Notch1 regulates invasion and metastasis of head and neck squamous cell carcinoma by inducing EMT through c-Myc

Enhanced antitumor immunity in breast cancer: Synergistic effects of ADAM10/ADAM17 inhibition, metabolic modulation, and camptothecin-loaded selenium nanoparticles

BACKGROUND

In this study, we investigate the impact of a multi-targeted therapeutic approach that includes camptothecin (CPT), a potent chemotherapeutic topoisomerase inhibitor; metformin (Met), a metabolic modulator with emerging anti-tumor effects; and GW280264X, an inhibitor of ADAM 10/ADAM 17 enzymes, which are associated with tumor invasion and immune response. The study aims to assess the combined effects of these agents in enhancing CD8+ T cell-mediated anti-tumor immunity and suppressing cancer cell growth in triple-negative breast cancer (TNBC) models, both in vitro and in vivo.

METHODS

Cell viability was performed on the 4 T1 human TNBC cell line. Furthermore, we examined c-MYC protein expression by western blot, TOX and NR4A expression by Real-time PCR, and the number of CD8+ CD28+ T cells by immunofluorescence assay to demonstrate the anticancer effects of combined of CPT, Met and GW280264X in BC growth, exhaustion and senescence of T cells.

RESULTS

Regarding cell viability, HA-Se@CPT + Met and HA-Se@CPT + Met + GW280264X treatments decreased 4 T1 cell growth (p < 0.001). Combination therapy of Met, HA-Se@CPT, and GW280264X significantly reduced tumor volume and weight in vivo. This treatment also increased the number of CD8+ CD28+ T cells in the tumor microenvironment (TME) of BC (p < 0.0001) and decreased the expression of TOX and NR4A (p < 0.0001, p < 0.01). Furthermore, decreased expression of c-MYC as an oncogene protein was seen in the single and combined treatment by HA-Se@CPT and GW280264X (p < 0.05).

CONCLUSION

These findings suggest that of HA-Se@CPT, Met, and GW280264X may inhibit tumor progression in BC by improving the function and infiltration of CD8+ T cells. Their effect is more pronounced when used in combination.

Panoramic view of key cross-talks underpinning the oral squamous cell carcinoma stemness - unearthing the future opportunities

The clinical management of oral cancer is often frequented with challenges that arise from relapse, recurrence, invasion and resistance towards the cornerstone chemo and radiation therapies. The recent conceptual advancement in oncology has substantiated the role of cancer stem cells (CSC) as a predominant player of these intricacies. CSC are a sub-group of tumor population with inherent adroitness to self-renew with high plasticity. During tumor evolution, the structural and functional reprogramming persuades the cancer cells to acquire stem-cell like properties, thus presenting them with higher survival abilities and treatment resistance. An appraisal on key features that govern the stemness is of prime importance to confront the current challenges encountered in oral cancer. The nurturing niche of CSC for maintaining its stemness characteristics is thought to be modulated by complex multi-layered components encompassing neoplastic cells, extracellular matrix, acellular components, circulatory vessels, various cascading signaling molecules and stromal cells. This review focuses on recapitulating both intrinsic and extrinsic mechanisms that impart the stemness. There are contemplating evidences that demonstrate the role of transcription factors (TF) in sustaining the neoplastic stem cell's pluripotency and plasticity alongside the miRNA in regulation of crucial genes involved in the transformation of normal oral mucosa to malignancy. This review illustrates the interplay between miRNA and various known TF of oral cancer such as c-Myc, SOX, STAT, NANOG and OCT in orchestrating the stemness and resistance features. Further, the cross-talks involved in tumor micro-environment inclusive of cytokines, macrophages, extra cellular matrix, angiogenesis leading pathways and influential factors of hypoxia on tumorigenesis and CSC survival have been elucidated. Finally, external factorial influence of oral microbiome gained due to the dysbiosis is also emphasized. There are growing confirmations of the possible roles of microbiomes in the progression of oral cancer. Given this, an attempt has been made to explore the potential links including EMT and signaling pathways towards resistance and stemness. This review provides a spectrum of understanding on stemness and progression of oral cancers at various regulatory levels along with their current therapeutic knowledge. These mechanisms could be exploited for future research to expand potential treatment strategies.

ZEB1-activated Notch1 promotes circulating tumor cell migration and invasion in lung squamous cell carcinoma

BACKGROUND

Lung squamous cell carcinoma (LUSC) is recognized as the major subtypes of non-small cell lung cancer (NSCLC). Circulating tumor cells (CTCs) are critical players in tumor metastasis. A molecular profiling of CTCs has previously identified notch receptor 1 (Notch1) as an important mediator in NSCLC. Therefore, we investigate Notch1 roles in LUSC and its related mechanisms.

METHODS

The serum levels of Notch1 were measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The CTCs isolated from blood samples were characterized via an immunofluorescence method. Cell motion was determined using Transwell chambers. The regulatory relationship between Notch1 and zinc finger E-box-binding homeobox 1 (ZEB1) was verified by chromatin immunoprecipitation (ChIP) and luciferase reporter assays. The protein levels were detected by western blotting.

RESULTS

Higher Notch1 expression in patients with LUSC than that in normal controls was observed. Notch1 knockdown inhibited cell motion and epithelial-mesenchymal transition (EMT). ZEB1 transcriptionally activated Notch1. ZEB1 upregulation exacerbated the malignant phenotypes of CTCs.

CONCLUSION

ZEB1-activated Notch1 promotes malignant phenotypes of CTCs in LUSC and indicates poor prognosis.

AL101, a gamma-secretase inhibitor, has potent antitumor activity against adenoid cystic carcinoma with activated NOTCH signaling

Adenoid cystic carcinoma (ACC) is an aggressive salivary gland malignancy with limited treatment options for recurrent or metastatic disease. Due to chemotherapy resistance and lack of targeted therapeutic approaches, current treatment options for the localized disease are limited to surgery and radiation, which fails to prevent locoregional recurrences and distant metastases in over 50% of patients. Approximately 20% of patients with ACC carry NOTCH-activating mutations that are associated with a distinct phenotype, aggressive disease, and poor prognosis. Given the role of NOTCH signaling in regulating tumor cell behavior, NOTCH inhibitors represent an attractive potential therapeutic strategy for this subset of ACC. AL101 (osugacestat) is a potent γ-secretase inhibitor that prevents activation of all four NOTCH receptors. While this investigational new drug has demonstrated antineoplastic activity in several preclinical cancer models and in patients with advanced solid malignancies, we are the first to study the therapeutic benefit of AL101 in ACC. Here, we describe the antitumor activity of AL101 using ACC cell lines, organoids, and patient-derived xenograft models. Specifically, we find that AL101 has potent antitumor effects in in vitro and in vivo models of ACC with activating NOTCH1 mutations and constitutively upregulated NOTCH signaling pathway, providing a strong rationale for evaluation of AL101 in clinical trials for patients with NOTCH-driven relapsed/refractory ACC.

NOTCH1 mutation associates with impaired immune response and decreased relapse-free survival in patients with resected T1-2N0 laryngeal cancer

Background

Patients with early-stage laryngeal cancer, even stage T1-2N0, are at considerable risk of recurrence and death. The genetic and immunologic characteristics of recurrent laryngeal cancer remain unclear.

Methods

A total of 52 T1-2N0 laryngeal cancer patients were enrolled. Of these, 42 tissue samples were performed by targeted DNA sequencing, and 21 cases were performed by NanoString immuno-oncology targeted RNA sequencing to identify the distinct molecular bases and immunologic features associated with relapse in patients with early laryngeal cancer, respectively.

Results

To the best to our knowledge, we present for the first time an overview of the genomic mutation spectrum of early-stage laryngeal cancers. A total of 469 genomic alterations were detected in 211 distinct cancer-relevant genes, and the genes found to be mutated in more than five patients (>10%) included tumor protein p53 (TP53, 78.5%), FAT atypical cadherin 1 (FAT1, 26%), LDL receptor related protein 1B (LRP1B, 19%), cyclin dependent kinase inhibitor 2A (CDKN2A, 17%), tet methylcytosine dioxygenase 2 (TET2, 17%), notch receptor 1 (NOTCH1, 12%) and neuregulin 1 (NRG1, 12%). Recurrent laryngeal cancer demonstrated a higher tumor mutation burden (TMB), as well as higher LRP1B mutation and NOTCH1 mutation rates. Univariate and multivariate analyses revealed that high TMB (TMB-H) and NOTCH1 mutation are independent genetic factors that are significantly associated with shorter relapse-free survival (RFS). Simultaneously, the results of the transcriptome analysis presented recurrent tumors with NOTCH1 mutation displayed upregulation of the cell cycle pathway, along with decreased B cells score, T cells score, immune signature score and tumor-infiltrating lymphocytes (TILs) score. The Cancer Genome Atlas (TCGA)-laryngeal cancer dataset also revealed weakened immune response and impaired adhesion functions in NOTCH1-mutant patients.

Conclusions

Genomic instability and impaired immune response are key features of the immunosurveillance escape and recurrence of early laryngeal cancer after surgery. These findings revealed immunophenotypic attenuation in recurrent tumors and provided valuable information for improving the management of these high-risk patients. Due to the small number of patients in this study, these differences need to be further validated in a larger cohort.

Loss of PFKFB4 induces cell cycle arrest and glucose metabolism inhibition by inactivating MEK/ERK/c-Myc pathway in cervical cancer cells

6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 (PFKFB4) was reported to be necessary for tumour growth in several cancers. However, the function of PFKFB4 in cervical cancer has not been clearly elucidated. Bioinformatics analysis was applied to detect the expression of PFKFB4 in cervical cancer and the association with survival prognosis. The effect of PFKFB4 on cervical cancer cells growth, cycle, invasion, migration and glucose metabolism was investigated by loss-of-function approaches in vitro. The association between PFKFB4 and MEK/ERK/c-Myc pathway was identified by western blot assay. We found that PFKFB4 was highly expressed in cervical cancer samples and its overexpression led to a poor prognosis of cervical cancer patients. Knock down of PFKFB4 reduced cell growth, blocked cell cycle, inhibited cell invasion and migration, and blocked glucose metabolism in cervical cancer cells. Our findings afforded a theoretical basis for further research on the treatment of cervical cancer based on the control of PFKFB4 expression. Impact StatementWhat is already known on this subject? PFKFB4 was overexpressed in several kinds of cancers and its requirement for tumour growth has been confirmed in cancers such as glioma and breast cancer. However, the function of PFKFB4 in cervical cancer cells has not been clearly elucidated. A bioinformatics study showed that PFKFB4 was a member of a six-gene signature associated with glycolysis to predict the prognosis of patients with cervical cancer. However, the relationship between PFKFB4 and glucose metabolism in cervical cancer has not been revealed.What do the results of this study add? Our results showed that PFKFB4 was highly expressed in cervical cancer samples and its overexpression led to a poor prognosis of cervical cancer patients. Moreover, the administration of si-PFKFB4 significantly reduced cell growth ability, blocked cell cycle, restrained the mobility and suppressed the glucose metabolism in cervical cancer cells partially by inactivating MEK/ERK/c-Myc pathway.What are the implications of these findings for clinical practice and/or further research? Our findings afforded a theoretical basis for further research on the treatment of cervical cancer based on the control of PFKFB4 expression.

Shooting at Moving and Hidden Targets-Tumour Cell Plasticity and the Notch Signalling Pathway in Head and Neck Squamous Cell Carcinomas

Head and Neck Squamous Cell Carcinoma (HNSCC) is often aggressive, with poor response to current therapies in approximately 40-50% of the patients. Current therapies are restricted to operation and irradiation, often combined with a small number of standard-of-care chemotherapeutic drugs, preferentially for advanced tumour patients. Only very recently, newer targeted therapies have entered the clinics, including Cetuximab, which targets the EGF receptor (EGFR), and several immune checkpoint inhibitors targeting the immune receptor PD-1 and its ligand PD-L1. HNSCC tumour tissues are characterized by a high degree of intra-tumour heterogeneity (ITH), and non-genetic alterations that may affect both non-transformed cells, such as cancer-associated fibroblasts (CAFs), and transformed carcinoma cells. This very high degree of heterogeneity likely contributes to acquired drug resistance, tumour dormancy, relapse, and distant or lymph node metastasis. ITH, in turn, is likely promoted by pronounced tumour cell plasticity, which manifests in highly dynamic and reversible phenomena such as of partial or hybrid forms of epithelial-to-mesenchymal transition (EMT), and enhanced tumour stemness. Stemness and tumour cell plasticity are strongly promoted by Notch signalling, which remains poorly understood especially in HNSCC. Here, we aim to elucidate how Notch signal may act both as a tumour suppressor and proto-oncogenic, probably during different stages of tumour cell initiation and progression. Notch signalling also interacts with numerous other signalling pathways, that may also have a decisive impact on tumour cell plasticity, acquired radio/chemoresistance, and metastatic progression of HNSCC. We outline the current stage of research related to Notch signalling, and how this pathway may be intricately interconnected with other, druggable targets and signalling mechanisms in HNSCC.

Cancer-associated fibroblast-secreted collagen triple helix repeat containing-1 promotes breast cancer cell migration, invasiveness and epithelial-mesenchymal transition by activating the Wnt/β-catenin pathway

Cancer-associated fibroblasts (CAFs) are continuously activated and are one of the most important cellular components of the tumor matrix. The role of CAFs in the tumor microenvironment has been widely recognized. However, the underlying molecular mechanism by which CAFs promote tumor characteristics in breast cancer (BC) remains poorly understood. The aim of the present study was to investigate the potential mechanisms and the possible pathways of collagen triple helix repeat containing-1 (CTHRC1) in the epithelial-mesenchymal transition (EMT) of BC cells. The level of CTHRC1 in BC tissues was found to be higher than that in adjacent-normal tissues. CAFs isolated from BC tissues secreted significantly greater amounts of CTHRC1 than normal fibroblasts. Furthermore, CAFs promoted the migration, invasiveness and EMT of BC cells by secreting CTHRC1, which activates the Wnt/β-catenin signaling pathway. However, the use of neutralizing antibodies towards CTHRC1, or the specific inhibitor Dickkopf-1, to inhibit the Wnt/β catenin pathway significantly alleviated the CAF-induced malignant phenotypes of BC cells. Collectively, the data indicate that CAFs in the tumor microenvironment promote BC cell malignant behaviors via the CTHRC1/Wnt/β-catenin signaling pathway. Furthermore, weakening CAF-BC cell communication by suppressing CTHRC1 expression may be a novel strategy for treating BC.

FAM83A promotes proliferation and metastasis via Wnt/β-catenin signaling in head neck squamous cell carcinoma

This research aimed to investigate the expression and function of FAM83A in the proliferation and metastasis in head and neck squamous cell carcinoma (HNSCC). FAM83A mRNA and protein expressions in HNSCC were detected in primary HNSCC samples and cell lines. The associations between FAM83A expression and clinicopathologic variables were evaluated through tissue microarrays. Besides, FAM83A knockdown and overexpression cell lines were constructed to assess cell growth and metastasis in vitro and the relationship between FAM83A and epithelial-mesenchymal transition (EMT). Furthermore, two models of xenograft tumors in nude mice were used to assess the tumorigenicity and metastasis ability of FAM83A in vivo. In the present study, overexpression of FAM83A in HNSCC samples was significantly associated with tumor size, lymph node status and clinical tumor stages. Mechanically, FAM83A could promote HNSCC cell growth and metastasis by inducing EMT via activating Wnt/β-catenin signaling pathway. Rescue experiment demonstrated the inhibition of β-catenin could counteract the function of FAM83A. Also, the FAM83A knockdown could suppress tumor growth and distant metastasis in the xenograft animal models of HNSCC. In conclusion, this study identifies FAM83A as an oncogene of HNSCC. This study provides new insights into the molecular pathways that contribute to EMT in HNSCC. We revealed a previously unknown FAM83A-Wnt–β-catenin signaling axis involved in the EMT of HNSCC. There may be a potential bi-directional signaling loop between FAM83A and Wnt/β-catenin signaling pathway in HNSCC.

NOTCH1 Signaling in Head and Neck Squamous Cell Carcinoma

Biomarker-driven targeted therapies are lacking for head and neck squamous cell carcinoma (HNSCC), which is common and lethal. Efforts to develop such therapies are hindered by a genomic landscape dominated by the loss of tumor suppressor function, including NOTCH1 that is frequently mutated in HNSCC. Clearer understanding of NOTCH1 signaling in HNSCCs is crucial to clinically targeting this pathway. Structural characterization of NOTCH1 mutations in HNSCC demonstrates that most are predicted to cause loss of function, in agreement with NOTCH1's role as a tumor suppressor in this cancer. Experimental manipulation of NOTCH1 signaling in HNSCC cell lines harboring either mutant or wild-type NOTCH1 further supports a tumor suppressor function. Additionally, the loss of NOTCH1 signaling can drive HNSCC tumorigenesis and clinical aggressiveness. Our recent data suggest that NOTCH1 controls genes involved in early differentiation that could have different phenotypic consequences depending on the cancer's genetic background, including acquisition of pseudo-stem cell-like properties. The presence of NOTCH1 mutations may predict response to treatment with an immune checkpoint or phosphatidylinositol 3-kinase inhibitors. The latter is being tested in a clinical trial, and if validated, it may lead to the development of the first biomarker-driven targeted therapy for HNSCC.

The Gain-of-Function Mutation p53R248W Suppresses Cell Proliferation and Invasion of Oral Squamous Cell Carcinoma through the Down-Regulation of Keratin 17

Keratin 17 (KRT17) expression promotes the proliferation and invasion of oral squamous cell carcinoma (OSCC), and mutations in TP53 have been reported in 65% to 85% of OSCC cases. We studied the correlation between KRT17 expression and TP53 mutants. Ca9-22 cells, which exhibit low KRT17 expression, carried mutant p53 (p53R248W) and p53R248W knockdown promoted KRT17 expression. p53R248W knockdown in Ca9-22 cells promoted migration and invasion activity. In contrast, in HSC3 cells, which have p53 nonsense mutations and exhibit high KRT17 expression, the overexpression of p53R248W decreased KRT17 expression, cell size, proliferation, and migration and invasion activities. In addition, p53R248W significantly suppressed MMP2 mRNA expression and enzyme activity. Moreover, s.c. and orthotopic xenografts were generated from p53R248W- or p53R248Q-expressing HSC3 cells. Tumors formed from p53R248W-expressing HSC3 cells grew more slowly and had a lower Ki-67 index than those derived from the control or p53R248Q-expressing HSC3 cells. Finally, the survival rate of the mice inoculated with p53R248W-expressing HSC3 cells was significantly higher than that of the control mice. These results indicate that the p53R248W mutant suppresses proliferation and invasion activity through the suppression of KRT17 expression. We propose that OSCC with p53R248W-expressing cells may be classified as a new OSCC type that has a good prognosis.

Upregulated circPDK1 Promotes RCC Cell Migration and Invasion by Regulating the miR-377-3P-NOTCH1 Axis in Renal Cell Carcinoma

Background

Circular RNAs (circRNAs) are novel clusters of endogenous noncoding RNAs (ncRNAs) that are involved in the regulation of multiple biological processes in diverse types of cancers. However, the roles and precise mechanisms of circRNAs in renal cell carcinoma (RCC) occurrence and progression have not been clearly elucidated.

Methods

We identified the aberrantly expressed circRNAs in RCC by high-throughput RNA-seq assay and used qRT-PCR to test the expression level of circRNAs in RCC tissues. Loss-of-function experiments were executed to detect the biological roles of circPDK1 in the RCC cells both in vivo and in vitro. RNA Fish, luciferase reporter assays and Western blotting were used to explore the molecular mechanism of circPDK1 function. All data were expressed as the means ± standard error of the mean (SEM). Student’s t-test, one-way ANOVA, Cox regression, an LSD-t-test, Pearson’s chi-squared test, a Log-rank test, and linear regression analyses were used to evaluate the group differences. P < 0.05 was considered significant.

Results

CircPDK1 was overexpressed in RCC tissues and positively associated with patient tumor metastasis and renal cell invasion. The in vivo functional assays also revealed that circPDK1 drove RCC xenograft metastasis. CircPDK1 was mainly located in the cytoplasm, serving as a sponge of miR-377-3P to regulate RCC invasion and metastasis through NOTCH1 (Notch Homolog 1). Ectopic express of NOTCH1 in RCC cell lines will block the metastasis inhibition effect after circPDK1 knockdown.

Conclusion

CircPDK1 is aberrantly expressed in RCC and promotes the metastasis of RCC cells mainly through sponging miR-377-3P and reducing its negative regulation of NOTCH1. Thus, circPDK1 may act as a therapeutic target and biomarker for RCC.

Anti-c-myc efficacy block EGFL7 induced prolactinoma tumorigenesis

Resistance to Dopamine agonists therapy is still a key factor that hinders the clinical treatment of prolactinoma. Consequently, a large number of investigations have been carried out to identify novel therapeutic targets. Our previous studies have suggested that the epidermal growth factor-like domain 7 (EGFL7) plays a crucial role in tumorigenesis of pituitary adenomas via EGFR/AKT/MAPK signaling pathway. In the present research, we found a positive staining of c-myc intimately associated with high-level EGFL7 in invasive prolactinoma compared to non-invasive prolactinoma and the normal pituitary gland. Meanwhile, PI3K/Akt and MAPK signaling cascades closely related to the activation of c-myc. Therefore, this research was conducted to explore the cooperation effect of c-myc and EGFL7 in prolactinoma. The inhibition of c-myc with anti-c-myc antibodies significantly reduced the proliferation, PRL secretion and invasion of rat prolactinoma MMQ cells. Notably, down regulation c-Myc by in vitro administration of anti-c-Myc antibodies could significantly depress EGFL7 induced MMQ cell proliferation, PRL secretion and invasion. An anti-c-Myc antibody could block EGFL7 induced Akt activation, but the expression of p-ERK was not altered by an anti-c-Myc antibody. Thus, our results suggest that anti-c-myc efficacy could block EGFL7 induced prolactinoma tumorigenesis via inhibited Akt activation in MMQ cells.

An essential role of RNF187 in Notch1 mediated metastasis of hepatocellular carcinoma

Background

Aberrant activation of Notch signaling has been causally linked to the metastasis of hepatocellular carcinoma (HCC), however the underlying molecular mechanisms are still poorly understood. RING finger protein 187 (RNF187) was recently revealed to be a driver of several cancers, but its expression pattern and biological function in HCC are unknown.

Methods

The expression levels of Notch1 and RNF187 were assessed in two independent cohorts of HCC tissues, and modulation of Notch1 in HCC cells was performed to explore the regulatory role of Notch1 in HCC metastasis. RNA-sequencing (RNA-seq), bioinformatics analysis, luciferase reporter analysis, and chromatin immunoprecipitation assay (ChIP) were used to clarify the relationship between Notch1 signaling and its potential target Ring finger protein 187 (RNF187). Gain- and loss-of-function studies were used to dissect the role of Notch1-RNF187 signaling in promoting HCC metastasis. The impact of Notch1-RNF187 activity in determining clinical prognosis for HCC patients was evaluated by multivariate Cox regression.

Results

By RNA-seq, luciferase reporter analysis, and ChIP assay, RNF187 was confirmed to be a direct transcriptional target of Notch1, as Notch1 could activate RNF187 promoter whereas the pro-migratory and pro-invasive effects of Notch1 were significantly attenuated by RNF187 knockdown. Meanwhile, RNF187 silencing could attenuate the Notch1-dependent epithelial-mesenchymal transition (EMT). Moreover, overexpression of RNF187 counteracted the inhibitory effect of Notch1 knockdown on cancer progression. Importantly, HCC patients with high level of hepatic Notch1 expression had shorter disease-free survival (DFS) than those with low level of hepatic Notch1 expression. Furthermore, patients with high level of Notch1 and RNF187 co-expression showed the shortest DFS. The expression level of Notch1 and RNF187 was an independent prognostic factor for HCC.

Conclusions

For the first time we identified that RNF187 is an essential factor for Notch1 to promote invasion and metastasis of HCC. Of highly clinical relevance, we found that activation of Notch1-RNF187 correlates with a worse prognosis of HCC patients. These findings provide a solid foundation for developing novel strategies to tackle HCC metastasis.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1382-x) contains supplementary material, which is available to authorized users.

SNORD89 promotes stemness phenotype of ovarian cancer cells by regulating Notch1-c-Myc pathway

Background

Ovarian cancer is the leading cause of death in gynecological cancer. Cancer stem cells (CSCs) contribute to the occurrence, progression and resistance. Small nucleolar RNAs (SnoRNAs), a class of small molecule non-coding RNA, involve in the cancer cell stemness and tumorigenesis.

Methods

In this study, we screened out SNORNAs related to ovarian patient’s prognosis by analyzing the data of 379 cases of ovarian cancer patients in the TCGA database, and analyzed the difference of SNORNAs expression between OVCAR-3 (OV) sphere-forming (OS) cells and OV cells. After overexpression or knockdown SNORD89, the expression of Nanog, CD44, and CD133 was measured by qRT-PCR or flow cytometry analysis in OV, CAOV-3 (CA) and OS cells, respectively. CCK-8 assays, plate clone formation assay and soft agar colony formation assay were carried out to evaluate the changes of cell proliferation and self-renewal ability. Scratch migration assay and trans-well invasion analysis were used for assessing the changes of migration and invasion ability.

Results

High expression of SNORD89 indicates the poor prognosis of ovarian cancer patients and was associated with patients’ age, therapy outcome. SNORD89 highly expressed in ovarian cancer stem cells. The overexpression of SNORD89 resulted in the increased stemness markers, S phase cell cycle, cell proliferation, invasion and migration ability in OV and CA cells. Conversely, these phenomena were reversed after SNORD89 silencing in OS cells. Further, we found that SNORD89 could upregulate c-Myc and Notch1 expression in mRNA and protein levels. SNORD89 deteriorates the prognosis of ovarian cancer patients by regulating Notch1-c-Myc pathway to promote cell stemness and acts as an oncogene in ovarian tumorigenesis. Consequently, SNORD89 can be a novel prognostic biomarker and therapeutic target for ovarian cancer.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-2005-1) contains supplementary material, which is available to authorized users.

Additive Pharmacological Interaction between Cisplatin (CDDP) and Histone Deacetylase Inhibitors (HDIs) in MDA-MB-231 Triple Negative Breast Cancer (TNBC) Cells with Altered Notch1 Activity-An Isobolographic Analysis

The aim of this study was to investigate the influence of the Notch1 activity level on the pharmacological interaction between cisplatin (CDDP) and two histone deacetylase inhibitors (HDIs)-valproic acid (VPA) and vorinostat (SAHA) in the triple negative breast cancer (TNBC) cells. Stable breast cancer (BC) cell lines with increased and decreased activity of Notch1 were generated using a transfection method. The type of interaction between CDDP and the HDIs was determined by isobolographic analysis of cell proliferation in MDA-MB-231 cells with differential levels of Notch1 activity in vitro. The combination of CDDP/SAHA and CDDP/VPA in the MDA-MB-231 triple negative breast cancer (TNBC) cells with increased activity of Notch1, as well as CDDP/VPA in the MDA-MB-231 cells with decreased activity of Notch1, yielded an additive interaction, whereas additivity with a tendency towards antagonism was observed for the combination of CDDP/SAHA in MDA-MB-231 cells with the decreased activity of Notch1. Our studies demonstrated that SAHA and VPA might be considered as potential therapeutic agents in combination therapy with CDDP against TNBC with altered Notch1 activity.

High Expression of long non-coding RNA PVT1 predicts metastasis in Han and Uygur Patients with Gastric Cancer in Xinjiang, China

To analyze the level and diagnostic value of plasmacytoma variant translocation 1 (PVT1) in gastric cancer (GC) of Han and Uygur in Xinjiang, China, we collected 42 GC and 47 normal gastric tissues and performed tissue microarray. In situ hybridization was used to detect PVT1, while immunohistochemistry was used to analyze c-myc. The relationship between PVT1, c-myc and clinical pathological features was investigated. We then analyzed the expression of PVT1 in six GC cell lines. RNA interference was used to silence PVT1 in BGC823 and AGS cells. c-myc was detected by western blotting after silencing PVT1, while proliferation, invasion and migration ability were also analyzed. We found that PVT1 and c-myc were highly expressed in both Han and Uygur GC tissues. In Han GC, PVT1 was correlated with lymph node metastasis and primary tumor site. In Uygur GC, both PVT1 and c-myc were correlated with lymph node metastasis and clinical staging. PVT1 was positively correlated with c-myc. BGC823 and AGS cells exhibited high levels of PVT1. When PVT1 expression was silenced, the expression of c-myc decreased, while migration and invasion ability were also decreased in cells. PVT1 could therefore be a potential biomarker to predict the metastatic tendency of GC in both Han and Uygur patients.

Membrane-tethered Notch1 exhibits oncogenic property via activation of EGFR-PI3K-AKT pathway in oral squamous cell carcinoma

Notch proteins are highly conserved cell surface receptors which play essential roles in cellular differentiation, proliferation, and apoptotic events at all stages of development. Recently, NOTCH1 mutations have been extensively observed in oral squamous cell carcinoma (OSCC) and are hinted to be Notch1-inactivating mutations. However, little is known about the biological effect of these reported mutations in OSCC. To mimic the inactivation of Notch1 due to inappropriate mutations and to determine the potential mechanisms, we utilized wild-type Notch1 vectors (Notch1^WT ) or mutant Notch1 vectors (Notch1^V1754L ) to transfect into OSCC cell lines. Membrane-tethered Notch1 induced by mutation was analyzed by immunofluorescence staining. γ-Secretase inhibitor PF-03084014 was utilized to determine the phenotype in the absence of endogenous Notch1 activation. Here we demonstrated that membrane-tethered Notch1 inactivated the canonical Notch1 signaling and oncogenic phenotypes were identified by promoting cell proliferation and invasion and by inducing epithelial-to-mesenchymal transition in cells. The γ-secretase inhibitor PF-03084014 also showed distinct oncogenic property after treatment. Importantly, both membrane-tethered Notch1 and PF-03084014 inhibitor activated the epidermal growth factor receptor (EGFR)-phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT) signaling pathway, which has been confirmed as an overwhelming modulator in OSCC. This was the first time that we clearly simulated the mutated Notch1 activities and determined the oncogenic phenotypes of membrane-tethered Notch1. Compared with wild-type Notch1, membrane-tethered Notch1 was strongly associated with activated EGFR-PI3K-AKT signaling pathway.

MicroRNA-133a inhibits gastric cancer cells growth, migration, and epithelial-mesenchymal transition process by targeting presenilin 1

Gastric cancer (GC) is one of the most common malignancies and a leading cause of cancer-related death worldwide. Accumulating evidence reported that microRNA (miR)-133a was involved in GC. This study aimed to investigate the function and mechanism of miR-133a in the development and progression of GC. The expression of miR-133a and presenilin 1 (PSEN1) in two GC cell lines, SGC-7901 and BGC-823, were inhibited and overexpressed by transient transfections. Thereafter, cell viability, migration, and apoptosis were measured by trypan blue exclusion assay, transwell migration assay, and flow cytometry assay, respectively. Dual-luciferase reporter assay was conducted to verify whether PSEN1 was a direct target of miR-133a. Furthermore, quantitative real-time polymerase chain reaction and Western blot analysis were mainly performed to assess the expression changes of epithelial-mesenchymal transition (EMT)-associated proteins, apoptosis-related proteins, and Notch pathway proteins. MiR-133a inhibitor significantly increased cell viability and migration, while miR-133a mimic decreased cell viability, migration, and induced apoptosis. miR-133a suppression accelerated transforming growth factor-β1 (TGF-β1)-induce EMT, as evidenced by upregulation of E-cadherin, and downregulation of N-cadherin, vimentin, and Slug. Of contrast, miR-133a overexpression blocked TGF-β1-induce EMT by altering these factors. PSEN1 was a direct target of miR-133a, and suppression of PSEN1 abolished the promoting functions of miR-133 suppression on cell growth and metastasis. Moreover, PSEN1 inhibition decreased Notch 1, Notch 2, and Notch 3 protein expressions. This study demonstrates an antigrowth and antimetastasis role of miR-133a in GC cells. Additionally, miR-133a acts as a tumor suppressor may be via targeting PSEN1.

miR-296-3p Negatively Regulated by Nicotine Stimulates Cytoplasmic Translocation of c-Myc via MK2 to Suppress Chemotherapy Resistance

This study aimed to identify mechanisms by which microRNA 296-3p (miR-296-3p) functions as a tumor suppressor to restrain nasopharyngeal carcinoma (NPC) cell growth, metastasis, and chemoresistance. Mechanistic studies revealed that miR-296-3p negatively regulated by nicotine directly targets the oncogenic protein mitogen-activated protein kinase-activated protein kinase-2 (Mapkapk2) (MK2). Suppression of MK2 downregulated Ras/Braf/Erk/Mek/c-Myc and phosphoinositide-3-kinase (PI3K)/Akt/c-Myc signaling and promoted cytoplasmic translocation of c-Myc, which activated miR-296-3p expression by a feedback loop. This ultimately inhibited cell cycle progression, epithelial-to-mesenchymal transition (EMT), and chemoresistance of NPC. In addition, nicotine as a key component of tobacco was observed to suppress miR-296-3p and thus elevate MK2 expression by inducing PI3K/Akt/c-Myc signaling. In clinical samples, reduced miR-296-3p as an unfavorable factor was inversely correlated with MK2 and c-Myc expression. These results reveal a novel mechanism by which miR-296-3p negatively regulated by nicotine directly targets MK2-induced Ras/Braf/Erk/Mek/c-Myc or PI3K/AKT/c-Myc signaling to stimulate its own expression and suppress NPC cell proliferation and metastasis. miR-296-3p may thus serve as a therapeutic target to reverse chemotherapy resistance of NPC.

A novel Notch1 missense mutation (C1133Y) in the Abruptex domain exhibits enhanced proliferation and invasion in oral squamous cell carcinoma

Background

Notch1 has been regarded as a fundamental regulator in tissue differentiation and stem cell properties. Recently, Notch1 mutations have been reported intensively both in solid tumors and in hematopoietic malignancies. However, little is known about the biological effect and the clinical implication of these reported mutations. Previously, we discovered several missense mutations in the Notch1 receptor in a Chinese population with oral squamous cell carcinoma (OSCC).

Methods

We selected a ‘hotspot’ mutation in the Abruptex domain (C1133Y). The expression of Notch1 was determined by western blot and real-time qPCR in OSCC cell lines transfected with pcDNA3.1-Notch1^WT, pcDNA3.1-Notch1^C1133Y, or pcDNA3.1 empty vector. CCK-8 assays were used to assess cell proliferation. Flow cytometry and western blot were used to confirm the alteration of cell cycle after transfection. Transwell assays and the detection of Epithelial-to-mesenchymal transition (EMT) markers were used to determine the invasive ability. The effects of Notch1 C1133Y mutation were analyzed by Immunofluorescence staining and the expression of EGFR-PI3K/AKT signaling.

Results

We demonstrated that Notch1^C1133Y mutation inactivated the canonical Notch1 signaling. We identified an oncogenic phenotype of this mutation by promoting cell proliferation, invasion and by inducing EMT in OSCC cell lines. We found that the Notch1^C1133Y mutation exhibited a decreased S1-cleavage due to the impaired transport of Notch1 protein from the endoplasmic reticulum (ER) to the Golgi complex, which was consistent with the observation of the failure of the Notch1^C1133Y mutated receptor to present at the cell surface. Importantly, the mutated Notch1 activated the EGFR-PI3K/AKT signaling pathway, which has been confirmed as an overwhelming modulator in OSCC.

Conclusions

Taken together, our findings revealed for the first time a novel Notch1 mutation that enhances proliferation and invasion in OSCC cell lines. The Notch1 C1133Y mutation impairs the processing of notch1 protein and the critical links between the mutated Notch1 and the activated EGFR-PI3K/AKT signaling pathway.

Electronic supplementary material

The online version of this article (10.1186/s12935-017-0496-5) contains supplementary material, which is available to authorized users.