Cooperation of Notch and Ras/MAPK signaling pathways in human breast carcinogenesis. Mol Cancer. 2009;8:128. [PMID: 20030805 PMCID: PMC2809056 DOI: 10.1186/1476-4598-8-128]

Dynamic modes of Notch transcription hubs conferring memory and stochastic activation revealed by live imaging the co-activator Mastermind

Developmental programming involves the accurate conversion of signalling levels and dynamics to transcriptional outputs. The transcriptional relay in the Notch pathway relies on nuclear complexes containing the co-activator Mastermind (Mam). By tracking these complexes in real time, we reveal that they promote the formation of a dynamic transcription hub in Notch ON nuclei which concentrates key factors including the Mediator CDK module. The composition of the hub is labile and persists after Notch withdrawal conferring a memory that enables rapid reformation. Surprisingly, only a third of Notch ON hubs progress to a state with nascent transcription, which correlates with polymerase II and core Mediator recruitment. This probability is increased by a second signal. The discovery that target-gene transcription is probabilistic has far-reaching implications because it implies that stochastic differences in Notch pathway output can arise downstream of receptor activation.

Biofunctional study on chemoresistance in esophageal squamous carcinoma cells induced by missense mutation of NOTCH1 p.E450K

Background

Neoadjuvant chemotherapy (nCT) combined with surgery is one of the main strategies for the treatment of resectable locally advanced esophageal squamous cell carcinoma (ESCC). However, nearly 40% of patients did not benefit from nCT, and the detection rate of NOTCH1 missense mutation was significantly increased in patients who did not respond to chemotherapy, suggesting that the missense mutation may be related to tumor chemoresistance. We aim to explore the effect of a NOTCH1 missense mutation on cell phenotype, to interpret the biofunctional changes in cell lines with a NOTCH1 missense mutation and to analyze the effect of a NOTCH1 missense mutation on drug resistance in ESCC cell lines.

Methods

Sanger sequencing was used to evaluate the exon mutations in the NOTCH1 ligand binding region of candidate ESCC cell lines. After screening, KYSE450 and KYSE140 cells were selected as the research objects, and point mutation cell lines [KYSE140-mutant-type (MT) and KYSE450-MT] were constructed by CRISPR/Cas9 technology. Then, functional experiments were performed with the four cell lines [KYSE450-MT/wild-type (WT) and KYSE140-MT/WT]. The drug resistance of ESCC cell lines was assessed with a drug sensitivity test, and the proliferation, invasion and migration of ESCC lines were evaluated by proliferation test, scratch test and Transwell test. The cell cycle status of ESCC cells was assessed using flow cytometry.

Results

Drug sensitivity tests showed that the NOTCH1 p.E450K point mutation caused chemotherapy resistance in KYSE140 and KYSE450 ESCC cell lines. Cell proliferation, Wound scratch and Transwell assays showed that the NOTCH1 p.E450K point mutation enhanced the proliferation, invasion and migration abilities of KYSE140 and KYSE450 cells. Flow cytometry analysis showed that the NOTCH1 p.E450K point mutation caused an increase in KYSE140 and KYSE450 cells in S phase.

Conclusions

The NOTCH1 p.E450K point mutation causes chemotherapy resistance in KYSE140 and KYSE450 ESCC cells. Cell functional experiments showed that the NOTCH1 p.E450K point mutation enhanced the proliferation, migration and invasion abilities of KYSE140 and KYSE450 cells and increased the number of cells in S phase.

Regulation of the Notch signaling pathway by natural products for cancer therapy

The Notch signaling pathway is an evolutionarily conserved pathway that modulates normal biological processes involved in cellular differentiation, apoptosis, and stem cell self-renewal in a context-dependent fashion. Attributed to its pleiotropic physiological roles, both overexpression and silencing of the pathway are associated with the emergence, progression, and poorer prognosis in various types of cancer. To decrease disease incidence and promote survival, targeting Notch may have chemopreventive and anti-cancer effects. Natural products with profound historical origins have distinguished themselves from other therapies due to their easy access, high biological compatibility, low toxicity, and reliable effects at specific physiological sites in vivo. This review describes the Notch signaling pathway, particularly its normal activation process, and some main illnesses related to Notch signaling pathway dysregulation. Emphasis is placed on the effects and mechanisms of natural products targeting the Notch signaling pathway in diverse cancer types, including curcumin, ellagic acid (EA), resveratrol, genistein, epigallocatechin-3-gallate (EGCG), quercetin, and xanthohumol and so on. Existing evidence indicates that natural products are feasible solution to fight against cancer by targeting Notch signaling, either alone or in combination with current therapeutic agents.

BTB protein family and human breast cancer: signaling pathways and clinical progress

BACKGROUND

Breast cancer is considered the number one killer of women both in China and abroad, and the leading cause of cancer death. It severely affects female health-related quality of life. Broad-complex, tramtrack, bric à brac (BTB) protein family was first discovered in drosophila as early as in 1993 by Godt D and peers, since then, more family members and their critical biological functions were uncovered. Moreover, researchers around the world have recently demonstrated that numerous signaling pathways connect BTB family members and human breast cancer.

PURPOSE

In this review, we critically discuss these findings regarding the essential mechanisms and functions of the BTB protein family in mediating the organic processes of human breast cancer. Meanwhile, we summarize the signaling pathways the BTB protein family participates in. And we address that BTB proteins regulate the growth, apoptosis, and other behaviors of breast cancer cells. We also point out the future directions for further studies in this field.

METHODS

The relevant online literatures have been reviewed for this article.

CONCLUSION

This review could offer an update on novel molecular targets for treating human breast cancer and new insights into BTB protein family research.

γ-Secretase fanning the fire of innate immunity

Innate immunity is the first line of defense against pathogens, alerting the individual cell and surrounding area to respond to this potential invasion. γ-secretase is a transmembrane protease complex that plays an intricate role in nearly every stage of this innate immune response. Through regulation of pattern recognition receptors (PRR) such as TREM2 and RAGE γ-secretase can modulate pathogen recognition. γ-secretase can act on cytokine receptors such as IFNαR2 and CSF1R to dampen their signaling capacity. While γ-secretase-mediated regulated intramembrane proteolysis (RIP) can further moderate innate immune responses through downstream signaling pathways. Furthermore, γ-secretase has also been shown to be regulated by the innate immune system through cytokine signaling and γ-secretase modulatory proteins such as IFITM3 and Hif-1α. This review article gives an overview of how γ-secretase is implicated in innate immunity and the maintenance of its responses through potentially positive and negative feedback loops.

Deletion of Notch1 during Cochlear Maturation Leads to Rapid Supporting Cell Death and Profound Deafness

The sensory region of the mammalian hearing organ contains two main cell types-hair cells and supporting cells. During development, Notch signaling plays an important role in whether a cell becomes either a hair cell or supporting cell by mediating lateral inhibition. However, once the cell fate decisions have been determined, little is understood about the role Notch plays in cochlear maturation. Here, we report that deletion of Notch1 from the early postnatal mouse cochlea in both male and female animals resulted in profound deafness at 6 weeks of age. Histologic analyses at 6 weeks revealed significant hair cell and supporting cell loss throughout the Notch1-deficient cochlea. Early analyses revealed a reduction in supporting cells in the outer hair cell region between postnatal day (P) 2 and P6, without a comparable increase in outer hair cell number, suggesting a mechanism other than lateral inhibition. Consistent with this, we found apoptotic cells in the outer supporting cell region of the cochlea at P1 and P2, indicating that Notch1 is required for outer supporting cell survival during early cochlear maturation. Interestingly, inner supporting cell types were not lost after Notch1 deletion. Surprisingly, we do not detect outer hair cell loss in Notch1 mutants until after the onset of hearing, around P14, suggesting that hair cell loss is caused by loss of the supporting cells. Together, these results demonstrate that Notch1 is required for supporting cell survival during early maturation and that loss of these cells causes later loss of the hair cells and cochlear dysfunction.SIGNIFICANCE STATEMENT During development, Notch signaling has been shown to be critical in regulating the cell fate choices between hair cells and supporting cells. However, little is known about how Notch functions after those cell fate choices are made. Here, we examine the role of Notch1 in the maturing cochlea. We demonstrate that deletion of Notch1 results in profound deafness by 6 weeks of age. Histologic analyses revealed rapid supporting cell death shortly after Notch1 deletion, followed by eventual loss of the hair cells. These results reveal an unexpected role for Notch in supporting cell survival during cochlear maturation.

Notch signaling pathway: a comprehensive prognostic and gene expression profile analysis in breast cancer

Breast cancer is a complex disease exhibiting a great degree of heterogeneity due to different molecular subtypes. Notch signaling regulates the differentiation of breast epithelial cells during normal development and plays a crucial role in breast cancer progression through the abnormal expression of the Notch up-and down-stream effectors. To date, there are only a few patient-centered clinical studies using datasets characterizing the role of Notch signaling pathway regulators in breast cancer; thus, we investigate the role and functionality of these factors in different subtypes using publicly available databases containing records from large studies. High-throughput genomic data and clinical information extracted from TCGA were analyzed. We performed Kaplan-Meier survival and differential gene expression analyses using the HALLMARK_NOTCH_SIGNALING gene set. To determine if epigenetic regulation of the Notch regulators contributes to their expression, we analyzed methylation levels of these factors using the TCGA HumanMethylation450 Array data. Notch receptors and ligands expression is generally associated with the tumor subtype, grade, and stage. Furthermore, we showed gene expression levels of most Notch factors were associated with DNA methylation rate. Modulating the expression levels of Notch receptors and effectors can be a potential therapeutic approach for breast cancer. As we outline herein, elucidating the novel prognostic and regulatory roles of Notch implicate this pathway as an essential mediator controlling breast cancer progression.

ADAMTS9-AS1 Long Non‑coding RNA Sponges miR‑128 and miR-150 to Regulate Ras/MAPK Signaling Pathway in Glioma

Glioma is a malignancy of the central nervous system with a poor prognosis. Therefore, the elaboration of its molecular features creates therapeutic opportunities. Looking for the regulatory non-coding RNAs (lncRNAs and miRNAs) that are involved in glioma incidence/progression, RNA-seq analysis introduced upregulated ADAMTS9-AS1 as a bona fide candidate that sponges miR-128 and miR-150 and shows the negative correlation of expression with them. Then, RT-qPCR verified the upregulation of ADAMTS9-AS1 in glioma tissues and cell lines. Furthermore, dual-luciferase assay supported that cytoplasmic ADAMTS9-AS1 is capable of sponging miR-128 and miR-150, which are known as regulators of Ras/MAPK, PI3K, and Wnt pathways. Following the overexpression of ADAMTS9-AS1 in 1321N1 and U87 glioma cells, tyrosine kinase receptors (IGF1R and TrkC), as well as Wnt receptors (Lrp6 and Fzd) were upregulated, detected by RT-qPCR. Furthermore, downstream genes of both Ras/MAPK and Wnt pathways were upregulated. Finally following the ADAMTS9-AS1 overexpression, upregulation of Ras/MAPK and Wnt signaling pathways was verified through western blotting and Top/Fop flash assay, respectively. At the cellular level, ADAMTS9-AS1 overexpression brought about reduced sub-G1 cell population, increased proliferation rate, reduced apoptosis level, increased migration rate, shortened Bax/Bcl2 ratio, induced EMT, and stemness characteristics of transfected cells, detected by flow cytometry, MTT assay, scratch test, and RT-qPCR. Overall, these results introduced ADAMTS9-AS1 as an oncogene that upregulates Ras/MAPK and Wnt pathways through sponging of the miR-128 and miR-150 in glioma cells. The outcome of ADAMTS9-AS1 expression is more aggression of the glioma cells through increased EMT and stemness characteristics. These features candidate ADAMTS9-AS1 locus for glioma therapy. As a result, we discovered the oncogenic properties of ADAMTS9-AS1 in glioma cancer. It sponges miR-128 and miR-150 and subsequently overstimulates RAS/MAPK and Wnt signaling pathways, particularly at the receptors level. Thus, ADAMTS9-AS1 increases proliferation, migration, and stemness in glioma cell lines. A schematic representation showing the functional effect of ADAMTS9-AS1.

The effect of Nrf2 deletion on the proteomic signature in a human colorectal cancer cell line

Background

Colorectal cancer is one of the most common cancer and the third leading cause of death worldwide. Increased generation of reactive oxygen species (ROS) is observed in many types of cancer cells. Several studies have reported that an increase in ROS production could affect the expression of proteins involved in ROS-scavenging, detoxification and drug resistance. Nuclear factor erythroid 2 related factor 2 (Nrf₂) is a known transcription factor for cellular response to oxidative stress. Several researches exhibited that Nrf₂ could exert multiple functions and expected to be a promising therapeutic target in many cancers. Here, Nrf₂ was knocked down in colorectal cancer cell line HT29 and changes that occurred in signaling pathways and survival mechanisms were evaluated.

Methods

The influence of chemotherapy drugs (doxorubicin and cisplatin), metastasis and cell viability were investigated. To explore the association between specific pathways and viability in HT29-Nrf₂⁻, proteomic analysis, realtime PCR and western blotting were performed.

Results

In the absence of Nrf₂ (Nrf₂⁻), ROS scavenging and detoxification potential were dramatically faded and the HT29-Nrf₂⁻ cells became more susceptible to drugs. However, a severe decrease in viability was not observed. Bioinformatic analysis of proteomic data revealed that in Nrf₂⁻ cells, proteins involved in detoxification processes, respiratory electron transport chain and mitochondrial-related compartment were down regulated. Furthermore, proteins related to MAPKs, JNK and FOXO pathways were up regulated that possibly helped to overcome the detrimental effect of excessive ROS production.

Conclusions

Our results revealed MAPKs, JNK and FOXO pathways connections in reducing the deleterious effect of Nrf₂ deficiency, which can be considered in cancer therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10055-y.

Effects of mRNA expression of five Notch ligands on prognosis of gastric carcinoma

Notch ligands are expression changes in a great many malignancies including gastric cancer (GC) frequently. The prognostic value of each Notch ligands in GC patients remains lack of large sample data results. In present research, we researched the prognostic value of Notch ligands in GC patients in order to fill the shortage areas. We used an online database ( http://kmplot.com/analysis/index.php?p=service&cancer=gastric ) to identify the relationship between mRNA expression of each Notch ligand and overall survival (OS) in GC. We analyze the relevance of overall survival and clinical data which includes gender, Lauren's classification, differentiation, clinical stage and treatment. The study found that high DLL1, DLL3, DLL4 and JAG2 mRNA expression were tied to worse OS in all GC patients followed up for 10 years. There is no significant relevance to the expression of JAG1 mRNA and OS in patients with GC. We also did a survey of each Notch ligands in different clinical and pathological features present different prognosis. The information will help to better understand the biology of gastric cancer heterogeneity, provide more accurate prognostic evaluation tools and provide new targets for targeted drug development besides.

The Notch Signaling Pathway Contributes to Angiogenesis and Tumor Immunity in Breast Cancer

Breast cancer in women is the first leading tumor in terms of incidence worldwide. Some subtypes of BC lack distinct molecular targets and exhibit therapeutic resistance; these patients have a poor prognosis. Thus, the search for new molecular targets is an ongoing challenge for BC therapy. The Notch signaling pathway is found in both vertebrates and invertebrates, and it is a highly conserved in the evolution of the species, controlling cellular fates such as death, proliferation, and differentiation. Numerous studies have shown that improper activation of Notch signaling may lead to excessive cell proliferation and cancer, with tumor-promoting and tumor-suppressive effects in various carcinomas. Thus, inhibitors of Notch signaling are actively being investigated for the treatment of various tumors. The role of Notch signaling in BC has been widely studied in recent years. There is a growing body of evidence suggesting that Notch signaling has a pro-oncogenic role in BC, and the tumor-promoting effect is largely a result of the diverse nature of tumor immunity. Immunological abnormality is also a factor involved in the pathogenesis of BC, suggesting that Notch signaling could be a target for BC immunotherapies. Furthermore, angiogenesis is essential for BC growth and metastasis, and the Notch signaling pathway has been implicated in angiogenesis, so studying the role of Notch signaling in BC angiogenesis will provide new prospects for the treatment of BC. We summarize the potential roles of the current Notch signaling pathway and its inhibitors in BC angiogenesis and the immune response in this review and describe the pharmacological targets of Notch signaling in BC, which may serve as a theoretical foundation for future research into exploring this pathway for novel BC therapies.

HSP90 N-terminal inhibitors target oncoprotein MORC2 for autophagic degradation and suppress MORC2-driven breast cancer progression

Aims

MORC family CW‐type zinc finger 2 (MORC2), a GHKL‐type ATPase, is aberrantly upregulated in multiple types of human tumors with profound effects on cancer aggressiveness, therapeutic resistance, and clinical outcome, thus making it an attractive drug target for anticancer therapy. However, the antagonists of MORC2 have not yet been documented.

Methods and Results

We report that MORC2 is a relatively stable protein, and the N‐terminal homodimerization but not ATP binding and hydrolysis is crucial for its stability through immunoblotting analysis and Quantitative real‐time PCR. The N‐terminal but not C‐terminal inhibitors of heat shock protein 90 (HSP90) destabilize MORC2 in multiple cancer cell lines, and strikingly, this process is independent on HSP90. Mechanistical investigations revealed that HSP90 N‐terminal inhibitors disrupt MORC2 homodimer formation without affecting its ATPase activities, and promote its lysosomal degradation through the chaperone‐mediated autophagy pathway. Consequently, HSP90 inhibitor 17‐AAG effectively blocks the growth and metastatic potential of MORC2‐expressing breast cancer cells both in vitro and in vivo, and these noted effects are not due to HSP90 inhibition.

Conclusion

We uncover a previously unknown role for HSP90 N‐terminal inhibitors in promoting MORC2 degradation in a HSP90‐indepentent manner and support the potential application of these inhibitors for treating MORC2‐overexpressing tumors, even those with low or absent HSP90 expression. These results also provide new clue for further design of novel small‐molecule inhibitors of MORC2 for anticancer therapeutic application.

Modulation of Notch Signaling Pathway by Bioactive Dietary Agents

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

Understanding the Notch Signaling Pathway in Acute Myeloid Leukemia Stem Cells: From Hematopoiesis to Neoplasia

The Notch signaling pathway is fundamental to early fetal development, but its role in acute myeloid leukemia is still unclear. It is important to elucidate the function that contains Notch, not only in acute myeloid leukemia, but in leukemic stem cells (LSCs). LSCs seem to be the principal cause of patient relapse. This population is in a quiescent state. Signaling pathways that govern this process must be understood to increase the chemosensitivity of this compartment. In this review, we focus on the conserved Notch signaling pathway, and its repercussions in hematopoiesis and hematological neoplasia. We found in the literature both visions regarding Notch activity in acute myeloid leukemia. On one hand, the activation of Notch leads to cell proliferation, on the other hand, the activation of Notch leads to cell cycle arrest. This dilemma requires further experiments to be answered, in order to understand the role of Notch not only in acute myeloid leukemia, but especially in LSCs.

Abnormal activation of notch 1 signaling causes apoptosis resistance in cervical cancer

Notch1 signaling pathway is an evolutionarily conserved and crucial regulator to determine cell fate and differentiation. Notch1 is often over expressed in several cancers, which plays an essential for cancer cell proliferation, survival, invasion and metastasis. The oncogenic function of Notch1 signaling in cervical cancer progression is not well-characterized. In the present study, we showed that Notch1 is significantly enhanced in cervical cancer tissues. Similarly, the relative mRNA and expression of Notch1 protein are significantly upregulated in cervical cancer cell lines such as HeLa and SiHa. Further, we have performed RNAi for NOTCH1 depletion to determine its specific role in cervical cancer progression. Flow cytometry analysis revealed that NOTCH1 depletion leads to activation of apoptotic cell death in cervical cancer. Further, the NOTCH1 depleted cells showed increased sensitivity towards DNA-targeting drugs and therefore cell viability was reduced efficiently. Altogether, our findings suggest that Notch1 overexpression in cervical cancer cells was involved in tumorigenesis and apoptosis resistance of cervical cancer.

Enzalutamide-Resistant Progression of Castration-Resistant Prostate Cancer Is Driven via the JAK2/STAT1-Dependent Pathway

Previous studies showed that CXCR7 expression was upregulated after enzalutamide (ENZ) treatment, and an increased level of CXCR7 could increase the invasion, migration, and angiogenesis of castration-resistant prostate cancer (CRPC) cells. This study demonstrated that the levels of p-JAK2, p-STAT1, C-Myc, and VEGFR2 were significantly reduced after CCX771, a specific CXCR7 inhibitor, treatment. This effect further increased after the combination treatment of ENZ and CCX771. Then, we verified that targeting the inhibition of JAK2 or STAT1 could remarkably increase apoptosis and DNA damage and decrease the migration of CRPC cells. More importantly, the combination treatment of ENZ + JAK2/STAT1 led to much greater suppression than the single-agent treatment of JAK2 or STAT1. Subcutaneous CRPC xenograft tumor growth was also reduced by single-agent ENZ treatment and single-agent FLUD, a specific STAT1 antagonist, treatment; but much superior effect was elicited by the combination treatment of ENZ + FLUD. The proliferative indices significantly decreased following combination treatment in tumor tissues compared with control-treatment tissues and single-agent-treatment tissues. Our results demonstrated that CXCR7, which signifies an androgen receptor (AR)-independent signaling pathway, caused CRPC progression via the downstream JAK2/STAT1 signal transduction cascade. Combined inhibition targeting both the AR and JAK2/STAT1 resulted in substantial tumor suppression due to the reduction in DNA damage repair ability and increment in apoptosis.

Combination therapy with miR34a and doxorubicin synergistically inhibits Dox-resistant breast cancer progression via down-regulation of Snail through suppressing Notch/NF-κB and RAS/RAF/MEK/ERK signaling pathway

Resistance to breast cancer (BCa) chemotherapy severely hampers the patient's prognosis. MicroRNAs provide a potential therapeutic prospect for BCa. In this study, the reversal function of microRNA34a (miR34a) on doxorubicin (Dox) resistance of BCa and the possible mechanism was investigated. We found that the relative level of miR34a was significantly decreased in Dox-resistant breast cancer cell MCF-7 (MCF-7/A) compared with Dox-sensitive MCF-7 cells. Transfection with miR34a significantly suppressed the invasion, migration, adhesion of MCF-7/A cells without inhibiting their growth obviously. The combination of miR34a and Dox could significantly inhibit the proliferation, migration, invasion and induce the apoptosis of MCF-7/A cells. The synergistic effect of this combination on resistant MCF-7/A cells has no obvious relation with the expressions of classical drug-resistant proteins P-GP, MRP and GST-π, while closely related with the down-regulation on TOP2A and BCRP. Moreover, we found both protein and mRNA expression of Snail were significantly up-regulated in MCF-7/A cells in comparison with MCF-7 cells. Transfection with small interfering RNA (siRNA) of Snail could inhibit the invasion, migration and adhesion of drug-resistant MCF-7/A cells, while high-expression of Snail could remarkably promote the invasion, migration and adhesion of MCF-7 cells, which might be related with regulation of N-cadherin and E-cadherin. Transfection with miR34a in MCF-7/A cells induced a decrease of Snail expression. The potential binding sites of miR34a with 3' UTR of Snail were predicted by miRDB target prediction software, which was confirmed by luciferase reporter gene method. Results showed that the relative activity of luciferase was reduced in MCF-7/A cells after co-transfection of miR34a and wild type (wt)-Snail, while did not change by co-transfection with miR34a and 3' UTR mutant type (mut) Snail. Combination of miR34a and Dox induced a stronger decrease of Snail in MCF-7/A cells in comparison to miR34a or Dox treatment alone. What' more, for the first time, we also found miR34a combined with Dox could obviously inhibit the expression of Snail through suppressing Notch/NF-κB and RAS/RAF/MEK/ERK pathway in MCF-7/A cells. In vivo study indicated that combination of miR34a and Dox significantly slowed down tumor growth in MCF-7/A nude mouse xenograft model compared with Dox alone, which was manifested by the down-regulation of Snail and pro-apoptosis effect in tumor xenografts. These results together underline the relevance of miR34a-driven regulation of Snail in drug resistance and co-administration of miR34a and Dox may produce an effective therapy outcome in the future in clinic.

Overexpression of CXCR7 is a Novel Indicator for Enzalutamide Resistance in Castration-Resistant Prostate Cancer Patients

Background

To evaluate whether the overexpression of chemokine receptor-7 (CXCR7) in prostatic tissues obtained from men with Castration-Resistant Prostate Cancer (CRPC) is associated with resistance to enzalutamide (Enza).

Methods

Based on the inclusion criteria of CRPC in EAU guidelines, all eligible patients treated in our hospital from January 2015 to December 2019 were included. Cases underwent radical prostatectomy, docetaxel-based chemotherapy, or new endocrine therapies (including Enza or abiraterone), and cases with severe cardiopulmonary disease or other malignant tumors were excluded. After immunohistochemical staining for CXCR7 expression in prostatic biopsy tissues, all enrolled cases were divided into two groups, namely, the CXCR7-positive group and the CXCR7-negative group. And then, PSA response to Enza treatment was recorded in detail and comparatively analyzed. In addition, the Cox proportional hazard modeling and the Kaplan-Meier analysis were used to determine PSA progression-free survival (PSAP-FS) and clinical or radiographic progression-free survival (CRP-FS) in this cohort.

Results

A total of 79 CRPC individuals were enrolled and evaluated in this study. Median follow-up durations were 24 months (range, 12-42) in the CXCR7-positive group (n = 47) and 28.5 months (range, 12-42) in the CXCR7-negative group (n = 32). The patients with lower CXCR7 expression showed much better PSA response to Enza treatment. There was 84.4% of CXCR7- cases showing decreasing PSA response, while there were 71.4% in the CXCR7/1+ group and 31.2% in the CXCR7/2+ group, respectively. All patients in the CXCR7/3+ group showed increasing PSA response to Enza treatment. And the percentage of patients whose PSA decreased over 50% is significantly higher in the CXCR7-negative group than in the CXCR7-positive group (68.8% vs. 8.5%, P < 0.001), and the percentage of patients whose PSA decreased over 90% is also remarkably higher in the CXCR7-negative group (43.8% vs. 0, P < 0.001). The Kaplan-Meier analysis demonstrated that the oncologic outcomes of CXCR7-negative patients were improved much significantly by Enza treatment in comparison with those of CXCR7-positive patients. Significantly increased median PSAP-FS (21 months vs. 6 months, P < 0.0001) and CRP-FS (27 months vs. 9 months, P < 0.0001) were obtained in the CXCR7-negative group. The further stratified analysis in all CXCR7-positive patients demonstrated that the patients with higher CXCR7 expression showed much worse outcome. The median time of PSAP-FS was 21 months in the CXCR7/1+ group, 9 months in the CXCR7/2+ group, and 6 months in the CXCR7/3+ group, while the median time of CRP-FS was 21 months in the CXCR7/1+ group, 12 months in the CXCR7/2+ group, and 6 months in the CXCR7/3+ group, respectively.

Conclusion

Overexpression of CXCR7 induced by an AR antagonist in CRPC patients displays much better treatment response to Enza. CXCR7 might be a novel therapeutic target gene for CRPC patients.

Development of Dl1.72, a Novel Anti-DLL1 Antibody with Anti-Tumor Efficacy against Estrogen Receptor-Positive Breast Cancer

Simple Summary

Over 70% of breast cancers (BCs) are estrogen receptor-positive (ER⁺). The development of endocrine therapy has considerably improved patient outcomes. However, there is a clinical need for novel effective therapies against ER⁺ BCs, since many of these do not respond to standard therapy, and more than one-third of responders acquire resistance, experience relapse and metastasize. The Notch ligand Delta-like 1 (DLL1) is a key player in ER⁺ BC development and aggressiveness. Contrary to complete Notch pharmacological inhibitors, antibody-targeting of individual Notch components is expected to have superior therapeutic efficacy and be better tolerated. In this study, we developed and characterized a novel specific anti-DLL1 antibody with efficacy in inhibiting BC cell proliferation, mammosphere formation and angiogenesis, as well as anti-tumor and anti-metastatic efficacy in an ER⁺ BC mouse model without side effects. Thus, our data suggest that this anti-DLL1 antibody is a promising candidate for ER⁺ BC treatment.

Abstract

The Notch-signaling ligand DLL1 has emerged as an important player and promising therapeutic target in breast cancer (BC). DLL1-induced Notch activation promotes tumor cell proliferation, survival, migration, angiogenesis and BC stem cell maintenance. In BC, DLL1 overexpression is associated with poor prognosis, particularly in estrogen receptor-positive (ER⁺) subtypes. Directed therapy in early and advanced BC has dramatically changed the natural course of ER⁺ BC; however, relapse is a major clinical issue, and new therapeutic strategies are needed. Here, we report the development and characterization of a novel monoclonal antibody specific to DLL1. Using phage display technology, we selected an anti-DLL1 antibody fragment, which was converted into a full human IgG1 (Dl1.72). The Dl1.72 antibody exhibited DLL1 specificity and affinity in the low nanomolar range and significantly impaired DLL1-Notch signaling and expression of Notch target genes in ER⁺ BC cells. Functionally, in vitro treatment with Dl1.72 reduced MCF-7 cell proliferation, migration, mammosphere formation and endothelial tube formation. In vivo, Dl1.72 significantly inhibited tumor growth, reducing both tumor cell proliferation and liver metastases in a xenograft mouse model, without apparent toxicity. These findings suggest that anti-DLL1 Dl1.72 could be an attractive agent against ER⁺ BC, warranting further preclinical investigation.

From late fatherhood to prenatal screening of monogenic disorders: evidence and ethical concerns

BACKGROUND

With the help of ART, an advanced parental age is not considered to be a serious obstacle for reproduction anymore. However, significant health risks for future offspring hide behind the success of reproductive medicine for the treatment of reduced fertility associated with late parenthood. Although an advanced maternal age is a well-known risk factor for poor reproductive outcomes, understanding the impact of an advanced paternal age on offspring is yet to be elucidated. De novo monogenic disorders (MDs) are highly associated with late fatherhood. MDs are one of the major sources of paediatric morbidity and mortality, causing significant socioeconomic and psychological burdens to society. Although individually rare, the combined prevalence of these disorders is as high as that of chromosomal aneuploidies, indicating the increasing need for prenatal screening. With the help of advanced reproductive technologies, families with late paternity have the option of non-invasive prenatal testing (NIPT) for multiple MDs (MD-NIPT), which has a sensitivity and specificity of almost 100%.

OBJECTIVE AND RATIONALE

The main aims of the current review were to examine the effect of late paternity on the origin and nature of MDs, to highlight the role of NIPT for the detection of a variety of paternal age-associated MDs, to describe clinical experiences and to reflect on the ethical concerns surrounding the topic of late paternity and MD-NIPT.

SEARCH METHODS

An extensive search of peer-reviewed publications (1980-2021) in English from the PubMed and Google Scholar databases was based on key words in different combinations: late paternity, paternal age, spermatogenesis, selfish spermatogonial selection, paternal age effect, de novo mutations (DNMs), MDs, NIPT, ethics of late fatherhood, prenatal testing and paternal rights.

OUTCOMES

An advanced paternal age provokes the accumulation of DNMs, which arise in continuously dividing germline cells. A subset of DNMs, owing to their effect on the rat sarcoma virus protein-mitogen-activated protein kinase signalling pathway, becomes beneficial for spermatogonia, causing selfish spermatogonial selection and outgrowth, and in some rare cases may lead to spermatocytic seminoma later in life. In the offspring, these selfish DNMs cause paternal age effect (PAE) disorders with a severe and even life-threatening phenotype. The increasing tendency for late paternity and the subsequent high risk of PAE disorders indicate an increased need for a safe and reliable detection procedure, such as MD-NIPT. The MD-NIPT approach has the capacity to provide safe screening for pregnancies at risk of PAE disorders and MDs, which constitute up to 20% of all pregnancies. The primary risks include pregnancies with a paternal age over 40 years, a previous history of an affected pregnancy/child, and/or congenital anomalies detected by routine ultrasonography. The implementation of NIPT-based screening would support the early diagnosis and management needed in cases of affected pregnancy. However, the benefits of MD-NIPT need to be balanced with the ethical challenges associated with the introduction of such an approach into routine clinical practice, namely concerns regarding reproductive autonomy, informed consent, potential disability discrimination, paternal rights and PAE-associated issues, equity and justice in accessing services, and counselling.

WIDER IMPLICATIONS

Considering the increasing parental age and risks of MDs, combined NIPT for chromosomal aneuploidies and microdeletion syndromes as well as tests for MDs might become a part of routine pregnancy management in the near future. Moreover, the ethical challenges associated with the introduction of MD-NIPT into routine clinical practice need to be carefully evaluated. Furthermore, more focus and attention should be directed towards the ethics of late paternity, paternal rights and paternal genetic guilt associated with pregnancies affected with PAE MDs.

Long-non-coding RNA RUSC1-AS1 accelerates osteosarcoma development by miR-101-3p-mediated Notch1 signalling pathway

Background

Long non-coding RNA (lncRNA) RUSC1-AS1 has been found to modulate several cancers development. In this study, we explored the role of RUSC1-AS1 on osteosarcoma (OS) progression.

Methods

Quantitative Real-time PCR (qRT-PCR) was conducted to test the relative expression of RUSC1-AS1, Notch1 mRNA and miR-101-3p in OS tissues and adjacent normal tissues. Gain- or loss- of functional assays were carried out to determine the roles of RUSC1-AS1 and miR-101-3p in OS progression both in vitro and in vivo. The expression of E-cadherin, N-cadherin, Vimentin, Snail, Notch1, Ras and ERK was determined by Western blot. Furthermore, the relationships between RUSC1-AS1 and miR-101-3p, Notch1 and miR-101-3p were confirmed through RNA immunoprecipitation (RIP) and dual luciferase reporter gene assay.

Results

RUSC1-AS1 and Notch1 were up-regulated in OS cells and tissues. Down-regulating RUSC1-AS1 significantly attenuated the proliferative, epithelial-mesenchymal transition (EMT), growth, lung metastasis, migrative and invasive abilities of MG-63 and Saos-2 cells, and aggravated apoptosis, accompanied with down-regulated Notch1-Ras-ERK1/2 in those cells both in vitro and in vivo, while overexpression of RUSC1-AS1 exerted opposite effects. Overexpressing miR-101-3p in OS cells had similar effects as RUSC1-AS1 inhibition. In addition, RUSC1-AS1 functioned as a competing endogenous RNA (ceRNA) to competitively sponge miR-101-3p, thus upregulating Notch1 expression and mediating the malignant behaviors of OS cells.

Conclusion

RUSC1-AS1 is a novel oncogenic lncRNA in OS through the miR-101-3p-Notch1-Ras-ERK pathway, which might be a potential therapeutic target for OS.

The expression of miR-513c and miR-3163 was downregulated in tumor tissues compared with normal adjacent tissue of patients with breast cancer

BACKGROUND

Breast cancer (BC) is the most invasive cancer with different subtypes that its metabolism is unique compared with normal cells. Glutamine is considered critical nutrition that many cancer cells, particularly BC cells, are dependent on it for growth and proliferation. Therefore, targeting glutamine metabolism, especially enzymes that are related to this pathway, can be beneficial to design anti-cancer agents. Recent evidence has shown that microRNAs (miRNAs), with a short length and single-strand properties, play a prominent role in regulating the genes related to glutamine metabolism, which may control the development of cancer.

METHODS

In silico analysis confirmed that miR-513c and miR-3163 might be involved in glutamine metabolism. The expression level of these two miRNAs was evaluated in eighty BC tissues and normal adjacent tissues. Furthermore, GSE38167, GSE38867, GSE42128, GSE45666, and GSE53179 were employed from gene expression omnibus (GEO). The Limma package was utilized to identify differentially expressed miRNAs (DEMs) of mentioned datasets to evaluate miR-513c and miR-3163 expression. Further, in silico analysis was utilized to predict the potential biological processes and molecular pathways of miR-513c and miR-3163, based on their target genes.

RESULTS

In silico studies revealed top categories of biological processes and cellular pathways that might play a critical role in metabolism reprogramming and cancer development and were target genes for miR-513c and miR-3163. The current study showed that miR-513c (p value = 0.02062 and FC =  - 2.3801) and miR-3163 (p value = 0.02034 and FC =  - 2.3792) were downregulated in tumor tissues compared to normal adjacent tissues. The analysis of GEO microarray datasets showed that miR-513c was downregulated in GSE38167, GSE38867, GSE42128, GSE45666 and GSE53179, whereas there was a significant downregulation of miR-3163 in only two studies, including GSE38867 and GSE42128 that they were in accordance with our experimental results. Furthermore, the subgroup analysis did not show any substantial relationship between expression levels of these two miRNAs and factors such as age, family history of cancer, and abortion history.

CONCLUSION

MiR-513c and miR-3163 were downregulated in BC tissues, which might serve as tumor suppressors. They are suggested as potential therapeutic targets for patients with BC.

Notch Signalling in Breast Development and Cancer

The Notch signalling pathway is a highly conserved developmental signalling pathway, with vital roles in determining cell fate during embryonic development and tissue homeostasis. Aberrant Notch signalling has been implicated in many disease pathologies, including cancer. In this review, we will outline the mechanism and regulation of the Notch signalling pathway. We will also outline the role Notch signalling plays in normal mammary gland development and how Notch signalling is implicated in breast cancer tumorigenesis and progression. We will cover how Notch signalling controls several different hallmarks of cancer within epithelial cells with sections focussed on its roles in proliferation, apoptosis, invasion, and metastasis. We will provide evidence for Notch signalling in the breast cancer stem cell phenotype, which also has implications for therapy resistance and disease relapse in breast cancer patients. Finally, we will summarise the developments in therapeutic targeting of Notch signalling, and the pros and cons of this approach for the treatment of breast cancer.

Gastrodin Attenuates Lipopolysaccharide-Induced Inflammatory Response and Migration via the Notch-1 Signaling Pathway in Activated Microglia

Microglia-mediated neuroinflammation is known to play a pivotal role in the pathogenesis of different neurological diseases. Gastrodin, a phenolic glucoside, has been reported to exert anti-inflammatory effects in activated microglia challenged with lipopolysaccharide (LPS); however, the underlying mechanism has remained obscure. The present study aimed to ascertain if Gastrodin would regulate the Notch signaling pathway involved in microglia activation. We show here that LPS increased the expression of various members of the Notch-1 pathway, including intracellular Notch receptor domain (NICD), recombining binding protein suppressor of hairless (RBP-Jκ) and transcription factor hairy and enhancer of split-1 (Hes-1) in microglia in postnatal rat brain and in BV-2 microglia. Remarkably, Gastrodin was found to markedly attenuate the expression of the above various biomarkers both in vivo and in vitro. Moreover, increased phosphorylation level of ERK, JNK and P38 induced by LPS was attenuated with pretreatment of Notch-1 signaling inhibitor, N-[N-(3,5-difluorophenacetyl)-1-alany1-Sphenyglycinet-butylester (DAPT) as well as Gastrodin. Gastrodin mimicked the effects of DAPT by inhibiting the LPS-induced expression of IL-1β, IL-6, IL-23, TNF-α and NO. Moreover, lentivirus transfection mediated NICD overexpression inhibited the anti-inflammatory effects of Gastrodin. Furthermore, the activation of Notch-1 signaling promoted microglia migration and Gastrodin could inhibit the migration of activated BV-2 microglia by regulating the Notch-1 signaling pathway. In light of the above, our results indicate that Notch-1 signaling pathway is involved in the anti-inflammatory effects of Gastrodin against LPS-induced microglia activation. These findings provide a new biological target of Gastrodin for the treatment of neuroinflammatory disorders.

HIF-1-induced mitochondrial ribosome protein L52: a mechanism for breast cancer cellular adaptation and metastatic initiation in response to hypoxia

Background: Hypoxia is a hallmark of the physical microenvironment of solid tumors. As a key factor that regulates tumor development and progression, hypoxia can reprogram the expression of multiple genes, whose biological function and molecular mechanism in cancer remain largely unclear. The mitochondrial ribosome protein family consists of nuclear-encoded mitochondrial proteins that are responsible for protein synthesis in the mitochondria.

Methods: A high-throughput RNA sequencing assay was carried out to identify differentially expressed mRNAs between breast cancer tissues and adjacent normal tissues as well as breast tumors with metastasis and those without metastasis. Our clinical samples and TCGA database were analyzed to observe the clinical value of mitochondrial ribosome protein L52 (MRPL52) in human breast cancer. Potent hypoxia response elements in the promoter region of MRPL52 were identified and validated by chromatin immunoprecipitation and luciferase reporter assays. Functional experiments were performed using breast cancer cell lines with MRPL52 ectopic expression and knockdown cultured in a 20% or 1% O₂ environment.

Results: MRPL52 expression was upregulated in human breast cancer and was significantly associated with aggressive clinicopathological characteristics and a higher metastatic risk of breast cancer patients. We found that the overexpression of MRPL52 in breast cancer is induced by hypoxia-inducible factor-1 in response to hypoxic exposure. The role of MRPL52 in suppressing apoptosis and promoting migration and invasion of hypoxic breast cancer cells was demonstrated by our experimental evidence. Mechanistically, MRPL52 promoted PTEN-induced putative kinase 1 /Parkin-dependent mitophagy to remove oxidatively damaged mitochondria and prevent uncontrolled reactive oxygen species (ROS) generation, thus repressing activation of the mitochondrial apoptotic cascade. Additionally, MRPL52 augmented epithelial-mesenchymal transition, migration and invasion of hypoxic breast cancer cells by activating the ROS-Notch1-Snail signaling pathway. Benefited from this bidirectional regulatory mechanism, MRPL52 is responsible for maintaining ROS levels in a window that can induce tumorigenic signal transduction without causing cytotoxicity in hypoxic breast cancer cells.

Conclusions: This work elucidates the molecular mechanism by which MRPL52 mediates hypoxia-induced apoptotic resistance and metastatic initiation of breast cancer, and provides new insights into the interplay between cancer and the tumor microenvironment.

Exploring miRNA Sponge Networks of Breast Cancer by Combining miRNA-disease-lncRNA and miRNA-target Networks

Background:

Recently, ample researches show that microRNAs (miRNAs) not only interact with coding genes but interact with a pool of different RNAs. Those RNAs are called miRNA sponges, including long non-coding RNAs (lncRNAs), circular RNA, pseudogenes and various messenger RNAs. Understanding regulatory networks of miRNA sponges can better help researchers to study the mechanisms of breast cancers.

Objective:

We develop a new method to explore miRNA sponge networks of breast cancer by combining miRNAdisease-lncRNA and miRNA-target networks (MSNMDL).

Method:

Firstly, MSNMDL infers miRNA-lncRNA functional similarity networks from miRNAdisease- lncRNA networks. Secondly, MSNMDL forms lncRNA-target networks by using lncRNA to replace the role of matched miRNA in miRNA-target networks according to the lncRNA-miRNA pair of miRNA-lncRNA functional similarity networks. And MSNMDL only retains the genes of breast cancer in lncRNA-target networks to construct candidate miRNA sponge networks. Thirdly, MSNMDL merges these candidate miRNA sponge networks with other miRNA sponge interactions and then selects top-hub lncRNA and its interactions to construct miRNA sponge networks.

Results:

MSNMDL is superior to other methods in terms of biological significance and its identified modules might act as module signatures for prognostication of breast cancer.

Conclusion:

MiRNA sponge networks identified by MSNMDL are biologically significant and are closely associated with breast cancer, which makes MSNMDL a promising way for researchers to study the pathogenesis of breast cancer.

In Silico Logical Modelling to Uncover Cooperative Interactions in Cancer

The multistep development of cancer involves the cooperation between multiple molecular lesions, as well as complex interactions between cancer cells and the surrounding tumour microenvironment. The search for these synergistic interactions using experimental models made tremendous contributions to our understanding of oncogenesis. Yet, these approaches remain labour-intensive and challenging. To tackle such a hurdle, an integrative, multidisciplinary effort is required. In this article, we highlight the use of logical computational models, combined with experimental validations, as an effective approach to identify cooperative mechanisms and therapeutic strategies in the context of cancer biology. In silico models overcome limitations of reductionist approaches by capturing tumour complexity and by generating powerful testable hypotheses. We review representative examples of logical models reported in the literature and their validation. We then provide further analyses of our logical model of Epithelium to Mesenchymal Transition (EMT), searching for additional cooperative interactions involving inputs from the tumour microenvironment and gain of function mutations in NOTCH.

Therapeutic and prognostic implications of NOTCH and MAPK signaling in bladder cancer

Signaling pathways that drive bladder cancer (BC) progression may be promising and specific targets for systemic therapy. Here, we investigated the clinical significance and targetability of NOTCH and mitogen-activated protein kinase (MAPK) signaling for this aggressive malignancy. We assessed NOTCH1 and MAPK activity in 222 stage III and IV BC specimens of patients that had undergone radical cystectomy, and tested for clinical associations including cancer-specific and overall survival. We examined therapeutic effects of NOTCH and MAPK repression in a murine xenograft model of human bladder cancer cells and evaluated tumor growth and tumor cell plasticity. In BC, NOTCH1 and MAPK signaling marked two distinct tumor cell subpopulations. The combination of high NOTCH1 and high MAPK activity indicated poor cancer-specific and overall survival in univariate and multivariate analyses. Inhibition of NOTCH and MAPK in BC xenografts in vivo depleted targeted tumor cell subpopulations and revealed strong plasticity in signaling pathway activity. Combinatorial inhibition of NOTCH and MAPK signaling most strongly suppressed tumor growth. Our findings indicate that tumor cell subpopulations with high NOTCH and MAPK activity both contribute to tumor progression. Furthermore, we propose a new concept for BC therapy, which advocates specific and simultaneous targeting of these different tumor cell subpopulations through combined NOTCH and MAPK inhibition.

Cancer stem cells: Culprits in endocrine resistance and racial disparities in breast cancer outcomes

Breast cancer stem cells (BCSCs) promote endocrine therapy (ET) resistance, also known as endocrine resistance in hormone receptor (HR) positive breast cancer. Endocrine resistance occurs via mechanisms that are not yet fully understood. In vitro, in vivo and clinical data suggest that signaling cascades such as Notch, hypoxia inducible factor (HIF), and integrin/Akt promote BCSC-mediated endocrine resistance. Once HR positive breast cancer patients relapse on ET, targeted therapy agents such as cyclin dependent kinase inhibitors are frequently implemented, though secondary resistance remains a threat. Here, we discuss Notch, HIF, and integrin/Akt pathway regulation of BCSC activity and potential strategies to target these pathways to counteract endocrine resistance. We also discuss a plausible link between elevated BCSC-regulatory gene levels and reduced survival observed among African American women with basal-like breast cancer which lacks HR expression. Should future studies reveal a similar link for patients with luminal breast cancer, then the use of agents that impede BCSC activity could prove highly effective in improving clinical outcomes among African American breast cancer patients.

Interaction of Long Noncoding RNAs and Notch Signaling: Implications for Tissue Homeostasis Loss

The Notch signaling is a crucial pathway involved in cellular development, progression, and differentiation. Deregulation of Notch signaling pathway commonly impacts tissue homeostasis, being highly associated with proliferative disorders. The long noncoding RNAs (lncRNAs), which are transcripts with more than 200 nucleotides that do not code for proteins, were already described as Notch signaling pathway-interacting molecules. Many of them act as important transcriptional and posttranscriptional regulators, affecting gene expression and targeting other regulatory molecules, such as miRNAs. Due to their strong impact on function and gene expression of Notch-related molecules, lncRNAs influence susceptibility to cancer and other diseases, and can be regarded as potential biomarkers and therapeutic targets. Along this chapter, we summarize the cross talk between the Notch signaling pathway and their most important modulating lncRNAs, as well as the pathological consequences of these interactions, in different tissues.

Highly Expressed DLL4 and JAG1: Their Role in Incidence of Breast Cancer Metastasis

BACKGROUND

The role of Notch signaling dysregulation in causing metastatic breast cancer is not yet elucidated, therefore, this study aimed to investigate the expression of DLL4 and JAG1 in metastatic breast cancer. Moreover, we examined the possible association between clinicopathological features and studied parameters.

DESIGN AND METHODS

A total of 90 patients with invasive ductal breast carcinomas (52 non-metastatic and 38 metastatic) were enrolled in the current study. Furthermore, there were 42 patients with benign breast diseases. The mRNA and protein expression of DLL4 and JAG1 were analyzed by RT-PCR and ELISA, respectively in breast cell lysates.

RESULTS

The mRNA and protein expression of DLL4 and JAG1 were obviously higher in patients with breast cancer compared to patients with benign breast diseases and in metastatic versus non-metastatic breast cancer. A significant positive correlation was declared between DLL4 and JAG1 at both mRNA and protein levels in metastatic and localized breast cancer patients. Highly expressed mRNA and protein of DLL4 and JAG1 were associated with late tumor stages; moreover, upregulation of mRNA and protein of JAG1 was correlated with poorly differentiated tumors.

CONCLUSION

Our data emphasize that overexpression of DLL4 and JAG1 could predict the development of distant metastasis in breast cancer patients.

LSD1 regulates Notch and PI3K/Akt/mTOR pathways through binding the promoter regions of Notch target genes in esophageal squamous cell carcinoma

Background: The aberrant activation of Lysine-specific demethylase 1(LSD1), Notch and PI3K/Akt/mTOR signaling pathways were frequently happened in many cancers, including esophageal squamous cell carcinoma (ESCC). However, the regulatory relationship between LSD1 and Notch as well as PI3K/Akt/mTOR pathways is still unclear. Purpose: This study aimed to explore the regulatory effects and mechanisms of LSD1 on Notch and PI3K/Akt/mTOR pathway in ESCC. Results: Firstly, we demonstrated that LSD1 and proteins in Notch and PI3K/Akt/mTOR pathway were expressed in ESCC cells. Secondly, inhibition of LSD1 by tranylcypromine (TCP) or shRNA could decrease the expressions of related proteins in Notch and PI3K/Akt/mTOR signaling pathways in ESCC cells. Finally, we found that LSD1 could bind to the promoter regions of Notch3, Hes1 and CR2, and the combinations between them were reduced by TCP in ESCC. Conclusion: Summarily, this study indicated that LSD1 might positively regulate Notch and PI3K/Akt/mTOR pathways through binding the promoter regions of related genes in Notch pathway in ESCC.

The Notch ligand DLL1 exerts carcinogenic features in human breast cancer cells

CONCLUSIONS

These findings provide further evidence that DLL1 exerts carcinogenic effects in BC cells. The dissimilar effects of DLL1 downregulation observed amongst MCF-7, BT474, and MDA-MB-231 cells is likely due to their distinctive genetic and biologic characteristics, suggesting that DLL1 contributes to BC through various mechanisms.

MCUR1 facilitates epithelial-mesenchymal transition and metastasis via the mitochondrial calcium dependent ROS/Nrf2/Notch pathway in hepatocellular carcinoma

Background

Mitochondrial Ca²⁺ plays a critical role in tumorigenesis, including cell proliferation and metastasis. Mitochondrial calcium uniporter regulator 1 (MCUR1) has been shown to be frequently upregulated in HCC and promote cancer cell survival. However, whether MCUR1 is involved in the metastasis of HCC and its underlying mechanisms remain unknown.

Methods

The effect of MCUR1 expression on epithelial-mesenchymal transition (EMT) in HCC cells was first evaluated by immunofluorescent staining and Western blot. Then, in vitro invasion and in vivo metastasis assays were used to evaluate the function of MCUR1 in HCC metastasis. The underlying mechanism has also been explored by investigating the effect of MCUR1 on ROS/Nrf2/Notch1 pathway.

Results

MCUR1 expression was significantly higher in HCC with metastasis and associated with tumor progression. MCUR1 promoted in vitro invasion and in vivo metastasis of HCC cells by promoting EMT via Snail. Mechanistically, MCUR1-mediated mitochondrial Ca²⁺ signaling promoted the EMT of HCC cells by activating ROS/Nrf2/Notch1 pathway. Inhibition of ROS production, mitochondrial Ca²⁺ uptake, Nrf2 expression or Notch1 activity significantly suppressed MCUR1-induced EMT of HCC cells. In addition, treatment with the mitochondrial Ca²⁺-buffering protein parvalbumin significantly inhibited ROS/Nrf2/Notch pathway and MCUR1-induced EMT and HCC metastasis.

Conclusions

Our study provides evidence supporting a metastasis-promoting role for MCUR1-dependent mitochondrial Ca²⁺ uptake in HCC. Our findings suggest that MCUR1 may be a potential therapeutic target for HCC treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1135-x) contains supplementary material, which is available to authorized users.

A prospect of cell immortalization combined with matrix microenvironmental optimization strategy for tissue engineering and regeneration

Cellular senescence is a major hurdle for primary cell-based tissue engineering and regenerative medicine. Telomere erosion, oxidative stress, the expression of oncogenes and the loss of tumor suppressor genes all may account for the cellular senescence process with the involvement of various signaling pathways. To establish immortalized cell lines for research and clinical use, strategies have been applied including internal genomic or external matrix microenvironment modification. Considering the potential risks of malignant transformation and tumorigenesis of genetic manipulation, environmental modification methods, especially the decellularized cell-deposited extracellular matrix (dECM)-based preconditioning strategy, appear to be promising for tissue engineering-aimed cell immortalization. Due to few review articles focusing on this topic, this review provides a summary of cell senescence and immortalization and discusses advantages and limitations of tissue engineering and regeneration with the use of immortalized cells as well as a potential rejuvenation strategy through combination with the dECM approach.

Moving Breast Cancer Therapy up a Notch

Breast cancer is the second most common malignancy, worldwide. Treatment decisions are based on tumor stage, histological subtype, and receptor expression and include combinations of surgery, radiotherapy, and systemic treatment. These, together with earlier diagnosis, have resulted in increased survival. However, initial treatment efficacy cannot be guaranteed upfront, and these treatments may come with (long-term) serious adverse effects, negatively affecting a patient's quality of life. Gene expression-based tests can accurately estimate the risk of recurrence in early stage breast cancers. Disease recurrence correlates with treatment resistance, creating a major need to resensitize tumors to treatment. Notch signaling is frequently deregulated in cancer and is involved in treatment resistance. Preclinical research has already identified many combinatory therapeutic options where Notch involvement enhances the effectiveness of radiotherapy, chemotherapy or targeted therapies for breast cancer. However, the benefit of targeting Notch has remained clinically inconclusive. In this review, we summarize the current knowledge on targeting the Notch pathway to enhance current treatments for breast cancer and to combat treatment resistance. Furthermore, we propose mechanisms to further exploit Notch-based therapeutics in the treatment of breast cancer.

The Notch Pathway in Breast Cancer Progression

Objective

Notch signaling pathway is a vital parameter of the mammalian vascular system. In this review, the authors summarize the current knowledge about the impact of the Notch signaling pathway in breast cancer progression and the therapeutic role of Notch's inhibition.

Methods

The available literature in MEDLINE, PubMed, and Scopus, regarding the role of the Notch pathway in breast cancer progression was searched for related articles from about 1973 to 2017 including terms such as “Notch,” “Breast Cancer,” and “Angiogenesis.” Results. Notch signaling controls the differentiation of breast epithelial cells during normal development. Studies confirm that the Notch pathway has a major participation in breast cancer progression through overexpression and/or abnormal genetic type expression of the notch receptors and ligands that determine angiogenesis. The cross-talk of Notch and estrogens, the effect of Notch in breast cancer stem cells formation, and the dependable Notch overexpression during breast tumorigenesis have been studied enough and undoubtedly linked to breast cancer development. The already applied therapeutic inhibition of Notch for breast cancer can drastically change the course of the disease.

Conclusion

Current data prove that Notch pathway has a major participation and multiple roles during breast tumor progression. Inhibition of Notch receptors and ligands provides innovative therapeutic results and could become the therapy of choice in the next few years, even though further research is needed to reach safe conclusions.

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.

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.

Production and characterization of a novel Delta-like 1 functional unit as a tool for Notch pathway activation and generation of a specific antibody

Notch signalling is an evolutionary conserved cell-to-cell communication pathway crucial for development and tissue homeostasis. Abnormal Notch signalling by mutations or deregulated expression of its receptors and/or ligands can lead to cancer making it a potential therapeutic target. Delta-like1 (DLL1) is a ligand of the Notch pathway implicated in different types of cancer, including breast cancer. Herein, we produced rhDLL1-DE3, a novel soluble form of DLL1 protein, which contains the DSL domain and EGF1-3 repeats critical for Notch pathway activation. cDNA fragments of human DLL1, encoding truncated versions of DLL1 with regions required to activate Notch receptors, were cloned and expressed as histidine-fused proteins in bacterial and mammalian cells. Expression tests in mammalian cells showed almost exclusively expression of the rhDLL1-DE3 protein form comprising the minimal binding regions DSL to EGF3 to Notch receptors. The highest yield of rhDLL1-DE3 was obtained from E. coli inclusion bodies. The produced protein, with purity higher than 95% bound to human Notch1 recombinant protein, by both Biolayer interferometry and ELISA assays. Cellular assays revealed rhDLL1-DE3 was biologically active as it increased expression of Notch-dependent genes in inducible pluripotent and breast cancer cells. Moreover, rhDLL1-DE3 allowed the generation of polyclonal antibodies by immunization that efficiently recognized DLL1 proteins by immunoblot, and caused a significant decrease of Notch1 expression in MCF7 breast cancer cells. The rhDLL1-DE3 protein might thus be used for Notch pathway activation and to generate anti-DLL1 monoclonal antibodies by immunization or phage display technology to unveil the effect of DLL1 in breast cancer.

microRNA-137 promotes endothelial progenitor cell proliferation and angiogenesis in cerebral ischemic stroke mice by targeting NR4A2 through the Notch pathway

Cerebral ischemic stroke (CIS) is one of the common causes of death and disability worldwide. This study aims to investigate effect of miR-137 on endothelial progenitor cells and angiogenesis in CIS by targeting NR4A2 via the Notch pathway. Brain tissues were extracted from CIS and normal mice. Immunohistochemistry was used to determine positive rate of NR4A2 expression. Serum VEGF, Ang, HGF, and IκBα levels were determined by ELISA. RT-qPCR and Western blotting were used to determine expression of related factors. Endothelial progenitor cells in CIS mice were treated and grouped into blank, NC, miR-137 mimic, miR-137 inhibitor, siRNA-NR4A2, and miR-137 inhibitor + siRNA-NR4A2 groups, and cells in normal mice into normal group. Proliferation and apoptosis were determined by MTT and flow cytometry, respectively. NR4A2 protein expression was strongly positive in CIS mice, which showed higher serum levels of VEGF, Ang, and HGF but lower IκBα than normal mice. Compared with normal group, the rest groups (endothelial progenitor cells from CIS mice) showed decreased expressions of miR-137, Hes1, Hes5, and IκBα but elevated NR4A2, Notch, Jagged1, Hey-2, VEGF, Ang, and HGF, inhibited proliferation and enhanced apoptosis. Compared with blank and NC groups, the miR-137 mimic and siRNA-NR4A2 groups exhibited increased expression of miR-137, Hes1, Hes5, and IκBα, but decreased NR4A2, Notch, Jagged1, and Hey-2, with enhanced proliferation and attenuated apoptosis. The miR-137 inhibitor group reversed the conditions. miR-137 enhances the endothelial progenitor cell proliferation and angiogenesis in CIS mice by targeting NR4A2 through the Notch signaling pathway.

Identification and characterization of a novel Sso7d scaffold-based binder against Notch1

Notch signaling has important functions in regulating cell growth and development, misregulation of which has been implicated in various cancers. Monoclonal antibodies (mAbs) targeting Notch protein activity have already moved into clinical trials. However due to the limitations associated with cost and productivity of mAbs, there has been a surge in the development of complementary approaches that are based on non-antibody scaffolds. Non-antibody scaffolds are small proteins that are stable and can be engineered to develop high-affinity binders against specific targets of interest. Here we describe the isolation and characterization of a novel Notch1-binding protein, N9, obtained by screening of a combinatorial library based on the ultra-stable Sso7d scaffold. N9 targets the extracellular EGF-like repeats (ELR) 11–13 in Notch1, and therefore serves as a competitive inhibitor for Notch ligands to decrease expression of Notch target genes. We demonstrate that N9 recognizes surface expression of Notch1 on the plasma membrane and binds preferentially to cell lines misexpressing Notch1. Although N9 was selected against Notch1, we also observe cross-reactivity against other Notch receptors, including Notch2/3. Finally, we demonstrate that N9 inhibits proliferation and generation of tumorspheres in Notch expressing cancer cell lines, suggesting its potential as a therapeutic agent in Notch-associated malignancies.

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.

miR-30a inhibits the biological function of breast cancer cells by targeting Notch1

miR-30a is situated on chromosome 6q.13 and is produced by an intronic transcriptional unit. However, its role in regulating the apoptosis, invasion and metastasis of breast cancer cells is not yet fully understood. The aim of this study was to research the biological function of miR‑30a and its direct target gene in breast cancer. The biological function of miR‑30a was determined by examining breast cancer cell growth, apoptosis, metastasis and invasion. In addition, Notch1 expression was measured by western blot analysis, and a luciferase reporter vector was constructed to identify the miR‑30a target gene. miR‑30a was found to be significantly downregulated in breast cancer cells. We also found that miR‑30a inhibited breast cancer cell viability, migration and invasion, and induced cell apoptosis. On the whole, our data indicate that miR‑30a attenuates the development of breast cancer by regulating the expression of the downstream target gene, Notch1.

Clinical Activity of the γ-Secretase Inhibitor PF-03084014 in Adults With Desmoid Tumors (Aggressive Fibromatosis)

Purpose Desmoid tumors (aggressive fibromatosis) arise from connective tissue cells or fibroblasts. In general, they are slow growing and do not metastasize; however, locally aggressive desmoid tumors can cause severe morbidity and loss of function. Disease recurrence after surgery and/or radiation and diagnosis of multifocal desmoid tumors highlight the need to develop effective systemic treatments for this disease. In this study, we evaluate objective response rate after therapy with the γ-secretase inhibitor PF-03084014 in patients with recurrent, refractory, progressive desmoid tumors. Patients and Methods Seventeen patients with desmoid tumors received PF-03084014 150 mg orally twice a day in 3-week cycles. Response to treatment was evaluated at cycle 1 and every six cycles, that is, 18 weeks, by RECIST (Response Evaluation Criteria in Solid Tumors) version 1.1. Patient-reported outcomes were measured at baseline and at every restaging visit by using the MD Anderson Symptoms Inventory. Archival tumor and blood samples were genotyped for somatic and germline mutations in APC and CTNNB1. Results Of 17 patients accrued to the study, 15 had mutations in APC or CTNNB1 genes. Sixteen patients (94%) were evaluable for response; five (29%) experienced a confirmed partial response and have been on study for more than 2 years. Another five patients with prolonged stable disease as their best response remain on study. Patient-reported outcomes confirmed clinician reporting that the investigational agent was well tolerated and, in subgroup analyses, participants who demonstrated partial response also experienced clinically meaningful and statistically significant improvements in symptom burden. Conclusion PF-03084014 was well tolerated and demonstrated promising clinical benefit in patients with refractory, progressive desmoid tumors who receive long-term treatment.

Regulation of ADSC Osteoinductive Potential Using Notch Pathway Inhibition and Gene Rescue: A Potential On/Off Switch for Clinical Applications in Bone Formation and Reconstructive Efforts

BACKGROUND

Although there has been tremendous research in the ability of mesenchymal-derived adipose derived stem cells (ADSCs) to form bone, less is known regarding the molecular mechanisms that regulate the osteogenic potential of ADSCs. Notch, which consists of a key family of regulatory ligands involved in bone formation, is expressed in the bone marrow-derived mesenchymal stem cell niche and is critical for proliferation, migration, and ultimately osseous differentiation. The authors investigate how Notch impacts ADSC proliferation and osteogenic differentiation to determine a translatable application of these cells in bone regeneration.

METHODS

Enriched ADSC populations were isolated from tissue and examined for their ability to respond to Notch pathway signaling events. Proliferation, viability, extracellular matrix deposition, and osteoinduction were assessed following Notch activation and inhibition. Notch pathway rescue was conducted using a lentiviral vector encoding a downstream Notch-1 intracellular domain (NICD).

RESULTS

Proliferation, osteogenic induction, and the ability to form bone elements were reduced following Notch inhibition (p < 0.05). However, ADSCs, while in the presence of the Notch inhibition, were able to be rescued following lentiviral transduction with NICD, restoring osteogenic potential at both the molecular and cellular functional levels (p < 0.05).

CONCLUSIONS

These data suggest a potential translatable "on/off switch," using endogenous Notch signaling to regulate the proliferation, differentiation, and osteogenic potential of ADSCs. Although Notch inhibition reduced ADSC proliferation and down-regulated osteoinduction, targeted gene therapy and the delivery of the downstream NICD peptide restored bone formation, suggesting pragmatic clinical utility of ADSCs for bone regeneration.