Up-regulated expression of Notch1 and Jagged1 in human colon adenocarcinoma

Signaling pathways in colorectal cancer implications for the target therapies

Colorectal carcinoma (CRC) stands as a pressing global health issue, marked by the unbridled proliferation of immature cells influenced by multifaceted internal and external factors. Numerous studies have explored the intricate mechanisms of tumorigenesis in CRC, with a primary emphasis on signaling pathways, particularly those associated with growth factors and chemokines. However, the sheer diversity of molecular targets introduces complexity into the selection of targeted therapies, posing a significant challenge in achieving treatment precision. The quest for an effective CRC treatment is further complicated by the absence of pathological insights into the mutations or alterations occurring in tumor cells. This study reveals the transfer of signaling from the cell membrane to the nucleus, unveiling recent advancements in this crucial cellular process. By shedding light on this novel dimension, the research enhances our understanding of the molecular intricacies underlying CRC, providing a potential avenue for breakthroughs in targeted therapeutic strategies. In addition, the study comprehensively outlines the potential immune responses incited by the aberrant activation of signaling pathways, with a specific focus on immune cells, cytokines, and their collective impact on the dynamic landscape of drug development. This research not only contributes significantly to advancing CRC treatment and molecular medicine but also lays the groundwork for future breakthroughs and clinical trials, fostering optimism for improved outcomes and refined approaches in combating colorectal carcinoma.

Regulation of signal transduction pathways in colorectal cancer: implications for therapeutic resistance

Resistance to anti-cancer treatments is a critical and widespread health issue that has brought serious impacts on lives, the economy and public policies. Mounting research has suggested that a selected spectrum of patients with advanced colorectal cancer (CRC) tend to respond poorly to both chemotherapeutic and targeted therapeutic regimens. Drug resistance in tumours can occur in an intrinsic or acquired manner, rendering cancer cells insensitive to the treatment of anti-cancer therapies. Multiple factors have been associated with drug resistance. The most well-established factors are the emergence of cancer stem cell-like properties and overexpression of ABC transporters that mediate drug efflux. Besides, there is emerging evidence that signalling pathways that modulate cell survival and drug metabolism play major roles in the maintenance of multidrug resistance in CRC. This article reviews drug resistance in CRC as a result of alterations in the MAPK, PI3K/PKB, Wnt/β-catenin and Notch pathways.

Expression of Notch pathway components (Numb, Itch, and Siah-1) in colorectal tumors: A clinicopathological study

BACKGROUND

The role of the Notch pathway in carcinogenesis and tumor progression has been demonstrated in many organs, including the colon. Accordingly, studies aimed at developing therapies targeting this pathway in various cancers require the identification of several factors that may play a role in regulating Notch-1 expression. Although Numb, Itch, and seven in absentia homolog-1 (Siah-1) have been shown to contribute to the regulation of Notch signaling, their role in colorectal carcinogenesis and tumor progression has not been fully elucidated to date.

AIM

To evaluate Numb, Itch, and Siah-1 expression in colorectal tumors to clarify their relationship with Notch-1 expression and their role in carcinogenesis and tumor behavior.

METHODS

Expression of Notch-1, Numb, Itch, and Siah-1 was investigated in 50 colorectal carcinomas, 30 adenomas, and 20 healthy colonic tissues by immunohistochemistry and quantitative real-time polymerase chain reaction (PCR) analyses.

RESULTS

In contrast to Notch-1, which is expressed at higher levels in tumor tissues and adenomas, expression of Numb, Itch, and Siah-1 was stronger and more frequent in normal mucosa (P < 0.01). There was a positive correlation between Notch-1 expression and high histological grade, the presence of lymph node metastasis, and advanced-stage tumors, whereas expression of Numb, Itch, and Siah-1 was absent or reduced in tumors with these clinicopathological parameters (P < 0.05). In survival analysis, expression of Notch was related to poor prognosis but that of Numb, Itch, and Siah-1 correlated with improved survival (P < 0.05). Multivariate analysis revealed Notch-1 expression and loss of Numb expression to be independent prognostic parameters together with lymph node metastasis (P < 0.05).

CONCLUSION

Our findings support the role of Notch-1 in colorectal carcinoma and indicate that loss of Numb, Itch, and Siah-1 expression is associated with carcinogenesis. Our data also suggest that these three proteins might be involved in the Notch-1 pathway during colorectal carcinoma (CRC) progression and might play an essential role in approaches targeting Notch as novel molecular therapies for CRC.

The oncogenic role of Jagged1/Notch signaling in cancer

Aberrant activation of Notch signaling plays an oncogenic role in cancer development. Jagged1 (JAG1) is an important Notch ligand that triggers Notch signaling through cell-cell interactions. JAG1 overexpression has been reported in many different types of cancer and correlates with a poor clinical prognosis. JAG1/Notch signaling controls oncogenic processes in different cell types and cellular contexts. Furthermore, JAG1/Notch signaling cascades activate a number of oncogenic factors that regulate cellular functions such as proliferation, metastasis, drug-resistance, and angiogenesis. To suppress the severe toxicity of pan-Notch inhibitors, JAG1 is attracting increasing attention as a source of therapeutic targets for cancers. In this review, the oncogenic role of JAG1/Notch signaling in cancer is discussed, as well as implications of strategies to inhibit JAG1/Notch signaling activity.

POFUT1 promotes colorectal cancer development through the activation of Notch1 signaling

Copy number variations (CNVs) are key drivers of colorectal cancer (CRC). Our previous studies revealed that protein O-fucosyltransferase 1 (POFUT1) overexpression is driven by CNVs during CRC development. The potential role and underlying mechanisms of POFUT1 in CRC were not investigated. In this study, we analyzed the expression of POFUT1 in CRC from cosmic and TCGA databases and confirmed that POFUT1 is highly expressed in CRC. We used well characterized CRC cell lines, including SW620 and HCT116 to establish a model POFUT1 knockdown cell line. Using these cells, we investigated the role of POFUT1 in CRC. Our data revealed that silencing POFUT1 in CRC cells inhibits cell proliferation, decreases cell invasion and migration, arrests cell cycle progression, and stimulates CRC cell apoptosis in vitro. We further demonstrate that POFUT1 silencing dramatically suppresses CRC tumor growth and transplantation in vivo. We additionally reveal new mechanistic insights into the role of POFUT1 during CRC, through demonstrating that POFUT1 silencing inhibits Notch1 signaling. Taken together, our findings demonstrate that POFUT1 is a tumor activating gene during CRC development, which positively regulates CRC tumor progression through activating Notch1.

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.

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.

NOTCH1 activates the Wnt/β-catenin signaling pathway in colon cancer

PURPOSE AND METHODS

The translocation of β-catenin/CTNNB1 to the nucleus activates Wnt signaling and cell proliferation; however, the precise mechanism underlying this phenomenon remains unknown. Previous reports have provided evidence that NOTCH1 is involved in the Wnt signaling pathway. Therefore, we sought to determine the mechanism by which NOTCH1 influences the Wnt/β-catenin pathway. We constructed a vector expressing the NOTCH1 intracellular domain (NICD1) and transfected the vector into HCT116 which has low expression of NICD1. Furthermore, inhibition of NOTCH signal pathway in SW480 which has abundant NICD1 expression, was performed by transfection of siNICD1 or DAPT, gamma secretase inhibitor, treatment. In addition, we evaluated NICD1 and β-catenin localization in colon cancer cell lines and in 189 colon cancer tissue samples and analyzed the correlation between the nuclear localization of NICD1 and the clinicopathological features of colon cancer patients.

RESULTS

Immunohistochemical assays demonstrated that NICD1 and β-catenin exhibited a similar localization pattern in colon cancer tissues. In addition, we found that NICD1 induced the translocation of β-catenin to the nucleus and that NICD1 and β-catenin co-localized in the nucleus. Overexpression of NICD1 increased luciferase activity of Wnt signal pathway. On the other hand, reduction of NICD1 reduced luciferase activity of Wnt signaling pathway. In the 189 analyzed colon cancer cases, multivariate COX regression analysis demonstrated the independent prognostic impact of nuclear localization of NICD1(p=0.0376).

CONCLUSION

NOTCH1 plays a key role in the Wnt pathway and activation of NOTCH1 is associated with the translocation of β-catenin to the nucleus.

Kaiso differentially regulates components of the Notch signaling pathway in intestinal cells

Background

In mammalian intestines, Notch signaling plays a critical role in mediating cell fate decisions; it promotes the absorptive (or enterocyte) cell fate, while concomitantly inhibiting the secretory cell fate (i.e. goblet, Paneth and enteroendocrine cells). We recently reported that intestinal-specific Kaiso overexpressing mice (Kaiso^Tg) exhibited chronic intestinal inflammation and had increased numbers of all three secretory cell types, hinting that Kaiso might regulate Notch signaling in the gut. However, Kaiso’s precise role in Notch signaling and whether the Kaiso^Tg secretory cell fate phenotype was linked to Kaiso-induced inflammation had yet to be elucidated.

Methods

Intestines from 3-month old Non-transgenic and Kaiso^Tg mice were “Swiss” rolled and analysed for the expression of Notch1, Dll-1, Jagged-1, and secretory cell markers by immunohistochemistry and immunofluorescence. To evaluate inflammation, morphological analyses and myeloperoxidase assays were performed on intestines from 3-month old Kaiso^Tg and control mice. Notch1, Dll-1 and Jagged-1 expression were also assessed in stable Kaiso-depleted colon cancer cells and isolated intestinal epithelial cells using real time PCR and western blotting. To assess Kaiso binding to the DLL1, JAG1 and NOTCH1 promoter regions, chromatin immunoprecipitation was performed on three colon cancer cell lines.

Results

Here we demonstrate that Kaiso promotes secretory cell hyperplasia independently of Kaiso-induced inflammation. Moreover, Kaiso regulates several components of the Notch signaling pathway in intestinal cells, namely, Dll-1, Jagged-1 and Notch1. Notably, we found that in Kaiso^Tg mice intestines, Notch1 and Dll-1 expression are significantly reduced while Jagged-1 expression is increased. Chromatin immunoprecipitation experiments revealed that Kaiso associates with the DLL1 and JAG1 promoter regions in a methylation-dependent manner in colon carcinoma cell lines, suggesting that these Notch ligands are putative Kaiso target genes.

Conclusion

Here, we provide evidence that Kaiso’s effects on intestinal secretory cell fates precede the development of intestinal inflammation in Kaiso^Tg mice. We also demonstrate that Kaiso inhibits the expression of Dll-1, which likely contributes to the secretory cell phenotype observed in our transgenic mice. In contrast, Kaiso promotes Jagged-1 expression, which may have implications in Notch-mediated colon cancer progression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12964-017-0178-x) contains supplementary material, which is available to authorized users.

Hes1 Increases the Invasion Ability of Colorectal Cancer Cells via the STAT3-MMP14 Pathway

The Notch pathway contributes to self-renewal of tumor-initiating cell and inhibition of normal colonic epithelial cell differentiation. Deregulated expression of Notch1 and Jagged1 is observed in colorectal cancer. Hairy/enhancer of split (HES) family, the most characterized targets of Notch, involved in the development of many cancers. In this study, we explored the role of Hes1 in the tumorigenesis of colorectal cancer. Knocking down Hes1 induced CRC cell senescence and decreased the invasion ability, whereas over-expression of Hes1 increased STAT3 phosphorylation activity and up-regulated MMP14 protein level. We further explored the expression of Hes1 in human colorectal cancer and found high Hes1 mRNA expression is associated with poor prognosis in CRC patients. These findings suggest that Hes1 regulates the invasion ability through the STAT3-MMP14 pathway in CRC cells and high Hes1 expression is a predictor of poor prognosis of CRC.

Hepatitis B virus X protein activates Notch signaling by its effects on Notch1 and Notch4 in human hepatocellular carcinoma

Deregulated expression of Notch receptors and abnormal activity of Notch signaling have been observed in a growing number of malignant tumors, however, the expression and activity of Notch in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) and their relationship with HBV X protein (HBx) are still not fully elucidated. To address this, we examined the overall expression of Notch receptors in HBV-associated HCC tissues, analyzed their relationship with HBx, and further investigated the role of Notch signaling in HBx stable transfected HepG2 cells (HepG2X). The results showed that Notch signaling could be activated by HBx in HepG2 cells. The expression of cytoplasmic Notch1 or nuclear Notch4 was correlated with the expression of HBx in HBV-associated HCC tissues. The expression of cytoplasmic Notch1 or nuclear Notch4 could also be upregulated by HBx in HepG2X cells. The upregulation of Notch1 by HBx was through p38 MAPK pathway. Moreover, HBx was found to directly interact with Notch1, whereas, not with Notch4 in HepG2X cells. Suppression of Notch signaling by γ-secretase inhibitor (GSI) decreased cell growth, blocked cell cycle progression and induced cell apoptosis in HepG2X cells. The present study indicates that HBx activates Notch signaling by its effects on Notch1 and Notch4, and therefore, recruits Notch signaling as a downstream pathway contributing to its carcinogenic role in HBV-associated HCC.

Notch3/Jagged1 circuitry reinforces notch signaling and sustains T-ALL

Deregulated Notch signaling has been extensively linked to T-cell acute lymphoblastic leukemia (T-ALL). Here, we show a direct relationship between Notch3 receptor and Jagged1 ligand in human cell lines and in a mouse model of T-ALL. We provide evidence that Notch-specific ligand Jagged1 is a new Notch3 signaling target gene. This essential event justifies an aberrant Notch3/Jagged1 cis-expression inside the same cell. Moreover, we demonstrate in Notch3-IC–overexpressing T lymphoma cells that Jagged1 undergoes a raft-associated constitutive processing. The proteolytic cleavage allows the Jagged1 intracellular domain to empower Notch signaling activity and to increase the transcriptional activation of Jagged1 itself (autocrine effect). On the other hand, the release of the soluble Jagged1 extracellular domain has a positive impact on activating Notch signaling in adjacent cells (paracrine effect), finally giving rise to a Notch3/Jagged1 auto-sustaining loop that supports the survival, proliferation, and invasion of lymphoma cells and contributes to the development and progression of Notch-dependent T-ALL. These observations are also supported by a study conducted on a cohort of patients in which Jagged1 expression is associated to adverse prognosis.

The notch ligand JAGGED1 as a target for anti-tumor therapy

The Notch pathway is increasingly attracting attention as a source of therapeutic targets for cancer. Ligand-induced Notch signaling has been implicated in various aspects of cancer biology; as a consequence, pan-Notch inhibitors and therapeutic antibodies targeting one or more of the Notch receptors have been investigated for cancer therapy. Alternatively, Notch ligands provide attractive options for therapy in cancer treatment due to their more restricted expression and better-defined functions, as well as their low rate of mutations in cancer. One of the Notch ligands, Jagged1 (JAG1), is overexpressed in many cancer types, and plays an important role in several aspects of tumor biology. In fact, JAG1-stimulated Notch activation is directly implicated in tumor growth through maintaining cancer stem cell populations, promoting cell survival, inhibiting apoptosis, and driving cell proliferation and metastasis. In addition, JAG1 can indirectly affect cancer by influencing tumor microenvironment components such as tumor vasculature and immune cell infiltration. This article gives an overview of JAG1 and its role in tumor biology, and its potential as a therapeutic target.

Silencing of Jagged1 inhibits cell growth and invasion in colorectal cancer

Dysregulated Notch signaling has a critical role in the tumorigenesis. Jagged1, a Notch ligand, is overexpressed in various human cancers. Recent studies revealed the involvement of Jagged1 in colorectal cancer (CRC) development. These basic studies provide a promising potential for inhibition of the Notch pathway for the treatment of CRC. Herein, we aimed to investigate the consequences of targeting Jagged1 using shRNA on CRC both in vitro and in vivo to test their potential to inhibit this key element for CRC treatment. We found that downregulation of Jagged1 with lentiviral Jagged1-shRNA resulted in decreased colon cancer cell viability in vitro, most likely mediated through reduced cell proliferation. Importantly, Jagged1 knockdown induced G₀/G₁ phase cell cycle arrest, with reduced Cyclin D1, Cyclin E and c-Myc expression. Silencing of Jagged1 reduced the migration and invasive capacity of the colon cancer cells in vitro. Furthermore, colon cancer cells with knockdown of Jagged1 had much slower growth rate than control cells in a xenograft mouse model in vivo, with a marked downregulation of cell proliferation markers (PCNA, Ki-67, and c-Myc) and metastasis markers (MMP-2 and MMP-9). These findings rationalize a mechanistic approach to CRC treatment based on Jagged1-targeted therapeutic development.

Expression profiling of stem cell signaling alters with spheroid formation in CD133high/CD44high prostate cancer stem cells

Cancer stem cells (CSC) isolated from multiple tumor types differentiate in vivo and in vitro when cultured in serum; however, the factors responsible for their differentiation have not yet been identified. The first aim of the present study was to identify CD133^high/CD44^high DU145 prostate CSCs and compare their profiles with non-CSCs as bulk counterparts of the population. Subsequently, the two populations continued to be three-dimensional multicellular spheroids. Differentiation was then investigated with stem cell-related genomic characteristics. Polymerase chain reaction array analyses of cell cycle regulation, embryonic and mesenchymal cell lineage-related markers, and telomerase reverse transcriptase (TERT) and Notch signaling were performed. Immunohistochemistry of CD117, Notch1, Jagged1, Delta1, Sox2, c-Myc, Oct4, KLF4, CD90 and SSEA1 were determined in CSC and non-CSC monolayer and spheroid subcultures. Significant gene alterations were observed in the CD133^high/CD44^high population when cultured as a monolayer and continued as spheroid. In this group, marked gene upregulation was determined in collagen type 9 α1, Islet1 and cyclin D2. Jagged1, Delta-like 3 and Notch1 were respectively upregulated genes in the Notch signaling pathway. According to immunoreactivity, the staining density of Jagged1, Sox2, Oct4 and Klf-4 increased significantly in CSC spheroids. Isolated CSCs alter their cellular characterization over the course of time and exhibit a differentiation profile while maintaining their former surface antigens at a level of transcription or translation. The current study suggested that this differentiation process may be a mechanism responsible for the malignant process and tumor growth.

Protein expression signatures for inhibition of epidermal growth factor receptor-mediated signaling

Analysis of cellular signaling networks typically involves targeted measurements of phosphorylated protein intermediates. However, phosphoproteomic analyses usually require affinity enrichment of phosphopeptides and can be complicated by artifactual changes in phosphorylation caused by uncontrolled preanalytical variables, particularly in the analysis of tissue specimens. We asked whether changes in protein expression, which are more stable and easily analyzed, could reflect network stimulation and inhibition. We employed this approach to analyze stimulation and inhibition of the epidermal growth factor receptor (EGFR) by EGF and selective EGFR inhibitors. Shotgun analysis of proteomes from proliferating A431 cells, EGF-stimulated cells, and cells co-treated with the EGFR inhibitors cetuximab or gefitinib identified groups of differentially expressed proteins. Comparisons of these protein groups identified 13 proteins whose EGF-induced expression changes were reversed by both EGFR inhibitors. Targeted multiple reaction monitoring analysis verified differential expression of 12 of these proteins, which comprise a candidate EGFR inhibition signature. We then tested these 12 proteins by multiple reaction monitoring analysis in three other models: 1) a comparison of DiFi (EGFR inhibitor-sensitive) and HCT116 (EGFR-insensitive) cell lines, 2) in formalin-fixed, paraffin-embedded mouse xenograft DiFi and HCT116 tumors, and 3) in tissue biopsies from a patient with the gastric hyperproliferative disorder Ménétrier's disease who was treated with cetuximab. Of the proteins in the candidate signature, a core group, including c-Jun, Jagged-1, and Claudin 4, were decreased by EGFR inhibitors in all three models. Although the goal of these studies was not to validate a clinically useful EGFR inhibition signature, the results confirm the hypothesis that clinically used EGFR inhibitors generate characteristic protein expression changes. This work further outlines a prototypical approach to derive and test protein expression signatures for drug action on signaling networks.