Relationship between vascular endothelial growth factor and Notch1 expression and lymphatic metastasis in tongue cancer

Crosstalk between CAFs and tumour cells in head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) are amongst the most aggressive, complex, and heterogeneous malignancies. The standard of care treatments for HNC patients include surgery, radiotherapy, chemotherapy, or their combination. However, around 50% do not benefit while suffering severe toxic side effects, costing the individuals and society. Decades have been spent to improve HNSCC treatment outcomes with only limited success. Much of the research in HNSCC treatment has focused on understanding the genetics of the HNSCC malignant cells, but it has become clear that tumour microenvironment (TME) plays an important role in the progression as well as treatment response in HNSCC. Understanding the crosstalk between cancer cells and TME is crucial for inhibiting progression and treatment resistance. Cancer-associated fibroblasts (CAFs), the predominant component of stroma in HNSCC, serve as the primary source of extra-cellular matrix (ECM) and various pro-tumoral composites in TME. The activation of CAFs in HNSCC is primarily driven by cancer cell-secreted molecules, which in turn induce phenotypic changes, elevated secretive status, and altered ECM production profile. Concurrently, CAFs play a pivotal role in modulating the cell cycle, stemness, epithelial-mesenchymal transition (EMT), and resistance to targeted and chemoradiotherapy in HNSCC cells. This modulation occurs through interactions with secreted molecules or direct contact with the ECM or CAF. Co-culture and 3D models of tumour cells and other TME cell types allows to mimic the HNSCC tumour milieu and enable modulating tumour hypoxia and reprograming cancer stem cells (CSC). This review aims to provide an update on the development of HNSCC tumour models comprising CAFs to obtain better understanding of the interaction between CAFs and tumour cells, and for providing preclinical testing platforms of current and combination with emerging therapeutics.

A γ-Secretase Inhibitor Attenuates Cell Cycle Progression and Invasion in Human Oral Squamous Cell Carcinoma: An In Vitro Study

Notch signaling is associated with many human malignancies, including oral squamous cell carcinoma (OSCC). However, the exact function of Notch signaling in OSCC remains unclear. Here, we investigated the effect of Notch signaling inhibition using a γ-secretase inhibitor (DAPT) on OSCC behaviours in vitro. Bioinformatic analysis of public-available gene expression profiles revealed the dysregulation of the Notch signaling pathway in OSCC compared with normal tissues, indicating the role of Notch signaling in OSCC regulation. RNA sequencing analysis of DAPT-treated human OSCC cells revealed the dysregulation of genes related to cell cycle-related pathways. Blocking Notch signaling significantly inhibited cell proliferation. DAPT-induced G0/G1 cell cycle arrest induced cell apoptosis. Furthermore, cell migration and invasion were also reduced in DAPT-treated cells. These findings indicate that Notch signaling activation participates in OSCC regulation by promoting cell growth, cell cycle progression, cell migration, and invasion. These mechanisms could facilitate OSCC progression. These results imply the potential use of Notch signaling inhibitors as a candidate adjuvant treatment in OSCC patients.

Receptor, Signal, Nucleus, Action: Signals That Pass through Akt on the Road to Head and Neck Cancer Cell Migration

This review aims to provide evidence for the role of the tumour microenvironment in cancer progression, including invasion and metastasis. The tumour microenvironment is complex and consists of tumour cells and stromal-derived cells, in addition to a modified extracellular matrix. The cellular components synthesise growth factors such as EGF, TGFα and β, VEGF, and NGF, which have been shown to initiate paracrine signalling in head and neck cancer cells by binding to cell surface receptors. One example is the phosphorylation, and hence activation, of the signalling protein Akt, which can ultimately induce oral cancer cell migration in vitro. Blocking of Akt activation by an inhibitor, MK2206, leads to a significant decrease, in vitro, of cancer-derived cell migration, visualised in both wound healing and scatter assays. Signalling pathways have therefore been popular targets for the design of chemotherapeutic agents, but drug resistance has been observed and is related to direct tumour-tumour cell communication, the tumour-extracellular matrix interface, and tumour-stromal cell interactions. Translation of this knowledge to patient care is reliant upon a comprehensive understanding of the complex relationships present in the tumour microenvironment and could ultimately lead to the design of efficacious treatment regimens such as targeted therapy or novel therapeutic combinations.

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.

Cystatin-B Negatively Regulates the Malignant Characteristics of Oral Squamous Cell Carcinoma Possibly Via the Epithelium Proliferation/Differentiation Program

Disturbance in the proteolytic process is one of the malignant signs of tumors. Proteolysis is highly orchestrated by cysteine cathepsin and its inhibitors. Cystatin-B (CSTB) is a general cysteine cathepsin inhibitor that prevents cysteine cathepsin from leaking from lysosomes and causing inappropriate proteolysis. Our study found that CSTB was downregulated in both oral squamous cell carcinoma (OSCC) tissues and cells compared with normal controls. Immunohistochemical analysis showed that CSTB was mainly distributed in the epithelial structure of OSCC tissues, and its expression intensity was related to the grade classification. A correlation analysis between CSTB and clinical prognosis was performed using gene expression data and clinical information acquired from The Cancer Genome Atlas (TCGA) database. Patients with lower expression levels of CSTB had shorter disease-free survival times and poorer clinicopathological features (e.g., lymph node metastases, perineural invasion, low degree of differentiation, and advanced tumor stage). OSCC cell models overexpressing CSTB were constructed to assess the effects of CSTB on malignant biological behaviors and upregulation of CSTB inhibited cell proliferation, migration, and invasion in vitro. Weighted gene correlation network analysis (WGCNA) and gene set enrichment analysis (GSEA) were performed based on the TCGA data to explore potential mechanisms, and CSTB appeared to correlate with squamous epithelial proliferation-differentiation processes, such as epidermal cell differentiation and keratinization. Moreover, in WGCNA, the gene module most associated with CSTB expression (i.e., the brown module) was also the one most associated with grade classification. Upregulation of CSTB promoted the expression levels of markers (LOR, IVL, KRT5/14, and KRT1/10), reflecting a tendency for differentiation and keratinization in vitro. Gene expression profile data of the overexpressed CSTB cell line were obtained by RNA sequencing (RNA-seq) technology. By comparing the GSEA enrichment results of RNA-seq data (from the OSCC models overexpressing CSTB) and existing public database data, three gene sets (i.e., apical junction, G2/M checkpoint, etc.) and six pathways (e.g., NOTCH signaling pathway, glycosaminoglycan degradation, mismatch repair, etc.) were enriched in the data from both sources. Overall, our study shows that CSTB is downregulated in OSCC and might regulate the malignant characteristics of OSCC via the epithelial proliferation/differentiation program.

Prognostic Implications of ALDH1 and Notch1 in Different Subtypes of Oral Cancer

Background

The present study aimed to investigate the clinical significance and prognostic value of the immunoexpression of cancer stem cell markers, ALDH1 and Notch1, in subtypes of oral squamous cell carcinoma.

Materials and Methods

The expression of ALDH1 and Notch1 in 63 patients with well and poorly differentiated oral squamous cell carcinomas and their subtypes, verrucous carcinoma and basaloid squamous cell carcinoma, was evaluated by immunohistochemistry. The semi-quantitative analysis of the ALDH1 and Notch immunoexpression levels, based on the capture of 10 microscopic fields, at 400X magnification, at the invasive tumor front was performed and associated with clinicopathological variables using the chi-square test or Fisher's exact test. The overall and disease-free survival rates were estimated according to the Kaplan-Meier method and the curves were compared using the log-rank test. The independent effects of variables were calculated using Cox's proportional hazards regression model.

Results

Strong ALDH1 and Notch1 expression was observed in 16 (25.4%) and 27 (42.9%) oral squamous cell carcinomas including their subtypes, respectively. Most tumors with strong immunoexpression of ALDH1 were basaloid squamous cell carcinoma (56.3%). Statistically significant associations were observed between the strong immunoexpression of Notch1 in poorly differentiated oral squamous cell carcinoma with perineural infiltration (p = 0.011) and lymph node involvement (pN+) (p = 0.034). The strong immunoexpression of ALDH1 was a prognostic factor associated with worse overall survival (p = 0.040) for patients with oral cancer.

Conclusion

The strong immunoexpression of Notch1 can contribute to identification of patients with poorly differentiated oral squamous cell carcinoma, who have perineural infiltration or lymph node metastasis. In addition, the strong immunoexpression of ALDH1 may help to identify a worse prognosis in patients with oral squamous cell carcinoma and their subtypes.

Notch Signaling and Human Papillomavirus-Associated Oral Tumorigenesis

The NOTCH pathway is critical for the development of many cell types including the squamous epithelium lining of cutaneous and mucosal surfaces. In genetically engineered mouse models, Notch1 acts as one of the first steps to commit basal keratinocytes to terminally differentiate. Similarly, in human head and neck squamous cell cancers (HNSCCs), NOTCH1 is often lost consistent with its essential tumor-suppressive role for initiating keratinocyte differentiation. However, constitutive NOTCH1 activity in the epithelium results in expansion of the spinous keratinocyte layers and impaired terminal differentiation is consistent with the role of NOTCH1 as an oncogene in other cancers, especially in T-cell acute lymphoblastic leukemia. We have previously observed that NOTCH1 plays a dual role as both a tumor suppressor and oncogene, depending on the mutational context of the tumor. Namely, gain or loss or NOTCH1 activity promotes the development of human papillomavirus (HPV)-associated cancers. The additional HPV oncogenes likely disrupt the tumor-suppressive activities of NOTCH and enable the oncogenic pathways activated by NOTCH to promote tumor growth. In this review, we detail the role of NOTCH pathway in head and neck cancers with a focus on HPV-associated cancers.

Reciprocal activation of HEY1 and NOTCH4 under SOX2 control promotes EMT in head and neck squamous cell carcinoma

Several comprehensive studies have demonstrated that the NOTCH pathway is altered in a bimodal manner in head and neck squamous cell carcinoma (HNSCC). In a previous study, it was found that the NOTCH4/HEY1 pathway was specifically upregulated in HNSCC and promoted epithelial-mesenchymal transition (EMT), and that HEY1 activation supported SOX2 expression. However, the interactions in this pathway have not yet been fully elucidated. The present study investigated the NOTCH4/HEY1/SOX2 axis in HNSCC using in vitro models and the Cancer Genome Atlas (TCGA) database. To explore the association, reporter and ChIP RT-qPCR assays using SOX2-overexpressing (SOX2-OE) cells were performed. The association between NOTCH4 and HEY1 was examined in the same manner using HEY1-overexpressing (HEY1-OE) cells. The results of the in vitro experiments indicated that HEY1 promoted EMT in the HNSCC cells. Furthermore, the overexpression of HEY1 also promoted sphere formation and increased murine xenograft tumorigenicity. Reporter assays and ChIP RT-qPCR experiments indicated that SOX2 regulated HEY1 expression via direct binding of the HEY1 promoter. HEY1 expression significantly correlated with SOX2 expression in primary lung SCC and other SCCs using the TCGA database. HEY1 also regulated NOTCH4 expression to create a positive reciprocal feedback loop. On the whole, the present study demonstrates that HEY1 expression in HNSCC is regulated via the promotion of SOX2 and promotes EMT. The NOTCH4/HEY1 pathway is specifically upregulated via a positive reciprocal feedback loop mediated by the HEY1-medaited regulation of NOTCH4 transcription, and SOX2 correlates with HEY1 expression in SCC from other primary sites.

Notch in Head and Neck Cancer

Head and neck cancer is a group of neoplastic diseases affecting the facial, oral, and neck region. It is one of the most common cancers worldwide with an aggressive, invasive evolution. Due to the heterogeneity of the tissues affected, it is particularly challenging to study the molecular mechanisms at the basis of these tumors, and to date we are still lacking accurate targets for prevention and therapy. The Notch signaling is involved in a variety of tumorigenic mechanisms, such as regulation of the tumor microenvironment, aberrant intercellular communication, and altered metabolism. Here, we provide an up-to-date review of the role of Notch in head and neck cancer and draw parallels with other types of solid tumors where the Notch pathway plays a crucial role in emergence, maintenance, and progression of the disease. We therefore give a perspective view on the importance of the pathway in neoplastic development in order to define future lines of research and novel therapeutic approaches.

Cancer Stem Cells, Quo Vadis? The Notch Signaling Pathway in Tumor Initiation and Progression

The Notch signaling pathway regulates cell proliferation, cytodifferentiation and cell fate decisions in both embryonic and adult life. Several aspects of stem cell maintenance are dependent from the functionality and fine tuning of the Notch pathway. In cancer, Notch is specifically involved in preserving self-renewal and amplification of cancer stem cells, supporting the formation, spread and recurrence of the tumor. As the function of Notch signaling is context dependent, we here provide an overview of its activity in a variety of tumors, focusing mostly on its role in the maintenance of the undifferentiated subset of cancer cells. Finally, we analyze the potential of molecules of the Notch pathway as diagnostic and therapeutic tools against the various cancers.

The NOTCH Pathway in Head and Neck Squamous Cell Carcinoma

Comprehensive genomic analyses have been performed for head and neck squamous cell carcinoma (HNSCC), revealing a significant rate of NOTCH1 mutations and identifying NOTCH1 as the second most frequently mutated gene after TP53. Most NOTCH1 mutations are considered inactivating, indicating that NOTCH1 is a tumor suppressor gene. On the other hand, cohorts from Asian populations with HNSCC have shown activating NOTCH1 mutations. HNSCC with NOTCH1 mutations have a worse prognosis than the NOTCH1 wild-type tumors. Additional data on other NOTCH family members have shown that NOTCH promotes HNSCC progression. NOTCH family members, including NOTCH pathway genes, are upregulated in HNSCC compared with normal tissues, and inhibition of the NOTCH pathway decreases cell proliferation and invasion. NOTCH activity in HNSCC is therefore contextual, and NOTCH in HNSCC is considered to have a bimodal role as a tumor suppressor and an oncogene. In this review, recent understandings of NOTCH pathway genes, including NOTCH genes, in HNSCC are described. In addition, the implications of NOTCH pathway alteration for HNSCC-specific NOTCH-targeted cancer therapy are explored.

Expression of Jagged1/Notch3 Signaling Pathway and their Relationship with the Tumor Angiogenesis in TNBC

BACKGROUND AND AIMS

Jagged1/Notch3 signaling pathway plays a key role in angiogenesis of breast cancer, but little is known in TNBC. This study was designed to investigate the expression of Jagged1/Notch3 mRNA and protein in TNBC, analyze their correlations with clinicopathological characteristics and prognosis. Moreover, the interrelationship among Jagged1/Notch3 and VEGF was initially evaluated.

METHODS

Jagged1/Notch3 mRNA and protein expression levels were determined by Q-RT-PCR and Western blotting. Additionally, Immunohistochemistry for Jagged1/Notch3 was detected by Ventana platform, VEGF and CD34 was performed using the EnVision/HRP technique.

RESULTS

mRNA transcriptionof Jagged1/Notch3 was in accord with protein expression. TNBC patients with positive Jagged1 expression had poorer DFS (p = 0.008) and OS (p = 0.004). Jagged1 expression was independent predictors of OS (p = 0.038). The expression of VEGF was positively correlative to MVD (p = 0.018), MVD was significantly associated with Jagged1 (p <0.0001) and Notch3 (p <0.0001). The expression of Jagged1/Notch3 has no correlation with VEGF, only in positive VEGF expression of TNBC patients Jagged1/Notch3 had influence on DFS and OS (p <0.05).

CONCLUSION

Jagged1/Notch3 was -expressed at both the mRNA and protein levels, Jagged1 served as an independent predictor of poor prognosis. We speculate that there is a cross-talk between Jagged1/Notch3 and VEGF in TNBC angiogenesis. Jagged1/Notch3 is expected to be an important signaling pathway for TNBC progression and a potential target for TNBC neovascularization therapy.

Expression and influence of Notch signaling in oral squamous cell carcinoma

Notch signaling dysregulation plays an important role in altering cancer cell behaviors; however, its role in oral squamous cell carcinoma (OSCC) remains controversial. This study aimed to investigate the role of Notch signaling related genes in human OSCC using a meta-analysis of Gene Expression Omnibus database (GEO-publicly available gene expression microarray data) and to examine the role of Notch signaling in OSCC behaviors. The meta-analysis included 13 GEO datasets and was performed by combining effect sizes in a random effect model. The results demonstrated that in OSCC dysregulated genes participated in the metabolic process and protein binding as determined by gene ontology analysis. Enriched pathway analysis demonstrated the majority of the dysregulated genes were involved in pathway categories as follow; pathway in cancers, small cell lung cancer, extracellular matrix-receptor interaction, focal adhesion, and cell cycle progression. Interestingly, the enriched pathway analysis also demonstrated that OSCC samples exhibited an upregulation of genes in Notch signaling pathway, namely JAG1, JAG2, ADAM17, NCSTN, PSEN1, NCOR2, NUMB, DVL3, HDAC1, and HDAC2. Furthermore, Notch signaling inhibition by a γ-secretase inhibitor significantly decreased OSCC cell proliferation in vitro, corresponding with a decrease in C-FOS mRNA expression. The study demonstrated that Notch signaling is dysregulated in human OSCC and plays a role in cell proliferation. (J Oral Sci 58, 283-294, 2016).

Notch1 Overexpression Correlates to Improved Survival in Cancer of the Oropharynx

Objectives The Notch1 signaling pathway has recently been shown to be highly dysregulated in head and neck squamous cell carcinoma, but the value of Notch1 as a predictive biomarker is yet to be elucidated in oropharyngeal squamous cell carcinoma (OPSCC). The objective of this study is to evaluate Notch1 expression in surgical OPSCC specimens and determine clinicopathologic correlates. Study Design Case series with planned data collection. Setting Tertiary academic medical center. Subjects and Methods Surgical specimens from 181 patients with OPSCC were collected to create a tissue microarray (TMA). Human papillomavirus (HPV) status and Notch1 expression were determined and correlated with clinicopathologic characteristics. Results In univariate analysis, Notch1 expression correlated with improved survival as a categorical variable (hazard ratio [HR], 0.346; P < .0001) and correlated with HPV/p16 positivity as a continuous variable ( P < .0001). In multivariate analysis, Notch1 expression retained significance in HPV-positive (HR, 0.303; P = .033) and HPV-negative (HR, 0.416; P = .0055) subgroups. Similarly, Notch1 expression positively correlated with survival in p16-positive (HR, 0.469; P = .031) and p16-negative subgroups (HR, 0.310; P = .014). Conclusions In the largest OPSCC cohort to date, we found that Notch1 receptor expression positively correlates with overall survival, regardless of HPV or p16 status. Furthermore, we found higher Notch1 receptor expression in HPV/p16-positive tumors than their HPV/p16-negative counterparts.

Elevated VEGFA mRNA levels in oral squamous cell carcinomas and tumor margins: a preliminary study

BACKGROUND

New blood vessel formation events are essential for tumor clonal expansion and progression. Despite the importance of vascular endothelial growth factor A (VEGFA) for tumor angiogenesis, few studies have evaluated the expression profile of this gene in oral squamous cell carcinoma (OSCC) and tumor margins (TM). This study aimed to evaluate the expression of the VEGFA gene and its protein in OSCC and TM.

METHODS

Gene expression was evaluated in cryopreserved samples of OSCCs (n = 44), TM (n = 7), and normal mucosa from healthy patients (n = 3; NM). Quantitative PCRs were performed using the TaqMan system for the VEGFA gene, and gene expression was determined using the 2(-∆∆CQ) method. For immunohistochemical evaluation, 27 OSCC samples were embedded in a tissue microarray (TMA) block and reactions were performed using the Advance system.

RESULTS

VEGFA transcript levels were 1.7-fold higher in OSCC than in NM samples. VEGFA mRNA was overexpressed in TM samples compared to NM (3.4-fold) and OSCC (2.0-fold) samples. VEGFA transcript level was overexpressed in T3-T4 tumors, metastatic lymph nodes, and stage III-IV OSCCs. Immunoreactivity of the VEGFA protein was detected in the cytoplasm of parenchymal and stromal cells, mainly in endothelial cells and fibroblasts.

CONCLUSION

Our results show that VEGFA was overexpressed in aggressive OSCCs and that VEGFA expression may be an important prognostic factor in this type of cancer. Finally, tumor margins may be involved in the production of angiogenic molecules.

TGFβ1-Smad3-Jagged1-Notch1-Slug signaling pathway takes part in tumorigenesis and progress of tongue squamous cell carcinoma

BACKGROUND

TGFβ1 and Smad3 play an important role in the process of EMT. TGFβ1 regulates the expression of Jagged1 by modulating Notch signaling. Jagged1 is related to tumor invasion, metastasis, chemotherapy resistance, and tumor immune escape. The aims of this study are to examine deregulation of TGFβ1-Smad3-Jagged1-Notch1-Slug signaling in TSCC and to investigate its roles in TSCC progression.

MATERIALS AND METHODS

Notch1, Smad3, Jagged1 and Slug proteins and mRNA expression were detected in specimens from 89 cases of patients. We analyzed the correlation between their expressions and histological grade, clinical stage and lymph node metastasis.

RESULTS

Notch1, Smad3, Jagged1 and Slug mRNA expressions in TSCC were higher than normal tissue (P <0.05). The protein expression of Notch1 and Smad3 in TSCC were higher (χ(2) =7.30, P <0.01 and χ(2) = 5.84, P <0.05). Notch1 and Smad3 expressions were correlated with clinical stage (χ(2) =18.81, P<0.01; χ(2) =22.29, P<0.01), but not Jagged1 (χ(2) =0.53, P>0.05). The Slug protein expression was correlated with clinical stage. The positive rate of Notch1 was higher in lymph node metastases positive cases (χ(2) =7.30, P<0.01). Moreover, higher expression of Jagged1 was found in lymph node positive cases (χ(2) =10.82, P<0.01).

CONCLUSIONS

The key protein expression in TGFβ1-Smad3-Jagged1-Notch1-Slug signaling pathway significantly correlated with the clinicopathological features of TSCC patients. It's potential as a biomarker and a novel therapeutic target for TSCC patients at risk of metastasis. It may play an irreplaceable role in TSCC progression which may attribute to promoting EMT which enhances cell migration, invasion and metastasis.

Cleaved NOTCH1 Expression Pattern in Head and Neck Squamous Cell Carcinoma Is Associated with NOTCH1 Mutation, HPV Status, and High-Risk Features

The Notch pathway is frequently altered in head and neck squamous cell carcinomas (HNSCC); however, the clinical significance of NOTCH1 dysregulation is poorly understood. This study was designed to characterize expression of the transcriptionally active NOTCH1 intracellular domain (NICD1) in HNSCCs and evaluate its association with NOTCH1 mutation status and clinical parameters. IHC for NICD1 was performed on 79 previously sequenced archival HNSCCs with known NOTCH1 mutation status. Three distinct immunohistochemical staining patterns were identified: positive/peripheral (47%), positive/nonperipheral (34%), and negative (19%). NICD1 expression was associated with NOTCH1 mutation status (P < 0.001). Most NOTCH1-wild-type tumors were peripheral (55%), whereas mutated NOTCH1 tumors were most commonly negative (47%). Nonperipheral tumors were more likely than peripheral tumors to have extracapsular spread [adjusted odds ratio (aOR), 16.01; 95% confidence interval (CI), 1.92-133.46; P = 0.010] and poor differentiation (aOR, 5.27; 95% CI, 0.90-30.86; P = 0.066). Negative staining tumors tended to be poorly differentiated (aOR, 24.71; 95% CI, 1.53-399.33; P = 0.024) and were less likely to be human papillomavirus (HPV) positive (aOR, 0.043; 95% CI, 0.001-1.59; P = 0.087). NOTCH1 mutagenesis was significantly associated with HPV status, with NOTCH1-wild-type tumors more likely to be HPV positive than NOTCH1-mutated tumors (aOR, 19.06; 95% CI, 1.31-276.15; P = 0.031). TP53 disruptive mutations were not associated with NICD1 expression or NOTCH1 mutation. In conclusion, NICD1 is expressed in three distinct patterns in HNSCC that are significantly associated with high-risk features. These findings further support a dual role for NOTCH1 as both tumor suppressor and oncogene in HNSCC. Further research is necessary to clarify the role of NOTCH1 in HNSCC and understand the clinical and therapeutic implications therein.

The opposing roles of NOTCH signalling in head and neck cancer: a mini review

NOTCH signalling can exert oncogenic or tumour suppressive effects in both solid and haematological malignancies. Similar to T-cell acute lymphoblastic leukaemia (T-ALL), early studies suggested a pro-tumorigenic role of NOTCH in head and neck squamous cell carcinoma (HNSCC), mainly based on the increased expression levels of the genes within the pathway. Recently, data from exome sequencing analyses unexpectedly pointed to a tumour suppressor role for NOTCH in HNSCC by identifying loss-of-function mutations in the NOTCH1 gene in a significant proportion of patients. These data have questioned the accepted role of NOTCH in HNSCC and the possible rationale of targeting NOTCH in this disease. This review summarises the current information on NOTCH signalling in HNSCC and discusses how this pathway can apparently exert opposing effects within the same disease.

Epithelial-mesenchymal transition: clinical implications for nodal metastasis and prognosis of tongue cancer

OBJECTIVE

The development of biomarkers for the prediction of lymph node metastasis and prognosis is critical for deciding the treatment modality of tongue cancer. The purpose of our study is to investigate the clinical implications of epithelial-mesenchymal transition (EMT) expression in tongue cancer.

STUDY DESIGN

Historical cohort study

SETTING

Tertiary-care hospital.

SUBJECTS AND METHODS

The study included 95 subjects with tongue cancer who underwent wide excision and neck dissection. According to characteristics of immunohistochemical staining for E-cadherin and vimentin, we classified the tumors as complete EMT phenotype, incomplete EMT phenotype, or epithelial phenotype. The correlation between risk factors and nodal metastasis was assessed, and disease-free survival (DFS) was analyzed.

RESULTS

Positive lymph nodes were detected in 46 (48.4%) patients and was found to correlate significantly with depth of invasion ≥ 4 mm and EMT expression on multivariate analysis (P = .030, P = .022, respectively). The mean follow-up period of all patients was 96.3 months (range, 6-149 months). Overall 5-year DFS was 61.7%. On multivariate analysis, the only factors affecting DFS were nodal stage and EMT expression (P = .033, P = .021, respectively).

CONCLUSIONS

Our study reveals that EMT expression is a significant biomarker for predicting lymph node metastasis and tumor recurrence in tongue cancer. Evaluation of EMT expression in tongue cancer can allow therapy to be offered accordingly.

Notch1 activation is a poor prognostic factor in patients with gastric cancer

Background:

Aberrant Notch1 activation has been studied in many malignant tumours, but its role in gastric cancer remains unknown. This study is aimed to investigate the prognostic significance of Notch1 activation in patients with gastric cancer.

Methods:

In this study, we prospectively enrolled two independent sets of patients with gastric cancer from China and defined the activation of Notch1 by immunohistochemical staining of its active form, intracellular domain of Notch1 (ICN1). The prognostic value of Notch1 activation and clinical outcomes in gastric cancer were evaluated.

Results:

Expression of ICN1 is elevated in gastric cancer tissues and is predominately localised in the cell cytoplasm and/or membrane. High ICN1 expression positively correlates with tumour invasion depth (P=0.032), lymph node metastasis (P<0.001), advanced TNM stage (P=0.003) and reduced overall survival (P=0.0004) in the training set. Multivariate Cox regression analysis identified ICN1 as an independent prognostic factor (P=0.031), which could be incorporated into the TNM system to generate a better predictive model for patient outcomes. The c-index was 0.7375 when assessed with the TNM stage and improved to 0.8037 when ICN1 expression was added in the training set. These results were validated in the validation set.

Conclusions:

Notch1 activation was correlated with gastric cancer progression and defined as a novel independent prognostic factor. Combining ICN1 expression with TNM stage may provide a better predictive model for outcomes of gastric cancer patients.

The pathological significance of Notch1 in oral squamous cell carcinoma

Notch signaling has been reported to be involved in several types of malignant tumors; however, the role and activation mechanism of Notch signaling in oral squamous cell carcinoma (OSCC) remains poorly characterized. The purpose of this study was to elucidate the pathological significance of Notch signaling and its activation mechanism in the development and progression of OSCC. In this study, we showed that the expression of Notch1 and intracellular Notch domain (NICD) are upregulated in OSCCs. In addition, Notch1 and NICD were found to be characteristically localized at the invasive tumor front. TNF-α, a major inflammatory cytokine, significantly activated Notch signaling in vitro. In a clinicopathological analysis, Notch1 expression correlated with both the T-stage and the clinical stage. Furthermore, loss of Notch1 expression correlated with the inhibition of cell proliferation and TNF-α-dependent invasiveness in an OSCC cell line. In addition, γ-secretase inhibitor (GSI) prevented cell proliferation and TNF-α-dependent invasion of OSCC cells in vitro. These results indicate that altered expression of Notch1 is associated with increased cancer progression and that Notch1 regulates the steps involved in cell metastasis in OSCC. Moreover, inactivating Notch signaling with GSI could therefore be a useful approach for treating patients with OSCC.

Notch1 and Notch4 are markers for poor prognosis of hepatocellular carcinoma

BACKGROUND

Notch signaling is critical to physiologic angiogenesis and has been implicated in tumor angiogenesis and metastasis. Notch signaling was reported to exert either oncogenic or tumor-suppressive function in hepatocellular carcinoma (HCC) tumorigenesis. However, the prognostic significance of Notch receptors in HCC remains uncertain. In this study, we investigated the roles of Notch receptors in the prognosis of HCC.

METHODS

We investigated the expressions of Notch receptors in tumor tissue microarrays of 288 patients with primary HCC who had undergone curative resection using immunohistochemistry. Additionally, prognostic factors of HCC were examined by univariate and multivariate analyses. The median follow-up period was 97.1 months. Tumor recurrence was detected in 189 patients (65.6%), and 99 (34.4%) died of HCC.

RESULTS

Cytoplasmic expression of Notch1, cytoplasmic expression of Notch3, coexistent nuclear expression of Notch3, and cytoplasmic Notch4 overexpression were observed in 145 (50.3%), 60 (20.8%), 17 (5.9%), and 172 (59.7%) of the 288 HCCs, respectively. Multivariate analyses revealed that Notch1 expression (P=0.029), Edmondson grade III (P=0.038), and higher BCLC stage (P<0.001) were independent predictors of shorter disease-free survival. Cytoplasmic Notch3 expression tended to be an independent predictor of shorter disease-free survival (P=0.055). Notch1 expression (P=0.039), Notch4 overexpression (P=0.012), and higher BCLC stage (P<0.001) were independent predictors of shorter disease-specific survival. On univariate analysis, Notch1 expression tended to show an unfavorable influence on disease-specific survival (P=0.063) and Notch4 overexpression did not show an unfavorable influence on disease-specific survival (P=0.103).

CONCLUSIONS

Notch1 expression might be an independent predictor of both shorter disease-free survival and shorter disease-specific survival in HCC patients after curative resection. Notch4 overexpression might be an independent predictor of shorter disease-specific survival. Notch1 could be used as an immunohistochemical biomarker to detect patients with a high-risk of recurrence. Notch1 and Notch4 could be used as immunohistochemical biomarkers to detect patients with a shorter disease-specific survival.

Expression of EGFR, VEGF, and NOTCH1 suggest differences in tumor angiogenesis in HPV-positive and HPV-negative head and neck squamous cell carcinoma

There is current interest in anti-angiogenesis therapies for head and neck squamous cell carcinomas (HNSCC), although the utility of these therapies in human papillomavirus (HPV) positive and HPV-negative HNSCC is unclear. Therefore, we explored heterogeneity in expression of a distal factor in angiogenesis (EGFR, the epidermal growth factor receptor), a proximal factor in angiogenesis (VEGF, the vascular endothelial growth factor) and a putative factor in angiogenesis (NOTCH1) in a HNSCC case series using immunohistochemistry in N = 67 cases (27 HPV-positive, 40 HPV-negative, by in situ hybridization). Box plots and the Wilcoxon rank sum or Kruskal-Wallis tests were used to compare staining scores (intensity × percent of cells staining) by HPV status and lifestyle factors. Associations between EGFR, VEGF, and NOTCH1 were assessed using box plots and Spearman correlation (ρ) in all cases, and stratified by HPV status. HPV-negative HNSCC over-expressed EGFR [median (range): 30 (0-300)] relative to HPV-positive HNSCC [7.5 (0-200)] (P = 0.006). VEGF and NOTCH1 were unrelated to HPV status (P > 0.05). EGFR was associated with VEGF in HPV-negative (ρ = 0.40, P = 0.01) but not HPV-positive HNSCC (ρ = 0.25, P = 0.20). NOTCH1 and VEGF were associated in HPV-negative (ρ = 0.40, P = 0.01) but not HPV-positive tumors (ρ = -0.12, P = 0.57). NOTCH1 was not associated with EGFR (P > 0.05). Our results are suggestive of heterogeneity in HNSCC angiogenesis. Future studies should explore angiogenesis mechanisms in HPV-positive and HPV-negative HNSCC.

Molecular mechanisms of curcumin action: signal transduction

Chemoprevention represents one of the most highly effective anti-cancer strategies and is accompanied by minimal secondary effects as compared to conventional chemotherapies. Many new anti-inflammatory and anti-cancer drug candidates have been derived from chemical scaffolds engineered from natural products discovered just a few decades ago. This approach is widely utilized in drug discovery in order to produce novel molecular entities with enhanced drug activities mediated through various signal transduction pathways for the treatment of different diseases. Curcumin, a polyphenolic derivative of turmeric, is a naturally occurring compound isolated from Curcuma longa that suppresses and inverts carcinogenesis via multifaceted molecular targets. Several reports have demonstrated that curcumin inhibits animal and human cancers, suggesting that it may serve as a chemopreventive agent. Numerous in vitro and in vivo experimental models have also revealed that curcumin regulates several molecules in cell signal transduction pathway including NF-κB, Akt, MAPK, p53, Nrf2, Notch-1, JAK/STAT, β-catenin, and AMPK. Modulation of cell signaling pathways through the pleiotropic effects of curcumin likely activate cell death signals and induce apoptosis in cancer cells, thereby inhibiting the progression of disease. This article provides insights into the natural chemopreventive role of curcumin via cellular transduction pathways and provides an in depth assessment of its physiological activities in the management of diseases.

Suppression of tongue squamous cell carcinoma growth by inhibition of Jagged1 in vitro and in vivo

BACKGROUND

The changes in Notch signaling are closely related to the occurrence and development of many cancers. We have investigated Notch signaling receptor and its ligand expressions in TSCC cell lines, tissues and its significance. We clarified Notch signaling pathway in TSCC and its mechanism. We regulated Notch signaling pathway of tumor cells, thereby inhibiting tumor cell proliferation and differentiation.

METHODS

We detected Jagged1 protein and mRNA expression levels in specimens (tongue cancer and adjacent tissues) from 74 patients with tongue cancer and in TSCC cell line. The Jagged1-targeted lentiviral vector RNAi system was constructed, and its suppressive effects on the proliferation and invasion of tongue carcinoma cells in in vivo and ex vivo were determined.

RESULTS

Jagged1 was expressed in tongue squamous cell cancer tissues and cell line, but there were differences in its expression. Jagged1 was knocked down and the tumor growth was inhibited accompanying cell cycle changes. Animal studies also showed that the tumor growth was inhibited.

CONCLUSIONS

Jagged1 may be involved in the differentiation and proliferation of tongue cancer. Targeting Jagged1 RNA interference lentiviral vector can effectively lower Jagged1 mRNA and protein expression levels of Tca8113 cells, thereby preventing the proliferation of TSCC cells. Jagged1 is expected to be a promising new target for curing tongue cancer. In-depth study of the interaction between Jagged1 and other molecules of Notch signaling pathway in the process of carcinogenesis has important theoretical guidance and clinical significance in revealing the mechanism of Jagged1 and its application in the therapy for tongue cancer.

Inhibitory effect of curcumin on oral carcinoma CAL-27 cells via suppression of Notch-1 and NF-κB signaling pathways

Curcumin has been reported to inhibit cell growth and induce apoptosis in oral cancer cells. Although many studies have been done to uncover the mechanisms by which curcumin exerts its antitumor activity, the precise molecular mechanisms remain to be unclear. In the present study, we assessed the effects of curcumin on cell viability and apoptosis in oral cancer. For mechanistic studies, we used multiple cellular and molecular approaches such as gene transfection, real-time RT-PCR, Western blotting, invasion assay, and ELISA. For the first time, we found a significant reduction in cell viability in curcumin-treated cells, which was consistent with induction of apoptosis and also associated with down-regulation of Notch-1 and nuclear factor-κB (NF-κB). Taken together, we conclude that the down-regulation of Notch-1 by curcumin could be an effective approach, which will cause down-regulation of NF-κB, resulting in the inhibition of cell growth and invasion. These results suggest that antitumor activity of curcumin is mediated through a novel mechanism involving inactivation of Notch-1 and NF-κB signaling pathways.

Recently identified biomarkers that promote lymph node metastasis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous cancer that arises in the upper aerodigestive tract. Despite advances in knowledge and treatment of this disease, the five-year survival rate after diagnosis of advanced (stage 3 and 4) HNSCC remains approximately 50%. One reason for the large degree of mortality associated with late stage HNSCC is the intrinsic ability of tumor cells to undergo locoregional invasion. Lymph nodes in the cervical region are the primary sites of metastasis for HNSCC, occurring before the formation of distant metastases. The presence of lymph node metastases is strongly associated with poor patient outcome, resulting in increased consideration being given to the development and implementation of anti-invasive strategies. In this review, we focus on select proteins that have been recently identified as promoters of lymph node metastasis in HNSCC. The discussed proteins are involved in a wide range of critical cellular functions, and offer a more comprehensive understanding of the factors involved in HNSCC metastasis while additionally providing increased options for consideration in the design of future therapeutic intervention strategies.

Activation of Notch signaling in human tongue carcinoma

BACKGROUND

Involvement of Notch signaling in several tumors is well known, but its role in tongue squamous cell carcinoma remains poorly characterized. The purpose of this study was to evaluate the roles of Notch signaling in the oncogenesis of tongue carcinoma.

MATERIALS AND METHODS

Tumor specimens and adjacent non-neoplastic tongue tissues from 74 patients with tongue carcinoma and human tongue carcinoma cell line Tca8113 were examined using immunohistochemistry and RT-PCR to determine the expressions of Notch1, Notch3, Jagged1, and Jagged2.

RESULTS

The mRNA expressions of Notch1, Notch3, Jagged1, and Jagged2 were detected in Tca8113, tongue carcinoma, and adjacent non-neoplastic tongue tissues. The expression levels of mRNAs in tongue carcinoma were higher than those in adjacent non-neoplastic tongue tissues (P < 0.05). Immunohistochemical examination showed that the Notch signal molecules were expressed in Tca8113, tongue carcinoma, and adjacent non-neoplastic tongue tissues. The expression rates of Notch1 and Notch3 protein in tongue carcinoma were higher than those in adjacent non-neoplastic tongue tissues (χ² = 6.10, P = 0.013; χ² = 3.94, P = 0.047). Notch1 and jagged1 were significantly more highly expressed in lymph node metastasis-positive tongue carcinoma (χ² = 6.108, P = 0.013; χ² = 7.354, P = 0.025). In addition, expressions of Notch3 and Jagged2 were highly correlated in tongue carcinoma tissues (χ² = 42.130, P < 0.001).

CONCLUSIONS

Expressions of Notch receptors and ligands in tongue carcinoma and adjacent non-neoplastic tongue tissues suggest that Notch signaling may control cell differentiation and proliferation of carcinoma cells. The disorder of Notch signaling may be a mechanism of the tongue carcinoma development.

VEGF expression and angiogenesis in oral squamous cell carcinoma: an immunohistochemical and morphometric study

Angiogenesis is involved in tumor progression of oral squamous cell carcinoma (OSCC). In this study, we have investigated by immunohistochemistry vascular endothelial growth factor (VEGF) expression in tumor cells and we have correlated VEGF expression to microvessel area, evaluated by using CD105 as a marker of endothelial cells, in bioptic specimens of 54 human OSCC. Results demonstrated that VEGF is highly expressed in OSCC tumor specimens when compared to pre-neoplastic and normal tissues, without differences between the edge and inside the tumor. Moreover, VEGF expression is reduced in poor differentiated OSCC tumors when compared to moderate and good differentiated forms, and tumor microvessel area is higher in tumors when compared to pre-neoplastic lesions and normal tissues. Finally, VEGF and CD105 may be considered as reliable markers of tumor angiogenesis and progression in OSCC, even if we did not demonstrate any correlation between VEGF expression, tumor microvascular area, clinical stage, and lymph node status.