The role of cetuximab in the management of head and neck cancers

Genetically engineered mouse models of head and neck cancers

The head and neck region is one of the anatomic sites commonly afflicted by cancer, with ~1.5 million new diagnoses reported worldwide in 2020 alone. Remarkable progress has been made in understanding the underlying disease mechanisms, personalizing care based on each tumor's individual molecular characteristics, and even therapeutically exploiting the inherent vulnerabilities of these neoplasms. In this regard, genetically engineered mouse models (GEMMs) have played an instrumental role. While progress in the development of GEMMs has been slower than in other major cancer types, several GEMMs are now available that recapitulate most of the heterogeneous characteristics of head and neck cancers such as the tumor microenvironment. Different approaches have been employed in GEMM development and implementation, though each can generally recapitulate only certain disease aspects. As a result, appropriate model selection is essential for addressing specific research questions. In this review, we present an overview of all currently available head and neck cancer GEMMs, encompassing models for head and neck squamous cell carcinoma, nasopharyngeal carcinoma, and salivary and thyroid gland carcinomas.

Targeted therapy for head and neck cancer: signaling pathways and clinical studies

Head and neck cancer (HNC) is malignant, genetically complex and difficult to treat and is the sixth most frequent cancer, with tobacco, alcohol and human papillomavirus being major risk factors. Based on epigenetic data, HNC is remarkably heterogeneous, and treatment remains challenging. There is a lack of significant improvement in survival and quality of life in patients with HNC. Over half of HNC patients experience locoregional recurrence or distal metastasis despite the current multiple traditional therapeutic strategies and immunotherapy. In addition, resistance to chemotherapy, radiotherapy and some targeted therapies is common. Therefore, it is urgent to explore more effective and tolerable targeted therapies to improve the clinical outcomes of HNC patients. Recent targeted therapy studies have focused on identifying promising biomarkers and developing more effective targeted therapies. A well understanding of the pathogenesis of HNC contributes to learning more about its inner association, which provides novel insight into the development of small molecule inhibitors. In this review, we summarized the vital signaling pathways and discussed the current potential therapeutic targets against critical molecules in HNC, as well as presenting preclinical animal models and ongoing or completed clinical studies about targeted therapy, which may contribute to a more favorable prognosis of HNC. Targeted therapy in combination with other therapies and its limitations were also discussed.

Electroporation in Head-and-Neck Cancer: An Innovative Approach with Immunotherapy and Nanotechnology Combination

Squamous cell carcinoma is the most common malignancy that arises in the head-and-neck district. Traditional treatment could be insufficient in case of recurrent and/or metastatic cancers; for this reason, more selective and enhanced treatments are in evaluation in preclinical and clinical trials to increase in situ concentration of chemotherapy drugs promoting a selectively antineoplastic activity. Among all cancer treatment types (i.e., surgery, chemotherapy, radiotherapy), electroporation (EP) has emerged as a safe, less invasive, and effective approach for cancer treatment. Reversible EP, using an intensive electric stimulus (i.e., 1000 V/cm) applied for a short time (i.e., 100 μs), determines a localized electric field that temporarily permealizes the tumor cell membranes while maintaining high cell viability, promoting cytoplasm cell uptake of antineoplastic agents such as bleomycin and cisplatin (electrochemotherapy), calcium (Ca²⁺ electroporation), siRNA and plasmid DNA (gene electroporation). The higher intracellular concentration of antineoplastic agents enhances the antineoplastic activity and promotes controlled tumor cell death (apoptosis). As secondary effects, localized EP (i) reduces the capillary blood flow in tumor tissue ("vascular lock"), lowering drug washout, and (ii) stimulates the immune system acting against cancer cells. After years of preclinical development, electrochemotherapy (ECT), in combination with bleomycin or cisplatin, is currently one of the most effective treatments used for cutaneous metastases and primary skin and mucosal cancers that are not amenable to surgery. To reach this clinical evidence, in vitro and in vivo models were preclinically developed for evaluating the efficacy and safety of ECT on different tumor cell lines and animal models to optimize dose and administration routes of drugs, duration, and intensity of the electric field. Improvements in reversible EP efficacy are under evaluation for HNSCC treatment, where the focus is on the development of a combination treatment between EP-enhanced nanotechnology and immunotherapy strategies.

Meet the Insidious Players: Review of Viral Infections in Head and Neck Cancer Etiology with an Update on Clinical Trials

Head and neck cancers (HNC) occur in the upper aerodigestive tract and are among the most common cancers. The etiology of HNC is complex, involving many factors, including excessive tobacco and alcohol consumption; over the last two decades, oncogenic viruses have also been recognized as an important cause of HNC. Major etiological agents of nasopharynx carcinoma and oropharyngeal carcinoma include Epstein-Barr virus (EBV) and human papillomaviruses (HPVs), both of which are able to interfere with cell cycle control. Additionally, the association of hepatitis C and hepatitis B infection was observed in oral cavity, oropharyngeal, laryngeal, and nasopharyngeal cancers. Overall prognoses depend on anatomic site, stage, and viral status. Current treatment options, including radiotherapy, chemotherapy, targeted therapies and immunotherapies, are distributed in order to improve overall patient prognosis and survival rates. However, the interplay between viral genome sequences and the health, disease, geography, and ethnicity of the host are crucial for understanding the role of viruses and for development of potential personalized treatment and prevention strategies. This review provides the most comprehensive analysis to date of a vast field, including HNC risk factors, as well as viral mechanisms of infection and their role in HNC development. Additionally, currently available treatment options investigated through clinical practice are emphasized in the paper.

Long-term disease control in a metastatic squamous cell carcinoma of the oral cavity treated with maintenance metronomic capecitabine

Recurrent or metastatic disease occurs in two-thirds of head and neck squamous cell carcinomas and it is associated with poor prognosis. Systemic treatment with platinum-based chemotherapy in combination with the epidermal growth factor receptor-targeting monoclonal antibody cetuximab represents a preferred option for these patients. Upon the achievement of tumor response by combined treatment, maintenance with single-agent cetuximab is usually administered with the aim of prolonging disease control at the price of reasonable toxicity. Although rarely, however, cetuximab needs to be discontinued in the absence of disease progression because of intolerable side effects. Here we describe the case of a 66-year-old man with a metastatic cancer of oral cavity, who had to discontinue maintenance cetuximab and who achieved prolonged disease control with metronomic capecitabine. We suggest that capecitabine could be an effective and safe maintenance option in case of cetuximab intolerance.

Antisense Oligonucleotides Targeting Angiogenic Factors as Potential Cancer Therapeutics

Cancer is one of the leading causes of death worldwide, and conventional cancer therapies such as surgery, chemotherapy, and radiotherapy do not address the underlying molecular pathologies, leading to inadequate treatment and tumor recurrence. Angiogenic factors, such as EGF, PDGF, bFGF, TGF-β, TGF-α, VEGF, endoglin, and angiopoietins, play important roles in regulating tumor development and metastasis, and they serve as potential targets for developing cancer therapeutics. Nucleic acid-based therapeutic strategies have received significant attention in the last two decades, and antisense oligonucleotide-mediated intervention is a prominent therapeutic approach for targeted manipulation of gene expression. Clinical benefits of antisense oligonucleotides have been recognized by the U.S. Food and Drug Administration, with full or conditional approval of Vitravene, Kynamro, Exondys51, and Spinraza. Herein we review the scope of antisense oligonucleotides that target angiogenic factors toward tackling solid cancers.

Tumor detection using magnetosome nanoparticles functionalized with a newly screened EGFR/HER2 targeting peptide

A novel peptide (P75) targeting EGFR and HER2 is successfully screened from a one-bead-one-compound (OBOC) library containing approximately 2 × 10⁵ peptides built with the aid of computational simulation. In vitro and in vivo analyses show that P75 binds to human epithelial growth factor receptor (EGFR) with nanomolar affinity and to epithelial growth factor receptor-2 (HER2) with a lower affinity but comparable to other reported peptides. The peptide is used to modify the surface of magnetosome nanoparticles (NPs) for targeted magnetic resonance imaging (MRI). In vitro and in vivo fluorescence imaging results suggest peptide P75 modified magnetosomes (Mag-P75) specifically bind to MDA-MB-468 and SKBR3 cells as well as xenograft tumors with surprisingly low accumulation in other organs including liver and kidney. In vivo T₂-weighted MR imaging studies of the xenograft tumors from SKBR3 and MDA-MB-468 cells show obviously negative contrast enhancement. The high affinity and specificity of P75 to EGFR and HER2 positive tumors, together with the success of peptide functionalized magnetosome NPs for targeted MRI demonstrate the potential of this peptide being used in the EGFR and HER2 positive tumors diagnosis and therapy.

A Monoclonal Antibody to ADAM17 Inhibits Tumor Growth by Inhibiting EGFR and Non-EGFR-Mediated Pathways

ADAM17 is the primary sheddase for HER pathway ligands. We report the discovery of a potent and specific ADAM17 inhibitory antibody, MEDI3622, which induces tumor regression or stasis in many EGFR-dependent tumor models. The inhibitory activity of MEDI3622 correlated with EGFR activity both in a series of tumor models across several indications as well in as a focused set of head and neck patient-derived xenograft models. The antitumor activity of MEDI3622 was superior to that of EGFR/HER pathway inhibitors in the OE21 esophageal model and the COLO205 colorectal model suggesting additional activity outside of the EGFR pathway. Combination of MEDI3622 and cetuximab in the OE21 model was additive and eradicated tumors. Proteomics analysis revealed novel ADAM17 substrates that function outside of the HER pathways and may contribute toward the antitumor activity of the monoclonal antibody.

Isogenic radiation resistant cell lines: development and validation strategies

PURPOSE

The comparison of cell lines with differing radiosensitivities and their molecular response to radiation exposure has been used in a number of human cancer models to study the molecular response to radiation. This review proposes to analyze and compare the protocols used by investigators for the development and validation of these isogenic models of radioresistance.

CONCLUSION

There is large variability in the strategies used to generate and validate isogenic models of radioresistance. Further characterization of these models is required.

Tailored immunotherapy for HPV positive head and neck squamous cell cancer

Human papilloma virus (HPV) associated oropharynx carcinoma (OPC) is increasingly common, with a distinct biology from HPV negative OPC. In spite of this better prognosis, morbidity is significant and treatment related after effects can be debilitating. Because the foreign viral proteins that drive HPV+ cancers are known, there are multiple options for tailored immune therapies. Herein we review the immunologic basis for disease and emerging immune therapies. The oncogenesis of HPV+ SCCHN goes beyond cell cycle deregulation, and relies on the immune escape through (E5, E6, and E7) downregulating antigen processing, interferon response, as well as STAT-1 signaling. Individual susceptibilities to HPV infection may vary. The treatment of HPV+ cancers has had a wide range of successes and failures. Perhaps the shining example of immunoprevention has been the L1 protein vaccines developed for cervical cancer prevention, however this vaccine has not been beneficial for people already infected. Therefore multiple strategies have been employed in the cancer therapeutic realm for people with existing disease. These agents range from peptides, to viral vectors, to adoptive cell therapy. In this review we consider the work done in both SCCHN and cervical cancer, as these therapeutic targets are the similar. The listed studies are not exhaustive, but rather illustrate experimental design and approach.

Interrogating tumor metabolism and tumor microenvironments using molecular positron emission tomography imaging. Theranostic approaches to improve therapeutics

Positron emission tomography (PET) is a noninvasive molecular imaging technology that is becoming increasingly important for the measurement of physiologic, biochemical, and pharmacological functions at cellular and molecular levels in patients with cancer. Formation, development, and aggressiveness of tumor involve a number of molecular pathways, including intrinsic tumor cell mutations and extrinsic interaction between tumor cells and the microenvironment. Currently, evaluation of these processes is mainly through biopsy, which is invasive and limited to the site of biopsy. Ongoing research on specific target molecules of the tumor and its microenvironment for PET imaging is showing great potential. To date, the use of PET for diagnosing local recurrence and metastatic sites of various cancers and evaluation of treatment response is mainly based on [(18)F]fluorodeoxyglucose ([(18)F]FDG), which measures glucose metabolism. However, [(18)F]FDG is not a target-specific PET tracer and does not give enough insight into tumor biology and/or its vulnerability to potential treatments. Hence, there is an increasing need for the development of selective biologic radiotracers that will yield specific biochemical information and allow for noninvasive molecular imaging. The possibility of cancer-associated targets for imaging will provide the opportunity to use PET for diagnosis and therapy response monitoring (theranostics) and thus personalized medicine. This article will focus on the review of non-[(18)F]FDG PET tracers for specific tumor biology processes and their preclinical and clinical applications.

Inherent phenotypic plasticity facilitates progression of head and neck cancer: endotheliod characteristics enable angiogenesis and invasion

The presence of the EMT (epithelial-mesenchymal transition), EndMT (endothelial-mesenchymal transition) and VM (vasculogenic mimicry) demonstrates the multidirectional extent of phenotypic plasticity in cancers. Previous findings demonstrating the crosstalk between head and neck squamous cell carcinoma (HNSCC) and vascular endothelial growth factor (VEGF) imply that HNSCC cells share some functional commonalities with endothelial cells. Our current results reveal that cultured HNSCC cells not only possess endothelial-specific markers, but also display endotheliod functional features including low density lipoprotein uptake, formation of tube-like structures on Matrigel and growth state responsiveness to VEGF and endostatin. HNSCC cell subpopulations are also highly responsive to transforming growth factor-β1 and express its auxiliary receptor, endoglin. Furthermore, the endotheliod characteristics observed in vitro recapitulate phenotypic features observed in human HNSCC tumors. Conversely, cultured normal human oral keratinocytes and intact or ulcerated human oral epithelia do not express comparable endotheliod characteristics, which imply that assumption of endotheliod features is restricted to transformed keratinocytes. In addition, this phenotypic state reciprocity facilitates HNSCC progression by increasing production of factors that are concurrently pro-proliferative and pro-angiogenic, conserving cell energy stores by LDL internalization and enhancing cell mobility. Finally, recognition of this endotheliod phenotypic transition provides a solid rationale to evaluate the antitumorigenic potential of therapeutic agents formerly regarded as exclusively angiostatic in scope.