Project description:BackgroundHead and neck squamous cell carcinoma (HNSCC) is a debilitating disease with poor survival. Although epidermal growth factor receptor (EGFR)-targeting antibody cetuximab improves survival in some settings, responses are limited suggesting that alternative approaches are needed.MethodsWe performed a high throughput drug screen to identify EGFR inhibitor-based synergistic combinations of clinically advanced inhibitors in models resistant to EGFR inhibitor monotherapies, and then performed downstream validation experiments on prioritized synergistic combinations.ResultsFrom our screen, we re-discovered known synergistic EGFR inhibitor combinations with FGFR or IGF-1R inhibitors that were broadly effective and also discovered novel synergistic combinations with XIAP inhibitor and DNMT inhibitors that were effective in only a subset of models.ConclusionsConceptually, our data identify novel synergistic combinations that warrant evaluation in future studies, and suggest that some combinations, although highly synergistic, will require parallel companion diagnostic development to be effectively advanced in patients.
Project description:EGFR is a prototypical receptor tyrosine kinase that is overexpressed in multiple cancers including head and neck squamous cell carcinoma (HNSCC). The standard of care for HNSCC remains largely unchanged despite decades of research. While EGFR blockade is an attractive target in HNSCC patients and anti-EGFR strategies including monoclonal antibodies and kinase inhibitors have shown some clinical benefit, efficacy is often due to the eventual development of resistance. In this review, we discuss how the acquisition of mutations in various domains of the EGFR gene not only alter drug binding dynamics giving rise to resistance, but also how mutations can impact radiation response and overall survival in HNSCC patients. A better understanding of the EGFR mutational landscape and its dynamic effects on treatment resistance hold the potential to better stratify patients for targeted therapies in order to maximize therapeutic benefits.
Project description:EGFR is an established therapeutic target in head and neck squamous cell carcinoma (HNSCC). The EGFR-targeting monoclonal antibody cetuximab (Erbitux, Imclone Systems, Inc., Branchburg, USA) was FDA-approved for use in HNSCC in 2006. The molecular basis for the efficacy of an antibody approach compared with inhibition of EGFR tyrosine kinase function using small-molecule inhibitors, or downregulation of protein expression via antisense strategies, remains incompletely understood.A literature search was performed to identify studies elucidating mechanisms of action of several approaches to targeting EGFR in HNSCC (monoclonal antibodies, tyrosine kinase inhibitors, antisense approaches, and ligand-toxin conjugates).Monoclonal antibodies decrease tumor growth via receptor endocytosis and recruitment of host immune defenses. Tyrosine kinase inhibitors bind to the ATP binding pocket of the tyrosine kinase domain, inhibiting signaling. Antisense approaches decrease EGFR expression with high specificity, though drug delivery remains problematic. Ligand-toxin conjugates facilitate the entry of toxin and the ADP-ribosylation of the ribosome, thereby inhibiting translation.Elucidation mechanisms by which these different strategies inhibit EGFR function may enhance the development of more effective treatments for HNSCC and enable prospective identification of individuals who will benefit from EGFR inhibition.
Project description:BACKGROUND:The epidermal growth factor receptor (EGFR) is pivotal for growth of epithelial cells and is overexpressed in several epithelial cancers like head and neck squamous cell carcinoma (HNSCC). EGFR signalling is also involved in diverse innate immune functions in epithelia. We previously found a role for EGFR in modulating the complement system in skin, this prompted an investigation into EGFR role in complement modulation in HNSCC. METHODS:We used patient derived HNSCC cell lines with varying sensitivities to EGFR inhibitors, and generated EGFR inhibition resistant cell lines to study the role of EGFR in modulating complement in HNSCC. RESULTS:We found that HNSCC cell lines activate the complement system when incubated with human serum. This complement activation was increased in cell lines sensitive to EGFR inhibition following the use of the tyrosine kinase inhibitor Iressa. Sensitive cell line made resistant to EGFR-inhibitors displayed complement activation and a decrease in complement regulatory proteins even in the absence of EGFR-inhibitors. Complement activation did not cause lysis of HNSCC cells, and rather led to increased extracellular signal-regulated kinase (ERK) phosphorylation in one cell line. CONCLUSION:These data indicate that EGFR has a complement modulatory role in HNSCC, and that a prolonged EGFR-inhibition treatment in sensitive cancer cells increases complement activation. This has implications in understanding the response to EGFR inhibitors, in which resistance and inflammatory skin lesions are two major causes for treatment cessation.
Project description:Total proteins were extracted in triplicate from cetuximab-sensitive and -resistant SC263 and SCC22b HNSCC cells. The LC system was coupled to a Q-Exactive Plus Orbitrap mass spectrometer (Thermo Fisher Scientific) programmed to acquire in data-dependent mode. A target of 1.7 x103 ions and a maximum injection time of 80 ms were used for MS/MS. The method was set to analyze the top 20 most intense ions from the survey scan and dynamic exclusion was enabled for 20 s. Tandem mass spectra were processed using MaxQuant software version 1.6.7.0. Proteins were identified using the Andromeda search engine and using the Homo sapiens proteome reference database (UniProt, release 20200130, 20366 entries). The parameters chosen for the identification include: digestion enzyme used was trypsin, maximum number of allowed missed cleavages was two. Oxidation of methionine, N-terminal acetylation, and phosphorylation of serine, threonine and tyrosine were set as variable modifications, while carbamidomethylation of cysteine was set as a fixed modification. A maximum number of 5 modifications per peptide was set. The precursor mass tolerance was set to 4.5 ppm and the fragmentation mass tolerance to 20 ppm. The peptide-to-spectrum match (PSM) and protein false discovery rates (FDR) were set at 1%. The match-between-runs and the label-free quantification (LFQ) methods were enabled using default parameters. After data treatment using MaxQuant, statistical analysis was done using Perseus software (version 1.6.7.0). The data matrix was filtered by removing the potential contaminants and decoy reverse sequences. The LFQ intensities were then log2-transformed and missing values were replaced by imputation based on the normal distribution. This resulted in the quantification of the expression of 2,741 unique proteins.
Project description:BackgroundRecurrent and metastatic head and neck squamous cell carcinoma (HNSCC) has a dismal prognosis with limited progression-free survival and overall survival, even when treated with different combinations of chemotherapy, targeted therapies and immunotherapy. We explored in vitro and in vivo the effect of the epidermal growth factor receptor (EGFR) inhibitor, osimertinib, alone and in combination with dihydroartemisinin (DHA) in HNSCC.MethodsThe combination of osimertinib with DHA was tested in the FaDu and CAL27 HNSCC cell lines. Tumor cell proliferation assays were conducted in cultured cells and mouse xenografts. Western blotting analysis of related signal pathways was performed to investigate the molecular mechanisms of the inhibitory effect of DHA and the combination. Other compounds, which inhibit signal transducer and activator of transcription 3 (STAT3), Src-family kinases (SFKs), sphingosine kinase 1 (SPHK1), or the receptor tyrosine kinase (RTK) AXL were also combined with osimertinib in vitro.ResultsOsimertinib exerted synergistic cytotoxicity toward FaDu and CAL27 HNSCC cells when combined with DHA. DHA reversed the osimertinib-induced STAT3 and Src phosphorylation. The double combination inhibited AXL expression. The anticancer potential of osimertinib plus DHA combination was validated in vivo on FaDu and CAL27 xenografts in mice without notable side effects.ConclusionsThe results illustrate that the combinatory therapy of osimertinib and DHA, as a repurposing anticancer drug, could be a novel therapeutic strategy for recurrent and/or metastatic HNSCC patients. The findings strongly indicate that a clinical trial is warranted to confirm the benefit of the combination.
Project description:BackgroundEpidermal 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.MethodsWe 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.ResultsWe 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.ConclusionOur 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.
Project description:UnlabelledEpidermal growth factor receptor (EGFR) is a well-characterized protooncogene that has been shown to promote tumor progression in solid cancers. Clinical results for EGFR targeting with specific monoclonal antibodies (mAbs) such as cetuximab and panitumumab are promising; however, most studies indicate that only a subgroup of patients receiving the mAbs benefit from the immunotherapy, independent of EGFR expression level. To understand the in vivo kinetics of antibody delivery and localization, we performed small-animal PET studies with (64)Cu-labeled panitumumab in xenografts derived from 3 cell lines of human head and neck squamous cell carcinoma (HNSCC).MethodsNude mice bearing HNSCC tumors with different levels of EGFR expression were imaged with small-animal PET using (64)Cu-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)-panitumumab. Antibody distribution in the tumors was confirmed by ex vivo immunostaining using panitumumab and fluorescein 5(6)-isothiocyanate (FITC) panitumumab. CD31 immunostaining and Evans blue assay were also performed to assess the tumor vascular density and permeability.ResultsAmong these 3 tumor models, UM-SCC-22B tumors with the lowest EGFR protein expression showed the highest (64)Cu-DOTA-panitumumab accumulation, whereas SQB20 tumors with the highest EGFR expression showed the lowest (64)Cu-DOTA-panitumumab accumulation. Ex vivo staining demonstrated that SQB20 cells still had extremely high EGFR expression after forming tumors in nude mice, indicating that the low uptake of (64)Cu-DOTA-panitumumab in SQB20 tumors was not due to the loss of EGFR expression. The results from CD31 immunostaining and Evans blue permeability assay suggest that the low vessel density, poor vascular permeability, and binding site barrier are likely responsible for the overall low tumor uptake of the highly EGFR-expressing SQB20 tumors.ConclusionThe results from this study provide a possible explanation for the lack of an observed correlation between therapeutic efficacy of cetuximab and panitumumab and EGFR expression level as determined by immunohistochemistry or fluorescent in situ hybridization and may shed new light on the complications of anti-EGFR mAb therapy for HNSCC and other malignancies.
Project description:The immune system plays a key role in preventing tumor formation by recognizing and destroying malignant cells. For over a century, researchers have attempted to harness the immune response as a cancer treatment, although this approach has only recently achieved clinical success. Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and is associated with cigarette smoking, alcohol consumption, betel nut use, and human papillomavirus infection. Unfortunately, worldwide mortality from HNSCC remains high, partially due to limits on therapy secondary to the significant morbidity associated with current treatments. Therefore, immunotherapeutic approaches to HNSCC treatment are attractive for their potential to reduce morbidity while improving survival. However, the application of immunotherapies to this disease has been challenging because HNSCC is profoundly immunosuppressive, resulting in decreased absolute lymphocyte counts, impaired natural killer cell function, reduced antigen-presenting cell function, and a tumor-permissive cytokine profile. Despite these challenges, numerous clinical trials testing the safety and efficacy of immunotherapeutic approaches to HNSCC treatment are currently underway, many of which have produced promising results. This review will summarize immunotherapeutic approaches to HNSCC that are currently undergoing clinical trials.