Dual tumor suppressing and promoting function of Notch1 signaling in human prostate cancer

The role of proinflammatory cytokines and CXC chemokines (CXCL1-CXCL16) in the progression of prostate cancer: insights on their therapeutic management

Reproductive cancers are malignancies that develop in the reproductive organs. One of the leading cancers affecting the male reproductive system on a global scale is prostate cancer (PCa). The negative consequences of PCa metastases endure and are severe, significantly affecting mortality and life quality for those who are affected. The association between inflammation and PCa has captured interest for a while. Inflammatory cells, cytokines, CXC chemokines, signaling pathways, and other elements make up the tumor microenvironment (TME), which is characterized by inflammation. Inflammatory cytokines and CXC chemokines are especially crucial for PCa development and prognosis. Cytokines (interleukins) and CXC chemokines such as IL-1, IL-6, IL-7, IL-17, TGF-β, TNF-α, CXCL1-CXCL6, and CXCL8-CXCL16 are thought to be responsible for the pleiotropic effects of PCa, which include inflammation, progression, angiogenesis, leukocyte infiltration in advanced PCa, and therapeutic resistance. The inflammatory cytokine and CXC chemokines systems are also promising candidates for PCa suppression and immunotherapy. Therefore, the purpose of this work is to provide insight on how the spectra of inflammatory cytokines and CXC chemokines evolve as PCa develops and spreads. We also discussed recent developments in our awareness of the diverse molecular signaling pathways of these circulating cytokines and CXC chemokines, as well as their associated receptors, which may one day serve as PCa-targeted therapies. Moreover, the current status and potential of theranostic PCa therapies based on cytokines, CXC chemokines, and CXC receptors (CXCRs) are examined.

GLIS1, Correlated with Immune Infiltrates, Is a Potential Prognostic Biomarker in Prostate Cancer

Prostate cancer (PCa) is a prevalent malignant disease and the primary reason for cancer-related mortality among men globally. GLIS1 (GLIS family zinc finger 1) is a key regulator in various pathologies. However, the expression pattern, clinical relevance, and immunomodulatory function of GLIS1 in PCa remain unclear. In this study, GLIS1 was discovered to serve as a key gene in PCa by integrating mRNA and miRNA expression profiles from GEO database. We systematically explored the expression and prognostic values of GLIS1 in cancers using multiple databases. Additionally, we examined the functions of GLIS1 and the relationship between GLIS1 expression levels and immune infiltration in PCa. Results showed that GLIS1 was differentially expressed between normal and tumor tissues in various cancer types and was significantly low-expressed in PCa. Low GLIS1 expression was associated with poor PCa prognosis. GLIS1 was also involved in the activation, proliferation, differentiation, and migration of immune cells, and its expression showed a positive correlation with the infiltration of various immune cells. Moreover, GLIS1 expression was positively associated with various chemokines/chemokine receptors, indicating the involvement in regulating immune cell migration. In summary, GLIS1 is a potential prognostic biomarker and a therapeutic target to modulate anti-tumor immune response in PCa.

Integrative characterisation of secreted factors involved in intercellular communication between prostate epithelial or cancer cells and fibroblasts

Reciprocal interactions between prostate cancer cells and carcinoma-associated fibroblasts (CAFs) mediate cancer development and progression; however, our understanding of the signalling pathways mediating these cellular interactions remains incomplete. To address this, we defined secretome changes upon co-culture of prostate epithelial or cancer cells with fibroblasts that mimic bi-directional communication in tumours. Using antibody arrays, we profiled conditioned media from mono- and co-cultures of prostate fibroblasts, epithelial and cancer cells, identifying secreted proteins that are upregulated in co-culture compared to mono-culture. Six of these (CXCL10, CXCL16, CXCL6, FST, PDGFAA, IL-17B) were functionally screened by siRNA knockdown in prostate cancer cell/fibroblast co-cultures, revealing a key role for follistatin (FST), a secreted glycoprotein that binds and bioneutralises specific members of the TGF-β superfamily, including activin A. Expression of FST by both cell types was required for the fibroblasts to enhance prostate cancer cell proliferation and migration, whereas FST knockdown in co-culture grafts decreased tumour growth in mouse xenografts. This study highlights the complexity of prostate cancer cell-fibroblast communication, demonstrates that co-culture secretomes cannot be predicted from individual cultures, and identifies FST as a tumour-microenvironment-derived secreted factor that represents a candidate therapeutic target.

The Potential of hsa-mir-106b-5p as Liquid Biomarker in Prostate Cancer Patients in Indonesia

Purpose:

This study aims to explore the potential of hsa-mir-106b-5p as a new liquid biomarker for prostate cancer sufferers in Indonesia.

Methods:

Analysis of hsa-mir-106b-5p expression of two tissue samples from BPH patients and two PCa patients used NanoString nCounter Expression Assay then validated by qRT-PCR using 10 patient urine samples for prostate cancer and BPH. Furthermore, analysis of the role of hsa-mir-106b-5p in prostate cancer was carried out bioinformatically.

Results:

The results of this study indicated that the expression of hsa-mir-106b-5p in prostate cancer tissue was 1.23 times higher than that of BPH and urine of Indonesian patients (1.72 times). Moreover, this miRNA was upregulated in prostate cancer cells compared to normal cells 1.37 times. The hsa-mir-106b-5p appeared to be involved in the development of prostate cancer through the binding of genes involved in endoplasmic reticulum stress pathways and tumor suppressor genes.

Conclusion:

hsa-mir-106b-5p could modulate prostate cancer by interfering with the endoplasmic reticulum stress repair pathways and decreasing the expression of tumor suppressor genes involved in many biological processes. These updates our understanding of the role of hsa-mir-106b-5p in cancer and its potential as a candidate of a biomarker for clinical diagnosis of prostate cancer.

MiR-543/Numb promotes proliferation, metastasis, and stem-like cell traits of prostate cancer cells

MiR-543 and Numb are associated with various malignancies, including prostate cancer (PCa). However, whether miR-543 regulates Numb in PCa development remains unclear. In this study, we identified Numb as a direct target of miR-543. The role of miR-543 was examined both in vitro and in vivo. The in vivo effects of miR-543 were investigated using tumor transplantation experiments and a lung metastasis model. The in vitro effects of miR-543 on proliferation, migration, invasion, and cancer stem-like cell (CSC)-associated properties were also examined. The binding sites of Numb were predicted using bioinformatics tools and confirmed by luciferase and rescue assays. QRT-PCR and western blot analyses were used to detect target expression levels. Expression levels of both miR-543 and Numb were manipulated in CD44+ and CD44-PCa cells followed by a series of functional assays. The results demonstrated that miR-543 promoted PCa growth and metastasis both in vivo and in vitro. Luciferase reporter assays, qRT-PCR, and western blot analyses revealed Numb as a direct target of miR-543. The function of miR-543 was abolished by Numb, as shown in rescue experiments. Moreover, miR-543 was verified to promote CSC properties, whereas Numb elicited the opposite effects. MiR-543 also influenced the expression of several stem-like factors, including Dll4, NF-κB, c-myc, and Oct-4, and the Numb/p53 signaling pathway. Taken together, these results demonstrate that miR-543 plays an oncogenic role by negatively controlling Numb, revealing the existence of an miR-543/Numb/p53 regulatory pathway in PCa tumorigenesis and development.

CDCP1 overexpression drives prostate cancer progression and can be targeted in vivo

The mechanisms by which prostate cancer shifts from an indolent castration-sensitive phenotype to lethal castration-resistant prostate cancer (CRPC) are poorly understood. Identification of clinically relevant genetic alterations leading to CRPC may reveal potential vulnerabilities for cancer therapy. Here we find that CUB domain-containing protein 1 (CDCP1), a transmembrane protein that acts as a substrate for SRC family kinases (SFKs), is overexpressed in a subset of CRPC. Notably, CDCP1 cooperates with the loss of the tumor suppressor gene PTEN to promote the emergence of metastatic prostate cancer. Mechanistically, we find that androgens suppress CDCP1 expression and that androgen deprivation in combination with loss of PTEN promotes the upregulation of CDCP1 and the subsequent activation of the SRC/MAPK pathway. Moreover, we demonstrate that anti-CDCP1 immunoliposomes (anti-CDCP1 ILs) loaded with chemotherapy suppress prostate cancer growth when administered in combination with enzalutamide. Thus, our study identifies CDCP1 as a powerful driver of prostate cancer progression and uncovers different potential therapeutic strategies for the treatment of metastatic prostate tumors.

Circulating let-7f-5p improve risk prediction of prostate cancer in patients with benign prostatic hyperplasia

Background: Although the prostate-specific antigen (PSA) testing was widely used for early detection of prostate cancer (PCa), it is difficult for PSA to distinguish the PCa from benign prostatic hyperplasia (BPH) patients. Emerging evidence has shown that microRNA (miRNA) was a promising biomarker for PCa screening.

Methods: We applied miRNA profiling from microarray or high-throughput sequencing in Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases to identify the differentially expressed miRNAs in PCa patients (n = 1,017) and controls (n = 413). Then, qRT-PCR analysis was used to validate the expression of candidate miRNAs in our independent cohort, include 66 PCa cases and 63 BPH patients diagnosed by biopsy. The area under the receiver operating characteristic curve (AUC) was conducted to evaluate the diagnostic efficacy of miRNAs and PSA.

Results: In the microarray analysis, we identified two consistently differently expressed miRNAs (miR-103a-3p and let-7f-5p) between PCa patients and controls. In the subsequent qRT-PCR analysis, the let-7f-5p was upregulated in PCa compared with BPH patients (P=2.17E-07), but no statistically difference of miR-103a-3p expression was observed (P=0.456). The AUC was 0.904 for combination of lef-7f-5p and PSA, which was significantly higher than that of let-7f-5p (0.782) or PSA (0.795) alone (P=7.55E-04 and P=2.09E-03, respectively). Besides, the results of decision curve analysis and nomogram prediction indicated that combination of let-7f-5p and PSA had superior predictive accuracy of PCa.

Conclusions: Our study suggests that plasma let-7f-5p combining PSA could serve as potentially diagnostic biomarkers for PCa.

LSGSP: a novel miRNA-disease association prediction model using a Laplacian score of the graphs and space projection federated method

Lots of research findings have indicated that miRNAs (microRNAs) are involved in many important biological processes; their mutations and disorders are closely related to diseases, therefore, determining the associations between human diseases and miRNAs is key to understand pathogenic mechanisms. Existing biological experimental methods for identifying miRNA-disease associations are usually expensive and time consuming. Therefore, the development of efficient and reliable computational methods for identifying disease-related miRNAs has become an important topic in the field of biological research in recent years. In this study, we developed a novel miRNA-disease association prediction model using a Laplacian score of the graphs and space projection federated method (LSGSP). This integrates experimentally validated miRNA-disease associations, disease semantic similarity scores, miRNA functional scores, and miRNA family information to build a new disease similarity network and miRNA similarity network, and then obtains the global similarities of these networks through calculating the Laplacian score of the graphs, based on which the miRNA-disease weighted network can be constructed through combination with the miRNA-disease Boolean network. Finally, the miRNA-disease score was obtained via projecting the miRNA space and disease space onto the miRNA-disease weighted network. Compared with several other state-of-the-art methods, using leave-one-out cross validation (LOOCV) to evaluate the accuracy of LSGSP with respect to a benchmark dataset, prediction dataset and compare dataset, LSGSP showed excellent predictive performance with high AUC values of 0.9221, 0.9745 and 0.9194, respectively. In addition, for prostate neoplasms and lung neoplasms, the consistencies between the top 50 predicted miRNAs (obtained from LSGSP) and the results (confirmed from the updated HMDD, miR2Disease, and dbDEMC databases) reached 96% and 100%, respectively. Similarly, for isolated diseases (diseases not associated with any miRNAs), the consistencies between the top 50 predicted miRNAs (obtained from LSGSP) and the results (confirmed from the above-mentioned three databases) reached 98% and 100%, respectively. These results further indicate that LSGSP can effectively predict potential associations between miRNAs and diseases.

Identification of biomarker microRNA-mRNA regulatory pairs for predicting the docetaxel resistance in prostate cancer

Background: Docetaxel resistance is a cursing problem with adverse effects on the therapeutic efficacy of prostate cancer (PCa), involving interactions among multiple molecular components. Single or limited molecules are not strong enough as prediction biomarkers of drug resistance. Network biomarkers are considered to outperform individual markers in disease characterization.

Methods: In this study, key microRNAs (miRNAs) as biomarkers were identified from the PubMed citations and miRNA expression profiles. Targets of miRNAs were predicted and enriched by biological function analysis. Key target mRNAs of the biomarker miRNAs were screened from protein-protein interaction network and gene expression profiles, respectively. The results were validated by the assessment of their predictive power and system biological analysis.

Results: With this approach, we identified 13 miRNAs and 31 target mRNAs with 66 interactions in the constructed network. Integrative functional enrichment analysis and literature exploration further confirmed that the network biomarkers were highly associated with the development of docetaxel resistance.

Conclusions: The findings from our results demonstrated that the identified network biomarkers provide a useful tool for predicting the docetaxel resistance and may be helpful for serving as prediction biomarkers and therapeutic targets. However, it is necessary to conduct biological experiments for further investigating their roles in the development of docetaxel resistance.

MicroRNA-488 inhibits proliferation and glycolysis in human prostate cancer cells by regulating PFKFB3

Prostate cancer (PCa) remains the second leading cause of cancer‐related death among men in the United States, and its molecular mechanism remains to be elucidated. Recent studies have suggested that microRNAs may play an important role in cancer development and progression. By analyzing the Gene Expression Omnibus dataset, we found lower expression for miR‐488 in PCa than in normal tissues. Moreover, CCK‐8, EdU, glucose uptake, and lactate secrete assays revealed that overexpression of miR‐488 in PCa cell lines PC3 and DU145 resulted in inhibition of proliferation and glycolysis. In contrast, downregulation of miR‐488 expression promoted proliferation and glycolysis in PCa cells. Using a bioinformatic approach and dual‐luciferase reporter assays, we identified 6‐phosphofructo‐2‐kinase/fructose‐2,6‐bisphosphatase, isoform3 (PFKFB3), as a direct target of miR‐488. Inhibition of PFKFB3 also suppressed PCa cell glycolysis and proliferation. Our study suggests that miR‐488 inhibits PCa cell proliferation and glycolysis by targeting PFKFB3, and thus, miR‐488 may be a novel therapeutic candidate for PCa.

Rho-Associated Protein Kinase (ROCK) Promotes Proliferation and Migration of PC-3 and DU145 Prostate Cancer Cells by Targeting LIM Kinase 1 (LIMK1) and Matrix Metalloproteinase-2 (MMP-2)

Background

In the pathogenesis and progression of prostate cancer, cell proliferation and cell migration results in tumor invasion and metastasis that is associated with patient morbidity and mortality. Rho-associated protein kinase (ROCK) has previously been shown to be upregulated in prostate cancer, but its biological role remains poorly understood. This study aimed to investigate the role of ROCK in the proliferation and migration of PC-3 and DU145 prostate cancer cells and to identify the possible targets involved by knockdown of ROCK1 and ROCK2 RNA expression.

Material/Methods

An RNA interference (RNAi) assay was performed to silence the expression of ROCK1 and ROCK2 in the PC-3 and DU145 human prostate cancer cell lines. Cells were also treated with a specific ROCK inhibitor, Y27632. A cell counting kit-8 (CCK-8) assay was used to determine the proliferation rate of prostate cancer cells, and cell migration and invasion assays were performed. Western blot and polymerase chain reaction were used to measure protein and RNA expression levels.

Results

In PC-3 and DU145 prostate cancer cells, knockdown of ROCK1 and ROCK2 reduced cell migration and invasion. ROCK1 and ROCK2 regulated cell proliferation in PC-3 and DU145 prostate cancer cells. Protein levels of phosphorylated LIM kinase 1 (p-LIMK1) and matrix metalloproteinase-2 (MMP-2) were reduced in ROCK1 and ROCK2 siRNA transfected cells.

Conclusions

In PC-3 and DU145 human prostate cancer cells, ROCK promoted cell proliferation and migration by targeting LIMK1 and MMP-2.

CUL4B/miR-33b/C-MYC axis promotes prostate cancer progression

BACKGROUND

Cullin 4B (CUL4B), a scaffold protein that assembles CRL4B ubiquitin ligase complexes, is overexpressed in many types of solid tumors and contributes to epigenetic silencing of tumor suppressors. However, its clinical significance and underlying molecular mechanisms in prostate cancer (PCa) remain unknown.

METHODS

The clinical significance of CUL4B in PCa was characterized by in silico method. RT-qPCR and Western blot were used to study the transcript and protein expression levels of CUL4B and C-MYC. Bioinformatics tools, chromatin immunoprecipitation (ChIP) and luciferase reporter assay were utilized to identify and characterize the microRNAs (miRNAs) regulated by CUL4B. The biological function of CUL4B and miR-33b-5p was evaluated by MTS, transwell, and wound healing assays, accordingly.

RESULTS

CUL4B is significantly overexpressed in PCa tissues compared with benign prostatic tissues and its overexpression is correlated with poor prognosis. CUL4B promotes proliferation and aggressiveness of PCa cells in vitro. Mechanistically, we demonstrate that CUL4B upregulates the expression of C-MYC at post-transcriptional level through epigenetic silencing of miR-33b-5p. Importantly, CUL4B-induced oncogenic activity in PCa by targeting C-MYC is repressed by miR-33b-5p.

CONCLUSIONS

Our results suggested a novel CUL4B/miR-33b/C-MYC axis implicated in PCa cell growth and progression. This might provide novel insight into how CUL4B contributed to PCa aggressiveness and progression.

Meeting Between Rumi and Shams in Notch Signaling; Implications for Pain Management: A Narrative Review

The meeting between Rumi and Shams, in the 13th century, was a turning point in the life of Rumi leading to a revolutionary effect in his thoughts, ideas, and poems. This was an ever-inspiring meeting with many results throughout the centuries. This meeting has created some footprints in cellular and molecular medicine: The discovery of two distinct genes in Drosophila, i.e. Rumi and Shams and their role in controlling Notch signaling, which has a critical role in cell biology. This nomination and the interactions between the two genes has led us to a number of novel studies during the last years. This article reviews the interactions between Rumi and Shams and their effects on Notch signaling in order to find potential novel drugs for pain control through drug development studies in the future.

Targeting the Notch1 oncogene by miR-139-5p inhibits glioma metastasis and epithelial-mesenchymal transition (EMT)

BACKGROUND

Glioma metastasis, invasion, epithelial-mesenchymal transition (EMT) and chemoresistance indicate poor prognosis. Accumulating evidence reveals that Notch1 is an important factor in tumour progression. However, the role of Notch1 in glioma EMT and associated microRNAs (miRNAs) with the Notch pathway remain controversial.

METHODS

Utilizing cBioPortal database to examine the gene signature of NOTCH1 (encoding Notch1), CDH2 (encoding N-cadherin) and SNAI1 (encoding Snail-1) in disease-free survival (DFS) and overall survival (OS). We analyzed the Notch1 expression from Oncomine. We used Western blot (WB), immunohistochemistry (IHC) and immunofluorescence to determine protein levels. Transcription was evaluated by quantitative real-time (qRT)-PCR. siRNA and lentivirus were used to knock down Notch1 and overexpress miR-139-5p, respectively. The migration and invasion of glioma cells were assessed by wound healing and transwell assays. Luciferase reporter assays were utilized to verify the relationship between Notch1 and miR-139-5p. A U87-implanted intracranial model was used to study the effect of miR-139-5p on tumour growth and Notch1 suppression efficacy or EMT reversion.

RESULTS

It revealed the association of NOTCH1, CDH2, SNAI1 genomic alterations with decreases in DFS and OS. Notch1 was upregulated in classical and proneural subtypes of GBM, and associated with tumour grade. Notch1 inhibition suppressed the biological behaviours of metastasis, invasion and EMT. Notch1 was identified as a novel direct target of miR-139-5p. MiR-139-5p overexpression partially phenocopied Notch1 siRNA, whereas the forced expression of Notch1 reversed the effects of miR-139-5p on the invasion of glioma. Moreover, intracranial tumourigenicity and EMT behaviours were reduced by the introduction of miR-139-5p and partially mediated by the decreased Notch1 expression.

CONCLUSIONS

miR-139-5p was identified as a tumour suppressor by negatively targeting Notch1, and this work suggests a possible molecular mechanism of the miR-139/Notch1/EMT axis for glioma treatment.

CD38 Inhibits Prostate Cancer Metabolism and Proliferation by Reducing Cellular NAD+ Pools

Tumor cells require increased rates of cell metabolism to generate the macromolecules necessary to sustain proliferation. They rely heavily on NAD⁺ as a cofactor for multiple metabolic enzymes in anabolic and catabolic reactions. NAD⁺ also serves as a substrate for PARPs, sirtuins, and cyclic ADP-ribose synthases. Dysregulation of the cyclic ADP-ribose synthase CD38, the main NAD'ase in cells, is reported in multiple cancer types. This study demonstrates a novel connection between CD38, modulation of NAD⁺, and tumor cell metabolism in prostate cancer. CD38 expression inversely correlates with prostate cancer progression. Expressing CD38 in prostate cancer cells lowered intracellular NAD⁺, resulting in cell-cycle arrest and expression of p21^Cip1 (CDKNA1). In parallel, CD38 diminishes glycolytic and mitochondrial metabolism, activates AMP-activated protein kinase (AMPK), and inhibits fatty acid and lipid synthesis. Pharmacologic inhibition of nicotinamide phosphoribosyltransferase (NAMPT) mimicked the metabolic consequences of CD38 expression, demonstrating similarity between CD38 expression and NAMPT inhibition. Modulation of NAD⁺ by CD38 also induces significant differential expression of the transcriptome, producing a gene expression signature indicative of a nonproliferative phenotype. Altogether, in the context of prostate cancer, the data establish a novel role for the CD38-NAD⁺ axis in the regulation of cell metabolism and development.Implications: This research establishes a mechanistic connection between CD38 and metabolic control. It also provides the foundation for the translation of agents that modulate NAD⁺ levels in cancer cells as therapeutics. Mol Cancer Res; 16(11); 1687-700. ©2018 AACR.

Expression and oncogenic properties of membranous Notch1 in oral leukoplakia and oral squamous cell carcinoma

Notch1 signaling is essential for tissue development and tumor progression. This signaling pathway has also been implicated in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC). However, the role of Notch1 expression in OL and its malignant transformation is unknown. This study aimed to examine the Notch1 expression patterns by immunohistochemistry (IHC) in a cohort of 78 Chinese patients with OL and to analyze the relationship between the patterns and progression of OL to OSCC. Strong Notch1 staining was observed in 10 (13%) of the 78 OL patients, but it was not associated with any of the clinicopathological parameters. However, we observed membranous Notch1 expression in 24 (31%) of the OL samples. Membranous Notch1 expression was significantly associated with the severity of dysplasia (P<0.001) and development of OSCC (P=0.003). By multivariate analysis, membranous Notch1 expression was found to be the only independent factor for OSCC development in the patient population (P=0.019). Among the 24 patients with membranous Notch1 expression, 11 (46%) developed OSCC compared to 8 (15%) of the 54 patients without such expression (P=0.001, determined by log‑rank test). Furthermore, we established a 4‑nitroquinoline‑1‑oxide (4NQO)‑induced murine OSCC model and studied the Notch1 expression patterns in different stages of carcinogenesis. We observed that the extent of expression of membranous Notch1 increased during carcinogenesis. These data indicated a relationship between membranous Notch1 expression and OSCC risk in patients with OL and suggested that membranous Notch1 served as a biomarker for assessing OSCC risk.

Cross-Talk between Myeloid-Derived Suppressor Cells and Mast Cells Mediates Tumor-Specific Immunosuppression in Prostate Cancer

Immunotherapy, including the use of checkpoint inhibitors, is a potent therapeutic approach for some cancers, but has limited success with prostate tumors, in which immune suppression is instigated by the tumor. The immunosuppressive capacity of mast cells, which promote adenocarcinoma development in the prostate, prompted our investigation on whether mast cells promote tolerance to SV40 Large-T antigen, the transforming oncogene in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice. The incidence of adenocarcinoma was reduced in the offspring of a cross between TRAMP mice and mast cell-deficient Kit^Wsh mice. TRAMP mice are tolerant to the SV40 Large T antigen, which is otherwise immunogenic in normal syngeneic B6 mice. Genetic ablation of mast cells in TRAMP mice restored their ability to mount a tumor-specific cytotoxic T-cell response. In Kit^Wsh-TRAMP mice, the restored T-cell immunity correlated with the reduced activity of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC), along with their reduced expression of Arg1, Nos2, and Stat3 Having found that CD40L-expressing mast cells can interact in vivo with CD40-expressing PMN-MDSC, we then determined that only Kit^Wsh-TRAMP mice reconstituted with mast cells expressing CD40L could restore PMN-MDSCs suppressive functions, T-cell unresponsiveness and adenocarcinoma development. Thus, mast cells have an immunoregulatory effect on PMN-MDSCs activity through CD40L-CD40 interaction, favoring immunosuppression and tumor onset. In prostate cancer patients, in silico analyses correlated poor clinical outcomes with high expression of genes related to mast cells and PMN-MDSCs. Cancer Immunol Res; 6(5); 552-65. ©2018 AACR.

Notch1 suppresses prostate cancer cell invasion via the metastasis-associated 1-KiSS-1 metastasis-suppressor pathway

Notch1 is a type-1 transmembrane receptor which has been demonstrated to be involved in proliferation in various organisms. A number of studies have proposed that Notch signaling may be aberrantly activated, thus contributing to development, invasion and metastasis in a variety of human cancers. In the present study, the function and mechanism of Notch1 in human prostate cancer (PCa) LNCaP cells in vitro was investigated. Notch1 and cleaved-Notch1 expression were evaluated in human PCa cell lines, including LNCaP, PC-3 and DU 145, and the human prostate epithelial RWPE-1 cell line. LNCaP cells were transfected with Notch1-targeting short hairpin RNAs (shRNAs) and the level of proliferation, the ability to invade and the expression of genes associated with cancer cell invasion were subsequently investigated. Notch1 was highly expressed in LNCaP, PC-3 and DU 145 cells compared with RWPE-1 cells, while cleaved-Notch1 was expressed in LNCaP, PC-3 and DU 145 cells, and only to a minimal extent in RWPE-1 cells. Knockdown of Notch1 by shRNA in LNCaP cells markedly decreased cell invasion through Matrigel and inhibited cell proliferation 48 h following transfection. Reverse transcription-quantitative polymerase chain reaction analysis indicated that Notch1-knockdown resulted in a significant reduction of metastasis-associated 1 (MTA1) and increase of KiSS-1 metastasis-suppressor (KISS-1), mitogen-activated protein kinase 4 (MKK4) and cluster of differentiation 82 (KAI1). The present data demonstrated that expression of Notch1 was significantly associated with the invasion of prostate cancer. Knockdown of Notch1 decreased the invasive ability of LNCaP cells, which may be caused by downregulating MTA1 and upregulating KISS-1, MKK4 and KAI1. These findings indicated that targeting Notch1 may provide a novel method of suppressing or treating metastasis in prostate cancer.

Notch system is differentially expressed and activated in pituitary adenomas of distinct histotype, tumor cell lines and normal pituitaries

Pituitary adenomas are among the most frequent intracranial neoplasms and treatment depends on tumor subtype and clinical features. Unfortunately, non responder cases occur, then new molecular targets are needed.

Notch system component expression and activation data are scarce in pituitary tumorigenesis, we therefore aimed to characterize Notch system in pituitary tumors of different histotype. In human pituitary adenomas we showed NOTCH1-4 receptors, JAGGED1 ligand and HES1 target gene expression with positive correlations between NOTCH1,2,4 and HES1, and NOTCH3 and JAGGED1 denoting Notch system activation in a subset of tumors. Importantly, NOTCH3 positive cells were higher in corticotropinomas and somatotropinomas compared to non functioning adenomas. In accordance, Notch activation was evidenced in AtT20 tumor corticotropes, with higher levels of NOTCH1-3 active domains, Jagged1 and Hes1 compared to normal pituitary.

In the prolactinoma cell lines GH3 and MMQ, in vivo GH3 tumors and normal glands, Notch system activation was lower than in corticotropes. In MMQ cells only the NOTCH2 active domain was increased, whereas NOTCH1 active domain was higher in GH3 tumors. High levels of Jagged1 and Dll1 were found solely in GH3 cells, and Hes1, Hey1 and Hey2 were expressed in a model dependent pattern.

Prolactinomas harbored by lacDrd2KO mice expressed high levels of NOTCH1 active domain and reduced Hes1.

We show a differential expression of Notch system components in tumoral and normal pituitaries and specific Notch system involvement depending on adenoma histotype, with higher activation in corticotropinomas. These data suggest that targeting Notch pathway may benefit non responder pituitary adenomas.

The Notch-1 receptor in prostate tumorigenesis

The Notch signalling pathway plays a fundamental role in tissue development due to its involvement in cell fate determination and postnatal tissue differentiation. Its capacity to regulate cell growth and development has been linked to the occurrence of several cancers including that of the prostate. The transmembrane receptor Notch-1 of this pathway has been linked to the oncogenic role of Notch signalling in prostate adenocarcinoma. Other studies have suggested a tumour suppressive function for Notch-1. This review focuses on the role of Notch-1 in prostate cancer development and maintenance and relates this to the fundamental role of Notch in normal prostate development. The current understanding of the aberrant Notch signalling characteristic of prostate cancer is discussed, and recent therapeutic advances in this field are presented.

Activation of Notch pathway is linked with epithelial-mesenchymal transition in prostate cancer cells

Notch signaling has been reported to play an essential role in tumorigenesis. Several studies have suggested that Notch receptors could be oncoproteins or tumor suppressors in different types of human cancers. Emerging evidence has suggested that Notch pathway regulates cell growth, apoptosis, cell cycle, and metastasis. In the current study, we explore whether Notch-1 could regulate the cell invasion and migration as well as EMT (epithelial-mesenchymal transition) in prostate cancer cells. We found that overexpression of Notch-1 enhanced cell migration and invasion in PC-3 cells. However, downregulation of Notch-1 retarded cell migration and invasion in prostate cancer cells. Importantly, we observed that overexpression of Notch-1 led to EMT in PC-3 cells. Notably, we found that EMT-type cells are associated with EMT markers change and cancer stem cell phenotype. Taken together, we concluded that downregulation of Notch-1 could be a promising approach for inhibition of invasion in prostate cancer cells, which could be useful for the treatment of metastatic prostate cancer.

Cinobufagin induces apoptosis of osteosarcoma cells through inactivation of Notch signaling

Osteosarcoma (OS) is a major cause of cancer-related mortality in children and young adults worldwide. Due to preexisting or acquired chemoresistance, the current standard neoadjuvant chemotherapy regimens show only moderate activity against OS. In the current study, we explored the potential anti-OS Cinobufagin in vitro and in vivo, and investigated its underlying mechanisms. The antitumor potential of Cinobufagin was assessed using cell viability assays, and cycle and apoptosis were determined. In a cell-based assay, the mRNA and protein expression of Notch-1, Hes-1, Hes-5 and Hey-1 were determined by quantitative polymerase chain reactions and western blotting. The involvement of Notch signaling in Cinobufagin-induced apoptosis was confirmed using gain and loss-of function assays. A xenograft OS model was established and the antitumor effect and biosafety of Cinobufagin were evaluated. Cinobufagin suppressed OS cells growth in a dose- and time-dependent manner, involving both cell cycle arrest at the S phase and programmed cell death. Cinobufagin treatment decreased the expression of Notch-1, and Hes-1, Hes-5 and Hey-1 gene expression in OS cell lines. Furthermore, Notch activation attenuated the Cinobufagin-induced apoptosis, while Notch inhibition enhanced this effect. Using a mouse xenograft model, we found that Cinobufagin inhibited OS cell growth in vivo. The mice showed excellent tolerance to Cinobufagin treatment. Taken together, our data suggested that Cinobufagin inhibited cell survival and induced apoptosis in OS cells both in vitro and in vivo, and these effects were partly mediated through the Notch pathway.