EGFR inhibition induces proinflammatory cytokines via NOX4 in HNSCC

Chemokine Receptor CXCR4 Radioligand Targeted Therapy Using 177Lutetium-pentixather for Pulmonary Neuroendocrine Cancers

Intermediate to high-grade lung neuroendocrine tumors (NETs; i.e., atypical carcinoid tumors) and neuroendocrine carcinomas (NECs) are currently difficult to cure. These tumors were found to express the CXCR4 G-protein coupled receptor that can be targeted with radioligands. PCR and flow cytometric analysis of lung NET and NEC cell lines using an anti-CXCR4 antibody demonstrated that all cell lines tested expressed CXCR4. PET/CT imaging with 68Galium-pentixafor in mouse xenografts of NETs and NECs verified tumor targeting that was blocked by a CXCR4 agonist. Clonogenic survival analysis demonstrated a more than additive enhancement of killing when 1 μM auranofin (a thioredoxin reductase inhibitor) was used as a radiosensitizer in combination with 177Lu-pentixather (10 μCi). DMS273 small cell lung cancer xenografts in female nude mice treated with 25 μCi/g 177Lu-pentixather induced inhibition of tumor growth and resulted in an increase in overall survival without causing unacceptable normal tissue toxicities. Immunohistochemical staining of 95 retrospective human samples (containing 90 small cell lung carcinomas) demonstrated 84% CXCR4 positivity. In a multivariable analysis of this cohort that included age, gender, stage, primary site, SSTR2 status, and CXCR4 status, Cox regression models determined that only distant metastasis at presentation (P < 0.01) and a CXCR4 H-score >30 (P = 0.04) were significantly associated with reduced survival. Prospective clinical testing of patient tumors identified CXCR4-positivity in 76% of 21 NECs, 67% of 15 lung NETs (including 8 of 10 atypical carcinoids), and 0% of 25 non-lung NETs (including 5 NETS G3s). These data support the hypothesis that CXCR4-targeted theranostics can be utilized effectively for select NETs and NECs.

FGFR2c Upregulation Contributes to Cancer-Associated Fibroblast Program Activation and to Enhanced Autophagy in Actinic Keratosis-Derived Dermal Fibroblasts: A Possible Role in Precancerous Cell/Stromal Cell Crosstalk

Actinic keratosis (AK) is a preneoplastic skin disorder which can rapidly progress to cutaneous squamous cell carcinomas (SCCs). In light of our previous findings, indicating a possible oncogenic role of the mesenchymal isoform of FGFR2 (FGFR2c) aberrantly expressed in AK keratinocytes, we analyzed the possible tumor-promoting role of this receptor in the stromal AK counterpart in this work. Molecular analysis showed that, particularly in early AK lesions, FGFR2c dermal upregulation is accompanied by the downregulation of the cancer-associated fibroblasts (CAF) transcription repressor CSL, the upregulation of the CAF activator ULK3, and the consequent CAF gene induction. Immunofluorescence and molecular analysis, coupled with silencing approaches by siRNA, applied on primary cultures of KIN I-derived fibroblasts, indicated that FGFR2c upregulation contribute to CAF signature and the increased autophagy in response to FGF2. Magnetic bead-based multiplex assay, combined with FGFR2 signaling shut-off approaches, indicated that, especially in response to FGF2, IL-6 secretion could depend on FGFR2c high expression and signaling, suggesting the possible establishment of FGFR2c-dependent secretory autophagy, contributing to tumor-promoting factor release. Overall, our results identified FGFR2c as a signaling molecule involved in controlling precancerous/stromal cell oncogenic crosstalk, pointing to this receptor as a possible early molecular marker predictive for AK’s rapid malignant progression.

Xijiao Dihuang decoction relieves the erlotinib-induced dermatitis

BACKGROUND

Erlotinib treatment can lead to skin diseases that drastically affected the quality of life of patients. Quercetin (Que), the active component in Xijiao Dihuang Decoction (XDD), was identified to improve inflammatory skin diseases. However, the mechanism of XDD treating erlotinib-induced cutaneous toxicity was not clear at the molecular level.

METHODS

Keratinocytes were treated with erlotinib, and the expression of inflammatory cytokines and chemokines was revealed by ELISA and qRT-PCR. The macrophage polarization was determined by flow cytometry. The key component of XDD, Que, and the target genes of dermatitis were selected via network pharmacology analysis. The binding effects of Que and target genes were verified using molecular docking and cellular thermal shift assay (CETSA)-western blot assay. Animal experiments were performed in vivo to verify the therapeutic effect of XDD on erlotinib-induced skin toxicity.

RESULTS

Erlotinib induced M1 polarization of macrophages after stimulating epidermal keratinocytes. While this effect was associated with increased production of inflammatory cytokines and chemokines, such production was prominently decreased by XDD treatment. By combining network pharmacological analysis, molecular docking, and CETSA, it was confirmed that Que had a binding relationship with IL-2 and CXCL8. In vivo results implied that erlotinib abated tumor growth and stimulated dermatitis in HR-1 nude mice, while Que alleviated erlotinib-induced skin damage without affecting this tumor repression effect.

CONCLUSION

The results indicated that XDD could relieve the dermatitis induced by erlotinib and provide a favorable theoretical basis for the clinical relief by using this method.

EGF‑IL2 bispecific and bivalent EGF fusion toxin efficacy against syngeneic head and neck cancer mouse models

The epidermal growth factor receptor (EGFR) remains one of the best molecules for developing targeted therapy for multiple human malignancies, including head and neck squamous cell carcinoma (HNSCC). Small molecule inhibitors or antibodies targeting EGFR have been extensively developed in recent decades. Immunotoxin (IT)‑based therapy, which combines cell surface binding ligands or antibodies with a peptide toxin, represents another cancer treatment option. A total of 3 diphtheria toxin (DT)‑based fusion toxins that target human EGFR‑monovalent EGFR IT (mono‑EGF‑IT), bivalent EGFR IT (bi‑EGF‑IT), and a bispecific IT targeting both EGFR and interleukin‑2 receptor (bis‑EGF/IL2‑IT) were recently generated by the authors. Improved efficacy and reduced toxicity of bi‑EGF‑IT compared with mono‑EGF‑IT in immunocompromised HNSCC mouse models was reported. In the present study, bis‑EGF/IL2‑IT were generated using a unique DT‑resistant yeast expression system and evaluated the in vitro and in vivo efficacy and toxicity of the 3 EGF‑ITs in immunocompetent mice. The results demonstrated that while the three EGF‑ITs had different efficacies in vitro and in vivo against HNSCC, bi‑EGF‑IT and bis‑EGF/IL2‑IT had significantly improved in vivo efficacy and remarkably less off‑target toxicity compared with mono‑EGF‑IT. In addition, bis‑EGF/IL2‑IT was superior to bi‑EGF‑IT in reducing tumor size and prolonging survival in the metastatic model. These data suggested that targeting either the tumor immune microenvironment or enhancing the binding affinity could improve the efficacy of IT‑based therapy. Bi‑EGF‑IT and bis‑EGF/IL2‑IT represent improved candidates for IT‑based therapy for future clinical development.

Potential ferroptosis-related diagnostic and prognostic biomarkers in laryngeal cancer

PURPOSE

Laryngeal cancer (LC) is a common malignant tumor of the head and neck. However, the relationship between ferroptosis and LC is still unclear. The aim of this study was to identify potential ferroptosis-related biomarkers for diagnosis and prognosis in LC.

METHODS

We screened differentially expressed genes (DEGs) related to ferroptosis in LC from the TCGA and FerrDb database. DEGs were identified and enrichment by GO/KEGG, GSEA, GSVA analysis. PPI analysis was performed using String and Cytoscape, then hub genes were extracted. Furthermore, ROC analysis, pan-cancer analysis, gene mutation analysis, immune infiltration correlation analysis and clinical correlation analysis of hub genes were performed.

RESULTS

A total of 59 DEGs were screened, which were more significantly enriched in biological processes and involved in HIF-1 signaling pathway, serotonergic synapse and ferroptosis. A total of 29 significant gene set pathways of LC data were performed by GSEA analysis. The GSVA analysis obtained 53 significant differential gene set pathways. The top 20 genes were identified by PPI. ROC curves revealed four of the top20 genes had a good performance, which were CA9 (AUC = 0.930), MAPK3 (AUC = 0.915), MUC1 (AUC = 0.945), and NOX4 (AUC = 0.933). Subsequent analysis found that CDKN2A has the highest mutation frequency in the top 20 gene, and IFNG had a significant correlation with age, tumor stage, degree of tumor differentiation and lymphatic clearance surgery.

CONCLUSION

Our study identified key genes closely related to ferroptosis in LC, which still need more studies to explore the mechanisms involved and may become effective clinical diagnostic and prognostic biomarkers.

A novel diphtheria toxin-based bivalent human EGF fusion toxin for treatment of head and neck squamous cell carcinoma

Epidermal growth factor receptor (EGFR) is often overexpressed in head and neck squamous cell carcinoma (HNSCC) and represents a top candidate for targeted HNSCC therapy. However, the clinical effectiveness of current Food and Drug Administration (FDA)-approved drugs targeting EGFR is moderate, and the overall survival rate for HNSCC patients remains low. Therefore, more effective treatments are urgently needed. In this study, we generated a novel diphtheria toxin-based bivalent human epidermal growth factor fusion toxin (bi-EGF-IT) to treat EGFR-expressing HNSCC. Bi-EGF-IT was tested for in vitro binding affinity, cytotoxicity, and specificity using 14 human EGFR-expressing HNSCC cell lines and three human EGFR-negative cancer cell lines. Bi-EGF-IT had increased binding affinity for EGFR-expressing HNSCC compared with the monovalent version (mono-EGF-IT), and both versions specifically depleted EGFR-positive HNSCC, but not EGFR-negative cell lines, in vitro. Bi-EGF-IT exhibited a comparable potency to that of the FDA-approved EGFR inhibitor, erlotinib, for inhibiting HNSCC tumor growth in vivo using both subcutaneous and orthotopic HNSCC xenograft mouse models. When tested in an experimental metastasis model, survival was significantly longer in the bi-EGF-IT treatment group than the erlotinib treatment group, with a significantly reduced number of metastases compared with mono-EGF-IT. In addition, in vivo off-target toxicities were significantly reduced in the bi-EGF-IT treatment group compared with the mono-EGF-IT group. These results demonstrate that bi-EGF-IT is more effective and markedly less toxic at inhibiting primary HNSCC tumor growth and metastasis than mono-EGF-IT and erlotinib. Thus, the novel bi-EGF-IT is a promising drug candidate for further development.

Correlations between serum cetuximab and EGFR-related markers, and skin disorders in head and neck cancer patients

PURPOSE

Cetuximab inhibits epidermal growth factor receptor (EGFR) signaling in cancer and skin cells, thereby inducing anti-cancer effects and skin disorders. The present study aimed to evaluate the relationships between serum cetuximab and EGFR-related markers, and adverse effects in head and neck cancer patients.

METHODS

Thirty-four head and neck cancer patients receiving weekly intravenous cetuximab were enrolled. Serum cetuximab levels were determined just before dosing. Blood samples for determination of serum EGFR-related markers including soluble epidermal growth factor receptor (sEGFR) and interleukin-6 (IL-6) were obtained. The severities of skin disorders, their medications, and hypomagnesemia treatment were also assessed.

RESULTS

Serum levels of cetuximab and sEGFR were negatively and positively correlated with that of IL-6, respectively. The serum cetuximab level was twofold higher in the patients with a grade 2-3 skin rash than with a grade 0-1 rash. The serum cetuximab cutoff value related to severe skin rash was 71 μg/mL (sensitivity, 59%; and specificity, 94%). The use of a strong topical corticosteroid for skin rash was also associated with a higher serum cetuximab level. Serum levels of sEGFR and IL-6 had no correlations with the skin disorder severities or their medications. Hypomagnesemia treatment using intravenous magnesium sulfate was not related to serum cetuximab and EGFR-related markers.

CONCLUSIONS

Head and neck cancer patients with a higher serum IL-6 level tended to have a lower serum cetuximab level. Serum cetuximab had positive correlations to skin rash severity and its medication in the study population.

The p38/MKP-1 signaling axis in oral cancer: Impact of tumor-associated macrophages

Oral squamous cell carcinomas (OSCC) constitute over 95% of all head and neck malignancies. As a key component of the tumor microenvironment (TME), chronic inflammation contributes towards the development, progression, and regional metastasis of OSCC. Tumor associated macrophages (TAMs) associated with OSSC promote tumorigenesis through the production of cytokines and pro-inflammatory factors that are critical role in the various steps of malignant transformation, including tumor growth, survival, invasion, angiogenesis, and metastasis. The mitogen-activated protein kinases (MAPKs) can regulate inflammation along with a wide range of cellular processes including cell metabolism, proliferation, motility, apoptosis, survival, differentiation and play a crucial role in cell growth and survival in physiological and pathological processes including innate and adaptive immune responses. Dual specificity MAPK phosphatases (MKPs) deactivates MAPKs. MKPs are considered as an important feedback control mechanism that limits MAPK signaling and subsequent target gene expression. This review outlines the role of MKP-1, the founding member of the MKP family, in OSCC and the TME. Herein, we summarize recent progress in understanding the regulation of p38 MAPK/MKP-1 signaling pathways via TAM-related immune responses in OSCC development, progression and treatment outcomes.

Integrative Analysis of Multi-omics Data Identified EGFR and PTGS2 as Key Nodes in a Gene Regulatory Network Related to Immune Phenotypes in Head and Neck Cancer

PURPOSE

Malignant progression exhibits a tightly orchestrated balance between immune effector response and tolerance. However, underlying molecular principles that drive the establishment and maintenance of the tumor immune phenotype remain to be elucidated.

EXPERIMENTAL DESIGN

We trained a novel molecular classifier based on immune cell subsets related to programmed death-ligand 1 (PD-L1) and interferon γ (IFNγ) expression, which revealed distinct subgroups with higher (cluster A) or lower (subcluster B3) cytotoxic immune phenotypes. Integrative analysis of multi-omics data was conducted to identify differences in genetic and epigenetic landscapes as well as their impact on differentially expressed genes (DEG) among immune phenotypes. A prognostic gene signature for immune checkpoint inhibition (ICI) was established by a least absolute shrinkage and selection operator (LASSO)-Cox regression model.

RESULTS

Mutational landscape analyses unraveled a higher frequency of CASP8 somatic mutations in subcluster A1, while subcluster B3 exhibited a characteristic pattern of copy-number alterations affecting chemokine signaling and immune effector response. The integrative multi-omics approach identified EGFR and PTGS2 as key nodes in a gene regulatory network related to the immune phenotype, and several DEGs related to the immune phenotypes were affected by EGFR inhibition in tumor cell lines. Finally, we established a prognostic gene signature by a LASSO-Cox regression model based on DEGs between nonprogressive disease and progressive disease subgroups for ICI.

CONCLUSIONS

Our data highlight a complex interplay between genetic and epigenetic events in the establishment of the tumor immune phenotype and provide compelling experimental evidence that a patient with squamous cell carcinoma of the head and neck at higher risk for ICI treatment failure might benefit from a combination with EGFR inhibition.

Interleukin 6 is increased in preclinical HNSCC models of acquired cetuximab resistance, but is not required for maintenance of resistance

The epidermal growth factor receptor inhibitor cetuximab is the only oncogene-targeted agent that has been FDA approved for the treatment of head and neck squamous cell carcinoma (HNSCC). Currently, there are no biomarkers used in the clinic to predict which HNSCC tumors will respond to cetuximab, and even in tumors that regress with treatment, acquired resistance occurs in the majority of cases. Though a number of mechanisms of acquired resistance to cetuximab have been identified in preclinical studies, no therapies targeting these resistance pathways have yet been effectively translated into the clinic. To address this unmet need, we examined the role of the cytokine interleukin 6 (IL-6) in acquired cetuximab resistance in preclinical models of HNSCC. We found that IL-6 secretion was increased in PE/CA-PJ49 cells that had acquired resistance to cetuximab compared to the parental cells from which they were derived. However, addition of exogenous IL-6 to parental cells did not promote cetuximab resistance, and inhibition of the IL-6 pathway did not restore cetuximab sensitivity in the cetuximab-resistant cells. Further examination of the IL-6 pathway revealed that expression of IL6R, which encodes a component of the IL-6 receptor, was decreased in cetuximab-resistant cells compared to parental cells, and that treatment of the cetuximab-resistant cells with exogenous IL-6 did not induce phosphorylation of signal transducer and activator of transcription 3, suggesting that the IL-6 pathway was functionally impaired in the cetuximab-resistant cells. These findings demonstrate that, even if IL-6 is increased in the context of cetuximab resistance, it is not necessarily required for maintenance of the resistant phenotype, and that targeting the IL-6 pathway may not restore sensitivity to cetuximab in cetuximab-refractory HNSCC.

NOX4 overexpression is a poor prognostic factor in patients undergoing curative esophagectomy for esophageal squamous cell carcinoma

BACKGROUND

Nox4 has been associated with tumor progression in various types of malignancies. This study aimed to evaluate the importance of the expression of Nox4 in patients undergoing curative esophagectomy for esophageal squamous cell carcinoma.

METHODS

We reviewed retrospectively 121 patients with esophageal squamous cell carcinoma who had undergone a curative esophagectomy, including 67 patients with overexpression and 54 patients with low expression of Nox4 as evaluated by immunohistochemical analysis. In addition, 2 esophageal squamous cell carcinoma cell lines, TE11 and KYSE270, were treated with the Nox4 inhibitor GKT-137831 to explore the expression of Nox4, cell proliferative activity, and selected downstream pathways in these esophageal squamous cell carcinoma cell lines by Western blot analysis.

RESULTS

Univariate analysis showed that T1-2 status, absence of nodal metastasis, and low Nox4 expression were associated with greater disease-free survival (P = .001) and overall survival (P < .001), and Nox4 overexpression was an independent prognostic factor of worse disease-free survival and overall survival (P = .013 and P = .007, respectively). The esophageal squamous cell carcinoma cell lines treated with the Nox4 inhibitor GKT-137831 showed decreased cell proliferation in a dose-dependent manner (P < .01). Western blot analysis demonstrated that expression of AKT, phosphorylated AKT, mammalian target of rapamycin, and phosphorylated mammalian target of rapamycin were less in esophageal squamous cell carcinoma cells treated with the Nox4 inhibitor (P < .01).

CONCLUSION

This study suggests that Nox4 overexpression is a poor prognostic factor for patients with esophageal squamous cell carcinoma undergoing curative esophagectomy.

Interleukin-1 alpha increases anti-tumor efficacy of cetuximab in head and neck squamous cell carcinoma

BACKGROUND

Despite the high prevalence of epidermal growth factor receptor (EGFR) overexpression in head and neck squamous cell carcinomas (HNSCCs), incorporation of the EGFR inhibitor cetuximab into the clinical management of HNSCC has not led to significant changes in long-term survival outcomes. Therefore, the identification of novel therapeutic approaches to enhance the clinical efficacy of cetuximab could lead to improved long-term survival for HNSCC patients. Our previous work suggests that EGFR inhibition activates the interleukin-1 (IL-1) pathway via tumor release of IL-1 alpha (IL-1α), although the clinical implications of activating this pathway are unclear in the context of cetuximab therapy. Given the role of IL-1 signaling in anti-tumor immune response, we hypothesized that increases in IL-1α levels would enhance tumor response to cetuximab.

METHODS

Parental and stable myeloid differentiation primary response gene 88 (MyD88) and IL-1 receptor 1 (IL-1R1) knockdown HNSCC cell lines, an IL-1R antagonist (IL-1RA), neutralizing antibodies to IL-1α and IL-1β, and recombinant IL-1α and IL-1β were used to determine cytokine production (using ELISA) in response to cetuximab in vitro. IL-1 pathway modulation in mouse models was accomplished by administration of IL-1RA, stable overexpression of IL-1α in SQ20B cells, administration of rIL-1α, and administration of a polyanhydride nanoparticle formulation of IL-1α. CD4⁺ and CD8⁺ T cell-depleting antibodies were used to understand the contribution of T cell-dependent anti-tumor immune responses. Baseline serum levels of IL-1α were measured using ELISA from HNSCC patients treated with cetuximab-based therapy and analyzed for association with progression free survival (PFS).

RESULTS

Cetuximab induced pro-inflammatory cytokine secretion from HNSCC cells in vitro which was mediated by an IL-1α/IL-1R1/MyD88-dependent signaling pathway. IL-1 signaling blockade did not affect the anti-tumor efficacy of cetuximab, while increased IL-1α expression using polyanhydride nanoparticles in combination with cetuximab safely and effectively induced a T cell-dependent anti-tumor immune response. Detectable baseline serum levels of IL-1α were associated with a favorable PFS in cetuximab-based therapy-treated HNSCC patients compared to HNSCC patients with undetectable levels.

CONCLUSIONS

Altogether, these results suggest that IL-1α in combination with cetuximab can induce a T cell-dependent anti-tumor immune response and may represent a novel immunotherapeutic strategy for EGFR-positive HNSCCs.

Tumoral NOX4 recruits M2 tumor-associated macrophages via ROS/PI3K signaling-dependent various cytokine production to promote NSCLC growth

M2-type tumor-associated macrophages (TAMs) infiltration contributes to cancer malignant progression. However, the mechanisms for controlling recruitment and M2 polarization of macrophages by cancer cells are largely unclear. NADPH oxidase 4 (NOX4) is abundantly expressed in non-small cell lung cancer (NSCLC) and mediates cancer progression. NOXs are in close relation with cancer-related inflammation, nevertheless, whether tumoral NOXs influence microenvironmental macrophages remains undentified. This study found that there was a close association between NOX4 expression and macrophage chemotaxis in patients with NSCLC analyzed using TCGA RNA-sequencing data. NOX4 in NSCLC cells (A549 and Calu-1 cell lines) efficiently enhanced murine peritoneal macrophage migration and induces M2 polarization. Immunohistochemical analysis of clinical specimens confirmed the positive correlation of NOX4 and CD68 or CD206. The mechanical study revealed that tumoral NOX4-induced reactive oxygen species (ROS) stimulated various cytokine production, including CCL7, IL8, CSF-1 and VEGF-C, via PI3K/Akt signaling-dependent manner. Blockade of the function of these cytokines reversed NOX4 effect on macrophages. Specifically, the results showed that tumoral NOX4-educated M2 macrophages exhibited elevated JNK activity, expressed and released HB-EGF, thus facilitating NSCLC proliferation in vitro. Pretreatment of macrophages with JNK inhibitor blocked tumoral NOX4-induced HB-EGF production in M2 macrophages. Finally, in a xenograft mouse model, overexpression of NOX4 in A549 cells enhanced the tumor growth. Elimination of ROS by NAC or inhibition of NOX4 activity by GKT137831 suppressed tumor growth accompanied by reduction in macrophage infiltration and the percentage of M2 macrophages. In conclusion, our study indicates that tumoral NOX4 recruits M2 TAMs via ROS/PI3K signaling-dependent various cytokine production, thus contributing NSCLC cell growth.

•

NOX4 has a novel function that affects cancer progression via action on TAM.

•

There exists a NOX4-dependent crosstalk between NSCLC cells and M2 macrophages.

•

GKT137831 has anti-cancer potential for targeting cancer microenvironmental TAM.

Co-targeting EGFR and IKKβ/NF-κB signalling pathways in head and neck squamous cell carcinoma: a potential novel therapy for head and neck squamous cell cancer

Background

Epidermal growth factor receptor (EGFR) plays an important role in head and neck squamous cell carcinoma (HNSCC) proliferation and therapy resistance, but the efficacy of targeting of EGFR for therapy has been limited. Here, we explore the molecular link between EGFR and inhibitor of κB kinase β/nuclear factor-κB (IKKβ/NF-κB) signalling pathways in the regulation of HNSCC EGFR inhibitor resistance.

Methods

We performed in vitro experiments in eight human HNSCC cell lines and a patient-derived HNSCC cell line as well as in vivo xenografts in a human HNSCC cell line.

Results

We found that treatment of all HNSCC cells with Gefitinib and Erlotinib, two Food Drug Administration-approved EGFR inhibitors, blocked the activity of Akt/mammalian target of the rapamycin (mTOR) and extracellular signal-regulated kinase, two crucial downstream effectors of EGFR, but up-regulated IKKβ/NF-κB signalling. In addition, induction of IKKβ/NF-κB by EGFR inhibitors required HER2 and HER3 expression. In keeping with these, IKKβ inhibitor CmpdA synergistically enhanced the efficacy of EGFR inhibitors to further inhibit in vitro HNSCC cell growth. Importantly, we demonstrated that the combination of Gefitinib with CmpdA inhibited xenograft tumour formation.

Conclusion

Our data demonstrated that co-targeting EGFR and IKKβ with Gefitinib and IKKβ inhibitors could provide a potential novel therapy for head and neck squamous cell cancer.

Nox4 Overexpression as a Poor Prognostic Factor in Patients with Oral Tongue Squamous Cell Carcinoma Receiving Surgical Resection

BACKGROUND

Nox4 has been reported to promote tumor progression of various types of cancer through many different pathways. The current study was designed to evaluate the prognostic significance of Nox4 in patients with oral tongue squamous cell carcinoma (OTSCC) receiving surgical resection.

METHODS

We retrospectively analyzed the 161 patients with OTSCC treated with surgical resection, including 81 patients with high expression of Nox4 and 80 patients with low expression of Nox4. Two OTSCC cell lines, SAS and SCC4, were used to investigate the proliferation activity.

RESULTS

The univariate and multivariable analyses showed that negative nodal metastasis and low expression of Nox4 were significantly associated with superior disease-free survival (DFS) and overall survival (OS). Western blotting analysis indicated that Nox4 was highly expressed in these two OTSCC cell lines and knockdown of Nox4 was successful by transfecting with Nox4 shRNA. In addition, these cell lines were also treated with a Nox4 inhibitor (GKT-137831) and the results showed GKT-137831 could inhibit the proliferation of OTSCC tumor cells in a dose-dependent manner.

CONCLUSION

Our study suggests that Nox4 plays an important role in disease progression of OTSCC and Nox4 overexpression is a poor prognostic factor for patients with OTSCC who received surgical resection.

Modulators of Redox Metabolism in Head and Neck Cancer

SIGNIFICANCE

Head and neck squamous cell cancer (HNSCC) is a complex disease characterized by high genetic and metabolic heterogeneity. Radiation therapy (RT) alone or combined with systemic chemotherapy is widely used for treatment of HNSCC as definitive treatment or as adjuvant treatment after surgery. Antibodies against epidermal growth factor receptor are used in definitive or palliative treatment. Recent Advances: Emerging targeted therapies against other proteins of interest as well as programmed cell death protein 1 and programmed death-ligand 1 immunotherapies are being explored in clinical trials.

CRITICAL ISSUES

The disease heterogeneity, invasiveness, and resistance to standard of care RT or chemoradiation therapy continue to constitute significant roadblocks for treatment and patients' quality of life (QOL) despite improvements in treatment modality and the emergence of new therapies over the past two decades.

FUTURE DIRECTIONS

As reviewed here, alterations in redox metabolism occur at all stages of HNSCC management, providing opportunities for improved prevention, early detection, response to therapies, and QOL. Bioinformatics and computational systems biology approaches are key to integrate redox effects with multiomics data from cells and clinical specimens and to identify redox modifiers or modifiable target proteins to achieve improved clinical outcomes. Antioxid. Redox Signal.

Genome-Scale Modeling of NADPH-Driven β-Lapachone Sensitization in Head and Neck Squamous Cell Carcinoma

AIMS

The purpose of this study was to investigate differential nicotinamide adenine dinucleotide phosphate, reduced (NADPH) production between radiation-sensitive and -resistant head and neck squamous cell carcinoma (HNSCC) cell lines and whether these differences are predictive of sensitivity to the chemotherapeutic β-lapachone.

RESULTS

We have developed a novel human genome-scale metabolic modeling platform that combines transcriptomic, kinetic, thermodynamic, and metabolite concentration data. Upon incorporation of this information into cell line-specific models, we observed that the radiation-resistant HNSCC model redistributed flux through several major NADPH-producing reactions. Upon RNA interference of canonical NADPH-producing genes, the metabolic network can further reroute flux through alternate NADPH biosynthesis pathways in a cell line-specific manner. Model predictions of perturbations in cellular NADPH production after gene knockdown match well with experimentally verified effects of β-lapachone treatment on NADPH/NADP⁺ ratio and cell viability. This computational approach accurately predicts HNSCC-specific oxidoreductase genes that differentially affect cell viability between radiation-responsive and radiation-resistant cancer cells upon β-lapachone treatment.

INNOVATION

Quantitative genome-scale metabolic models that incorporate multiple levels of biological data are applied to provide accurate predictions of responses to a NADPH-dependent redox cycling chemotherapeutic drug under a variety of perturbations.

CONCLUSION

Our modeling approach suggests differences in metabolism and β-lapachone redox cycling that underlie phenotypic differences in radiation-sensitive and -resistant cancer cells. This approach can be extended to investigate the synergistic action of NAD(P)H: quinone oxidoreductase 1 bioactivatable drugs and radiation therapy. Antioxid. Redox Signal. 29, 937-952.

EGFR signaling suppresses type 1 cytokine-induced T-cell attracting chemokine secretion in head and neck cancer

Resistance to antitumor immunity can be promoted by the oncogenic pathways operational in human cancers, including the epidermal growth factor receptor (EGFR) pathway. Here we studied if and how EGFR downstream signaling in head and neck squamous cell carcinoma (HNSCC) can affect the attraction of immune cells. HPV-negative and HPV-positive HNSCC cell lines were analyzed in vitro for CCL2, CCL5, CXCL9, CXCL10, IL-6 and IL-1β expression and the attraction of T cells under different conditions, including cetuximab treatment and stimulation with IFNγ and TNFα using qPCR, ELISA and migration experiments. Biochemical analyses with chemical inhibitors and siRNA transfection were used to pinpoint the underlying mechanisms. Stimulation of HNSCC cells with IFNγ and TNFα triggered the production of T-cell attracting chemokines and required c-RAF activation. Blocking of the EGFR with cetuximab during this stimulation increased chemokine production in vitro, and augmented the attraction of T cells. Mechanistically, cetuximab decreased the phosphorylation of MEK1, ERK1/2, AKT, mTOR, JNK, p38 and ERK5. Chemical inhibition of EGFR signaling showed a consistent and pronounced chemokine production with MEK1/2 inhibitor PD98059 and JNK inhibitor SP600125, but not with inhibitors of p38, PI3K or mTOR. Combination treatment with cetuximab and a MEK1/2 or JNK inhibitor induced the highest chemokine expression. In conclusion, overexpression of EGFR results in the activation of multiple downstream signaling pathways that act simultaneously to suppress type 1 cytokine stimulated production of chemokines required to amplify the attraction of T cells.

Targeting the Myofibroblastic Cancer-Associated Fibroblast Phenotype Through Inhibition of NOX4

Background

Cancer-associated fibroblasts (CAFs) are tumor-promoting and correlate with poor survival in many cancers, which has led to their emergence as potential therapeutic targets. However, effective methods to manipulate these cells clinically have yet to be developed.

Methods

CAF accumulation and prognostic significance in head and neck cancer (oral, n = 260; oropharyngeal, n = 271), and colorectal cancer (n = 56) was analyzed using immunohistochemistry. Mechanisms regulating fibroblast-to-myofibroblast transdifferentiation were investigated in vitro using RNA interference/pharmacological inhibitors followed by polymerase chain reaction (PCR), immunoblotting, immunofluorescence, and functional assays. RNA sequencing/bioinformatics and immunohistochemistry were used to analyze NAD(P)H Oxidase-4 (NOX4) expression in different human tumors. NOX4's role in CAF-mediated tumor progression was assessed in vitro, using CAFs from multiple tissues in Transwell and organotypic culture assays, and in vivo, using xenograft (n = 9-15 per group) and isograft (n = 6 per group) tumor models. All statistical tests were two-sided.

Results

Patients with moderate/high levels of myofibroblastic-CAF had a statistically significant decrease in cancer-specific survival rates in each cancer type analyzed (hazard ratios [HRs] = 1.69-7.25, 95% confidence intervals [CIs] = 1.11 to 31.30, log-rank P ≤ .01). Fibroblast-to-myofibroblast transdifferentiation was dependent on a delayed phase of intracellular reactive oxygen species, generated by NOX4, across different anatomical sites and differentiation stimuli. A statistically significant upregulation of NOX4 expression was found in multiple human cancers (P < .001), strongly correlating with myofibroblastic-CAFs (r = 0.65-0.91, adjusted P < .001). Genetic/pharmacological inhibition of NOX4 was found to revert the myofibroblastic-CAF phenotype ex vivo (54.3% decrease in α-smooth muscle actin [α-SMA], 95% CI = 10.6% to 80.9%, P = .009), prevent myofibroblastic-CAF accumulation in vivo (53.2%-79.0% decrease in α-SMA across different models, P ≤ .02) and slow tumor growth (30.6%-64.0% decrease across different models, P ≤ .04).

Conclusions

These data suggest that pharmacological inhibition of NOX4 may have broad applicability for stromal targeting across cancer types.

The level of caveolin-1 expression determines response to TGF-β as a tumour suppressor in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is a heterogeneous tumour associated with poor prognostic outcome. Caveolin-1 (CAV1), a membrane protein involved in the formation of caveolae, is frequently overexpressed in HCC. Transforming growth factor-beta (TGF-β) is a pleiotropic cytokine having a dual role in hepatocarcinogenesis: inducer of apoptosis at early phases, but pro-tumourigenic once cells acquire mechanisms to overcome its suppressor effects. Apoptosis induced by TGF-β is mediated by upregulation of the NADPH oxidase NOX4, but counteracted by transactivation of the epidermal growth factor receptor (EGFR) pathway. Previous data suggested that CAV1 is required for the anti-apoptotic signals triggered by TGF-β in hepatocytes. Whether this mechanism is relevant in hepatocarcinogenesis has not been explored yet. Here we analysed the TGF-β response in HCC cell lines that express different levels of CAV1. Accordingly, stable CAV1 knockdown or overexpressing cell lines were generated. We demonstrate that CAV1 is protecting HCC cells from TGF-β-induced apoptosis, which attenuates its suppressive effect on clonogenic growth and increases its effects on cell migration. Downregulation of CAV1 in HLE cells promotes TGF-β-mediated induction of the pro-apoptotic BMF, which correlates with upregulation of NOX4, whereas CAV1 overexpression in Huh7 cells shows the opposite effect. CAV1 silenced HLE cells show attenuation in TGF-β-induced EGFR transactivation and activation of the PI3K/AKT pathway. On the contrary, Huh7 cells, which do not respond to TGF-β activating the EGFR pathway, acquire the capacity to do so when CAV1 is overexpressed. Analyses in samples from HCC patients revealed that tumour tissues presented higher expression levels of CAV1 compared with surrounding non-tumoural areas. Furthermore, a significant positive correlation among the expression of CAV1 and TGFB1 was observed. We conclude that CAV1 has an essential role in switching the response to TGF-β from cytostatic to tumourigenic, which could have clinical meaning in patient stratification.

Secretory Autophagy in Cancer-Associated Fibroblasts Promotes Head and Neck Cancer Progression and Offers a Novel Therapeutic Target

Despite therapeutic advancements, there has been little change in the survival of patients with head and neck squamous cell carcinoma (HNSCC). Recent results suggest that cancer-associated fibroblasts (CAF) drive progression of this disease. Here, we report that autophagy is upregulated in HNSCC-associated CAFs, where it is responsible for key pathogenic contributions in this disease. Autophagy is fundamentally involved in cell degradation, but there is emerging evidence that suggests it is also important for cellular secretion. Thus, we hypothesized that autophagy-dependent secretion of tumor-promoting factors by HNSCC-associated CAFs may explain their role in malignant development. In support of this hypothesis, we observed a reduction in CAF-facilitated HNSCC progression after blocking CAF autophagy. Studies of cell growth media conditioned after autophagy blockade revealed levels of secreted IL6, IL8, and other cytokines were modulated by autophagy. Notably, when HNSCC cells were cocultured with normal fibroblasts, they upregulated autophagy through IL6, IL8, and basic fibroblast growth factor. In a mouse xenograft model of HNSCC, pharmacologic inhibition of Vps34, a key mediator of autophagy, enhanced the antitumor efficacy of cisplatin. Our results establish an oncogenic function for secretory autophagy in HNSCC stromal cells that promotes malignant progression. Cancer Res; 77(23); 6679-91. ©2017 AACR.

Biological mechanisms of immune escape and implications for immunotherapy in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy with high morbidity and mortality. Despite advances in cytotoxic therapies and surgical techniques, overall survival (OS) has not improved over the past few decades. This emphasises the need for intense investigation into novel therapies with good tumour control and minimal toxicity. Cancer immunotherapy has led this endeavour, attempting to improve tumour recognition and expand immune responses against tumour cells. While various forms of HNSCC immunotherapy are in preclinical trials, the most promising direction thus far has been with monoclonal antibodies (mAbs), targeting growth factor and immune checkpoint receptors. Preclinical and early phase trials have shown unprecedented efficacy with minimal adverse effects. This article will review biological mechanisms of immune escape and implications for immunotherapy in HNSCC.

Oncogenic growth factor signaling mediating tumor escape from cellular immunity

Unrestrained growth factor signals can promote carcinogenesis, as well as other hallmarks of cancer such as immune evasion. Our understanding of the function and complex regulation of HER family of receptors has led to the development of targeted therapeutic agents that suppress tumor growth. However, these receptors also mediate escape from recognition by the host immune system. We discuss how HER family of oncogenic receptors downregulate tumor antigen presentation and upregulate suppressive membrane-bound or soluble secreted inhibitory molecules that ultimately lead to impaired cellular immunity mediated by cytotoxic T lymphocyte (CTL) recognition. Implementing this knowledge into new therapeutic strategies to enhance tumor immunogenicity may restore effector cell mediated immune clearance of tumors and clinical efficacy of tumor-targeted immunotherapy against HER receptor overexpression.

Interleukin-1 blockade overcomes erlotinib resistance in head and neck squamous cell carcinoma

Erlotinib has demonstrated poor clinical response rates for head and neck squamous cell carcinoma (HNSCC) to date and the majority of respondents acquire resistance to erlotinib relatively quickly. To elucidate novel pathways involved in erlotinib resistance, we compared the gene expression profiles of erlotinib-resistant (ER) vs. erlotinib-sensitive (ES) HNSCC cell lines. Enrichment analysis of microarray data revealed a deregulation of the IL-1 signaling pathway in ER versus ES-HNSCC cells. Gene expression of interleukin-1 alpha (IL1A) and interleukin-1 beta (IL1B) were significantly upregulated by > 2 fold in ER-SQ20B and ER-CAL 27 cells compared to their respective ES-cells. Secretion of the IL-1 receptor antagonist (IL-1RA) was significantly reduced in ER-cells compared to ES-cells. Blockade of IL-1 signaling using a recombinant IL-1R antagonist (anakinra) was able to inhibit the growth of ER-SQ20B and ER-CAL 27 but not ES-SQ20B and ES-CAL 27 xenografts as a single agent and in combination with erlotinib. ER-SQ20B xenografts treated with anakinra ± erlotinib were found to be less vascularized than ER-SQ20B xenografts treated with water or erlotinib. Mice bearing ER-SQ20B xenografts had significantly lesser circulating levels of G-CSF and IL-1β when treated with anakinra ± erlotinib compared to those treated with water or erlotinib alone. Furthermore, augmented mRNA levels of IL1A or interleukin-1 receptor accessory protein (IL1RAP) were associated with shortened survival in HNSCC patients. Altogether, blockade of the IL-1 pathway using anakinra overcame erlotinib resistance in HNSCC xenografts and may represent a novel strategy to overcome EGFR inhibitor resistance for treatment of HNSCC patients.

Overcoming radioresistance in head and neck squamous cell carcinoma

Radiation therapy plays an essential role in the treatment of head and neck squamous cell carcinoma (HNSCC), yet therapeutic efficacy is hindered by treatment-associated toxicity and tumor recurrence. In comparison to other cancers, innovation has proved challenging, with the epidermal growth factor receptor (EGFR) antibody cetuximab being the only new radiosensitizing agent approved by the FDA in over half a century. This review examines the physiological mechanisms that contribute to radioresistance in HNSCC as well as preclinical and clinical data regarding novel radiosensitizing agents, with an emphasis on those with highest translational promise.

Systemic and Tumor Th1 and Th2 Inflammatory Profile and Macrophages in Lung Cancer: Influence of Underlying Chronic Respiratory Disease

INTRODUCTION

Chronic respiratory conditions, especially chronic obstructive pulmonary disease (COPD), and inflammatory events underlie lung cancer (LC). We hypothesized that profiles of T helper 1 and T helper 2 cytokines and type 1 and type 2 macrophages (M1 and M2) are differentially expressed in lung tumors and blood of patients with NSCLC with and without COPD and that the ratio M1/M2 specifically may influence their survival.

METHODS

In blood, inflammatory cytokines (determined by enzyme-linked immunosorbent assay) were quantified in 80 patients with LC (60 with LC and COPD [the LC-COPD group] and 20 with LC only [the LC-only group]) and lung specimens (tumor and nontumor) from those undergoing thoracotomy (20 in the LC-COPD group and 20 in the LC-only group).

RESULTS

In the LC-COPD group compared with in the LC-only group, systemic levels of tumor necrosis factor-α, interleukin-2 (IL-2), transforming growth factor-β, and IL-10 were increased, whereas vascular endothelial growth factor and IL-4 levels were decreased. In lung tumors, levels of tumor necrosis factor-α, transforming growth factor-β, and IL-10 were higher than in nontumor parenchyma in the LC-COPD group, whereas IL-2 and vascular endothelial growth factor levels were higher in tumors of both the LC-only and LC-COPD groups. Compared with in nontumor lung, M1 macrophage counts were reduced whereas M2 counts were increased in tumors of both patient groups, and the M1/M2 ratio was higher in the LC-COPD group than the LC-only group. M1 and M2 counts did not influence patients' survival.

CONCLUSIONS

The relative predominance of T helper 1 cytokines and M1 macrophages in the blood and tumors of patients with underlying COPD imply that a stronger proinflammatory pattern exists in these patients. Inflammation should not be targeted systematically in all patients with LC. Screening for the presence of underlying respiratory diseases and identification of the specific inflammatory pattern should be carried out in patients with LC, at least in early stages of their disease.

Lapatinib increases motility of triple-negative breast cancer cells by decreasing miRNA-7 and inducing Raf-1/MAPK-dependent interleukin-6

Lapatinib, a dual epidermal growth factor receptor (EGFR) and HER2 tyrosine kinase inhibitor (TKI), has been approved for HER2-positive breast cancer patients. Nevertheless, its inhibitory effect on EGFR did not deliver clinical benefits for triple-negative breast cancer (TNBC) patients even EGFR overexpression was frequently found in this disease. Moreover, lapatinib was unexpectedly found to enhance metastasis of TNBC cells, but the underlying mechanisms are not fully understood. In this study, we explored that the level of interleukin-6 (IL-6) was elevated in lapatinib-treated TNBC cells. Treatment with IL-6 antibody abolished the lapatinib-induced migration. Mechanistically, the signaling axis of Raf-1/mitogen-activated protein kinases (MAPKs), c-Jun N-terminal kinases (JNKs), p38 MAPK, and activator protein 1 (AP-1) was activated in response to lapatinib treatment to induce IL-6 expression. Furthermore, our data showed that microRNA-7 directly binds and inhibits Raf-1 3'UTR activity, and that down-regulation of miR-7 by lapatinib contributes to the activation of Raf-1 signaling pathway and the induction of IL-6 expression. Our results not only revealed IL-6 as a key regulator of lapatinib-induced metastasis, but also explored the requirement of miR7/Raf-1/MAPK/AP-1 axis in lapatinib-induced IL-6 expression.

Inhibition of Nox1 induces apoptosis by attenuating the AKT signaling pathway in oral squamous cell carcinoma cell lines

NADPH oxidases, also known as the Nox family, are major sources of reactive oxygen species generation that regulate redox-sensitive signaling pathways. Recent studies have implicated the Nox family in cancer development and progression. However, the involvement of its members in the development of oral squamous cell carcinoma (OSCC) remains to be elucidated. To clarify this issue, we first analyzed mRNA expression of Nox/Duox family members (Nox1, Nox2, Nox3, Nox4, Nox5, Duox1 and Duox2) in five OSCC cell lines. Nox1 and Nox4 mRNAs were highly expressed in four OSCC cell lines. Western blot analysis revealed that the protein expression level of Nox1 was higher than that of Nox4 in the OSCC cell lines. In addition, knockdown of Nox1, but not Nox4, significantly suppressed cell viability and induced apoptosis in the HSC-2 and HSC-3 cells. We also found that a specific AKT inhibitor, perifosine, dose-dependently suppressed OSCC cell growth. Notably, Nox1 knockdown significantly attenuated the phosphorylation level of AKT. Furthermore, both Nox1 knockdown and perifosine treatment markedly enhanced the cisplatin-induced cytotoxic effect. Taken together, our results highlight that the Nox1/AKT signaling pathway plays an important role in cell survival in OSCC cells.

The potential for chemical mixtures from the environment to enable the cancer hallmark of sustained proliferative signalling

The aim of this work is to review current knowledge relating the established cancer hallmark, sustained cell proliferation to the existence of chemicals present as low dose mixtures in the environment. Normal cell proliferation is under tight control, i.e. cells respond to a signal to proliferate, and although most cells continue to proliferate into adult life, the multiplication ceases once the stimulatory signal disappears or if the cells are exposed to growth inhibitory signals. Under such circumstances, normal cells remain quiescent until they are stimulated to resume further proliferation. In contrast, tumour cells are unable to halt proliferation, either when subjected to growth inhibitory signals or in the absence of growth stimulatory signals. Environmental chemicals with carcinogenic potential may cause sustained cell proliferation by interfering with some cell proliferation control mechanisms committing cells to an indefinite proliferative span.

Mechanisms underlying skin disorders induced by EGFR inhibitors

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is frequently mutated or overexpressed in a large number of tumors such as carcinomas or glioblastoma. Inhibitors of EGFR activation have been successfully established for the therapy of some cancers and are more and more frequently being used as first or later line therapies. Although the side effects induced by inhibitors of EGFR are less severe than those observed with classic cytotoxic chemotherapy and can usually be handled by out-patient care, they may still be a cause for dose reduction or discontinuation of treatment that can reduce the effectiveness of antitumor therapy. The mechanisms underlying these cutaneous side effects are only partly understood. Important questions, such as the reasons for the correlation between the intensity of the side effects and the efficiency of treatment with EGFR inhibitors, remain to be answered. Optimized adjuvant strategies to accompany anti-EGFR therapy need to be found for optimal therapeutic application and improved quality of life of patients. Here, we summarize current literature on the molecular and cellular mechanisms underlying the cutaneous side effects induced by EGFR inhibitors and provide evidence that keratinocytes are probably the optimal targets for adjuvant therapy aimed at alleviating skin toxicities.

STAT1-Induced HLA Class I Upregulation Enhances Immunogenicity and Clinical Response to Anti-EGFR mAb Cetuximab Therapy in HNC Patients

The goal of this study was to characterize the molecular mechanisms underlying cetuximab-mediated upregulation of HLA class I antigen-processing machinery components in head and neck cancer (HNC) cells and to determine the clinical significance of these changes in cetuximab-treated HNC patients. Flow cytometry, signaling studies, and chromatin immunoprecipitation (ChIP) assays were performed using HNC cells treated with cetuximab alone or with Fcγ receptor (FcγR)-bearing lymphocytes to establish the mechanism of EGFR-dependent regulation of HLA APM expression. A prospective phase II clinical trial of neoadjuvant cetuximab was used to correlate HLA class I expression with clinical response in HNC patients. EGFR blockade triggered STAT1 activation and HLA upregulation, in a src homology-containing protein (SHP)-2-dependent fashion, more prominently in HLA-B/C than in HLA-A alleles. EGFR signaling blockade also enhanced IFNγ receptor 1 (IFNAR) expression, augmenting induction of HLA class I and TAP1/2 expression by IFNγ, which was abrogated in STAT1(-/-) cells. Cetuximab enhanced HNC cell recognition by EGFR853-861-specific CTLs, and notably enhanced surface presentation of a non-EGFR peptide (MAGE-3271-279). HLA class I upregulation was significantly associated with clinical response in cetuximab-treated HNC patients. EGFR induces HLA downregulation through SHP-2/STAT1 suppression. Reversal of HLA class I downregulation was more prominent in clinical responders to cetuximab therapy, supporting an important role for adaptive immunity in cetuximab antitumor activity. Abrogating EGFR-induced immune escape mechanisms and restoring STAT1 signaling to reverse HLA downregulation using cetuximab should be combined with strategies to enhance adaptive cellular immunity.

More than a headache: a case of cetuximab-induced aseptic meningitis

While the wide belief is that monoclonal antibodies, due to their large size, would not be able to penetrate the blood-brain barrier, we present a rare case of aseptic meningitis induced by intravenous cetuximab administration. A 58-year-old man with tonsillar squamous cell cancer presented with headache and fever, which started approximately 1 h after his first dose of cetuximab (loading dose of 400 mg/m(2) equalling 800 mg). CT scan of the head was non-revealing and laboratory tests including complete blood count, serum comprehensive metabolic panel and coagulation profile were within normal limits. Aseptic meningitis in the setting of cetuximab therapy has been reported on 6 previous occasions. Consistent with these prior reports, it is interesting to note that this case also occurred after administration of the initial higher loading dose of Cetuximab. This is of interest as Cetuximab is more frequently being dosed at 500 mg/m(2) (higher dose) every 2 weeks in colorectal cancer.

Upregulated interleukin-6 expression contributes to erlotinib resistance in head and neck squamous cell carcinoma

Despite the role of epidermal growth factor receptor (EGFR) signaling in head and neck squamous cell carcinoma (HNSCC) development and progression, clinical trials involving EGFR tyrosine kinase inhibitors (TKIs) have yielded poor results in HNSCC patients. Mechanisms of acquired resistance to the EGFR TKI erlotinib was investigated by developing erlotinib-resistant HNSCC cell lines and comparing their gene expression profiles with their parental erlotinib-sensitive HNSCC cell lines using microarray analyses and subsequent pathway and network analyses. Erlotinib-resistant HNSCC cells displayed a significant upregulation in immune response and inflammatory pathways compared to parental cells. Interleukin-6 (IL-6) was one of thirteen genes that was significantly differentially expressed in all erlotinib-resistant HNSCC cell lines, which was validated using RT-PCR and ELISA. Blockade of IL-6 signaling using the IL-6 receptor antagonist tocilizumab, was able to overcome erlotinib-resistance in erlotinib-resistant SQ20B tumors in vivo. Overall, erlotinib-resistant HNSCC cells display elevated IL-6 expression levels compared to erlotinib-sensitive HNSCC cells and blockade of the IL-6 signaling pathway may be an effective strategy to overcome resistance to erlotinib and possibly other EGFR TKIs for HNSCC therapy.

Xilonix, a novel true human antibody targeting the inflammatory cytokine interleukin-1 alpha, in non-small cell lung cancer

BACKGROUND

Advanced non-small cell lung cancer (NSCLC) patients were treated as part of a Phase I dose escalation and expansion study evaluating a true human monoclonal antibody targeting IL-1α (Xilonix), which is intended to modulate the malignant phenotype-inhibiting tumor growth, spread and offering relief of symptoms.

METHODS

Sixteen NSCLC patients were included. Patients failed a median of 4 chemotherapy regimens, including 10/16 failing anti-EGFR therapy. Disease progression was evaluated using a multi-modal approach: tumor response, patient reported outcomes (EORTC-QLQC30), and lean body mass (LBM). Patients received infusions every 2 or 3 weeks until progression, and were followed 24 months to assess survival.

RESULTS

There were no infusion reactions, dose-limiting toxicities, or deaths due to therapy. Albeit not statistically significant, there was a trend in IL-6 (-2.6 ± 18.5 (0.1 [-2.8-2.4]), platelet counts (-11 ± 54 (-4[-36.0-1.0]), CRP (-3.3 ± 30.2 (0.4 [-10.7-1.8]) and LBM (1.0 ± 2.5 (0.4 [-0.5-2.6]). Self-reported outcomes revealed reductions in pain, fatigue and improvement in appetite. Median survival was 7.6 (IQR 4.4-11.5) months, stratification based on prior anti-EGFR therapy revealed a median survival of 9.4 months (IQR 7.6-12.5) for those pretreated (N = 10) versus a survival of 4.8 months (IQR 4.3-5.7) for those without (N = 6, logrank p = 0.187).

CONCLUSION

Xilonix was well tolerated, with gains in LBM and improvement in symptoms suggesting a clinically important response. Although not statistically significant, the survival outcomes observed for patients with and without prior anti-EGFR therapy raises intriguing questions about the potential synergy of IL-1α blockade and anti-EGFR therapy. Further study for this agent in NSCLC is warranted.

NADPH oxidases and cancer

The mechanism by which reactive oxygen species (ROS) are produced by tumour cells remained incompletely understood until the discovery over the last 15 years of the family of NADPH oxidases (NOXs 1–5 and dual oxidases DUOX1/2) which are structural homologues of gp91phox, the major membrane-bound component of the respiratory burst oxidase of leucocytes. Knowledge of the roles of the NOX isoforms in cancer is rapidly expanding. Recent evidence suggests that both NOX1 and DUOX2 species produce ROS in the gastrointestinal tract as a result of chronic inflammatory stress; cytokine induction (by interferon-γ, tumour necrosis factor α, and interleukins IL-4 and IL-13) of NOX1 and DUOX2 may contribute to the development of colorectal and pancreatic carcinomas in patients with inflammatory bowel disease and chronic pancreatitis, respectively. NOX4 expression is increased in pre-malignant fibrotic states which may lead to carcinomas of the lung and liver. NOX5 is highly expressed in malignant melanomas, prostate cancer and Barrett's oesophagus-associated adenocarcinomas, and in the last it is related to chronic gastro-oesophageal reflux and inflammation. Over-expression of functional NOX proteins in many tissues helps to explain tissue injury and DNA damage from ROS that accompany pre-malignant conditions, as well as elucidating the potential mechanisms of NOX-related damage that contribute to both the initiation and the progression of a wide range of solid and haematopoietic malignancies.

MyD88-Dependent Signaling Decreases the Antitumor Efficacy of Epidermal Growth Factor Receptor Inhibition in Head and Neck Cancer Cells

EGFR is upregulated in the majority of head and neck squamous cell carcinomas (HNSCC). However, many patients with HNSCC respond poorly to the EGFR inhibitors (EGFRI) cetuximab and erlotinib, despite tumor expression of EGFR. Gene expression analysis of erlotinib-treated HNSCC cells revealed an upregulation of genes involved in MyD88-dependent signaling compared with their respective vehicle-treated cell lines. We therefore investigated whether MyD88-dependent signaling may reduce the antitumor efficacy of EGFRIs in HNSCC. Erlotinib significantly upregulated IL6 secretion in HNSCC cell lines, which our laboratory previously reported to result in reduced drug efficacy. Suppression of MyD88 expression blocked erlotinib-induced IL6 secretion in vitro and increased the antitumor activity of erlotinib in vivo. There was little evidence of Toll-like receptor or IL18 receptor involvement in erlotinib-induced IL6 secretion. However, suppression of IL1R signaling significantly reduced erlotinib-induced IL6 production. A time-dependent increase of IL1α but not IL1β was observed in response to erlotinib treatment, and IL1α blockade significantly increased the antitumor activity of erlotinib and cetuximab in vivo. A pan-caspase inhibitor reduced erlotinib-induced IL1α secretion, suggesting that IL1α was released because of cell death. Human HNSCC tumors showed higher IL1α mRNA levels compared with matched normal tissue, and IL1α was found to be negatively correlated with survival in patients with HNSCC. Overall, the IL1α/IL1R/MYD88/IL6 pathway may be responsible for the reduced antitumor efficacy of erlotinib and other EGFRIs, and blockade of IL1 signaling may improve the efficacy of EGFRIs in the treatment of HNSCC.

EGFR-TKI, erlotinib, causes hypomagnesemia, oxidative stress, and cardiac dysfunction: attenuation by NK-1 receptor blockade

To determine whether the epidermal growth factor receptor tyrosine kinase inhibitor, erlotinib may cause hypomagnesemia, inflammation, and cardiac stress, erlotinib was administered to rats (10 mg · kg(-1)· d(-1)) for 9 weeks. Plasma magnesium decreased progressively between 3 and 9 weeks (-9% to -26%). Modest increases in plasma substance P (SP) occurred at 3 (27%) and 9 (25%) weeks. Neutrophil superoxide-generating activity increased 3-fold, and plasma 8-isoprostane rose 210%, along with noticeable appearance of cardiac perivascular nitrotyrosine. The neurokinin-1 (NK-1) receptor antagonist, aprepitant (2 mg · kg(-1) · d(-1)), attenuated erlotinib-induced hypomagnesemia up to 42%, reduced circulating SP, suppressed neutrophil superoxide activity and 8-isoprostane elevations; cardiac nitrotyrosine was diminished. Echocardiography revealed mild to moderately decreased left ventricular ejection fraction (-11%) and % fractional shortening (-17%) by 7 weeks of erlotinib treatment and significant reduction (-17.5%) in mitral valve E/A ratio at week 9 indicative of systolic and early diastolic dysfunction. Mild thinning of the left ventricular posterior wall suggested early dilated cardiomyopathy. Aprepitant completely prevented the erlotinib-induced systolic and diastolic dysfunction and partially attenuated the anatomical changes. Thus, chronic erlotinib treatment does induce moderate hypomagnesemia, triggering SP-mediated oxidative/inflammation stress and mild-to-moderate cardiac dysfunction, which can largely be corrected by the administration of the SP receptor blocker.

Tumor-derived TGF-β and prostaglandin E2 attenuate anti-tumor immune responses in head and neck squamous cell carcinoma treated with EGFR inhibitor

BACKGROUND

EGFR-targeted therapy is an attractive option for head and neck squamous cell carcinoma patients. We have recently reported the use of EGFR inhibitors as an adjunct treatment to enhance HLA-DR expression in tumor cells to improve cancer immunotherapy. Nevertheless, we observed that EGFR inhibitors resulted in decreased anti-tumor responses, regardless of upregulation of HLA-DR expression on the tumor cell. In this study, we specifically investigated the mechanisms by which EGFR inhibition modulated anti-tumor responses.

METHODS

An EGFR inhibitor erlotinib was used to assess the modulation of anti-tumor responses by tumor antigen-specific helper T cells. We then examined whether administration of the EGFR inhibitor altered tumor cytokine profiles and expression of immune-related molecules on tumor cells.

RESULTS

Despite the augmented HLA-DR expression on a gingival cancer cell line by EGFR inhibition, anti-tumor responses of EGFR reactive helper T cell clones against tumor cells were decreased. EGFR inhibition did not change the expression of CD80, CD86, or PD-L1 on the tumor cells. Conversely, production of transforming growth factor beta (TGF-β) and prostaglandin E2 was increased by EGFR inhibition, indicating that these immunosuppressive molecules were involved in diminishing tumor recognition by T cells. Significantly, attenuation of HTL responses against tumors after EGFR inhibition was reversed by the addition of anti-TGF-β antibody or COX2 inhibitors.

CONCLUSIONS

Targeting TGF-β and prostaglandin E2 may allow for improved outcomes for cancer patients treated with combination immunotherapy and EGFR inhibitors.

Tumor-derived TGF-β and prostaglandin E2 attenuate anti-tumor immune responses in head and neck squamous cell carcinoma treated with EGFR inhibitor

BACKGROUND

EGFR-targeted therapy is an attractive option for head and neck squamous cell carcinoma patients. We have recently reported the use of EGFR inhibitors as an adjunct treatment to enhance HLA-DR expression in tumor cells to improve cancer immunotherapy. Nevertheless, we observed that EGFR inhibitors resulted in decreased anti-tumor responses, regardless of upregulation of HLA-DR expression on the tumor cell. In this study, we specifically investigated the mechanisms by which EGFR inhibition modulated anti-tumor responses.

METHODS

An EGFR inhibitor erlotinib was used to assess the modulation of anti-tumor responses by tumor antigen-specific helper T cells. We then examined whether administration of the EGFR inhibitor altered tumor cytokine profiles and expression of immune-related molecules on tumor cells.

RESULTS

Despite the augmented HLA-DR expression on a gingival cancer cell line by EGFR inhibition, anti-tumor responses of EGFR reactive helper T cell clones against tumor cells were decreased. EGFR inhibition did not change the expression of CD80, CD86, or PD-L1 on the tumor cells. Conversely, production of transforming growth factor beta (TGF-β) and prostaglandin E2 was increased by EGFR inhibition, indicating that these immunosuppressive molecules were involved in diminishing tumor recognition by T cells. Significantly, attenuation of HTL responses against tumors after EGFR inhibition was reversed by the addition of anti-TGF-β antibody or COX2 inhibitors.

CONCLUSIONS

Targeting TGF-β and prostaglandin E2 may allow for improved outcomes for cancer patients treated with combination immunotherapy and EGFR inhibitors.

Lentivirus-mediated Nox4 shRNA invasion and angiogenesis and enhances radiosensitivity in human glioblastoma

Radioresistance remains a significant therapeutic obstacle in glioblastoma. Reactive oxygen species (ROS) are associated with multiple cellular functions such as cell proliferation and apoptosis. Nox4 NADPH oxidase is abundantly expressed and has proven to be a major source of ROS production in glioblastoma. Here we investigated the effects of Nox4 on GBM tumor cell invasion, angiogenesis, and radiosensitivity. A lentiviral shRNA vector was utilized to stably knockdown Nox4 in U87MG and U251 glioblastoma cells. ROS production was measured by flow cytometry using the fluorescent probe DCFH-DA. Radiosensitivity was evaluated by clonogenic assay and survival curve was generated. Cell proliferation activity was assessed by a cell counting proliferation assay and invasion/migration potential by Matrigel invasion assay. Tube-like structure formation assay was used to evaluate angiogenesis ability in vitro and VEGF expression was assessed by MTT assay. Nox4 knockdown reduced ROS production significantly and suppressed glioblastoma cells proliferation and invasion and tumor associated angiogenesis and increased their radiosensitivity in vitro. Our results indicate that Nox4 may play a crucial role in tumor invasion, angiogenesis, and radioresistance in glioblastoma. Inhibition of Nox4 by lentivirus-mediated shRNA could be a strategy to overcome radioresistance and then improve its therapeutic efficacy for glioblastoma.