), and gene set enrichment analysis (GSEA) were performed to investigate the potential mechanism of EMID1 expression on the prognosis of LUAD and suggested that Notch signaling pathway may be an important biological pathway for EMID1 to play a role in LUAD. Further, combined with univariate and multivariate Cox regression analysis, it was speculated that high and low levels of EMID1 expression and the logistic regression analysis of related clinical variables had significant clinical significance to verify the underlying mechanism of LUAD focus and prognosis. EMID1 plays an important role in the immune milieu of LUAD. Meanwhile, the correlation between tumor-infiltrating immune cells and genes was assessed using CIBERSORT, and it was found that the level of B cell infiltration was positively correlated with the expression of EMID1, all of which were validated in the GEO and GEPIA databases. In all, this study helps to understand the immune microenvironment of LUAD and improve the survival of patients with LUAD. Thus, EMID1 may be a novel immune-related prognostic marker of LUAD.

RNA-sequencing reveals the expression profiles of tsRNAs and their potential carcinogenic role in cholangiocarcinoma

Background

Recently, the incidence of cholangiocarcinoma (CCA) has gradually increased. As CCA has a poor prognosis, the ideal survival rate is scarce for patients. The abnormal expressed tsRNAs may regulate the progression of a variety of tumors, and tsRNAs is expected to become a new diagnostic biomarker of cancer. However, the expression of tsRNAs is obscure and should be elucidated in CCA.

Methods

High‐throughput RNA sequencing technology (RNA‐seq) was utilized to determine the overall expression profiles of tsRNAs in three pairs CCA and adjacent normal tissues and to screen the tsRNAs that were differentially expressed. The target genes of dysregulated tsRNAs were predicted and the biological effects and potential signaling pathways of these target genes were explored by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Quantitative real‐time polymerase chain reaction (qRT‐PCR) was used to validate 11 differentially expressed tRFs with 12 pairs CCA and adjacent normal tissues.

Results

High‐throughput RNA‐seq totally demonstrated 535 dysregulated tsRNAs, of which 241 tsRNAs were upregulated, such as tRF‐21‐YLKZKWE5D，tRF‐16‐9NF5W8B，tRF‐27‐78YLKZKWE52，tRF‐19‐RLXN48KP，tRF‐33‐IK9NJ4S2I7L7DV，tRF‐19‐F8DHXYIV, and 294 tsRNAs were downregulated (tRF‐20‐739P8WQ0, tRF‐34‐JJ6RRNLIK898HR, tRF‐17‐VL8RPY5, tRF‐23‐YP9LON4VDP, tRF‐39‐EH623K76IR3DR2I2, tRF‐17‐18YKISM, tRF‐19‐Q1Q89PJZ, etc.) in CCA compared with adjacent normal tissues (|log2 [fold change] | ≥ 1 and p value <0.05). GO and KEGG enrichment analyses indicated that the target genes of dysregulated tRFs (tRF‐34‐JJ6RRNLIK898HR, tRF‐38‐0668K87SERM492V, and tRF‐39‐0668K87SERM492E2) were mainly enriched in the Notch signaling pathway, Hippo signaling pathway, cAMP signaling pathway and in growth hormone synthesis, secretion and action, etc. qRT‐PCR result showed that tRF‐34‐JJ6RRNLIK898HR/tRF‐38‐0668K87SERM492V/tRF‐39‐0668K87SERM492E2 was downregulated (p = 0.021), and tRF‐20‐LE2WMK81 was upregulated in CCA (p = 0.033).

Conclusion

Differentially expressed tRFs in CCA are enriched in many pathways associated with neoplasms, which may impact the tumor progression and have potential to be diagnostic biomarkers and therapeutic targets of CCA.

The role of intestinal stem cell within gut homeostasis: Focusing on its interplay with gut microbiota and the regulating pathways

Intestinal stem cells (ISCs) play an important role in maintaining intestinal homeostasis via promoting a healthy gut barrier. Within the stem cell niche, gut microbiota linking the crosstalk of dietary influence and host response has been identified as a key regulator of ISCs. Emerging insights from recent research reveal that ISC and gut microbiota interplay regulates epithelial self-renewal. This article reviews the recent knowledge on the key role of ISC in their local environment (stem cell niche) associating with gut microbiota and their metabolites as well as the signaling pathways. The current progress of intestinal organoid culture is further summarized. Subsequently, the key challenges and future directions are discussed.

Proteomic profiling of plasma exosomes from patients with B-cell acute lymphoblastic leukemia

We aimed to comprehensively investigate the proteomic profile and underlying biological function of exosomal proteins associated with B-cell acute lymphoblastic leukemia. Exosomes were isolated from plasma samples collected from five patients with B-ALL and five healthy individuals, and their protein content was quantitatively analyzed by liquid chromatography with tandem mass spectrometry. A total of 342 differentially expressed proteins were identified in patients with B-ALL. The DEPs were mainly associated with protein metabolic processes and protein activity regulation and were significantly enriched in the Notch and autophagy pathways. Furthermore, we found that ADAM17 and ATG3 were upregulated in patients with B-ALL and enriched in the Notch and autophagy pathways, respectively. Further western blot analysis of exosomes collected from additional 18 patients with B-ALL and 10 healthy controls confirmed that both ADAM17 and ATG3 were overexpressed in exosomes derived from patients with B-ALL (p < 0.001). The areas under the curves of ADAM17 and ATG3 were 0.989 and 0.956, respectively, demonstrating their diagnostic potential. In conclusion, ADAM17 and ATG3 in plasma-derived exosomes may contribute to the progression of B-ALL by regulating the Notch and autophagy pathways. Hence, these proteins may represent valuable diagnostic biomarkers and therapeutic targets for B-ALL.

NOTCH gene alterations in metastatic colorectal cancer in the Nationwide Cancer Genome Screening Project in Japan (SCRUM-Japan GI-SCREEN)

PURPOSE

Activated Notch receptor signaling has been implicated in tumor growth and progression in colorectal cancer (CRC). However, the pathogenic relevance of NOTCH gene alterations remains unclear. The aim of this study was to clarify mutational landscapes and assess their clinical significance in patients with metastatic CRC.

METHODS

Pre-chemotherapy tumor tissues obtained from 1154 metastatic CRC patients in the Nationwide Cancer Genome Screening Project in Japan between April 2017 and March 2019 were studied using the Oncomine Comprehensive Assay.

RESULTS

The frequencies of NOTCH1, NOTCH2, and NOTCH3 nonsynonymous sequence variants were 11.5%, 4.4%, and 10.4%, respectively. The majority of variants were missense of unknown significance that were distributed across all domains of all three NOTCH genes. The gain-of-function mutations in NOTCH reported in multiple malignancies were not identified. The NOTCH amplification rate was less than 1%. No NOTCH fusions were detected. In patients who were registered before, or within 1 year of, first-line chemotherapy, overall survival for 51 patients with only NOTCH3 variants was significantly longer than for 540 patients with no NOTCH variants (median, 40.2 months vs 27.7 months; P = 0.04). Multivariate analysis revealed that variant NOTCH3 was an independent prognostic factor for increased survival (hazard ratio 0.61, 95% confidence interval, 0.39-0.94; P = 0.03) besides poor prognostic factors associated with mutant TP53, KRAS, and BRAF, as well as amplified MYC.

CONCLUSION

NOTCH genes are unlikely to harbor driver mutations and amplifications in patients with metastatic CRC. NOTCH3 variant should be further investigated as a favorable prognostic marker.

A conserved YAP/Notch/REST network controls the neuroendocrine cell fate in the lungs

The Notch pathway is a conserved cell-cell communication pathway that controls cell fate decisions. Here we sought to determine how Notch pathway activation inhibits the neuroendocrine cell fate in the lungs, an archetypal process for cell fate decisions orchestrated by Notch signaling that has remained poorly understood at the molecular level. Using intratumoral heterogeneity in small-cell lung cancer as a tractable model system, we uncovered a role for the transcriptional regulators REST and YAP as promoters of the neuroendocrine to non-neuroendocrine transition. We further identified the specific neuroendocrine gene programs repressed by REST downstream of Notch in this process. Importantly, we validated the importance of REST and YAP in neuroendocrine to non-neuroendocrine cell fate switches in both developmental and tissue repair processes in the lungs. Altogether, these experiments identify conserved roles for REST and YAP in Notch-driven inhibition of the neuroendocrine cell fate in embryonic lungs, adult lungs, and lung cancer.

Expression of NOTCH1, NOTCH4, HLA-DMA and HLA-DRA is synergistically associated with T cell exclusion, immune checkpoint blockade efficacy and recurrence risk in ER-negative breast cancer

PURPOSE

Reliable biomarkers to predict the outcome and treatment response of estrogen receptor (ER)-negative breast cancer (BC) are urgently needed. Since immune-related signaling plays an important role in the tumorigenesis of ER-negative BC, we asked whether Notch genes, alone or in combination with other immune genes, can be used to predict the clinical outcome and immune checkpoint blockade (ICB) for this type of cancer.

METHODS

We analyzed transcriptome data of 6918 BC samples from five independent cohorts, 81 xenograft triple-negative BC tumors that respond differently to ICB treatment and 754 samples of different cancer types from patients treated with ICB agents.

RESULTS

We found that among four Notch genes, the expression levels of NOTCH1 and NOTCH4 were positively associated with recurrence of ER-negative BC, and that combined expression of these two genes (named Notch14) further enhanced this association, which was comparable with that of the Notch pathway signature. Analysis of 1182 immune-related genes revealed that the expression levels of most HLA genes, particularly HLA-DMA and -DRA, were reversely associated with recurrence in ER-negative BC with low, but not high Notch14 expression. A combined expression signature of NOTCH1, NOTCH4, HLA-DMA and HLA-DRA was more prognostic for ER-negative and triple-negative BCs than previously reported immune-related signatures. Furthermore, we found that the expression levels of these four genes were also synergistically associated with T cell exclusion score, infiltration of specific T cells and ICB efficacy in ER-negative BC, thereby providing a potential molecular mechanism for the synergistic effect of these genes on BC.

CONCLUSIONS

Our data indicate that a gene signature composed of NOTCH1, NOTCH4, HLA-DMA and HLA-DRA may serve as a potential promising biomarker for predicting ICB therapy efficacy and recurrence in ER-negative/triple-negative BCs.

The EPH/Ephrin System in Bone and Soft Tissue Sarcomas' Pathogenesis and Therapy: New Advancements and a Literature Review

Musculoskeletal sarcomas represent rare heterogenous malignancies of mesenchymal origin that can be divided in two distinct subtypes, bone and soft tissue sarcomas. Current treatment options combine the surgical excision of local tumors and multidrug chemotherapy to prevent metastatic widespread disease. Due to the grim prognosis that usually accompanies such tumors, researchers have attempted to shed light on the molecular pathways implicated in their pathogenesis in order to develop novel, innovative, personalized therapeutic strategies. Erythropoietin-producing human hepatocellular receptors (EPHs) are tyrosine-kinase transmembrane receptors that, along with their ligands, ephrins, participate in both tumor-suppressive or tumor-promoting signaling pathways in bone and soft tissue sarcomas. The EPH/ephrin axis orchestrates cancerous processes such as cell–cell and cell–substrate adhesion and enhances the remodeling of the intracellular cytoskeleton to stimulate the motility and invasiveness of sarcoma cells. The purpose of our study was to review published PubMed literature to extract results from in vitro, in vivo and clinical trials indicative of the role of EPH/ephrin signaling in bone and soft tissue sarcomas. Based on these reports, significant interactions between the EPH/ephrin signaling pathway and a plethora of normal and abnormal cascades contribute to molecular mechanisms enhancing malignancy during sarcoma progression. In addition, EPHs and ephrins are prospective candidates for diagnostic, monitoring and therapeutic purposes in the clinical setting against bone and soft tissue sarcomas.

Reduced chromatin accessibility correlates with resistance to Notch activation

The Notch signalling pathway is a master regulator of cell fate transitions in development and disease. In the brain, Notch promotes neural stem cell (NSC) proliferation, regulates neuronal migration and maturation and can act as an oncogene or tumour suppressor. How NOTCH and its transcription factor RBPJ activate distinct gene regulatory networks in closely related cell types in vivo remains to be determined. Here we use Targeted DamID (TaDa), requiring only thousands of cells, to identify NOTCH and RBPJ binding in NSCs and their progeny in the mouse embryonic cerebral cortex in vivo. We find that NOTCH and RBPJ associate with a broad network of NSC genes. Repression of NSC-specific Notch target genes in intermediate progenitors and neurons correlates with decreased chromatin accessibility, suggesting that chromatin compaction may contribute to restricting NOTCH-mediated transactivation.