Notch1 and Notch2 have opposite prognostic effects on patients with colorectal cancer

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.

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.

Advances in Understanding the Notch Signaling Pathway in the Cochlea

The cochlear structure is highly complex and specific, and its development is regulated by multiple signaling pathways. Abnormalities in cochlear development can lead to different degrees of loss of function. Hair cells (HCs), which are difficult to regenerate in the mature mammalian cochlea, are susceptible to damage from noise and ototoxic drugs, and damage to HCs can cause hearing loss to varying degrees. Notch, a classical developmental signaling molecule, has been shown to be closely associated with embryonic cochlear development and plays an important role in HC regeneration in mammals, suggesting that the Notch signaling pathway may be a potential therapeutic target for cochlear development and hearing impairment due to HC damage. In recent years, the important role of the Notch signaling pathway in the cochlea has received increasing attention. In this paper, we review the role of Notch signaling in cochlear development and HC regeneration, with the aim of providing new research ideas for the prevention and treatment of related diseases.

Notch1 and Notch2 Signaling Exclusively but Cooperatively Maintain Fetal Myogenic Progenitors

Myogenic progenitors (MPs) generate myocytes that fuse to form myofibers during skeletal muscle development while maintaining the progenitor pool, which is crucial for generating sufficient muscle. Notch signaling has been known to reserve a population of embryonic MPs during primary myogenesis by promoting cell cycle exit and suppressing premature differentiation. However, the roles of individual Notch receptors (Notch1-4) during embryonic/fetal myogenesis are still elusive. In this study, we found that Notch1 and Notch2, which exhibit the highest structural similarity among Notch receptors, maintain the MP population by distinct mechanisms: Notch1 induces cell cycle exit and Notch2 suppresses premature differentiation. Moreover, genetic and cell culture studies showed that Notch1 and Notch2 signaling in MPs are distinctively activated by interacting with Notch ligand-expressing myofibers and MP-lineage cells, respectively. These results suggest that through different activation modes, Notch1 and Notch2 distinctively and cooperatively maintain MP population during fetal myogenesis for proper muscle development.

Inhibition and potential treatment of colorectal cancer by natural compounds via various signaling pathways

Colorectal cancer (CRC) is a common type of malignant digestive tract tumor with a high incidence rate worldwide. Currently, the clinical treatment of CRC predominantly include surgical resection, postoperative chemotherapy, and radiotherapy. However, these treatments contain severe limitations such as drug side effects, the risk of recurrence and drug resistance. Some natural compounds found in plants, fungi, marine animals, and bacteria have been shown to inhibit the occurrence and development of CRC. Although the explicit molecular mechanisms underlying the therapeutic effects of these compounds on CRC are not clear, classical signaling transduction pathways such as NF-kB and Wnt/β-catenin are extensively regulated. In this review, we have summarized the specific mechanisms regulating the inhibition and development of CRC by various types of natural compounds through nine signaling pathways, and explored the potential therapeutic values of these natural compounds in the clinical treatment of CRC.

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.

Copy-number intratumor heterogeneity increases the risk of relapse in chemotherapy-naive stage II colon cancer

Optimal selection of high-risk patients with stage II colon cancer is crucial to ensure clinical benefit of adjuvant chemotherapy. Here, we investigated the prognostic value of genomic intratumor heterogeneity and aneuploidy for disease recurrence. We combined targeted sequencing, SNP arrays, fluorescence in situ hybridization, and immunohistochemistry on a retrospective cohort of 84 untreated stage II colon cancer patients. We assessed the clonality of copy-number alterations (CNAs) and mutations, CD8⁺ lymphocyte infiltration, and their association with time to recurrence. Prognostic factors were included in machine learning analysis to evaluate their ability to predict individual relapse risk. Tumors from recurrent patients displayed a greater proportion of CNAs compared with non-recurrent (mean 31.3% versus 23%, respectively; p = 0.014). Furthermore, patients with elevated tumor CNA load exhibited a higher risk of recurrence compared with those with low levels [p = 0.038; hazard ratio (HR) 2.46], which was confirmed in an independent cohort (p = 0.004; HR 3.82). Candidate chromosome-specific aberrations frequently observed in recurrent cases included gain of the chromosome arm 13q (p = 0.02; HR 2.67) and loss of heterozygosity at 17q22-q24.3 (p = 0.05; HR 2.69). CNA load positively correlated with intratumor heterogeneity (R = 0.52; p < 0.0001). Consistently, incremental subclonal CNAs were associated with an elevated risk of relapse (p = 0.028; HR 2.20), which we did not observe for subclonal single-nucleotide variants and small insertions and deletions. The clinico-genomic model rated an area under the curve of 0.83, achieving a 10% incremental gain compared with clinicopathological markers (p = 0.047). In conclusion, tumor aneuploidy and copy-number intratumor heterogeneity were predictive of poor outcome and improved discriminative performance in early-stage colon cancer. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Suppressive effect of α-mangostin for cancer stem cells in colorectal cancer via the Notch pathway

Background

Since colon cancer stem cells (CSCs) play an important role in chemoresistance and in tumor recurrence and metastasis, targeting of CSCs has emerged as a sophisticated strategy for cancer therapy. α-mangostin (αM) has been confirmed to have antiproliferative and apoptotic effects on cancer cells. This study aimed to evaluate the selective inhibition of αM on CSCs in colorectal cancer (CRC) and the suppressive effect on 5-fluorouracil (5-FU)-induced CSCs.

Methods

The cell viability assay was performed to determine the optimal concentration of αM. A sphere forming assay and flow cytometry with CSC markers were carried out to evaluate the αM-mediated inhibition of CSCs. Western blot analysis and quantitative real-time PCR were performed to investigate the effects of αM on the Notch signaling pathway and colon CSCs. The in vivo anticancer efficacy of αM in combination with 5-FU was investigated using a xenograft mouse model.

Results

αM inhibited the cell viability and reduced the number of spheres in HT29 and SW620 cells. αM treatment decreased CSCs and suppressed the 5-FU-induced an increase in CSCs on flow cytometry. αM markedly suppressed Notch1, NICD1, and Hes1 in the Notch signaling pathway in a time- and dose-dependent manner. Moreover, αM attenuated CSC markers CD44 and CD133, in a manner similar to that upon DAPT treatment, in HT29 cells. In xenograft mice, the tumor and CSC makers were suppressed in the αM group and in the αM group with 5-FU treatment.

Conclusion

This study shows that low-dose αM inhibits CSCs in CRC and suppresses 5-FU–induced augmentation of CSCs via the Notch signaling pathway.

Predicting Mutational Status of Driver and Suppressor Genes Directly from Histopathology With Deep Learning: A Systematic Study Across 23 Solid Tumor Types

In the last four years, advances in Deep Learning technology have enabled the inference of selected mutational alterations directly from routine histopathology slides. In particular, recent studies have shown that genetic changes in clinically relevant driver genes are reflected in the histological phenotype of solid tumors and can be inferred by analysing routine Haematoxylin and Eosin (H&E) stained tissue sections with Deep Learning. However, these studies mostly focused on selected individual genes in selected tumor types. In addition, genetic changes in solid tumors primarily act by changing signaling pathways that regulate cell behaviour. In this study, we hypothesized that Deep Learning networks can be trained to directly predict alterations of genes and pathways across a spectrum of solid tumors. We manually outlined tumor tissue in H&E-stained tissue sections from 7,829 patients with 23 different tumor types from The Cancer Genome Atlas. We then trained convolutional neural networks in an end-to-end way to detect alterations in the most clinically relevant pathways or genes, directly from histology images. Using this automatic approach, we found that alterations in 12 out of 14 clinically relevant pathways and numerous single gene alterations appear to be detectable in tissue sections, many of which have not been reported before. Interestingly, we show that the prediction performance for single gene alterations is better than that for pathway alterations. Collectively, these data demonstrate the predictability of genetic alterations directly from routine cancer histology images and show that individual genes leave a stronger morphological signature than genetic pathways.

Gamma Secretase Inhibitors in Cancer: A Current Perspective on Clinical Performance

Gamma secretase inhibitors (GSIs), initially developed as Alzheimer's therapies, have been repurposed as anticancer agents given their inhibition of Notch receptor cleavage. The success of GSIs in preclinical models has been ascribed to induction of cancer stem-like cell differentiation and apoptosis, while also impairing epithelial-to-mesenchymal transition and sensitizing cells to traditional chemoradiotherapies. The promise of these agents has yet to be realized in the clinic, however, as GSIs have failed to demonstrate clinical benefit in most solid tumors with the notable exceptions of CNS malignancies and desmoid tumors. Disappointing clinical performance to date reflects important questions that remain to be answered. For example, what is the net impact of these agents on antitumor immune responses, and will they require concurrent targeting of tumor-intrinsic compensatory pathways? Addressing these limitations in our current understanding of GSI mechanisms will undoubtedly facilitate their rational incorporation into combinatorial strategies and provide a valuable tool with which to combat Notch-dependent cancers. In the present review, we provide a current understanding of GSI mechanisms, discuss clinical performance to date, and suggest areas for future investigation that might maximize the utility of these agents. IMPLICATIONS FOR PRACTICE: The performance of gamma secretase inhibitors (GSIs) in clinical trials generally has not reflected their encouraging performance in preclinical studies. This review provides a current perspective on the clinical performance of GSIs across various solid tumor types alongside putative mechanisms of antitumor activity. Through exploration of outstanding gaps in knowledge as well as reasons for success in certain cancer types, the authors identify areas for future investigation that will likely enable incorporation of GSIs into rational combinatorial strategies for superior tumor control and patient outcomes.

Neo-Fs Index: A Novel Immunohistochemical Biomarker Panel Predicts Survival and Response to Anti-Angiogenetic Agents in Clear Cell Renal Cell Carcinoma

Background: Frameshift indels have emerged as a predictor of immunotherapy response but were not evaluated yet to predict anti-angiogenetic agent (AAA) response or prognosis in clear cell renal cell carcinoma (ccRCC). Methods: Here, to develop biomarkers that predict survival and response to AAA, we evaluated the immunohistochemical expression of proteins whose genes frequently harbor frameshift indels in 638 ccRCC patients and correlated the individual and integrated markers with prognosis and AAA response. The mutational landscape was evaluated using targeted next-generation sequencing in 12 patients concerning protein markers. Immune gene signatures were retrieved from TCGA RNA seq data. Results: Five proteins (APC, NOTCH1, ARID1A, EYS, and filamin A) were independent adverse prognosticators and were incorporated into the Neo-fs index. Better overall, disease-specific and recurrence-free survival were observed with high Neo-fs index in univariate and multivariate survival analyses. Better AAA responses were observed with a high Neo-fs index, which reflected increased MHC class I, CD8+ T cell, cytolytic activity, and plasmacytoid dendritic cell signatures and decreased type II-IFN response signatures, as well as greater single-nucleotide variant (SNV) and indel counts. Conclusions: Neo-fs index, reflecting antitumor immune signature and more SNVs. and indels, is a powerful predictor of survival and AAA response in ccRCC.

Notch Signaling Pathway in Cancer-Review with Bioinformatic Analysis

Simple Summary

The Notch signaling pathway, which controls multiple cell differentiation processes during the embryonic stage and adult life, is associated with carcinogenesis and disease progression. The aim of the present study was to highlight cancer heterogeneity with respect to the Notch pathway. Our analysis concerns the effects of the Notch signaling at different levels, including core components and downstream target genes. We also demonstrate overall and disease-free survival results, pointing out the characteristics of particular Notch components. Depending on tissue context, Notch members can be either oncogenic or suppressive. We observed different expression profile core components and target genes that could be associated with distinct survival of patients. Advances in our understanding of the Notch signaling in cancer are very promising for the development of new treatment strategies for the benefit of patients.

Abstract

Notch signaling is an evolutionarily conserved pathway regulating normal embryonic development and homeostasis in a wide variety of tissues. It is also critically involved in carcinogenesis, as well as cancer progression. Activation of the Notch pathway members can be either oncogenic or suppressive, depending on tissue context. The present study is a comprehensive overview, extended with a bioinformatics analysis of TCGA cohorts, including breast, bladder, cervical, colon, kidney, lung, ovary, prostate and rectum carcinomas. We performed global expression profiling of the Notch pathway core components and downstream targets. For this purpose, we implemented the Uniform Manifold Approximation and Projection algorithm to reduce the dimensions. Furthermore, we determined the optimal cutpoint using Evaluate Cutpoint software to established disease-free and overall survival with respect to particular Notch members. Our results demonstrated separation between tumors and their corresponding normal tissue, as well as between tumors in general. The differentiation of the Notch pathway, at its various stages, in terms of expression and survival resulted in distinct profiles of biological processes such as proliferation, adhesion, apoptosis and epithelial to mesenchymal transition. In conclusion, whether oncogenic or suppressive, Notch signaling is proven to be associated with various types of malignancies, and thus may be of interest as a potential therapeutic target.

NOTCH3 is a Prognostic Factor and Is Correlated With Immune Tolerance in Gastric Cancer

Introduction

Although traditional treatments confer survival benefits to patients with gastric cancer (GC), many patients experience relapse soon after postoperative adjuvant therapy. Immune-related mechanisms play an important role in GC, and immunotherapeutic strategies are considered to be a promising direction for the treatment of GC. Thus, our study aimed to investigate the expression and prognostic significance of immune-related genes in GC.

Methods

Formalin-fixed, paraffin-embedded samples were collected from 48 resectable GC patients. The transcriptome data of the tumor immune microenvironment were assessed using an immuno-oncology 395-gene panel RNA sequencing platform. The prognostic value of the 395 genes was analyzed and validated in the KM plotter and GEPIA databases. The data from The Cancer Genome Atlas (TCGA, downloaded from UCSC Xena repository) and Tumor IMmune Estimation Resource (TIMER) were used to evaluate the correlations between prognostic factors and immune signatures.

Results

Among the 395 genes, NOTCH3 was identified as a good prognostic factor for GC patients. Its prognostic value was also suggested in both our GC cohort from Zhongshan Hospital and the public databases (KM plotter and GEPIA database). Mechanistically, high NOTCH3 expression correlated with a lower infiltration of activated CD8⁺ T cells and a higher infiltration of immunosuppressive cells including Tregs and M2 macrophages in the tumor microenvironment. Moreover, high NOTCH3 expression was accompanied by the increased expression of a series of immune checkpoint inhibitors, resulting in a dampened immune response. Interestingly, NOTCH3 expression had a negative association with well-documented predictive biomarkers of immune checkpoint blockade (ICB) immunotherapy, including tumor mutation burden (TMB), gene expression profiling (GEP) score and innate anti-PD-1 resistance (IPRES) signature.

Conclusion

These findings uncovered a new mechanism by which NOTCH3 participates in the immune tolerance of GC, implying the potential of NOTCH3 as a therapeutic target or predictive marker for GC patients.

Emerging Role and Therapeutic Potential of lncRNAs in Colorectal Cancer

Maintenance of the intestinal epithelium is dependent on the control of stem cell (SC) proliferation and differentiation. The fine regulation of these cellular processes requires a complex dynamic interplay between several signaling pathways, including Wnt, Notch, Hippo, EGF, Ephrin, and BMP/TGF-β. During the initiation and progression of colorectal cancer (CRC), key events, such as oncogenic mutations, influence these signaling pathways, and tilt the homeostatic balance towards proliferation and dedifferentiation. Therapeutic strategies to specifically target these deregulated signaling pathways are of particular interest. However, systemic blocking or activation of these pathways poses major risks for normal stem cell function and tissue homeostasis. Interestingly, long non-coding RNAs (lncRNAs) have recently emerged as potent regulators of key cellular processes often deregulated in cancer. Because of their exceptional tissue and tumor specificity, these regulatory RNAs represent attractive targets for cancer therapy. Here, we discuss how lncRNAs participate in the maintenance of intestinal homeostasis and how they can contribute to the deregulation of each signaling pathway in CRC. Finally, we describe currently available molecular tools to develop lncRNA-targeted cancer therapies.

The Prognostic Value of Cancer Stem Cell Markers (Notch1, ALDH1, and CD44) in Primary Colorectal Carcinoma

BACKGROUND

Cancer stem cells proved to have a vital role in cell migration, invasion, metastasis, and treatment resistance of colorectal cancer (CRC) that subsequently lead to poor clinical outcomes. These stem cells may be a novel therapeutic target for the management of CRC progression. Signals of the Notch-1 pathway are responsible for acquisition of stem cell characters. ALDH1 and CD44 are usually detected in stem cells in colorectal cancer.

AIM

The aims of this work are to evaluate the immunohistochemical expression of cancer stem cell markers ALDH1, Notch1, and CD44 in colorectal cancer and investigate their correlation with clinicopathological characters and patient survival.

METHODS

Paraffin-embedded specimens of 70 patients with primary colorectal carcinoma were analyzed for Notch 1, ALDH1, and CD44 expressions by immunohistochemistry.

RESULTS

Notch1 was mainly located in the cytoplasm of CRC tissues, rarely expressed in adjacent normal tissues. A highly statistically significant relationship was found between grading, lymphovascular invasion, the degree of lymphocytic infiltration, peritumoral budding, lymph node ratio, lymph node metastasis, and Notch1 expression (p < 0.001). There was a highly statistically significant relationship found between AJCC stage and Notch1 expression (p < 0.001). CD44 was mainly located in the cell membrane of CRC tissues. A highly statistically significant relationship was found between grading (p = 0.006), lymphovascular invasion, the degree of lymphocytic infiltration, peritumoral budding, lymph node metastasis, lymph node ratio, and CD44 expression (p < 0.001). There was a highly statistically significant relationship found between AJCC stage and CD44 expression (p < 0.001). ALDH1 was detected in the cytoplasm of the CRC tissue. A highly statistically significant relationship was found between grading, lymphovascular invasion, the degree of lymphocytic infiltration, peritumoral budding, lymph node metastasis, lymph node ratio, and ALDH1 expression (p < 0.001). There was a highly statistically significant relationship found between AJCC stage and ALDH1 expression (p < 0.001). There is a highly statistically significant direct correlation between Notch1, CD44 expression, and ALDH1 expression (p < 0.001).

CONCLUSIONS

There is a substantial correlation between Notch 1, ALDH1, and CD44 as cancer stem cell markers and lymph node metastasis, advanced stage and tumor recurrence in colorectal carcinoma.

CONCLUSION

Expression of stem cell markers ALDH1, Notch1, and CD44 correlates with poor prognosis in a CRC and represents an independent prognostic factor. They are associated with a feature of epithelial-mesenchymal transition evidenced by their association with high tumor burden.

Glutamate dehydrogenase inhibits tumor growth in gastric cancer through the Notch signaling pathway

Glutamate dehydrogenase (GDH) is a key enzyme in glutaminolysis and can regulate allosteric functions. Immunohistochemical study found that GDH expressed in gastric cancer cell cytoplasm and membrane, and a few located in the nucleus, ranging from light yellow to tan to sepia. According to the analysis by Kaplan Meier survival curve and the Log-Rank test, the median survival of GDH high expression in patients was 51.7 months with 95% confidence intervals (CI) was 41.138-55.262. The expression level of GDH was significantly reduced after silencing GDH gene in gastric cancer cells and tissues. Further, after silencing GDH gene, gastric cancer cell migration and invasion ability were decreased significantly. Protein expression of. In addition, tumor growth was significantly reduced after silencing GDH gene. In vivo and in vitro experiments suggest that GDH can decrease gastric cancer cell migration and invasion, thus inhibiting tumor growth.

Frequent Activation of Notch Signaling Pathway in Colorectal Cancers and Its Implication in Patient Survival Outcome

Colorectal cancer is a major health concern as it ranks third in incidence and second major cause of cancer-related deaths worldwide. A leading cause of treatment failure has been attributed to cancer stem cells that can invariably resist existing chemotherapeutic regimens. Notch signaling pathway has been involved in the maintenance of stem cells besides being crucial in cell fate decision and embryonic development. This pathway has also been implicated in several human malignancies including colorectal cancer. We investigated mRNA expression of four Notch receptors (Notch1–4), five ligands (Jag1, Jag2, Dll1, Dll3, and Dll4), and four target genes (Hes1, Hes5, Hey1, and Hey2) using highly specific TaqMan gene expression assays in colorectal adenomas and cancers. Upregulated expression of Notch receptors ranged between 29 and 73% in colorectal cancers and between 11 and 56% in adenomas. Expression of Notch3 and Notch4 receptors was significantly higher in colorectal cancers compared to normal and adenoma tissues. The Jagged and Delta-like ligands were overexpressed between 25 and 52% in colorectal cancers, while in adenomas, it ranged between 0 and 33%. Combining the data for upregulation of receptors and ligands suggests that 86% colorectal cancers and 56% adenomas exhibited overexpression of Notch pathway genes in our cohort. Notch target genes were upregulated between 24 and 33% in colorectal cancers and between 11 and 22% in adenomas. Collating upregulation of Notch receptors and ligands with the target genes showed concordance in 58% colorectal tumors. Additionally, we evaluated expression of Notch receptors, ligands, and target genes with prognosis using the TCGA mRNA expression dataset. Patients overexpressing Notch3, Notch4, and Hey1 had significantly poorer overall survival relative to those having lower levels of these genes. Taken together, Notch signaling components are aberrantly overexpressed in colorectal tumors, and development of therapeutics targeting the Notch pathway may prove to be beneficial in the management of colorectal cancers.

The Novel Notch-induced Long Noncoding RNA LUNAR1 Determines the Proliferation and Prognosis of Colorectal Cancer

In contrast to what is known about the complicated roles of Notch signalling in human malignancies, the direct target genes of Notch signalling are still unclear. Recently, long noncoding RNAs (lncRNAs) have been found to play various roles in the post-transcriptional regulation of gene expression. In the present study, we investigated the potential role of the Notch-induced lncRNA LUNAR1 in colorectal cancer (CRC). We recruited 196 cases of clinical CRC specimens and investigated LUNAR1 levels in these specimens. The associations of LUNAR1 with tumour aggressiveness and clinical outcomes were evaluated. Moreover, the impact of LUNAR1 on the malignant behaviour of tumour cells was tested in cell lines. Significantly increased expression of LUNAR1 in clinical CRC specimens was detected compared with that in matching normal tissues. LUNAR1 expression in CRC was found to be associated with the tumour aggressiveness, disease-free survival and overall survival of patients. The downregulation of LUNAR1 in SW620 cells inhibited cell proliferation, migration, invasion and tumour growth while inducing apoptosis. Moreover, the inhibition of LUNAR1 can significantly suppress IGF1 signalling in CRC. These results indicated that LUNAR1 was increased in CRC and might promote tumour progression. Thus, LUNAR1 may constitute a promising prognostic marker for the clinical management of CRC.

Inflammation-induced colon cancer in uPA-deficient mice is associated with a deregulated expression of Notch signaling pathway components

Notch is an evolutionarily conserved signaling pathway with an important role in development and cell fate determination. Deregulation of Notch signaling has been associated with several pathological conditions, including cancer. Acting as an oncogene in some types of cancers and as a tumor suppressor in other, Notch effects seem to be highly context-dependent in solid tumors. In the present study, we aimed to investigate gene expression levels of Notch pathway constituents, including ligands, receptors, and target genes, during the early stages of inflammation-associated intestinal carcinogenesis. To achieve so, we used our recently developed mouse model, in which colon cancer arises in the absence of urokinase-type plasminogen activator (uPA) due to colitis induced by dextran sodium sulfate (DSS) treatment. Among the cell surface components, ligands Jag1/Jag2 and receptors Notch1/Notch2 were found to be significantly upregulated in the uPA-deficient protumorigenic inflammatory microenvironment. Moreover, several intracellular Notch modulators, i.e. Hes1, Hey1, and Klf4, were also shown to be deregulated with inflammation, yet irrespective of uPA status. Sox9 transcription factor, however, was significantly downregulated in the uPA-deficient/DSS-treated mice that developed colon adenomas as compared to the wild-type/DSS-treated group with no neoplasia identified. The latter finding supports a tumor suppressive role of Sox9 in intestinal carcinogenesis. Our results point towards an early activation of Notch signaling pathway at the receptor-ligand level in inflammation-associated colon neoplasmatogenesis developed in the absence of uPA. Interestingly, such activation may not be accompanied by deregulation of downstream Notch-target genes, possibly due to the effects of other inter-related signaling pathways.

MicroRNA-16 is involved in the pathogenesis of pre-eclampsia via regulation of Notch2

In recent years, the role of microRNAs (miRNAs) in pre-eclampsia (PE) has been demonstrated, while the relevant mechanisms of miR-16 in PE await to be unearthed. Thus, the aim of this study is to explore whether miR-16 exerts its function in PE, and we assumed that miR-16 may be implicated in the occurrence of PE by adjusting the biological functions of trophoblast cells via modulating Notch2. Placental tissues of pregnant women with normal pregnancy and PE were collected to detect the expression of miR-16, Notch2, and Notch3. The effects of miR-16 and Notch2 on the biological functions of BeWo and JEG-3 cells were further determined. Expression of miR-16 and Notch2 in trophoblast cells was detected by reverse transcription quantitative polymerase chain reaction and western blot assay. Downregulated Notch2 and upregulated miR-16 and Notch3 were found in placental tissues of PE. There was a negative correlation between Notch2 and miR-16 expression (r = -0.769), and a positive correlation between Notch3 and miR-16 expression (r = 0.676; p < .05). Overexpression of miR-16 inhibited proliferation, migration, and invasion, and facilitated the apoptosis of BeWo and JEG-3 cells, but overexpression of Notch2 reversed this trend. Overexpression of miR-16 inhibited Notch2 expression in BeWo and JEG-3 cells, and Notch2 was the target gene of miR-16. Our study highlights that overexpression of miR-16 is involved in PE by regulating the biological functions of trophoblast cells via inhibition of Notch2. This paper provides a new idea for further study of the pathogenesis of PE.

Gains of Chromosome 1p and 15q are Associated with Poor Survival After Cytoreductive Surgery and HIPEC for Treating Colorectal Peritoneal Metastases

Purpose

Genetic alterations in colorectal peritoneal metastases (PM) are largely unknown. This study was designed to analyze whole-genome copy number alterations (CNA) in colorectal PM and to identify alterations associated with prognosis after cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).

Methods

All patients with PM, originating from a colorectal adenocarcinoma, who were treated with CRS and HIPEC in Uppsala Sweden, between 2004 and 2015, were included (n = 114). DNA derived from formalin-fixed paraffin-embedded (FFPE) specimens were analyzed for CNA using molecular inversion probe arrays.

Results

There were extensive but varying degrees of CNA, ranging from minimal CNA to total aneuploidy. In particular, gain of parts of chromosome 1p and major parts of 15q were associated with poor survival. A combination of gains of 1p and 15q was associated with poor survival, also after adjustment for differences in peritoneal cancer index and completeness of cytoreduction score [hazard ratio (HR) 5.96; 95% confidence interval (CI) 2.19–16.18]. These patients had a mean copy number (CN) of 3.19 compared with 2.24 in patients without gains. Complete CN analysis was performed in 53 patients. Analysis was unsuccessful for the remaining patients due to insufficient amounts of DNA and signals caused by interstitial components and normal cells. There was no difference in survival between patients with successful and unsuccessful CN analysis.

Conclusions

This study shows that gains of parts of chromosome 1p and of major parts of chromosome 15q were significantly associated with poor survival after CRS and HIPEC, which could represent future prognostic biomarkers.

Electronic supplementary material

The online version of this article (10.1245/s10434-019-07923-6) contains supplementary material, which is available to authorized users.

Mutual regulation of JAG2 and PRAF2 promotes migration and invasion of colorectal cancer cells uncoupled from epithelial-mesenchymal transition

Background

Our previous studies revealed that Jagged 2 (JAG2) is involved in the regulation of migration and invasion of colon cancer cells without affecting cell proliferation. This study further explored the specific mechanism by which JAG2 promotes migration and invasion of colorectal cancer cells.

Methods

JAG2 mRNA expression in different clinical stages of colorectal cancer and normal intestinal tissues was detected by quantitative PCR (QPCR). QPCR and Western Blot were used to analyze the differential expression of JAG2 mRNA and protein between normal human colon tissue cells and various colorectal cancer cells. Co-expression status of JAG2 and epithelial–mesenchymal transition (EMT) markers in colon cancer tissues and cells was analyzed. The difference between TGF-β-induced EMT model and the JAG2 overexpression model were compared in promoting migration and invasion of HT29 cells. HT29 cells were treated with EMT pathway inhibitors (LY2157299 and Slug siRNA) to identify a cross-talk between the JAG2 effect and the Notch pathway. Co-expressed genes of JAG2 in colorectal cancer cells were identified using siRNA and transcriptome microarray technology. The mutual regulation of JAG2 and the co-expressed gene PRAF2 and the regulation of the paracrine effect of exosomes were analyzed.

Results

JAG2 was abnormally expressed in colorectal cancer tissues and directly related to clinical stages. Similar to the findings in tissues, the expression of both JAG2 mRNA and protein was significantly increased in the colorectal cancer cell lines compared with that of normal colorectal cell line CCD18-Co. It was shown in our cell model that JAG2 was involved in the regulation of migration and invasion independent of the canonical Notch signaling pathway. More interestingly, JAG2 also promoted the migration and invasion of colon cancer cells in a non-EMT pathway. Further analysis revealed the co-expression of JAG2 with PRAF2 in colorectal cancer cells. JAG2-rich exosomes were released from colorectal cancer cells in a PRAF2-dependent way, while these exosomes regulated the metastasis of colorectal cancer cells in a paracrine manner.

Conclusions

This is the evidence supporting the biological function of JAG2 through non-canonical Notch and non-EMT-dependent pathways and also the first demonstration of the functions of PRAF2 in colorectal cancer cells. These findings also provide theoretical basis for the development of small molecules or biological agents for therapeutic intervention targeting JAG2/PRAF2.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0871-5) contains supplementary material, which is available to authorized users.

Relationship between the upregulation of Notch1 signaling and the clinical characteristics of patients with papillary thyroid carcinoma in East Asia: a systematic review and meta-analysis

Background

Many studies have aimed to clarify the relationship between Notch1 signaling and papillary thyroid carcinoma (PTC), but the results have been inconsistent to date. In the present study, a systematic review and meta-analysis were performed to analyze the relationship between Notch1 signaling and the clinical characteristics of PTC.

Methods

Literature databases, including PubMed (Medline), Embase and China National Knowledge Infrastructure, were searched for relevant studies from inception to April 2018. A total of five studies, including 421 patients with PTC from China and South Korea, were included in the meta-analysis.

Results

The results revealed that the upregulation of Notch1 signaling was positively correlated with lymph node metastasis in patients with PTC (OR = 3.25, 95% CI 1.14–9.23, P = 0.03). Additionally, positive correlations were found between Notch1 signaling and tumor size (OR = 4.34, 95% CI 1.66–11.38, P = 0.003), capsular invasion (OR = 3.49, 95% CI 1.90–6.41, P < 0.0001) and clinical stage of PTC (OR = 2.31, 95% CI 1.05–5.11, P = 0.04).

Conclusions

The Notch1 signaling pathway may play a catalytic role in the progression of PTC, and upregulation of Notch1 signaling may have significant predictive value for the clinical prognosis of PTC.

A systematic analysis of the association between Notch1 expression and the patients with digestive tract cancers

AIM

Notch1 expression remains controversial on digestive tract cancers. This meta-analysis was performed to assess the clinicopathological significance of Notch1 expression in individuals with digestive tract cancers, mainly involving esophageal squamous cell carcinoma (ESCC), gastric cancer (GC), pancreatic cancer (PC) and colorectal cancer (CRC).

METHODS

Available articles were searched from the online databases, and the meta-analysis was done using Review Manager software 5.3.

RESULTS

35 studies were included in this analysis (6187 samples). Notch1 is downregulated in esophageal squamous cell carcinoma (p < 0.00001), Notch1 expression at high levels was detected in GC (p = 0.02) and CRC (p < 0.001), and no significant difference exists between PC and normal tissue (p = 0.76).

CONCLUSION

Notch1 overexpression in GC and CRC suggested aggressive biological behaviors, and Notch1 may be a biomarker in digestive tract cancers.

Presenilin gene function and Notch signaling feedback regulation in the developing mouse lens

Presenilins (Psen1 and Psen2 in mice) are polytopic transmembrane proteins that act in the γ-secretase complex to make intra-membrane cleavages of their substrates, including the well-studied Notch receptors. Such processing releases the Notch intracellular domain, allowing it to physically relocate from the cell membrane to the nucleus where it acts in a transcriptional activating complex to regulate downstream genes in the signal-receiving cell. Previous studies of Notch pathway mutants for Jagged1, Notch2, and Rbpj demonstrated that canonical signaling is a necessary component of normal mouse lens development. However, the central role of Psens within the γ-secretase complex has never been explored in any developing eye tissue or cell type. By directly comparing Psen single and double mutant phenotypes during mouse lens development, we found a stronger requirement for Psen1, although both genes are needed for progenitor cell growth and to prevent apoptosis. We also uncovered a novel genetic interaction between Psen1 and Jagged1. By quantifying protein and mRNA levels of key Notch pathway genes in Psen1/2 or Jagged1 mutant lenses, we identified multiple points in the overall signaling cascade where feedback regulation can occur. Our data are consistent with the loss of particular genes indirectly influencing the transcription level of another. However, we conclude that regulating Notch2 protein levels is particularly important during normal signaling, supporting the importance of post-translational regulatory mechanisms in this tissue.

FOXF1 Mediates Endothelial Progenitor Functions and Regulates Vascular Sprouting

Endothelial colony forming cells (ECFC) or late blood outgrowth endothelial cells (BOEC) have been proposed to contribute to neovascularization in humans. Exploring genes characteristic for the progenitor status of ECFC we have identified the forkhead box transcription factor FOXF1 to be selectively expressed in ECFC compared to mature endothelial cells isolated from the vessel wall. Analyzing the role of FOXF1 by gain- and loss-of-function studies we detected a strong impact of FOXF1 expression on the particularly high sprouting capabilities of endothelial progenitors. This apparently relates to the regulation of expression of several surface receptors. First, FOXF1 overexpression specifically induces the expression of Notch2 receptors and induces sprouting. Vice versa, knock-down of FOXF1 and Notch2 reduces sprouting. In addition, FOXF1 augments the expression of VEGF receptor-2 and of the arterial marker ephrin B2, whereas it downmodulates the venous marker EphB4. In line with these findings on human endothelial progenitors, we further show that knockdown of FOXF1 in the zebrafish model alters, during embryonic development, the regular formation of vasculature by sprouting. Hence, these findings support a crucial role of FOXF1 for endothelial progenitors and connected vascular sprouting as it may be relevant for tissue neovascularization. It further implicates Notch2, VEGF receptor-2, and ephrin B2 as downstream mediators of FOXF1 functions.

NOTCH4 Is a Novel Prognostic Marker that Correlates with Colorectal Cancer Progression and Prognosis

Notch family plays vital role in carcinogenesis and progression of various cancer, however, its clinical significance and prognostic value in colorectal cancer isn't fully investigated. In present study, we first investigated the NOTCH4 expression in The Cancer Genome Atlas (TCGA) (n=361) and GSE39582 (n=474) database and then validated with our own database (n=248). The transcriptional and protein levels of NOTCH4 were evaluated by RT-PCR and immunohistochemistry study, respectively. Univariate and multivariate survival analyses were performed to explore the relationship between various prognostic factors and survival outcomes. In the univariate analysis, NOTCH3 and NOTCH4 were significantly correlated with prognosis in TCGA and GSE39582 database, respectively (P<0.05). For NOTCH3 has been studied in CRC, we chosen NOTCH4 for further study. NOTCH4 mRNA was higher in liver metastases than their primary colorectal cancer or normal mucosa. Increased NOTCH4 levels significantly correlated with advanced N stage (P= 0.002), M stage (P= 0.002), lymphovascular invasion (P= 0.026), and CEA status (P= 0.030). Patients with high NOTCH4 expression had shorter 5-year disease-free survival (DFS) (HR 6.809; 95% CI 3.334-13.904; P< 0.001) and overall survival (OS) (HR 6.476; 95% CI 3.307-12.689; P<0.001) than those with low NOTCH4 expression. Multivariate survival analysis demonstrated that NOTCH4 was an independent prognostic biomarker for both DFS (HR 7.848; 95% CI 3.777-16.308; P<0.001) and OS (HR 5.323; 95% CI 2.668-10.623; P<0.001).Collectively, NOTCH4 may play critical role in colorectal cancer progression and could serve as a novel biomarker to predict survival after colectomy.

Notch-1-PTEN-ERK1/2 signaling axis promotes HER2+ breast cancer cell proliferation and stem cell survival

Trastuzumab targets the HER2 receptor on breast cancer cells to attenuate HER2-driven tumor growth. However, resistance to trastuzumab-based therapy remains a major clinical problem for women with HER2+ breast cancer. Breast cancer stem cells (BCSCs) are suggested to be responsible for drug resistance and tumor recurrence. Notch signaling has been shown to promote BCSC survival and self-renewal. Trastuzumab-resistant cells have increased Notch-1 expression. Notch signaling drives cell proliferation in vitro and is required for tumor recurrence in vivo. We demonstrate herein a mechanism by which Notch-1 is required for trastuzumab resistance by repressing PTEN expression to contribute to activation of ERK1/2 signaling. Furthermore, Notch-1-mediated inhibition of PTEN is necessary for BCSC survival in vitro and in vivo. Inhibition of MEK1/2-ERK1/2 signaling in trastuzumab-resistant breast cancer cells mimics effects of Notch-1 knockdown on bulk cell proliferation and BCSC survival. These findings suggest that Notch-1 contributes to trastuzumab resistance by repressing PTEN and this may lead to hyperactivation of ERK1/2 signaling. Furthermore, high Notch-1 and low PTEN mRNA expression may predict poorer overall survival in women with breast cancer. Notch-1 protein expression predicts poorer survival in women with HER2+ breast cancer. These results support a potential future clinical trial combining anti-Notch-1 and anti-MEK/ERK therapy for trastuzumab-resistant breast cancer.

NOTCH4 regulates colorectal cancer proliferation, invasiveness, and determines clinical outcome of patients

Notch signal has complex roles in human malignancies, which might be attributed to the diversity of Notch receptors. Here, we set out to identify the association of NOTCH4 with colorectal cancer (CRC). In the hospital-based study cohort, we investigated NOTCH4 mRNA levels in primary CRC, as well as its association with clinicopathologic characteristics. Besides, NOTCH4 cDNA and siRNA was transfected into colorectal cancer cell line to elucidate its impact on tumor cell proliferation and migration. Results revealed a statistically significant lower expression of NOTCH4 mRNA in tumor specimens compared with that in control. NOTCH4 level in CRC was found to be related to tumor differentiation, invasion, and node metastasis. Moreover, it was demonstrated that NOTCH4 mRNA level could be an independent prognostic factor for both disease-free and overall survival of CRC patients. Overexpression of NOTCH4 in CRC cell lines suppressed tumor cell proliferation, migration, and invasion, while induced apoptosis. In the opposite, the malignant behavior of CRC cells was enhanced by NOTCH4 knockdown. These results demonstrated for the first time that NOTCH4 expression was decreased in CRC, which could determine tumor proliferation, relapse, and prognosis.

Chemistry-First Approach for Nomination of Personalized Treatment in Lung Cancer

Diversity in the genetic lesions that cause cancer is extreme. In consequence, a pressing challenge is the development of drugs that target patient-specific disease mechanisms. To address this challenge, we employed a chemistry-first discovery paradigm for de novo identification of druggable targets linked to robust patient selection hypotheses. In particular, a 200,000 compound diversity-oriented chemical library was profiled across a heavily annotated test-bed of >100 cellular models representative of the diverse and characteristic somatic lesions for lung cancer. This approach led to the delineation of 171 chemical-genetic associations, shedding light on the targetability of mechanistic vulnerabilities corresponding to a range of oncogenotypes present in patient populations lacking effective therapy. Chemically addressable addictions to ciliogenesis in TTC21B mutants and GLUT8-dependent serine biosynthesis in KRAS/KEAP1 double mutants are prominent examples. These observations indicate a wealth of actionable opportunities within the complex molecular etiology of cancer.

Identification of copy number alterations in colon cancer from analysis of amplicon-based next generation sequencing data

The objective of this study was to determine the feasibility to detect copy number alterations in colon cancer samples using Next Generation Sequencing data and to elucidate the association between copy number alterations in specific genes and the development of cancer in different colon segments. We report the successful detection of somatic changes in gene copy number in 37 colon cancer patients by analysis of sequencing data through Amplicon CNA Algorithm. Overall, we have found a total of 748 significant copy number alterations in 230 significant genes, of which 143 showed CN losses and 87 showed CN gains. Validation of results was performed on 20 representative genes by quantitative qPCR and/or immunostaining. By this analysis, we have identified 4 genes that were subjected to copy number alterations in tumors arising in all colon segments (defined "common genes") and the presence of copy number alterations in 14 genes that were significantly associated to one specific site (defined "site-associated genes"). Finally, copy number alterations in ASXL1, TSC1 and IL7R turned out to be clinically relevant since the loss of TSC1 and IL7R was associated with advanced stages and/or reduced survival whereas copy number gain of ASXL1 was associated with good prognosis.

Taming the Notch Transcriptional Regulator for Cancer Therapy

Abstract Notch signaling is a highly conserved pathway in all metazoans, which is deeply involved in the regulation of cell fate and differentiation, proliferation and migration during development. Research in the last decades has shown that the various components of the Notch signaling cascade are either upregulated or activated in human cancers. Therefore, its downregulation stands as a promising and powerful strategy for cancer therapy. Here, we discuss the recent advances in the development of small molecule inhibitors, blocking antibodies and oligonucleotides that hinder Notch activity, and their outcome in clinical trials. Although Notch was initially identified as an oncogene, later studies showed that it can also act as a tumor suppressor in certain contexts. Further complexity is added by the existence of numerous Notch family members, which exert different activities and can be differentially targeted by inhibitors, potentially accounting for contradictory data on their therapeutic efficacy. Notably, recent evidence supports the rationale for combinatorial treatments including Notch inhibitors, which appear to be more effective than single agents in fighting cancer.

MicroRNAs in the etiology of colorectal cancer: pathways and clinical implications

MicroRNAs (miRNAs) are small single-stranded RNAs that repress mRNA translation and trigger mRNA degradation. Of the ∼1900 miRNA-encoding genes present in the human genome, ∼250 miRNAs are reported to have changes in abundance or altered functions in colorectal cancer. Thousands of studies have documented aberrant miRNA levels in colorectal cancer, with some miRNAs reported to actively regulate tumorigenesis. A recurrent phenomenon with miRNAs is their frequent participation in feedback loops, which probably serve to reinforce or magnify biological outcomes to manifest a particular cellular phenotype. Here, we review the roles of oncogenic miRNAs (oncomiRs), tumor suppressive miRNAs (anti-oncomiRs) and miRNA regulators in colorectal cancer. Given their stability in patient-derived samples and ease of detection with standard and novel techniques, we also discuss the potential use of miRNAs as biomarkers in the diagnosis of colorectal cancer and as prognostic indicators of this disease. MiRNAs also represent attractive candidates for targeted therapies because their function can be manipulated through the use of synthetic antagonists and miRNA mimics.

Summary: This Review provides an overview of some important microRNAs and their roles in colorectal cancer.

The expression profile and clinicopathological significance of Notch1 in patients with colorectal cancer: a meta-analysis

AIM

This meta-analysis was conducted to evaluate the clinicopathological significance of Notch1 expression in patients with colorectal cancer (CRC).

METHODS

Available articles were searched from diverse databases, and the meta-analysis was done by using Stata 12.0 software.

RESULTS

Thirteen studies were included in this analysis (3401 samples). The Notch1 expression in CRC tissues was significantly higher than that in normal tissues statistically (OR: 15.46; 95% CI: 8.11-29.45; p = 0.003), and were associated with lymph node metastasis, tumor stage, depth of infiltration and histological differentiation.

DISCUSSION

 There is a close relationship between higher Notch1 expression in CRC. Notch1 may be involved in tumor progression, invasion and metastasis with CRC.

CONCLUSION

Notch1 overexpression in CRC suggested aggressive biological behaviors and thus implying that Notch1 may be a useful biomarker in CRCs.

Notch and its oncogenic activity in human malignancies

BACKGROUND

Increasing evidence has demonstrated that Notch signaling is deregulated in human hematological malignancies and solid tumors. This signaling has a protumorigenic effect but may also act as a tumor suppressor. How induction of a single pathway gives rise to the opposite effects in different cell types is still unknown.

METHODS

This review article includes available data from peer-reviewed publications associated with the role of Notch signaling during cancer pathogenesis.

RESULTS

Numerous reports have indicated that alterations in Notch signaling and its oncogenic activity were originally associated with the pathogenesis of T‑cell acute lymphoblastic leukemia/lymphoma (T-ALL), an aggressive hematologic tumor affecting children and adolescents. The possibility that Notch could play a significant role in human breast cancer development comes from studies on mouse mammary tumor virus-induced cancer. Numerous findings over the past several years have indicated that alterations in Notch signaling are also responsible for ovarian cancer development. Mention should also be made of the connection between expression of Notch 3 and increased resistance to chemotherapy, which remains a major obstacle to successful treatment. Notch as an oncogenic factor is also involved in the development of colon cancer, lung carcinoma and Kaposi's sarcoma.

CONCLUSION

Notch is a binary cell fate determinant and its overexpression has been described as oncogenic in a wide array of human malignancies. This finding led to interest in therapeutically targeting this pathway, especially by the use of gamma-secretase inhibitors (GSIs) blocking the cleavage of Notch receptors at the cell membrane by the inhibition of Notch intracellular domain (NICD) releasing. Preclinical cancer models have revealed that GSIs suppress the growth of cancers such as pancreatic, breast and lung cancer.

Notch1 maintains dormancy of olfactory horizontal basal cells, a reserve neural stem cell

The remarkable capacity of the adult olfactory epithelium (OE) to regenerate fully both neurosensory and nonneuronal cell types after severe epithelial injury depends on life-long persistence of two stem cell populations: the horizontal basal cells (HBCs), which are quiescent and held in reserve, and mitotically active globose basal cells. It has recently been demonstrated that down-regulation of the ΔN form of the transcription factor p63 is both necessary and sufficient to release HBCs from dormancy. However, the mechanisms by which p63 is down-regulated after acute OE injury remain unknown. To identify the cellular source of potential signaling mechanisms, we assessed HBC activation after neuron-only and sustentacular cell death. We found that ablation of sustentacular cells is sufficient for HBC activation to multipotency. By expression analysis, next-generation sequencing, and immunohistochemical examination, down-regulation of Notch pathway signaling is coincident with HBC activation. Therefore, using HBC-specific conditional knockout of Notch receptors and overexpression of N1ICD, we show that Notch signaling maintains p63 levels and HBC dormancy, in contrast to its suppression of p63 expression in other tissues. Additionally, Notch1, but not Notch2, is required to maintain HBC dormancy after selective neuronal degeneration. Taken together, our data indicate that the activation of HBCs observed after tissue injury or sustentacular cell ablation is caused by the reduction/elimination of Notch signaling on HBCs; elimination of Jagged1 expressed by sustentacular cells may be the ligand responsible.

Annonaceous acetogenins mediated up-regulation of Notch2 exerts growth inhibition in human gastric cancer cells in vitro

Background

Gastric cancer (GC) is a global health problem because of limited treatments and poor prognosis. Annonaceous acetogenins (ACGs) has been reported to exert anti-tumorigenic effects in cancer, yet the mechanism underlying its effects on GC remains largely unknown. Notch signaling plays a critical role in cell proliferation, differentiation and apoptosis. Therefore, it may contribute to the development of GC. This study aims to explore the role of Notch2 in ACGs’ activities in GC cells.

Results

ACGs inhibited GC cells’ viability in a dose dependent manner and led to cell apoptosis and cell cycle arrest in G0/G1 phase with an increased Notch2 expression. Additionally, Notch2 siRNA reduced ACGs-induced cell growth inhibition while Notch2 cDNA transfection did the opposite.

Materials and Methods

ACGs were administrated in GC cells and cell proliferation was assayed by MTS, cell apoptosis and cell cycle were detected by flow cytometry. Additionally, the expression of Notch2 and the downstream target Hes1 were identified by Western blot. Furthermore, Notch2-siRNA transfection and Notch2-cDNA were performed to investigate the role of Notch2 in the antitumor effect of ACGs. Conclusions: Up-regulation of Notch2 by ACGs is a potential therapeutic strategy for GC.

NDRG4 stratifies the prognostic value of body mass index in colorectal cancer

NDRG4 is a novel candidate tumor suppressor and can inhibit PI3K/AKT signal which is related with energy balance and related carcinogenesis. In the present study, we investigated whether NDRG4 status could modify the association of obesity with clinical outcome of colorectal cancer. For this purpose, a hospital-based prospective study cohort of 226 colorectal cancer patients was involved. NDRG4 mRNA levels were determined by real-time PCR. Association of NDRG4 mRNA expression with disease-free and overall survival was studied first. Then, the association of obesity with clinical outcome was determined according to NDRG4 level. Multivariate Cox proportional hazards model was used to compute hazard ratio, adjusting for covariates including microsatellite instability, KRAS, BRAF and PIK3CA mutation. Results showed that NDRG4 mRNA expression was decreased in tumor specimens and significantly correlated with tumor differentiation, invasion and metastasis. Patients with tumor of reduced NDRG4 mRNA level had unfavorable disease-free and overall survival. Obesity was found to be adversely associated with disease-free and overall survival in tumors with reduced NDRG4 level, not in preserved NDRG4 level group, in both univariate and multivariate analysis. These data provided the first evidence that NDRG4 level in colorectal cancer could effectively stratify the prognostic value of obesity, which would better the understanding of the prognostic role of obesity in colorectal cancer. Our results also support the notion that the host-tumor interactions in colorectal cancer might influence tumor aggressiveness.

NOTCH receptors in gastric and other gastrointestinal cancers: oncogenes or tumor suppressors?

Gastric cancer (GC) ranks the most common cancer types and is one of the leading causes of cancer-related death. Due to delayed diagnosis and high metastatic frequency, 5-year survival rate of GC is rather low. It is a complex disease resulting from the interaction between environmental factors and host genetic alterations that deregulate multiple signaling pathways. The Notch signaling pathway, a highly conserved system in the regulation of the fate in several cell types, plays a pivotal role in cell differentiation, survival and proliferation. Notch is also one of the most commonly activated signaling pathways in tumors and its aberrant activation plays a key role in cancer advancement. Whether Notch cascade exerts oncogenic or tumor suppressive function in different cancer types depends on the cellular context. Mammals have four NOTCH receptors that modulate Notch pathway activity. In this review, we provide a comprehensive summary on the functional role of NOTCH receptors in gastric and other gastrointestinal cancers. Increasing knowledge of NOTCH receptors in gastrointestinal cancers will help us recognize the underlying mechanisms of Notch signaling and develop novel therapeutic strategies for GC.

A 19-Gene expression signature as a predictor of survival in colorectal cancer

Background

Histopathological assessment has a low potential to predict clinical outcome in patients with the same stage of colorectal cancer. More specific and sensitive biomarkers to determine patients’ survival are needed. We aimed to determine gene expression signatures as reliable prognostic marker that could predict survival of colorectal cancer patients with Dukes’ B and C.

Methods

We examined microarray gene expression profiles of 78 archived tissues of patients with Dukes’ B and C using the Illumina DASL assay. The gene expression data were analyzed using the GeneSpring software and R programming.

Results

The outliers were detected and replaced with randomly chosen genes from the 90 % confidence interval of the robust mean for each group. We performed three statistical methods (SAM, LIMMA and t-test) to identify significant genes. There were 19 significant common genes identified from microarray data that have been permutated 100 times namely NOTCH2, ITPRIP, FRMD6, GFRA4, OSBPL9, CPXCR1, SORCS2, PDC, C12orf66, SLC38A9, OR10H5, TRIP13, MRPL52, DUSP21, BRCA1, ELTD1, SPG7, LASS6 and DUOX2. This 19-gene signature was able to significantly predict the survival of patients with colorectal cancer compared to the conventional Dukes’ classification in both training and test sets (p < 0.05). The performance of this signature was further validated as a significant independent predictor of survival using patient cohorts from Australia (n = 185), USA (n = 114), Denmark (n = 37) and Norway (n = 95) (p < 0.05). Validation using quantitative PCR confirmed similar expression pattern for the six selected genes.

Conclusion

Profiling of these 19 genes may provide a more accurate method to predict survival of patients with colorectal cancer and assist in identifying patients who require more intensive treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-016-0218-1) contains supplementary material, which is available to authorized users.

Notch2 as a promising prognostic biomarker for oesophageal squamous cell carcinoma

We aimed to examine Notch2 expression in oesophageal squamous cell carcinoma (ESCC) patients and to evaluate its prognostic potential. Immunohistochemical (IHC) staining, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis were utilized to investigate the Notch2 expression status and prognostic value. Furtherly, CCK8 and clonogenic assays were conducted to determine if Notch2 inhibition by shRNA could lead to a decrease in the proliferation and survival of ESCC cells. A notably higher Notch2 expression level was found in ESCC tissues at the mRNA (P < 0.0001) and protein levels (IHC: P = 0.004; western blot: P = 0.021). Log-rank analysis demonstrated that Notch2 overexpression was significantly associated with worse overall survival (OS) (29.1% vs. 49.1%; P = 0.013) and progression-free survival (PFS) (15.3% vs. 34.4%; P = 0.006) rates in ESCC patients. The multivariate analysis revealed Notch2 as an independent prognostic factor for OS and PFS (P = 0.002 and 0.006, resp.). Besides, in vitro assays showed that OD450 values and colony formations were significantly reduced in Notch2-shRNA group (all P < 0.0001). In conclusion, these results show that Notch2 is up-regulated in ESCC tissues and could serve as a promising biomarker for identifying individuals with poor prognostic potential.

Notch1 and Notch2 in Podocytes Play Differential Roles During Diabetic Nephropathy Development

Notch pathway activation in podocytes has been shown to play an important role in diabetic kidney disease (DKD) development; however, the receptors and ligands involved in the process have not been identified. Here, we report that conditional deletion of Notch1 in podocytes using NPHS2(cre)Notch1(flox/flox) animals resulted in marked amelioration of DKD. On the contrary, podocyte-specific genetic deletion of Notch2 had no effect on albuminuria and mesangial expansion. Notch1-null podocytes were protected from apoptosis and dedifferentiation in vitro, likely explaining the protective phenotype in vivo. Deletion of Notch1 in podocytes also resulted in an increase in Notch2 expression, indicating an interaction between the receptors. At the same time, transgenic overexpression of Notch2 in podocytes did not induce phenotypic changes, while constitutive expression of Notch1 caused rapid development of albuminuria and glomerulosclerosis. In summary, our studies indicate that Notch1 plays a distinct (nonredundant) role in podocytes during DKD development.

Notch2 signaling contributes to cell growth, invasion, and migration in salivary adenoid cystic carcinoma

Many studies have explored whether the Notch signaling pathway has a tumor-suppressive or an oncogenic role in various tumors; however, the role of the Notch signaling pathway in salivary adenoid cystic carcinoma (SACC) is still unknown. In this study, we attempt to define the role of Notch2 signaling in cell growth, invasion, and migration in SACC. We compared Notch2 expression in clinical SACC samples with that of normal samples by using immunohistochemical staining. Then, we down-regulated Notch2 expression to observe the effect of Notch2 on proliferation, invasion, migration, and the expression of known target genes of Notch signal pathway. According to our results, Notch2 expression was higher in SACC tissues compared with normal tissues. Knockdown of Notch2 inhibited cell proliferation, invasion, and migration in vitro and down-regulated the expression of HEY2 and CCND1. The results of this study suggest that Notch2 has an essential role in the cell growth, invasion, and migration of SACC. Notch2 may therefore be a potential target gene for the treatment of SACC by interfering with cell growth and metastasis.

Angiogenesis-related protein expression in bevacizumab-treated metastatic colorectal cancer: NOTCH1 detrimental to overall survival

Background

The development of targeted therapies has undoubtedly broadened therapeutic options for patients with colorectal cancer (CRC). The use of bevacizumab to reduce angiogenesis has been associated with improved clinical outcomes. However, an urgent need for prognostic/predictive biomarkers for anti-angiogenic therapies still exists.

Methods

Clinical data of 105 CRC patients treated with bevacizumab in conjunction with chemotherapy were analyzed. The expression of vascular endothelial growth factor (VEGF) receptors, NOTCH1 receptor and its ligand DLL4 were determined by immunohistochemistry. Tumor samples were arranged on a tissue microarray. The association between protein expression and clinicopathological characteristics and outcomes was determined.

Results

Bevacizumab was administered as a first-line of treatment in 70.5 % of our cases. The median progression-free survival (PFS) was 10.2 months. The median overall survival (OS) of the total cohort was 24.4 months. Bevacizumab, as the first-line of treatment, and the presence of liver metastasis were independently associated with objective response rate. Membrane VEGFR1 and VEGFR3 expressions were associated with the presence of lung metastasis; interestingly, VEGFR3 was associated with less liver metastasis. NOTCH1 expression was associated with lymph node metastasis. There was a trend toward association between improved PFS and lower NOTCH1 expression (p = 0.06). Improved OS was significantly associated with lower NOTCH1 expression (p = 0.01). In a multivariate analysis, ECOG (Eastern Cooperative Oncology Group) performance status, liver metastasis, histological grade, and NOTCH1 expression were independently associated with OS.

Conclusion

Our findings illustrated the expression profile of angiogenesis-related proteins and their association with clinicopathological characteristics and outcomes. NOTCH1 expression is a detrimental prognostic factor in metastatic CRC patients treated with chemotherapy plus bevacizumab.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1648-4) contains supplementary material, which is available to authorized users.

The Notch pathway in colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer death worldwide. It is also the third most common cancer diagnosis among men, and the second most common cancer diagnosis among women. Globally, CRC can account for nearly 694,000 annual deaths. It is widely appreciated that CRC is the result of dysregulated cellular pathways that promote an inappropriate stem-cell-like phenotype, apoptotic resistance, unchecked proliferation and metastatic spread. While no single pathway is responsible for all of these attributes, an array of recent studies suggests a pivotal role for abnormal Notch-1 signaling in CRC, in part due to interconnectivity of Notch with other pathways. This review will summarize recent evidence for a role of Notch signaling in CRC, will consider interconnectivity between Notch and other pathways involved in CRC and will discuss the possible utility of targeting Notch as a CRC therapeutic.

The intracellular domains of Notch1 and Notch2 are functionally equivalent during development and carcinogenesis

Although Notch1 and Notch2 are closely related paralogs and function through the same canonical signaling pathway, they contribute to different outcomes in some cell and disease contexts. To understand the basis for these differences, we examined in detail mice in which the Notch intracellular domains (N1ICD and N2ICD) were swapped. Our data indicate that strength (defined here as the ultimate number of intracellular domain molecules reaching the nucleus, integrating ligand-mediated release and nuclear translocation) and duration (half-life of NICD-RBPjk-MAML-DNA complexes, integrating cooperativity and stability dependent on shared sequence elements) are the factors that underlie many of the differences between Notch1 and Notch2 in all the contexts we examined, including T-cell development, skin differentiation and carcinogenesis, the inner ear, the lung and the retina. We were able to show that phenotypes in the heart, endothelium, and marginal zone B cells are attributed to haploinsufficiency but not to intracellular domain composition. Tissue-specific differences in NICD stability were most likely caused by alternative scissile bond choices by tissue-specific γ-secretase complexes following the intracellular domain swap. Reinterpretation of clinical findings based on our analyses suggests that differences in outcome segregating with Notch1 or Notch2 are likely to reflect outcomes dependent on the overall strength of Notch signals.

Role of Notch signaling pathway in gastric cancer: A meta-analysis of the literature

AIM: To perform a meta-analysis to quantitatively summarize the evidence for the association between the Notch signaling pathway and gastric cancer (GC).

METHODS: An electronic search of the MEDLINE, EMBASE and Chinese National Knowledge Infrastructure, which contain articles published from 1966 onwards, was conducted to select studies for this meta-analysis.

RESULTS: Fifteen studies with a total of 1547 gastric cancer cases and 450 controls were included in this meta-analysis. Overall, the expression of Notch1, Notch2, Delta-like 4 and Hes1 was significantly higher in tumor tissues of GC compared to normal tissues. Specifically, stratified analyses showed that significantly increased expression of Notch1 was associated with non-cardia location, > 5 cm size, diffuse type, positive lymphovascular invasion and distal metastasis. Statistically significant higher expression of Notch3 was found in diffuse type GC. Jagged1 was also significantly over-expressed in diffuse type and poor differentiation type of GC. DLL4 was significantly over-expressed in advanced T stage, N stage and TNM stage in GC patients. However, the stratified analysis showed that there was no statistically significant difference in Hes1 expression between different subgroups. Sporadic reports showed that Notch1 and Jagged1 were independent poor prognostic predictors in GC.

CONCLUSION: The Notch signaling pathway plays an important role in tumor progression of gastric cancer.