IL-8 promotes HNSCC progression on CXCR1/2-meidated NOD1/RIP2 signaling pathway

Inhibition of ATM or ATR in combination with hypo-fractionated radiotherapy leads to a different immunophenotype on transcript and protein level in HNSCC

Background

The treatment of head and neck tumors remains a challenge due to their reduced radiosensitivity. Small molecule kinase inhibitors (smKI) that inhibit the DNA damage response, may increase the radiosensitivity of tumor cells. However, little is known about how the immunophenotype of the tumor cells is modulated thereby. Therefore, we investigated whether the combination of ATM or ATR inhibitors with hypo-fractionated radiotherapy (RT) has a different impact on the expression of immune checkpoint markers (extrinsic), the release of cytokines or the transcriptome (intrinsic) of head and neck squamous cell carcinoma (HNSCC) cells.

Methods

The toxic and immunogenic effects of the smKI AZD0156 (ATMi) and VE-822 (ATRi) in combination with a hypo-fractionated scheme of 2x5Gy RT on HPV-negative (HSC4, Cal-33) and HPV-positive (UM-SCC-47, UD-SCC-2) HNSCC cell lines were analyzed as follows: cell death (necrosis, apoptosis; detected by AnxV/PI), expression of immunostimulatory (ICOS-L, OX40-L, TNFSFR9, CD70) and immunosuppressive (PD-L1, PD-L2, HVEM) checkpoint marker using flow cytometry; the release of cytokines using multiplex ELISA and the gene expression of Cal-33 on mRNA level 48 h post-RT.

Results

Cell death was mainly induced by the combination of RT with both inhibitors, but stronger with ATRi. Further, the immune phenotype of cancer cells, not dying from combination therapy itself, is altered predominantly by RT+ATRi in an immune-stimulatory manner by the up-regulation of ICOS-L. However, the analysis of secreted cytokines after treatment of HNSCC cell lines revealed an ambivalent influence of both inhibitors, as we observed the intensified secretion of IL-6 and IL-8 after RT+ATRi. These findings were confirmed by RNAseq analysis and further the stronger immune-suppressive character of RT+ATMi was enlightened. We detected the down-regulation of a central protein of cytoplasmatic sensing pathways of nucleic acids, RIG-1, and found one immune-suppressive target, EDIL3, strongly up-regulated by RT+ATMi.

Conclusion

Independent of a restrictive toxicity, the combination of RT + either ATMi or ATRi leads to comprehensive and immune-modulating alterations in HNSCC. This includes pro-inflammatory signaling induced by RT + ATRi but also anti-inflammatory signals. These findings were confirmed by RNAseq analysis, which further highlighted the immune-suppressive nature of RT + ATMi.

Aberrant expression of VASP serves as a potential prognostic biomarker and therapeutic target for oral squamous cell carcinoma

OBJECTIVE

To address the molecular markers linked to the development and progression of oral squamous cell carcinoma (OSCC), we sought to analyze the expression of vasodilator-stimulated phosphoproteins (VASP) in OSCC samples.

STUDY DESIGN

This study used 51 OSCC patients and The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HNSC) dataset to analyze VASP expression. The association between VASP mRNA expression and HNSCC clinicopathological features, tumor infiltration, functional roles, and gene co-expression of VASP also were evaluated.

RESULTS

Our study observed increased VASP mRNA expression in OSCC tumor tissues compared to normal tissues, supported by TCGA-HNSC dataset analysis. Elevated VASP levels correlated with advanced tumor stage, higher grade, nodal metastasis, and poor survival, indicating its potential as a prognostic marker. Protein analysis and immunohistochemistry confirmed these findings, and in silico analysis revealed VASP involvement in key cancer-related processes and its correlation with IL8, RAP1A expression, and tumor infiltration levels.

CONCLUSIONS

In conclusion, VASP emerges as a promising diagnostic and prognostic marker for OSCC within HNSCC, emphasizing the importance of exploring its regulatory mechanisms and therapeutic applications. The revealed pathways present avenues for targeted treatment in OSCC. Despite limitations, this study provides valuable insights with potential implications for improving patient outcomes.

Targeting neutrophils: Mechanism and advances in cancer therapy

BACKGROUND

Cancer is a thorny problem which cannot be conquered by mankind at present and recent researchers have put their focus on tumor microenviroment. Neutrophils, the prominent leukocytes in peripheral blood that accumulate in tumours, serves as frontline cells in response to tumour progression owing to the rapid development of micro biotechnology. Hence, targeted therapy with these neutrophils has made targeting treatment a promising field in cancer therapy.

MAIN BODY

We broadly summarise some studies on the phenotypes and functions of tumour-associated neutrophils as well as the unique web-like products of neutrophils that play a role in cancer progression-neutrophil extracellular traps-and the interactions between neutrophils and the tumour microenvironment. Moreover, several targeted neutrophils therapeutic studies have made some progress and provided potential strategies for the treatment of cancer.

CONCLUSION

This review aims to offer a holistic perspective on therapeutic interventions targeting neutrophils to further inspire more researches on cancer therapies.

Immune checkpoint blockade induced shifts in cytokine expression patterns in peripheral blood of head and neck cancer patients are linked to outcome

Background

Immune-checkpoint blockade (ICB) of programmed-death-1 (PD-1) with pembrolizumab or nivolumab is approved for treating recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). NadiHN and ADRISK are phase IIB trials investigating in locally advanced (LA) HNSCC having low or high risk of recurrence the potential benefits from adding nivolumab to post-operative radiotherapy or pembrolizumab to cisplatin-based radio-chemotherapy.

Methods

Along five randomized controlled ICB trials including NadiHN and ADRISK, blood samples were taken before and after starting ICB in n=25 patients. Concentrations of vascular endothelial growth factor A (VEGF), CCL2 (MCP-1), interleukin-6 (IL-6), IL-8, interferon-gamma (IFN-γ), and CXCL10 (IP-10) pre- and post-ICB in EDTA-anticoagulated plasma and serum were compared. We used receiver operating characteristic (ROC) curves to identify optimal cutoff for defining subgroups before analyzing overall survival (OS) applying Kaplan-Meier plots and multivariate Cox regression.

Results

We detected huge heterogeneity between cytokine patterns in pre-and post-ICB plasma and serum. We observed high correlation between concentrations of some cytokines. Despite absent systematic OS differences after ICB with pembrolizumab or nivolumab or between LA-HNSCC versus R/M HNSCC patients, we noticed improved outcome of patients having lower IFN-γ concentrations pre- and post-ICB and following ICB reduced concentrations of VEGF, IL-6, and IL-8 but not MCP-1. Contrarily, increases in IL-6, IL-8, and VEGF levels correlated with impaired outcome. Multivariate Cox regression revealed five independent OS predictors among cytokines; using natural logarithms of their hazard ratios to estimate an individual's risk of dying, three cytokine-expression pattern (CEP)-risk groups with no death within mean (95% confidence interval) follow-up of 29.2 (22.1-36.2) months and median OS of 11.3 (8.8-13.8) and 2.9 (0.4-5.4) months were found.

Conclusion

Whereas individual pre- or post-ICB cytokine concentrations in serum or plasma alone failed to predict the survivor group, CEP-risk groups may support the identification of individual patients with long-lasting benefit from ICB.

Prostaglandin-endoperoxide synthase 2 (PTGS2) gene expression and its association with genes regulating the VEGF signaling pathway in head and neck squamous cell carcinoma

Introduction

The PTGS2 gene codes for the cyclooxygenase-2 (COX-2) enzyme that catalyzes the committed step in prostaglandin (PG) synthesis. Various in-vivo and in-vitro data suggest that prostaglandin E2 mediates as a signaling molecule for activating the VEGF signaling pathway (VSP), forming an association between COX-2 and VSP. Several chemotherapy regimens increasingly rely on preventing the synthesis of PGs. The targeted and metronomic chemotherapy agents, which suppress the COX-2 enzymes, have a major role in suppressing the oral cancer cascade. Hence, this study was designed to understand the pattern of PTGS2 expression and genes regulating VSP in head and neck cancers.

Methods

PTGS2 expression was analyzed in the TCGA database computationally with the help of the UALCAN web-server. The expression of VEGF signaling pathway genes was mined, and their expression pattern was determined. Co-expression analysis was done to elucidate the association between VEGF signaling genes and PTGS2. The ShineyGo web server was used for gene set enrichment.

Results

Significantly high PTGS2 expression was observed in tumor samples. Further genes regulating VEGF signaling were significantly overexpressed in tumor samples. Co-expression analysis results showed a significant positive correlation between PTGS2 and angiogenesis-regulating genes. The majority of the genes were enriched for angiogenesis pathways.

Conclusion

PTGS2 was significantly expressed in head and neck cancer, and its expression was associated with genes regulating angiogenesis.

RIPK2: a promising target for cancer treatment

As an essential mediator of inflammation and innate immunity, the receptor-interacting serine/threonine-protein kinase-2 (RIPK2) is responsible for transducing signaling downstream of the intracellular peptidoglycan sensors nucleotide oligomerization domain (NOD)-like receptors 1 and 2 (NOD1/2), which will further activate nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, leading to the transcription activation of pro-inflammatory cytokines and productive inflammatory response. Thus, the NOD2-RIPK2 signaling pathway has attracted extensive attention due to its significant role in numerous autoimmune diseases, making pharmacologic RIPK2 inhibition a promising strategy, but little is known about its role outside the immune system. Recently, RIPK2 has been related to tumorigenesis and malignant progression for which there is an urgent need for targeted therapies. Herein, we would like to evaluate the feasibility of RIPK2 being the anti-tumor drug target and summarize the research progress of RIPK2 inhibitors. More importantly, following the above contents, we will analyze the possibility of applying small molecule RIPK2 inhibitors to anti-tumor therapy.

The Clinical and Biological Effects of Receptor Expression-Enhancing Protein 6 in Tongue Squamous Cell Carcinoma

There are currently no effective biomarkers for the diagnosis and treatment of tongue squamous cell carcinoma (TSCC), which causes a poor 5-year overall survival rate. Thus, it is crucial to identify more effective diagnostic/prognostic biomarkers and therapeutic targets for TSCC patients. The receptor expression-enhancing protein 6 (REEP6), a transmembrane endoplasmic reticulum resident protein, controls the expression or transport of a subset of proteins or receptors. Although it was reported that REEP6 plays a role in lung and colon cancers, its clinical impact and biological role in TSCC are still unknown. The present study aimed to identify a novel effective biomarker and therapeutic target for TSCC patients. Expression levels of REEP6 in specimens from TSCC patients were determined with immunohistochemistry. Gene knockdown was used to evaluate the effects of REEP6 in cancer malignancy (colony/tumorsphere formation, cell cycle regulation, migration, drug resistance and cancer stemness) of TSCC cells. The clinical impact of REEP6 expression and gene co-expression on prognosis were analyzed in oral cancer patients including TSCC patients from The Cancer Genome Atlas database. Tumor tissues had higher levels of REEP6 compared to normal tissues in TSCC patients. Higher REEP6 expression was related to shorter disease-free survival (DFS) in oral cancer patients with poorly differentiated tumor cells. REEP6-knocked-down TSCC cells showed diminished colony/tumorsphere formation, and they also caused G1 arrest and decreased migration, drug resistance and cancer stemness. A high co-expression of REEP6/epithelial-mesenchymal transition or cancer stemness markers also resulted in poor DFS in oral cancer patients. Thus, REEP6 is involved in the malignancy of TSCC and might serve as a potential diagnostic/prognostic biomarker and therapeutic target for TSCC patients.

Targeted blockade of interleukin-8 negates metastasis and chemoresistance via Akt/Erk-NFκB axis in oral cancer

BACKGROUND

The tumor microenvironment plays a significant role in tumor growth, metastasis and chemoresistance via dysregulated signaling pathways. Toward this, an inflammatory chemokine, interleukin-8 (IL-8), is overexpressed in various cancers and is involved in tumor progression and chemoresistance. However, the mechanistic role of IL-8 in mediating metastasis and chemoresistance in oral squamous cell carcinoma (OSCC) is not known.

METHODS AND RESULTS

In the present study, we evaluated the effect of IL-8 in regulating metastasis as well as chemoresistance in OSCC cell lines. For this, IL-8 was blocked exogenously using neutralizing IL-8 monoclonal antibody and IL-8 levels were enhanced by exogenous supply of recombinant human IL-8 (rhIL-8) to OSCC cells. The epithelial-to-mesenchymal transition (EMT) was evaluated using qPCR, migration by scratch/wound healing assay and invasion ability using transwell assay. rIL-8 induced chemoresistance was studied by apoptosis assay and the nuclear localization of NFκB using immunocytochemistry. IL-8 was significantly overexpressed in OSCC patients and cell lines. While exogenous blockade of IL-8 significantly reduced EMT, migration and invasion potential in OSCC cells, IL-8 overexpression upregulated these cellular traits thereby confirming the role of IL-8 in OSCC metastasis. Exogenous blockade of IL-8 also reversed chemoresistance in cisplatin resistant OSCC subline via NFκB signaling.

CONCLUSION

IL-8 plays a crucial role in OSCC metastasis and its targeted blockade can help in management of cisplatin resistance.

Cytokines secreted by inflamed oral mucosa: implications for oral cancer progression

The oral mucosa has an essential role in protecting against physical, microbial, and chemical harm. Compromise of this barrier triggers a wound healing response. Key events in this response such as immune infiltration, re-epithelialization, and stroma remodeling are coordinated by cytokines that promote cellular migration, invasion, and proliferation. Cytokine-mediated cellular invasion and migration are also essential features in cancer dissemination. Therefore, exploration of cytokines that regulate each stage of oral wound healing will provide insights about cytokines that are exploited by oral squamous cell carcinoma (SCC) to promote tumor development and progression. This will aid in identifying potential therapeutic targets to constrain SCC recurrence and increase patient survival. In this review, we discuss cytokines that overlap in oral wounds and SCC, emphasizing how these cytokines promote cancer progression.

Growth Regulated Oncogene-α Upregulates TNF-α and COX-2 and Activates NOD1/RIPK2 mediated-MAPK Pathway in Head and Neck Squamous Cell Carcinoma

Purpose: The long-term prognosis and survival rate of patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) are poor, although the identification of specific biomarkers that reveal its nature and aggressiveness has improved it. Growth-related oncogene alpha (Groα) and NOD1 (nucleotide-binding oligomerization domain 1) can be used as prognosis markers to identify subgroups of HNSCC patients with low survival rates and as potential therapeutic targets for HNSCC patients. However, the mechanism associated with the Groα-mediated NOD pathway in HNSCC progression remains unclear. Method: Overall survival analysis and multiple-gene comparison were analyzed using Gene Expression Profiling Interactive Analysis (GEPIA). qRT-PCR and RT-PCR were used to analyze mRNA expression. Microarray, immunofluorescence staining or western blot analyses were carried out to detect protein expression. Results: Groα was significantly higher in the grade 4 HNSCC tumor tissues compared with that in grade 1-3 and healthy subjects. High expression of Groα, NOD1 and RIPK2 (receptor-interacting serine-threonine kinase 2) is correlated with survival rate in HNSCC patients. Treatment of SCC25 and OECM-1 cells with Groα increased the expression of NOD1 and RIPK2 in a concentration-dependent manner. The findings herein reveal the association of Groα, NOD1 and RIPK2 biomarkers with HNSCC carcinogenesis. Moreover, Groα is the major stimulus of inflammatory mediation and promotes TNF-α (tumor necrosis factor-α) and COX-2 (cyclooxygenase-2) expression in HNSCC. Groα induces TNF-α and COX-2 expression through regulation involving ERK (extracellular signal-regulated kinase)-, JNK (C-Jun N-terminal kinase)- and p38 MAPK (mitogen-activated protein kinase)-dependent signaling pathways. Conclusions: Our findings herein constitute the first evidence that Groα is important in HNSCC progression and metastasis via the NOD1-mediated MAPK pathway, suggesting a role for Groα and NOD1 in mediating metastasis and its potential as a therapeutic target.

Cigarette smoking induces the activation of RIP2/caspase-12/NF-κB axis in oral squamous cell carcinoma

Cigarette smoking is one of the major risk factors for the occurrence and progression of oral squamous cell carcinoma (OSCC). Receptor-interacting protein 2 (RIP2) has been involved in mucosal immunity and homeostasis via a positive regulation of nuclear factor κB (NF-κB) transcription factor activity. Caspase-12 can bind to RIP2 and dampen mucosal immunity. However, the roles of RIP2/NF-κB and caspase-12 in OSCC induced by cigarette smoking remain unknown. Herein, we investigated the effects of cigarette smoking on the RIP2/NF-κB and caspase-12 in human OSCC tissues and OSCC cell lines (HSC-3). We first observed that RIP2 mediated NF-κB activation and caspase-12 upregulation in OSCC patients with cigarette smoking and cigarette smoke extract (CSE)-treated HSC-3 cells, respectively. Moreover, we confirmed that the downregulation of RIP2 by siRNA resulted in the reduction of caspase-12 expression and NF-κB activity in the presence of CSE treatment in vitro. In summary, our results indicated that cigarette smoking induced the activation of the RIP2/caspase-12/NF-κB axis and it played an important role in the development of OSCC. The RIP2/caspase-12/NF-κB axis could be a target for OSCC prevention and treatment in the future.

Checkpoint Inhibitors in Cancer Therapy: Clinical Benefits for Head and Neck Cancers

Recently, considerable progress has been achieved in cancer immunotherapy. Targeted immune checkpoint therapies have been established for several forms of cancers, which resulted in a tremendous positive impact on patient survival, even in more advanced tumor stages. With a better understanding of cellular responses to immune checkpoint therapies, it will soon be feasible to find targeted compounds which will make personalized medicine practicable. This is a great opportunity, but it also sets tremendous challenges on both the scientific and clinical aspects. Head and neck tumors evade immune surveillance through various mechanisms. They contain fewer lymphocytes (natural killer cells) than normal tissue with an accumulation of immunosuppressive regulatory T cells. Standard therapies for HNSCC, such as surgery, radiation, and chemotherapy, are becoming more advantageous by targeting immune checkpoints and employing combination therapies. The purpose of this review is to provide an overview of the expanded therapeutic options, particularly the combination of immune checkpoint inhibition with various conventional and novel therapeutics for head and neck tumor patients.

NOD1 and NOD2 Are Potential Therapeutic Targets for Cancer Immunotherapy

The nucleotide oligomerization domain (NOD)-like receptors (NLRs) are a group of intracellular proteins that are essential for controlling the host's innate immune response. The cytosolic nucleotide binding oligomerization domains 1 and 2 receptors (NOD1 and NOD2) are the most widely investigated NLRs. As pattern recognition receptors (PRRs), NOD1 and NOD2 may recognize and bind endogenous damage associated molecular patterns (DAMPs) and external pathogenic associated molecular patterns (PAMPs), directing the activation of inflammatory caspases through engaging the adaptor protein RIP2, which further activates the NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways, thereby mediating host innate immunity and regulating the adaptive immunity. Previous research has identified NOD1 and NOD2 as key players in inflammatory disease and host-microbial defense. Despite numerous studies claiming that NOD1 and NOD2 are linked to tumorigenesis and tumor development, it is still unclear whether NOD1 and NOD2 act as cancer's friends or foes. In this review, we focus on concluding the current research progress on the role of NOD1 and NOD2 in a variety of cancers and discussing the potential reasons for the contradicting role of NOD1 and NOD2 in cancers. This review may help better understand the role of NOD1 and NOD2 in cancer and shed light on NOD1 and NOD2 as potential therapeutic targets for tumor immunotherapy.

The Assessment of Serum Cytokines in Oral Squamous Cell Carcinoma Patients: An Observational Prospective Controlled Study

Background: The oral squamous cell carcinoma (OSCC) tumor microenvironment (TME) is a complex interweb of cells and mediators balancing carcinogenesis, inflammation, and the immune response. However, cytokines are not only secreted within the TME but also released by a variety of other cells that do not comprise the TME; therefore, a thorough assessment of humoral changes in OSCC should include the measurement of serum cytokines. Methods: We assessed the role of various serum cytokines in the evolution of OSCC, before and after treatment, versus a control group. We measured the serum concentrations of MIP-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, and TNF-α. Results: Significantly higher values (p < 0.01) were noted for IL-1β, IL-6, IL-8, IL-10, and TNF-α in the OSCC group before treatment (n = 13) compared with the control group (n = 14), and the increased concentrations persisted after treatment (n = 11). Furthermore, the variations in the values of MIP-1α, IL-1β, IL-10, and TNF-α are correlated both before and after treatment (p < 0.01). In the pretherapeutic group, IL-6 and IL-8 concentrations also correlate with IL-1β and IL-10 serum levels (p < 0.01), while in the posttherapeutic group, IL-4 varies with MIP-1α and TNF-α (p < 0.01). Conclusion: In OSCC patients, serum cytokine levels are significantly higher compared with control, but they are not significantly altered by treatment, therefore implying that they are also influenced by systemic factors. The interactions between all involved cytokines and the various pathways they regulate warrant further studies to clarify their definitive roles.

Growth regulated oncogene-α contribute to EMT/MMPs pathway by binding its receptors in head and neck squamous cell carcinoma

Squamous cell carcinoma (SCC) is the most common malignant tumor of the head and neck and generally detected in the late stages when the cancer has advanced, and therefore has a poor prognosis and survival rate. A high expression of growth-related oncogene alpha (Groα) is associated with tumor metastasis and invasion and the poor survival rate of patients. Microarray reveals that Groα exhibits a cancer-specific response in HNSCC. Quantitative real-time PCR (qRT-PCR) results concerning the mRNA expression of Groα in HNSCC tissues; indicate that Groα was more highly expressed in HNSCC than in non-cancerous matched tissue (NCMT). The serum of HNSCC patients and healthy subjects demonstrates that the expression of Groα in the HNSCC patients significantly exceeded than in healthy subjects. Furthermore, exposure Groα to stimulated the proliferation, clonogenicity and migration with HNSCC cells (SCC4, SCC9, SCC25 and OECM-1), yielding a stronger response than in non-malignant HaCaT and DOK cells. A high expression of Groα and its receptors CXCR1/2 (chemokine (C-X-C motif) receptor) in HNSCC tissues are highly correlated with tumor progression stage and metastasis. Following the treatment of SCC25 and OECM-1 cells with Groα, β-catenin, matrix metalloproteinases (MMP)-2, MMP-7 and MMP-9 expressions significantly increased but E-cadherin expression was slightly decreased, suggesting that the EMT and metastasis processes were activated by Groα. These findings constitute the first evidence that Groα promotes epithelial mesenchymal transition (EMT) and MMPs expressions in HNSCC via activating CXCR1/2, suggesting a role for Groα in mediating metastasis and its potential as a therapeutic target.

Predictive capacity of IL-8 expression in head and neck squamous carcinoma patients treated with radiotherapy or chemoradiotherapy

OBJECTIVE

To analyse the relationship between the transcriptional expression of interleukin-8 (IL-8) and response to treatment with radiotherapy or chemo-radiotherapy in patients with squamous cell carcinoma of the head and neck (SCCHN).

MATERIAL AND METHODS

Retrospective study from tumour biopsies obtained before a treatment with radiotherapy or chemo-radiotherapy in 87 patients with SCCHN. We had a sample of healthy mucosa in 35 cases. We determined the transcriptional expression of IL-8 with RT-PCR. The transcriptional expression of IL-8 was categorized according to the local control of the disease with a recursive partitioning analysis.

RESULTS

The transcriptional expression of IL-8 in tumour tissue was about 50 times higher than that in the samples of healthy mucosa. Patients with a high transcriptional expression of IL-8 (n = 56) had a 5-year local recurrence-free survival of 65.6%, and for patients with low expression (n = 31) it was 90.2% (P = 0.017). According to the results of a multivariate analysis, patients with high expression of IL-8 had a 4.1 higher risk of local recurrence of the tumour.

CONCLUSIONS

SCCHN have a significant increase in transcriptional expression of IL-8 in relation to non-tumour tissue. Tumours with high IL-8 expression have an increased risk of local recurrence after treatment with radiotherapy or chemo-radiotherapy.

Activation of RIPK2-mediated NOD1 signaling promotes proliferation and invasion of ovarian cancer cells via NF-κB pathway

The goal of this study was to investigate the role and mechanism of action of nucleotide oligomerization domain receptor 1 (NOD1) in ovarian cancer. Results showed that the expressions of NOD1 and receptor interacting serine/threonine kinase 2 (RIPK2) were notably upregulated in non-metastatic and metastatic ovarian tumors compared with matched non-tumor tissues, and their expression in metastatic tumor tissues was higher than that in non-metastatic tumors. Overexpression of NOD1 facilitated the expression of proliferation-related proteins (PCNA and Ki67) and proliferation and invasion of ovarian cancer cells. Overexpression of NOD1 promoted NF-κB expression and phosphorylation. Importantly, NOD1 bound with RIPK2, and silencing of RIPK2 partly rescued the promotion of NOD1 to NF-κB expression and its phosphorylation. The promotion of NOD1 to ovarian cancer cell proliferation and invasion was partly reversed by RIPK2 silencing. Results from our in vivo study indicate that overexpression of NOD1 accelerated the growth of ovarian cancer tumors, expression of proliferation-related proteins, and activation of NF-κB. However, silencing of NOD1 suppressed tumor growth. In summary, NOD1 facilitates ovarian cancer progression by activating NF-κB signaling by binding to RIPK2. We suggest a new strategy for the treatment of ovarian cancer.

In vivo monitoring of the therapeutic efficacy of a CXCR1/2 inhibitor with 18F-FDG PET/CT imaging in experimental head and neck carcinoma: A feasibility study

The chemokine receptors CXCR1/2 play a key role in the aggressiveness of several types of cancers including head and neck squamous cell carcinomas (HNSCCs). In HNSCCs, CXCR1/2 signaling promotes cell proliferation and angiogenesis leading to tumor growth and metastasis. The competitive inhibitor of CXCR1/2, C29, inhibits the growth of experimental HNSCCs in mice. However, a non-invasive tool to monitor treatment response is essential to implement the use of C29 in clinical practices. 18F-FDG PET/CT is a gold-standard tool for the staging and the post-therapy follow-up of HNSCCs patients. Our study aimed to perform the first in vivo monitoring of C29 efficacy by non-invasive 18F-FDG PET/CT imaging. Mice bearing experimental HNSCCs (CAL33) were injected with 18F-FDG (T0) and thereafter treated (n = 7 mice, 9 tumors, 50 mg/kg by gavage) or not (n = 7 mice, 10 tumors) with C29 for 4 consecutive days. Final 18F-FDG-tumor uptake was determined at day 4 (TF). The average relative change (TF-T0) in 18F-FDG tumor uptake was +25.85 ± 10.93 % in the control group vs -5.72 ± 10.07 % in the C29-treated group (p < 0.01). These results were consistent with the decrease of the tumor burden and with the decrease of tumor proliferating Ki67+ cells. These results paved the way for the use of 18F-FDG to monitor tumor response following C29 treatment.

Receptor-Interacting Serine/Threonine-Protein Kinase-2 as a Potential Prognostic Factor in Colorectal Cancer

Background and objectives: Receptor-interacting serine/threonine-protein kinase-2 (RIPK2) is an important mediator in different pathways in the immune and inflammatory response system. RIPK2 was also shown to play different roles in different cancer types; however, in colorectal cancer (CRC), its role is not well established. This study aims at identifying the role of RIPK2 in CRC progression and survival. Materials and methods: Data of patients and mRNA protein expression level of genes associated with CRC (RIPK2, tumor necrosis factor (TNF), TRAF1, TRAF7, KLF6, interlukin-6 (Il6), interlukin-8 (Il8), vascular-endothelial growth factor A (VEGFA), MKI67, TP53, nuclear factor-kappa B (NFKB), NFKB2, BCL2, XIAP, and RELA) were downloaded from the PrognoScan online public database. Patients were divided between low and high RIPK2 expression and different CRC characteristics were studied between the two groups. Survival curves were evaluated using a Kaplan-Meier estimator. The Pearson correlation was used to study the correlation between RIPK2 and the other factors. Statistical analysis was carried out using SPSS version 25.0. The Human Protein Atlas was also used for the relationship between RIPK2 expression in CRC tissues and survival. Differences were considered statistically significant at p < 0.05. Results: A total of 520 patients were downloaded from the PrognoScan database, and RIPK2 was found to correlate with MKI67, TRAF1, KLF6, TNF, Il6, Il8, VEGFA, NFKB2, BCL2, and RELA. High expression of RIPK2 was associated with high expression of VEGFA (p < 0.01) and increased mortality (p < 0.01). Conclusions: In this study, RIPK2 is shown to be a potential prognostic factor in CRC; however, more studies are needed to assess and verify its potential role as a prognostic marker and in targeted therapy.

NOD1-Targeted Immunonutrition Approaches: On the Way from Disease to Health

Immunonutrition appears as a field with great potential in modern medicine. Since the immune system can trigger serious pathophysiological disorders, it is essential to study and implement a type of nutrition aimed at improving immune system functioning and reinforcing it individually for each patient. In this sense, the nucleotide-binding oligomerization domain-1 (NOD1), one of the members of the pattern recognition receptors (PRRs) family of innate immunity, has been related to numerous pathologies, such as cancer, diabetes, or cardiovascular diseases. NOD1, which is activated by bacterial-derived peptidoglycans, is known to be present in immune cells and to contribute to inflammation and other important pathways, such as fibrosis, upon recognition of its ligands. Since immunonutrition is a significant developing research area with much to discover, we propose NOD1 as a possible target to consider in this field. It is relevant to understand the cellular and molecular mechanisms that modulate the immune system and involve the activation of NOD1 in the context of immunonutrition and associated pathological conditions. Surgical or pharmacological treatments could clearly benefit from the synergy with specific and personalized nutrition that even considers the health status of each subject.

Interleukin-6 and Interleukin-8 Regulate STAT3 Activation Migration/Invasion and EMT in Chrysophanol-Treated Oral Cancer Cell Lines

The tumor microenvironment plays a critical role in the control of metastasis. The epithelial–mesenchymal transition (EMT) is strongly associated with tumor metastasis, and consists of several protein markers, including E-cadherin and vimentin. We discovered that chrysophanol causes oral cancer cell apoptosis and the inhibition of migration/invasion and EMT. However, the detailed mechanisms of chrysophanol and its role in oral cancer with respect to the tumor microenvironment remain unknown. In the clinic, proinflammatory cytokines, such as IL-6 and IL-8, exhibit a higher expression in patients with oral cancer. However, the effect of chrysophanol on the production of IL-6 and IL-8 is unknown. We evaluated the expression of IL-6 and IL-8 in human SAS and FaDu oral cancer cell lines in the presence or absence of chrysophanol. The migration and invasion abilities were also determined using a Boyden chamber assay. Our results showed that treatment with chrysophanol significantly decreased the expression of IL-6 and IL-8, as well as the invasion ability of oral cancer cells. Moreover, chrysophanol also attenuated the EMT by increasing the expression of E-cadherin and reducing the expression of vimentin. Mechanistically, chrysophanol inhibited IL-6- and IL-8-induced invasion and STAT3 phosphorylation. IL-6 and IL-8 promote EMT and cell invasion, which is potentially related to the STAT3 signaling pathway in oral cancer. These findings provide insight into new aspects of chrysophanol activity and may contribute to the development of new therapeutic strategies for oral cancer.

Chemokine-Cytokine Networks in the Head and Neck Tumor Microenvironment

Head and neck squamous cell carcinomas (HNSCCs) are aggressive diseases with a dismal patient prognosis. Despite significant advances in treatment modalities, the five-year survival rate in patients with HNSCC has improved marginally and therefore warrants a comprehensive understanding of the HNSCC biology. Alterations in the cellular and non-cellular components of the HNSCC tumor micro-environment (TME) play a critical role in regulating many hallmarks of cancer development including evasion of apoptosis, activation of invasion, metastasis, angiogenesis, response to therapy, immune escape mechanisms, deregulation of energetics, and therefore the development of an overall aggressive HNSCC phenotype. Cytokines and chemokines are small secretory proteins produced by neoplastic or stromal cells, controlling complex and dynamic cell-cell interactions in the TME to regulate many cancer hallmarks. This review summarizes the current understanding of the complex cytokine/chemokine networks in the HNSCC TME, their role in activating diverse signaling pathways and promoting tumor progression, metastasis, and therapeutic resistance development.

RIPK2 is an unfavorable prognosis marker and a potential therapeutic target in human kidney renal clear cell carcinoma

Receptor Interacting Serine/Threonine Kinase 2 (RIPK2) is located on chromosome 8q21 and encodes a protein containing a C-terminal caspase activation and recruitment domain (CARD), which is a component of signaling complexes in both the innate and adaptive immune pathways. To estimate the value of RIPK2 in evaluating the prognosis and guiding the targeted therapy for patients with kidney renal clear cell carcinoma (KIRC), we analyzed total 526 KIRC samples from The Cancer Genome Atlas (TCGA) database. Our result showed that RIPK2 was upregulated in KIRC tumor samples compared with normal samples. Cox regression was performed to calculate the hazard ratio of RIPK2 expression as an unfavorable prognosis feature for overall survival. Moreover, RIPK2 expression was positively correlated to the high-risk clinical stage, and metastasis features. The upregulation of RIPK2 was strongly correlated with various immune signaling pathway dysregulations as well as immune phenotypes changes in KIRC patient’s cohort. In addition, inhibition of RIPK2 activity by either shRNA-mediated knockdown or inhibitor significantly reduced kidney cancer cell viability, trans-migration in vitro, and impaired tumor growth in vivo. In conclusion, elevated RIPK2 expression indicates a worse prognosis for KIRC patients and could serve as a potential prognostic biomarker and therapeutic target in kidney cancer.

Analysis of the Prognosis and Therapeutic Value of the CXC Chemokine Family in Head and Neck Squamous Cell Carcinoma

The CXC chemokines belong to a family which includes 17 different CXC members. Accumulating evidence suggests that CXC chemokines regulate tumor cell proliferation, invasion, and metastasis in various types of cancers by influencing the tumor microenvironment. The different expression profiles and specific function of each CXC chemokine in head and neck squamous cell carcinoma (HNSCC) are not yet clarified. In our work, we analyzed the altered expression, interaction network, and clinical data of CXC chemokines in patients with HNSCC by using the following: the Oncomine dataset, cBioPortal, Metascape, String analysis, GEPIA, and the Kaplan–Meier plotter. The transcriptional level analysis suggested that the mRNA levels of CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, CXCL8, CXCL9, CXCL10, CXCL11, and CXCL13 increased in HNSCC tissue samples when compared to the control tissue samples. The expression levels of CXCL9, CXCL10, CXCL11, CXCL12, and CXCL14 were associated with various tumor stages in HNSCC. Clinical data analysis showed that high transcription levels of CXCL2, CXCL3, and CXCL12, were linked with low relapse-free survival (RFS) in HNSCC patients. On the other hand, high CXCL14 levels predicted high RFS outcomes in HNSCC patients. Meanwhile, increased gene transcription levels of CXCL9, CXCL10, CXCL13, CXCL14, and CXCL17 were associated with a higher overall survival (OS) advantage in HNSCC patients, while high levels of CXCL1, and CXCL8 were associated with poor OS in all HNSCC patients. This study implied that CXCL1, CXCL2, CXCL3, CXCL8, and CXCL12 could be used as prognosis markers to identify low survival rate subgroups of patients with HNSCC as well as be potential suitable therapeutic targets for HNSCC patients. Additionally, CXCL9, CXCL10, CXCL13, CXCL14, and CXCL17 could be used as functional prognosis biomarkers to identify better survival rate subgroups of patients with HNSCC.

Expression of Interleukin-1ß and Interleukin-8 in Oral Potentially Malignant Disorders and Carcinomas

Objective: To evaluate interleukin-1ß (IL-1ß) and interleukin-8 (IL-8) epithelial expressions in potentially malignant disorders of the oral mucosa as malignant predictive markers. Study design: About 55 tissues embedded in paraffin, comprising 15 oral lichen planus (OLP) lesions, 15 leukoplakias, 15 oral squamous cell carcinomas (OSCC), and 10 samples of normal oral mucosa were included in the study. IL-1ß and 8 expressions were assessed by immunohistochemistry using antibodies antihuman IL-1ß human (sc-7884, Santa Cruz® H-153) and antihuman IL-8 (ab7747, abcam®). The number of positive cells was compared using Student's t-test. Any p-value < 0.05 was considered statistically significant. Results: Nuclear and cytoplasmatic keratinocyte staining were positive for both cytokines in all study groups. However, a statistically significant decrease was observed within all cases compared to normal mucosa, both staining for IL-1β and 8. Moreover, IL-8 showed significant differences between OLP and leukoplakia, and when compared to OSCC. Conclusions: Oral epithelial expression of IL-1β and 8 seems to decrease when the malignant transformation of the oral mucosa increases.

Predictive capacity of IL-8 expression in head and neck squamous carcinoma patients treated with radiotherapy or chemoradiotherapy

OBJECTIVE

To analyse the relationship between the transcriptional expression of interleukin-8 (IL-8) and response to treatment with radiotherapy or chemo-radiotherapy in patients with squamous cell carcinoma of the head and neck (SCCHN).

MATERIAL AND METHODS

Retrospective study from tumour biopsies obtained before a treatment with radiotherapy or chemo-radiotherapy in 87 patients with SCCHN. We had a sample of healthy mucosa in 35 cases. We determined the transcriptional expression of IL-8 with RT-PCR. The transcriptional expression of IL-8 was categorized according to the local control of the disease with a recursive partitioning analysis.

RESULTS

The transcriptional expression of IL-8 in tumour tissue was about 50 times higher than that in the samples of healthy mucosa. Patients with a high transcriptional expression of IL-8 (n=56) had a 5-year local recurrence-free survival of 65.6%, and for patients with low expression (n=31) it was 90.2% (P=.017). According to the results of a multivariate analysis, patients with high expression of IL-8 had a 4.1 higher risk of local recurrence of the tumour.

CONCLUSIONS

SCCHN have a significant increase in transcriptional expression of IL-8 in relation to non-tumour tissue. Tumours with high IL-8 expression have an increased risk of local recurrence after treatment with radiotherapy or chemo-radiotherapy.

Leukoplakia and Immunology: New Chemoprevention Landscapes?

Oral potentially malignant disorders (OPMDs) comprise a range of clinical-pathological alterations frequently characterized by an architectural and cytological derangements upon histological analysis. Among them, oral leukoplakia is the most common type of these disorders. This work aims to analyze the possible use of drugs such as immunochemopreventive agents for OPMDs. Chemoprevention is the use of synthetic or natural compounds for the reversal, suppression, or prevention of a premalignant lesion conversion to malignant form. Experimental and in vivo data offer us the promise of molecular prevention through immunomodulation; however, currently, there is no evidence for the efficacy of these drugs in the chemoprevention action. Alternative ways to deliver drugs, combined use of molecules with complementary antitumor activities, diet influence, and better definition of individual risk factors must also be considered to reduce toxicity, improve compliance to the protocol treatment and offer a better individualized prevention. In addition, we must carefully reconsider the mode of action of many traditional cancer chemoprevention agents on the immune system, such as enhancing immunosurveillance and reversing the immune evasion. Several studies emphasize the concept of green chemoprevention as an alternative approach to accent healthy lifestyle changes in order to decrease the incidence of HNSCC.

The Role of the NOD1/Rip2 Signaling Pathway in Myocardial Remodeling in Spontaneously Hypertensive Rats

BACKGROUND Chronic hypertension changes the function and structure of the heart and blood vessels. This study aimed to explore the role of the NOD1/Rip2 (nucleotide-binding oligomerization domain 1/receptor-interacting protein 2) signaling pathway in myocardial remodeling in spontaneously hypertensive rats (SHRs). MATERIAL AND METHODS Blood pressure was measured using a tail cuff. The cardiac structure was observed using echocardiography. Slices of the myocardium were stained with hematoxylin and eosin. The expression of NOD1 and Rip2 was detected using real-time polymerase chain reaction, western blot, and immunohistochemistry. The content and distribution of collagen in the myocardium were observed using Van Gieson staining. Enzyme-linked immunosorbent assay was used to detect the interleukin-1 (IL-1) concentrations. SHRs were treated with the NOD1 agonist iE-DAP and NOD1 inhibitor ML130. RESULTS The NOD1 agonist increased blood pressure in SHRs, and the NOD1 inhibitor decreased blood pressure; the interventricular septum thickness (IVST) and left ventricular posterior wall thickness (LVPWT) of the agonist-treated group were thicker than those of the control group, and the antagonist exerted the opposite effects. The levels of the NOD1 and Rip2 mRNAs and proteins, serum IL-1 concentration, and myocardial collagen volume fraction (CVF%) increased in SHRs in the NOD1 agonist group, but the levels of NOD1 and Rip2, serum IL-1 concentration, and myocardial collagen volume fraction (CVF%) decreased in SHRs in the NOD1 inhibitor group. CONCLUSIONS NOD1/Rip2 expression increased during the progression of myocardial remodeling in SHRs. The NOD1 agonist increased NOD1 expression and promoted myocardial remodeling, while the NOD1 antagonist reduced NOD1/Rip2 expression and protected against myocardial remodeling.

miRNA- and cytokine-associated extracellular vesicles mediate squamous cell carcinomas

Exosomes, or small extracellular vesicles (sEVs), serve as intercellular messengers with key roles in normal and pathological processes. Our previous work had demonstrated that Dsg2 expression in squamous cell carcinoma (SCC) cells enhanced both sEV secretion and loading of pro-mitogenic cargo. In this study, using wild-type Dsg2 and a mutant form that is unable to be palmitoylated (Dsg2cacs), we investigated the mechanism by which Dsg2 modulates SCC tumour development and progression through sEVs. We demonstrate that palmitoylation was required for Dsg2 to regulate sub-cellular localisation of lipid raft and endosomal proteins necessary for sEV biogenesis. Pharmacological inhibition of the endosomal pathway abrogated Dsg2-mediated sEV release. In murine xenograft models, Dsg2-expressing cells generated larger xenograft tumours as compared to cells expressing GFP or Dsg2cacs. Co-treatment with sEVs derived from Dsg2-over-expressing cells increased xenograft size. Cytokine profiling revealed, Dsg2 enhanced both soluble and sEV-associated IL-8 and miRNA profiling revealed, Dsg2 down-regulated both cellular and sEV-loaded miR-146a. miR-146a targets IRAK1, a serine-threonine kinase involved in IL-8 signalling. Treatment with a miR-146a inhibitor up-regulated both IRAK1 and IL-8 expression. RNAseq analysis of HNSCC tumours revealed a correlation between Dsg2 and IL-8. Finally, elevated IL-8 plasma levels were detected in a subset of HNSCC patients who did not respond to immune checkpoint therapy, suggesting that these patients may benefit from prior anti-IL-8 treatment. In summary, these results suggest that intercellular communication through cell-cell adhesion, cytokine release and secretion of EVs are coordinated, and critical for tumour growth and development, and may serve as potential prognostic markers to inform treatment options.

Abbreviations

Basal cell carcinomas, BCC; Betacellulin, BTC; 2-bromopalmitate, 2-Bromo; Cluster of differentiation, CD; Cytochrome c oxidase IV, COX IV; Desmoglein 2, Dsg2; Early endosome antigen 1, EEA1; Epidermal growth factor receptor substrate 15, EPS15; Extracellular vesicle, EV; Flotillin 1, Flot1; Glyceraldehyde-3-phosphate dehydrogenase, GAPH; Green fluorescent protein, GFP; Head and neck squamous cell carcinoma, HNSCC; Interleukin-1 receptor-associated kinase 1, IRAK1; Interleukin 8, IL-8; Large EV, lEV; MicroRNA, miR; Palmitoylacyltransferase, PAT; Ras-related protein 7 Rab7; Small EV, sEV; Squamous cell carcinoma, SCC; Tissue inhibitor of metalloproteinases, TIMP; Tumour microenvironment, TME

Saponin Facilitates Anti-Robo1 Immunotoxin Cytotoxic Effects on Maxillary Sinus Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers worldwide. The standard treatment of surgery, chemotherapy, and radiotherapy can result in long-term complications which lower the patient's quality of life, such as eating disorders, speech problems, and disfiguring or otherwise untoward cosmetic issues. Antibody therapy against cancer-specific antigens is advantageous in terms of its lesser side effects achieved by its greater specificity, though the antitumor activity is still usually not enough to obtain a complete cure. Robo1, an axon guidance receptor, has received considerable attention as a possible drug target in various cancers. We have shown previously the enhanced cytotoxic effects of saporin-conjugated anti-Robo1 immunotoxin (IT-Robo1) on the HNSCC cell line HSQ-89 in combination with a photochemical internalization technique. Considering the light source, which has only limited tissue penetrance, we examined the drug internalization effect of saponin. Treatment with saponin facilitated significant cytotoxic effects of IT-Robo1 on HSQ-89 cells. Saponin exerts its own nonspecific cytotoxicity, which may cover the actual extent of the internalization effect. We thus examined whether a flashed treatment with saponin exerted a significant specific cytotoxic effect on cancer cells. The combination of an immunotoxin with saponin also exhibited a significant tumor-suppressive effect on mice HSQ-19 xenografts. These results suggest the utility of saponin treatment as an enhancer of immunotoxin treatment in cancer.

Fenretinide, Tocilizumab, and Reparixin Provide Multifaceted Disruption of Oral Squamous Cell Carcinoma Stem Cell Properties: Implications for Tertiary Chemoprevention

Locoregional recurrence of oral squamous cell carcinoma (OSCC) dramatically reduces patient survival. Further, as many OSCC recurrences are inoperable, radiotherapy and chemotherapy with or without biological adjuncts are the remaining treatment options. Although the tumors may initially respond, radiotherapy- and chemotherapy-resistant cancer stem cells (CSC) can readily repopulate OSCC tumors. Currently, following the initial OSCC treatment, patients are closely monitored until a recurrence or a second primary is detected. Identification of agents with complementary mechanisms to suppress CSC tumorigenic functions could change this passive approach. The goals of this study were twofold: (1) develop and validate CSC-enriched (CSCE) OSCC cell lines and (2) identify chemopreventive agents that obstruct multiple CSCE protumorigenic pathways. CSCE cultures, which were created by paclitaxel treatment followed by three tumorsphere passes, demonstrated CSC characteristics, including increased expression of stem cell and inflammatory genes, increased aldehyde dehydrogenase (ALDH) activity, and enhanced in vitro/in vivo proliferation and invasion. Three chemopreventives, fenretinide, tocilizumab, and reparixin, were selected due to their distinct and complementary CSC-disruptive mechanisms. The CSCE selection process modulated the cells' intermediate filaments resulting in an epithelial-predominant (enhanced cytokeratin, proliferation, IL6 release) line and a mesenchymal-predominant (upregulated vimentin, invasive, IL8 release) line. Our results confirm that 4HPR binds with appreciably higher affinity than Wnt at the Frizzled binding site and significantly inhibits CSC-enabling Wnt-β-catenin downstream signaling. Notably, combination fenretinide-tocilizumab-reparixin treatment significantly suppressed IL6 and IL8 release, stem cell gene expression, and invasion in these diverse CSCE populations. These promising multiagent in vitro data provide the basis for our upcoming in vivo CSCE tertiary chemoprevention studies.

Immunotherapies and Future Combination Strategies for Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is often diagnosed at an advanced stage and has a dismal prognosis. Nearly 10 years after the approval of cetuximab, anti-PD1/PD-L1 checkpoint inhibitors are the first drugs that have shown any survival benefit for the treatment on platinum-refractory recurrent/metastatic (R/M) HNSCC. Furthermore, checkpoint inhibitors are better tolerated than chemotherapy. The state of the art in the treatment of R/M HNSCC is changing, thanks to improved results for checkpoint inhibitors. Results for these treatments are also awaited in curative settings and for locally advanced HNSCC. Unfortunately, the response rate of immunotherapy is low. Therefore, the identification of predictive biomarkers of response and resistance to anti-PD1/PD-L1 is a key point for better selecting patients that would benefit the most from immunotherapy. Furthermore, the combination of checkpoint inhibitors with various agents is being currently evaluated to improve the response rate, prolong response duration, and even increase the chances for a cure. In this review, we summarize the most important results regarding immune targeting agents for HNSCC, predictive biomarkers for resistance to immune therapies, and future perspectives.

Tris(8-Hydroxyquinoline)iron induces apoptotic cell death via oxidative stress and by activating death receptor signaling pathway in human head and neck carcinoma cells

BACKGROUND

8-Hydroxyquinoline derivatives have highly sensitive fluorescent chemosensors for metal ions, which are associated with anti-oxidant, anti-tumor and anti-HIV-1 properties. Head and neck squamous cell carcinoma (HNSCC) is associated with a high rate of mortality and novel anti-HNSCC drugs must be developed. Therefore, effective chemotherapy agents are required to address this public health issue.

HYPOTHESIS/PURPOSE

The aim of this study was to investigate the inhibitory effect of tris(8-hydroxyquinoline)iron (Feq₃) on the HNSCC and the underlying mechanism.

STUDY DESIGN/METHODS

A novel 8-hydroxyquinoline derivative, Feq₃, was synthesized. The cell viabilities were analyzed using MTT reagent. Apoptosis and the cell cycle distributions were determined by flow cytometer. Reverse transcription-polymerase chain reaction (RT-PCR), immunofluorescence, western blot, MitoSOX and CellROX stain assay were used to study the mechanism of Feq₃. Feq₃ combined with antioxidants NAC (N-acetylcysteine) and BSO (buthionine sulfoximine) measured the cell viability and intracellular ROS.

RESULTS

Feq₃ induced the death of HNSCC cells and caused them to exhibit the morphological features of apoptosis. Feq₃ also induced apoptosis of SCC9 cells by cell cycle arrest during the G₂/M phase and the induced arrest of SCC25 cells in the G₀/G₁ and G₂/M phases, which was associated with decreased cyclin B1/cdc2 and cyclin D/cdk4 expressions. Feq₃ increases reactive oxygen species (ROS) and reduces glutathione (GSH) levels, and responds to increased p53 and p21 expressions. Feq₃ induced apoptosis by mitochondria-mediated Bax and cytochrome c up-expression and down-expression Bcl-2. Feq₃ also up-regulated tBid, which interacts with the mitochondrial pathway and tumor necrosis factor-α (TNF-α)/TNF-Rs, FasL/Fas, and TNF-related apoptosis inducing ligand receptors (TRAIL-Rs)/TRAIL-dependent caspases apoptotic signaling pathway in HNSCC cells. However, Feq₃ activates Fas but not FasL in SCC25 cells. Feq₃ arrests the growth of HNSCC cells and is involved in the mitochondria- and death receptor (DR)-mediated caspases apoptotic pathway.

CONCLUSION

This study is the first to suggest that apoptosis mediates the anti-HNSCC of Feq₃. Feq₃ has potential as a cancer therapeutic agent against HNSCC.

Screening and identification of potential target genes in head and neck cancer using bioinformatics analysis

Head and neck cancer (HNC) is the sixth most common cancer worldwide. Recent studies on the pathogenesis of HNC have identified some biochemical associations of this disease, but the molecular mechanisms are not clear. To explore the genetic alterations in head and neck tumors, to identify new high-specificity and high-sensitivity tumor markers, and to investigate potentially effective therapeutic targets, in silico methods were used to study HNC. The GSE58911 microarray dataset was downloaded from the Gene Expression Omnibus online database to identify potential target genes in the carcinogenesis and progression of HNC. Differentially expressed genes (DEGs) were identified and functional enrichment analysis was performed. In addition, a protein-protein interaction network was also constructed, and gene analysis was undertaken using Search Tool for the Retrieval of Interacting Genes and Cytoscape. A total of 648 differentially expressed genes were identified. Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology functional enrichment analysis of DEGs included muscle system process, extracellular matrix organization, actin binding, structural molecule activity, structural constituent of muscle, extracellular region part, ECM-receptor interaction, amoebiasis, focal adhesion, drug metabolism-cytochrome P450, and chemical carcinogenesis. There were 26 hub genes identified and biological process analysis revealed that these genes were mainly enriched in extracellular matrix organization, serine-type endopeptidase activity, extracellular matrix, and complement and coagulation cascades. Survival analysis revealed that interleukin (IL)-8 (C-X-C motif chemokine ligand 8), IL1B, and serpin family A member 1 may be involved in the carcinogenesis of HNC. In summary, the DEGs and hub genes identified in the present study may increase understanding of the molecular mechanisms of development of HNC and provide potential target genes for clinical diagnosis and targeted therapy.

New CXCR1/CXCR2 inhibitors represent an effective treatment for kidney or head and neck cancers sensitive or refractory to reference treatments

Clear cell Renal Cell (RCC) and Head and Neck Squamous Cell Carcinomas (HNSCC) are characterized by a pro-angiogenic/pro-inflammatory context. Despite conventional or targeted therapies, metastatic RCC and HNSCC remain incurable. Alternative treatments to reference therapies (sunitinib, a multi tyrosine kinase inhibitor for RCC or cisplatin for HNSCC) are urgently needed on relapse. Here, we described the relevance of targeting the ELR+CXCL cytokines receptors, CXCR1/2, for the treatment of these two cancer types. Methods: The relevance to patient treatment was evaluated by correlating the ELR⁺CXCL/CXCR1/2 levels to survival using online available data. We report herein the synthesis of new pharmacological inhibitors of CXCR1/2 with anti-proliferation/survival activity. The latter was evaluated with the XTT assay with leukemic, breast, RCC and HNSCC cell lines. Their relevance as an alternative treatment was tested on sunitinib- and cisplatin- resistant cells. The most efficient compound was then tested in a mouse model of RCC and HNSCC. Results: RCC and HNSCC expressed the highest amounts of CXCR1/2 of all cancers. High levels of ELR⁺CXCL cytokines (CXCL1, 2, 3, 5, 6, 7, 8) correlated to shorter survival. Among the 33 synthesized and tested molecules, compound C29 reduced ELR⁺CXCL/CXCR1/2-dependent proliferation and migration of endothelial cells. C29 exerted an anti-proliferation/survival activity on a panel of cancer cells including naive and resistant RCC and HNSCC cells. C29 reduced the growth of experimental RCC and HNSCC tumors by decreasing tumor cell proliferation, angiogenesis and ELR⁺/CXCL-mediated inflammation. Conclusion: Our study highlights the relevance of new CXCR1/2 inhibitors for the treatment of RCC or HNSCC as first-line treatment or at relapse on reference therapies.

Human Beta Defensins and Cancer: Contradictions and Common Ground

Human beta-defensins (hBDs, −1, 2, 3) are a family of epithelial cell derived antimicrobial peptides (AMPs) that protect mucosal membranes from microbial challenges. In addition to their antimicrobial activities, they possess other functions; e.g., cell activation, proliferation, regulation of cytokine/chemokine production, migration, differentiation, angiogenesis, and wound healing processes. It has also become apparent that defensin levels change with the development of neoplasia. However, inconsistent observations published by various laboratories make it difficult to reach a consensus as to the direction of the dysregulation and role the hBDs may play in various cancers. This is particularly evident in studies focusing on oral squamous cell carcinoma (OSCC). By segregating each hBD by cancer type, interrogating methodologies, and scrutinizing the subject cohorts used in the studies, we have endeavored to identify the “take home message” for each one of the three hBDs. We discovered that (1) consensus-driven findings indicate that hBD-1 and−2 are down- while hBD-3 is up-regulated in OSCC; (2) hBD dysregulation is cancer-type specific; (3) the inhibition/activation effect an hBD has on cancer cell lines is related to the direction of the hBD dysregulation (up or down) in the cancer from which the cell lines derive. Therefore, studies addressing hBD dysregulation in various cancers are not generalizable and comparisons should be avoided. Systematic delineation of the fate and role of the hBDs in a specific cancer type may lead to innovative ways to use defensins as prospective biomarkers for diagnostic/prognostic purposes and/or in novel therapeutic modalities.

The Selection of NFκB Inhibitors to Block Inflammation and Induce Sensitisation to FasL-Induced Apoptosis in HNSCC Cell Lines Is Critical for Their Use as a Prospective Cancer Therapy

Inflammation is a central aspect of tumour biology and can contribute significantly to both the origination and progression of tumours. The NFκB pathway is one of the most important signal transduction pathways in inflammation and is, therefore, an excellent target for cancer therapy. In this work, we examined the influence of four NFκB inhibitors—Cortisol, MLN4924, QNZ and TPCA1—on proliferation, inflammation and sensitisation to apoptosis mediated by the death ligand FasL in the HNSCC cell lines PCI1, PCI9, PCI13, PCI52 and SCC25 and in the human dermal keratinocyte cell line HaCaT. We found that the selection of the inhibitor is critical to ensure that cells do not respond by inducing counteracting activities in the context of cancer therapy, e.g., the extreme IL-8 induction mediated by MLN4924 or FasL resistance mediated by Cortisol. However, TPCA1 was qualified by this in vitro study as an excellent therapeutic mediator in HNSCC by four positive qualities: (1) proliferation was inhibited at low μM-range concentrations; (2) TNFα-induced IL-8 secretion was blocked; (3) HNSCC cells were sensitized to TNFα-induced cell death; and (4) FasL-mediated apoptosis was not disrupted.

Drug repositioning in head and neck squamous cell carcinoma: An integrated pathway analysis based on connectivity map and differential gene expression

The severe damage to health and social burden caused by head and neck squamous cell carcinoma (HNSCC) generated an urgent need to develop novel anti-cancer therapy. Currently, drug repositioning has risen in responses to the proper time as an efficient approach to invention of new anti-cancer therapies. In the present study, we aimed to screen candidate drugs for HNSCC by integrating HNSCC-related pathways from differentially expressed genes (DEGs) and drug-affected pathways from connectivity map (CMAP). We also endeavored to unveil the molecular mechanism of HNSCC through creating drug-target network and protein-to-protein (PPI) network of component DEGs in key overlapping pathways. As a result, a total of 401 DEGs were obtained from TCGA and GTEx mRNA-seq data. Taking the intersection part of 27 HNSCC-related Kyoto Encyclopedia of Genes and Genomes pathways and 33 drug-affected pathways, we retained 22 candidate drugs corresponding to two key pathways (cell cycle and p53 signaling pathways) of the five overlapping pathways. Two of the hub genes (PCNA and CCND1) identified from the PPI network of component DEGs in cell cycle and p53 signaling pathways were defined as the critical targets of candidate drugs with increased protein expression in HNSCC tissues, which was reported by the human protein atlas (HPA) database and cBioPortal. Finally, we validated via molecular docking analysis that two drugs with unknown effects in HNSCC: MG-262 and bepridil might perturb the development of HNSCC through targeting PCNA. These candidate drugs possessed broad application prospect as medication for HNSCC.

Harnessing the untapped potential of nucleotide-binding oligomerization domain ligands for cancer immunotherapy

In the last decade, cancer immunotherapy has emerged as an effective alternative to traditional therapies such as chemotherapy and radiation. In contrast to the latter, cancer immunotherapy has the potential to distinguish between cancer and healthy cells, and thus to avoid severe and intolerable side‐effects, since the cancer cells are effectively eliminated by stimulated immune cells. The cytosolic nucleotide‐binding oligomerization domains 1 and 2 receptors (NOD1 and NOD2) are important components of the innate immune system and constitute interesting targets in terms of strengthening the immune response against cancer cells. Many NOD ligands have been synthesized, in particular NOD2 agonists that exhibit favorable immunostimulatory and anticancer activity. Among them, mifamurtide has already been approved in Europe by the European Medicine Agency for treating patients with osteosarcoma in combination with chemotherapy after complete surgical removal of the primary tumor. This review is focused on NOD receptors as promising targets in cancer immunotherapy as well as summarizing current knowledge of the various NOD ligands exhibiting antitumor and even antimetastatic activity in vitro and in vivo.

Evodiamine Induces Apoptosis in SMMC-7721 and HepG2 Cells by Suppressing NOD1 Signal Pathway

Hepatocellular cancer (HCC) is a lethal malignancy with poor prognosis and easy recurrence. There are few agents with minor toxic side effects that can be used for treatment of HCC. Evodiamine (Evo), one of the major bioactive components derived from fructus Evodiae, has long been shown to exert anti-hepatocellular carcinoma activity by suppressing activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK). In addition, in the Nucleotide-Binding Oligomerization Domain 1 (NOD1) pathway, NOD1 could initiate NF-κB-dependent and MAPK-dependent gene transcription. Recent experimental studies reported that the NOD1 pathway was related to controlling development of various tumors. Here we hypothesize that Evo exerts anti-hepatocellular carcinoma activity by inhibiting NOD1 to suppress NF-κB and MAPK activation. Therefore, we proved the anti-hepatocellular carcinoma activity of Evo on HCC cells and detected the effect of Evo on the NOD1 pathway. We found that Evo significantly induced cell cycle arrest at the G2/M phase, upregulated P53 and Bcl-2 associated X proteins (Bax) proteins, and downregulated B-cell lymphoma-2 (Bcl-2), cyclinB1, and cdc2 proteins in HCC cells. In addition, Evo reduced levels of NOD1, p-P65, p-ERK, p-p38, and p-JNK, where the level of IκBα of HCC cells increased. Furthermore, NOD1 agonist γ-D-Glu-mDAP (IE-DAP) treatment weakened the effect of Evo on suppression of NF-κB and MAPK activation and cellular proliferation of HCC. In an in vivo subcutaneous xenograft model, Evo also exhibited excellent tumor inhibitory effects via the NOD1 signal pathway. Our results demonstrate that Evo could induce apoptosis remarkably and the inhibitory effect of Evo on HCC cells may be through suppressing the NOD1 signal pathway in vitro and in vivo.

Cell culture models of oral mucosal barriers: A review with a focus on applications, culture conditions and barrier properties

Understanding the function of oral mucosal epithelial barriers is essential for a plethora of research fields such as tumor biology, inflammation and infection diseases, microbiomics, pharmacology, drug delivery, dental and biomarker research. The barrier properties are comprised by a physical, a transport and a metabolic barrier, and all these barrier components play pivotal roles in the communication between saliva and blood. The sum of all epithelia of the oral cavity and salivary glands is defined as the blood-saliva barrier. The functionality of the barrier is regulated by its microenvironment and often altered during diseases. A huge array of cell culture models have been developed to mimic specific parts of the blood-saliva barrier, but no ultimate standard in vitro models have been established. This review provides a comprehensive overview about developed in vitro models of oral mucosal barriers, their applications, various cultivation protocols and corresponding barrier properties.

Immune Checkpoint Inhibition in Head and Neck Cancer

Head and Neck Squamous Cell Carcinoma (HNSCC) is the 6th most common cancer globally and commonly presents with locally advanced disease, which has a recurrence rate of around 50% despite aggressive multi-modality treatment involving surgery, radiotherapy and chemotherapy or EGFR inhibition where appropriate. As understanding of the underlying cancer biology and the complex interactions within the tumor microenvironment improves, there is gathering interest in and evidence for the role of immunomodulating agents in the management of HNSCC. Immune checkpoint inhibitors, which aim to hinder the inhibitory interaction between programmed cell death protein 1 (PD-1) and its ligand PD-L1, have demonstrated durable improvements in patient outcomes in advanced / metastatic HNSCC, with both pembrolizumab and nivolumab being granted FDA approval in 2016. There are numerous ongoing clinical trials exploring the role of checkpoint inhibitors both as single agents and in combination, administered with established treatment modalities such as chemotherapy and radiotherapy, as well as alongside other novel immune modulators. These trials are not limited to advanced / metastatic HNSCC, but also to the neo-adjuvant or adjuvant settings. As studies complete and more results become available, the role immunotherapy agents will have within the treatment strategies for HNSCC may change, with increasing biomarker selection resulting in personalized therapy aiming to further improve patient outcomes.

RNA interference: new mechanistic and biochemical insights with application in oral cancer therapy

Over the last few decades, the incidence of oral cancer has gradually increased, due to the negative influence of environmental factors and also abnormalities within the genome. The main issues in oral cancer treatment consist in surpassing resistance and recurrence. However, continuous discovery of altered signaling pathways in these tumors provides valuable information for the identification of novel gene candidates targeted in personalized therapy. RNA interference (RNAi) is a natural mechanism that involves small interfering RNA (siRNA); this can be exploited in biomedical research by using natural or synthetic constructs for activation of the mechanism. Synthetic siRNA transcripts were developed as a versatile class of molecular tools that have a diverse range of programmable roles, being involved in the regulation of several biological processes, thereby providing the perspective of an alternative option to classical treatment. In this review, we summarize the latest information related to the application of siRNA in oral malignancy together with molecular aspects of the technology and also the perspective upon the delivery system. Also, the emergence of newer technologies such as clustered regularly interspaced short palindromic repeats/Cas9 or transcription activator-like effector nucleases in comparison with the RNAi approach is discussed in this paper.

A link between RelB expression and tumor progression in laryngeal cancer

Laryngeal cancer is a frequent malignancy originating from the squamous vocal epithelium in a multi-stage fashion in response to environmental carcinogens. Although most cases can be cured by surgery and/or radiotherapy, advanced and relapsing disease is common, and biomarkers of such dismal cases are urgently needed. The cancer genome of laryngeal cancers was recently shown to feature a signature of aberrant nuclear factor (NF)-κB activation, but this finding has not been clinically exploited. We analyzed primary tumor samples of 96 well-documented and longitudinally followed patients covering the whole spectrum of laryngeal neoplasia, including 21 patients with benign laryngeal diseases, 15 patients with dysplasia, 43 patients with early-stage carcinoma, and 17 patients with locally advanced carcinoma, for immunoreactivity of RelA, RelB, P50, and P52/P100, the main NF-κB subunits that activate transcription. Results were cross-examined with indices of tumor progression and survival. Interestingly, RelB expression increased with tumor stage, grade, and local extent. Moreover, patients displaying high RelB immunoreactivity exhibited statistically significantly poorer survival compared with patients featuring low levels of RelB expression (P = 0.018 by log-rank test). Using Cox regression analyses and tumor stage, local extent, grade and RelA/RelB immunoreactivity, we develop a new score that can independently predict survival of patients with laryngeal cancer. Hence we provide a simple and affordable NF-κB-based test to predict prognosis in laryngeal cancer.

IL-8 promotes inflammatory mediators and stimulates activation of p38 MAPK/ERK-NF-κB pathway and reduction of JNK in HNSCC

This investigation identifies interleukin 8 (IL-8) as the main inflammatory mediator in head and neck squamous cell carcinoma (HNSCC). The expressions of chemokines of IL-8, IL-1β and IL-6 and the cytokines of tumor necrosis factor-α (TNF-α) were higher in HNSCC patient tissues than in non-cancerous matched tissues (NCMT) whereas the expression of IL-10 was lower. IL-8 is most highly expressed in the tissues of patients with HNSCC. Treatment of HNSCC cells with IL-8 increased the secretion of IL-1β, IL-6 and TNF-α and reduced IL-10 expression; the increase in the expression of IL-1β was particularly considerable. IL-8 silencing by siRNA reduced IL-1β expression in HNSCC cells, suggesting that IL-8 as a main inflammatory mediator improved IL-1β expression in HNSCC. The expressions of p-p38 mitogen-activated protein kinases (MAPK) and p-extracellular signal regulated kinase (p-ERK) were higher and that of p-c-Jun-NH2-terminal kinase (p-JNK) was lower in HNSCC patient tissues than in NCMT. IL-8 treatment induced p-p38 MAPK and p-ERK expression, but reduced p-JNK expressions in HNSCC cells. IL-8 siRNA suppressed p38 MAPK and ERK but increased JNK expression in HNSCC cells. Exposure of SCC25 cells to IL-8, increased the expressions of p-IκB-α and nuclear factor (NF)-κB, suggesting that IL-8 regulates inflammatory response by modulating the MAPK and NF-κB pathway in HNSCC cells. IL-8 promotes the migration of SCC25 cells and increases matrix metalloproteinase-2 (MMP-2) and MMP-9 expressions. These results reveal that IL-8 is the major stimulus of inflammatory mediation in HNSCC progression and migration by activating the p38 MAPK/ERK-NF-κB pathway and reducing JNK.