Targeted Treatment of Head and Neck (Pre)Cancer: Preclinical Target Identification and Development of Novel Therapeutic Applications

Current treatments for oropharyngeal squamous cell carcinoma and the move towards molecular therapy

OBJECTIVES

In this review, we discuss oropharyngeal squamous cell carcinoma (OPSCC) treatment options with a focus on the molecular mechanisms of OPSCC in head and neck squamous cell carcinoma (HNSCC) and head and neck cancers (HNCs). Treatment can be radical intent (aim for cure) or palliative intent (aim for disease control and symptom management). OPSCC is a prominent subset of HNSCCs in Australia and the Western World.

METHOD

We looked at the current conventional treatment options with an overview of recent advances and future endeavours.

KEY FINDINGS

We identified that radiotherapy is the primary management for OPSCC in most countries, including the USA, UK, NZ, and Australia. In contrast, surgery is only considered for superficial OPSCC or neck surgery. If surgery is incomplete, then definitive management still requires radiotherapy.

CONCLUSION

Molecular therapy is largely at the preclinical stage, with cetuximab, nivolumab, pembrolizumab, Lenvatinib, and bevacizumab being tested clinically currently.

Gemcitabine as chemotherapy of head and neck cancer in Fanconi anemia patients

Fanconi anemia (FA) is a rare hereditary disease resulting from an inactivating mutation in the FA/BRCA pathway, critical for the effective repair of DNA interstrand crosslinks (ICLs). The disease is characterized by congenital abnormalities, progressing bone marrow failure, and an increased risk of developing malignancies early in life, in particular head and neck squamous cell carcinoma (HNSCC). While ICL-inducing cisplatin combined with radiotherapy is a mainstay of HNSCC treatment, cisplatin is contra-indicated for FA-HNSCC patients. This dilemma necessitates the identification of novel treatment modalities tolerated by FA-HNSCC patients. To identify druggable targets, an siRNA-based genetic screen was previously performed in HNSCC-derived cell lines from FA and non-FA tumor origin. Here, we report that the Ribonucleotide Reductase (RNR) complex, consisting of the RRM1 and RRM2 subunits, was identified as a therapeutic target for both, FA and non-FA HNSCC. While non-FA HNSCC cells responded differentially to RNR depletion, FA-HNSCC cells were consistently found hypersensitive. This insight was confirmed pharmacologically using 2', 2'-difluoro 2'deoxycytidine (dFdC), also known as gemcitabine, a clinically used nucleotide analog that is a potent inhibitor of the RNR complex. Importantly, while cisplatin exposure displayed severe, long-lasting toxicity on the hematopoietic stem and progenitor compartments in Fancg-/- mice, gemcitabine was well tolerated and had only a mild, transient impact. Taken together, our data implicate that gemcitabine-based chemoradiotherapy could serve as an alternative HNSCC treatment in Fanconi patients, and deserves clinical testing.

KLK7 expression in human tumors: a tissue microarray study on 13,447 tumors

BACKGROUND

Kallikrein-related peptidase 7 (KLK7) is a chymotrypsin-like serine protease which is essential for the desquamation of corneocytes and thus plays a pivotal role in maintaining skin homeostasis. In cancer, KLK7 overexpression was suggested to represent a route for metastasis through cleavage of cell junction and extracellular matrix proteins of cancer cells.

METHODS

To comprehensively determine KLK7 protein expression in normal and neoplastic tissues, a tissue microarray containing 13,447 samples from 147 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry.

RESULTS

KLK7 positivity was found in 64 of 147 tumor categories, including 17 tumor categories with at least one strongly positive case. The highest rate of KLK7 positivity was found in squamous cell carcinomas from various sites of origin (positive in 18.1%-63.8%), ovarian and endometrium cancers (4.8%-56.2%), salivary gland tumors (4.8%-13.7%), bilio-pancreatic adenocarcinomas (20.0%-40.4%), and adenocarcinomas of the upper gastrointestinal tract (3.3%-12.5%). KLK7 positivity was linked to nodal metastasis (p = 0.0005), blood vessel infiltration (p = 0.0037), and lymph vessel infiltration (p < 0.0001) in colorectal adenocarcinoma, nodal metastasis in hepatocellular carcinoma (p = 0.0382), advanced pathological tumor stage in papillary thyroid cancer (p = 0.0132), and low grade of malignancy in a cohort of 719 squamous cell carcinomas from 11 different sites of origin (p < 0.0001).

CONCLUSIONS

These data provide a comprehensive overview on KLK7 expression in normal and neoplastic human tissues. The prognostic relevance of KLK7 expression and the possible role of KLK7 as a drug target need to be further investigated.

Genomic Engineering of Oral Keratinocytes to Establish In Vitro Oral Potentially Malignant Disease Models as a Platform for Treatment Investigation

Precancerous cells in the oral cavity may appear as oral potentially malignant disorders, but they may also present as dysplasia without visual manifestation in tumor-adjacent tissue. As it is currently not possible to prevent the malignant transformation of these oral precancers, new treatments are urgently awaited. Here, we generated precancer culture models using a previously established method for the generation of oral keratinocyte cultures and incorporated CRISPR/Cas9 editing. The generated cell lines were used to investigate the efficacy of a set of small molecule inhibitors. Tumor-adjacent mucosa and oral leukoplakia biopsies were cultured and genetically characterized. Mutations were introduced in CDKN2A and TP53 using CRISPR/Cas9 and combined with the ectopic activation of telomerase to generate cell lines with prolonged proliferation. The method was tested in normal oral keratinocytes and tumor-adjacent biopsies and subsequently applied to a large set of oral leukoplakia biopsies. Finally, a subset of the immortalized cell lines was used to assess the efficacy of a set of small molecule inhibitors. Culturing and genomic engineering was highly efficient for normal and tumor-adjacent oral keratinocytes, but success rates in oral leukoplakia were remarkably low. Knock-out of CDKN2A in combination with either the activation of telomerase or knock-out of TP53 seemed a prerequisite for immortalization. Prolonged culturing was accompanied by additional genetic aberrations in these cultures. The generated cell lines were more sensitive than normal keratinocytes to small molecule inhibitors of previously identified targets. In conclusion, while very effective for normal keratinocytes and tumor-adjacent biopsies, the success rate of oral leukoplakia cell culturing methods was very low. Genomic engineering enabled the prolonged culturing of OL-derived keratinocytes but was associated with acquired genetic changes. Further studies are required to assess to what extent the immortalized cultures faithfully represent characteristics of the cells in vivo.

Prognostic and clinicopathological role of pretreatment systemic immune-inflammation index in patients with oral squamous cell carcinoma: a meta-analysis

Background

There are many studies regarding the use of systemic immune-inflammation index (SII) to help predict oral squamous cell carcinoma (OSCC) prognosis, but findings have been inconsistent. The present meta-analysis was conducted to determine whether SII could contribute to predicting OSCC prognosis.

Methods

PubMed, Embase, Cochrane Library and Web of Science databases were thoroughly searched from their inceptions through August 20, 2023. The role of SII in predicting OSCC prognosis was determined through combined hazard ratios (HRs) with relevant 95% confidence intervals (CIs). Correlations of SII with clinicopathological characteristics of OSCC patients were analyzed based on combined odds ratios (ORs) with 95% CIs.

Results

This meta-analysis utilized 11 articles in total, involving 3,464 patients. According to the results, an elevated SII was markedly associated with dismal overall survival (OS) (HR=1.85, 95%CI=1.48-2.29, p<0.001) and poor disease-free survival (DFS) (HR=1.77, 95%CI=1.20-2.61, p=0.004) of OSCC. Moreover, a higher SII was markedly correlated with stage T3-T4 (OR=2.47, 95%CI=1.40-4.37, p=0.002), TNM stage III-IV (OR=2.29, 95%CI=1.53-3.44, p<0.001), and low differentiation (OR=1.74, 95%CI=1.25-2.43, p=0.001).

Conclusion

According to the present meta-analysis, an increased SII is significantly associated with dismal OS and DFS, advanced tumor stage and poor differentiation in OSCC. SII could be a potential and important biomarker for clinical management and predicting the prognosis of patients with OSCC.

Systematic review registration

https://inplasy.com/inplasy-2023-9-0033/), identifier INPLASY202390033.

Lipid metabolism reprogramming in head and neck cancer

Lipid metabolism reprogramming is one of the most prominent metabolic anomalies in cancer, wherein cancer cells undergo dysregulation of lipid metabolism to acquire adequate energy, cell membrane building blocks, as well as signaling molecules essential for cell proliferation, survival, invasion, and metastasis. These adaptations enable cancer cells to effectively respond to challenges posed by the tumor microenvironment, leading to cancer therapy resistance and poor cancer prognosis. Head and neck cancer, ranking as the seventh most prevalent cancer, exhibits numerous abnormalities in lipid metabolism. Nevertheless, the precise role of lipid metabolic rewiring in head and neck cancer remains unclear. In line with the LIPID MAPS Lipid Classification System and cancer risk factors, the present review delves into the dysregulated molecules and pathways participating in the process of lipid uptake, biosynthesis, transportation, and catabolism. We also present an overview of the latest advancements in understanding alterations in lipid metabolism and how they intersect with the carcinogenesis, development, treatment, and prognosis of head and neck cancer. By shedding light on the significance of metabolic therapy, we aspire to improve the overall prognosis and treatment outcomes of head and neck cancer patients.

An integrated genomic approach identifies follistatin as a target of the p63-epidermal growth factor receptor oncogenic network in head and neck squamous cell carcinoma

Although numerous putative oncogenes have been associated with the etiology of head and neck squamous cell carcinoma (HNSCC), the mechanisms by which these oncogenes and their downstream targets mediate tumor progression have not been fully elucidated. We performed an integrative analysis to identify a crucial set of targets of the oncogenic transcription factor p63 that are common across multiple transcriptomic datasets obtained from HNSCC patients, and representative cell line models. Notably, our analysis revealed FST which encodes follistatin, a secreted glycoprotein that inhibits the transforming growth factor TGFβ/activin signaling pathways, to be a direct transcriptional target of p63. In addition, we found that FST expression is also driven by epidermal growth factor receptor EGFR signaling, thus mediating a functional link between the TGF-β and EGFR pathways. We show through loss- and gain-of-function studies that FST predominantly imparts a tumor-growth and migratory phenotype in HNSCC cells. Furthermore, analysis of single-cell RNA sequencing data from HNSCC patients unveiled cancer cells as the dominant source of FST within the tumor microenvironment and exposed a correlation between the expression of FST and its regulators with immune infiltrates. We propose FST as a prognostic biomarker for patient survival and a compelling candidate mediating the broad effects of p63 on the tumor and its associated microenvironment.

Advantages of the Combinatorial Molecular Targeted Therapy of Head and Neck Cancer-A Step before Anakoinosis-Based Personalized Treatment

The molecular initiators of Head and Heck Squamous Cell Carcinoma (HNSCC) are complex. Human Papillomavirus (HPV) infection is linked to an increasing number of HNSCC cases, but HPV-positive tumors generally have a good prognosis. External factors that promote the development of HPV-negative HNSCC include tobacco use, excessive alcohol consumption, and proinflammatory poor oral hygiene. On a molecular level, several events, including the well-known overexpression of epidermal growth factor receptors (EGFR) and related downstream signaling pathways, contribute to the development of HNSCC. Conventional chemotherapy is insufficient for many patients. Thus, molecular-based therapy for HNSCC offers patients a better chance at a cure. The first molecular target for therapy of HNSCC was EGFR, inhibited by monoclonal antibody cetuximab, but its use in monotherapy is insufficient and induces resistance. This article describes attempts at combinatorial molecular targeted therapy of HNSCC based on several molecular targets and exemplary drugs/drug candidates. The new concept of anakoinosis-based therapy, which means treatment that targets the intercellular and intracellular communication of cancer cells, is thought to be the way to improve the clinical outcome for HNSCC patients. The identification of a link between molecular targeted therapy and anakoinosis raises the potential for further progress in HPV-negative HNSCC therapy.

ATHENA: an independently validated autophagy-related epigenetic prognostic prediction model of head and neck squamous cell carcinoma

The majority of these existing prognostic models of head and neck squamous cell carcinoma (HNSCC) have unsatisfactory prediction accuracy since they solely utilize demographic and clinical information. Leveraged by autophagy-related epigenetic biomarkers, we aim to develop a better prognostic prediction model of HNSCC incorporating CpG probes with either main effects or gene-gene interactions. Based on DNA methylation data from three independent cohorts, we applied a 3-D analysis strategy to develop An independently validated auTophagy-related epigenetic prognostic prediction model of HEad and Neck squamous cell carcinomA (ATHENA). Compared to prediction models with only demographic and clinical information, ATHENA has substantially improved discriminative ability, prediction accuracy and more clinical net benefits, and shows robustness in different subpopulations, as well as external populations. Besides, epigenetic score of ATHENA is significantly associated with tumor immune microenvironment, tumor-infiltrating immune cell abundances, immune checkpoints, somatic mutation and immunity-related drugs. Taken together these results, ATHENA has the demonstrated feasibility and utility of predicting HNSCC survival ( http://bigdata.njmu.edu.cn/ATHENA/ ).

A Novel External Auditory Canal Squamous Cell Carcinoma Cell Line Sensitive to CDK4/6 Inhibition

OBJECTIVE

To characterize cell line CAE606 derived from a squamous cell carcinoma (SCC) of the external auditory canal (EAC) and to show its usefulness as a model for testing candidate therapeutic agents.

STUDY DESIGN

Preclinical translational research.

SETTING

Biomedical research institute.

METHODS

The cell line was initiated from a moderately differentiated T2N0M0 EAC SCC. We studied its histologic and genetic features as well as growth and invasion parameters. Sensitivity to cell CDK4/6 cell cycle inhibitor palbociclib was analyzed.

RESULTS

CAE606 cells expressed heavy molecular weight cytokeratin, p63, and vimentin. The population doubling time was 25.8 hours, and the cells showed fast collective cell migration in a wound-healing assay. Short tandem repeat analysis confirmed it to be derived from the primary tumor of the patient. Next-generation sequencing revealed alterations in cell cycle regulation genes, including inactivating mutations in CDKN2A and TP53 and high-level amplification of CCND1 and EGFR. CAE606 showed a strong decrease of phospo-Rb expression upon exposure to the CDK4/6 inhibitor palbociclib, causing significant growth inhibition with an IC₅₀ of 0.46 µM.

CONCLUSION

This is the first report of a stable EAC SCC cell line. Its genetic features make it a useful tool for preclinical testing of new therapeutic agents for EAC SCC, particularly those targeting cell cycle regulation in combination with radio- and chemotherapy or other specific signaling pathway inhibitors.

Molecular Biomarkers of Malignant Transformation in Head and Neck Dysplasia

Head and neck squamous cell carcinoma (HNSCC) and its treatments are associated with substantial morbidity, often resulting in cosmetic deformity and loss of physiologic functions including speech and swallowing. Despite advancements in treatment, 5-year survival rates for mucosal malignancies remain below 70%. Effective prevention of HNSCC demands an understanding of the molecular pathways of carcinogenesis. Specifically, defining features of pre-cancerous dysplastic lesions that indicate a better or worse prognosis is necessary to help identify patients who are likely to develop a carcinoma and allow a more aggressive approach to management. There remains a need for identification of biomarkers that can provide both early prognostic and predictive value in clinical decision-making by serving as both therapeutic targets as well as predictors of therapy response. Here, we comprehensively review the most frequently altered molecular biomarkers of malignant transformation in head and neck dysplasia. These markers are involved in a wide range of cellular processes in head and neck carcinogenesis, including extracellular matrix degradation, cell motility and invasion, cell-cell adhesion, solute transport, immortalization, metabolism, the cell cycle and apoptosis, transcription, and cell signaling.

Cytokeratin 10 (CK10) expression in cancer: A tissue microarray study on 11,021 tumors

Cytokeratin 10 (CK10) is a type I acidic low molecular weight cytokeratin which is mainly expressed in keratinizing squamous epithelium of the skin. Variable levels of CK10 protein have been described in squamous carcinomas of different sites and in some other epithelial neoplasms. To comprehensively determine the prevalence of CK10 expression in normal and neoplastic tissues, a tissue microarray containing 11,021 samples from 131 different tumor types and subtypes was analyzed by immunohistochemistry. CK10 immunostaining was detectable in 41 (31.3 %) of 131 tumor categories, including 18 (13.7 %) tumor types with at least one strongly positive case. The highest rate of positive staining was found in squamous cell carcinomas from various sites of origin (positive in 18.6 %-66.1 %) and in Warthin tumors of salivary glands (47.8 %), followed by various tumor entities known to potentially exhibit areas with squamous cell differentiation such as teratomas (33.3 %), basal cell carcinomas of the skin (14.3 %), adenosquamous carcinomas of the cervix (11.1 %), and several categories of urothelial neoplasms (3.1 %-16.8 %). In a combined analysis of 956 squamous cell carcinomas from 11 different sites of origin, reduced CK10 staining was linked to high grade (p < 0.0001) and advanced stage (p = 0.0015) but unrelated to HPV infection. However, CK10 staining was not statistically related to grade (p = 0.1509) and recurrence-free (p = 0.5247) or overall survival (p = 0.5082) in 176 cervical squamous cell carcinomas. In the urinary bladder, CK10 staining occurred more commonly in muscle-invasive (17.7 %) than in non-invasive urothelial carcinomas (4.0 %-6.0 %; p < 0.0001). In summary, our data corroborate a role of CK10 as a suitable marker for mature, keratinizing squamous cell differentiation in epithelial tissues. CK10 immunohistochemistry may thus be instrumental for a more objective evaluation of the clinical significance of focal squamous differentiation in cancer.

Current trends of targeted therapy for oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a malignant disease in the world which has a profound effect on human health and life quality. According to tumor stage and pathological diagnosis, OSCC is mainly treated by combinations of surgery, radiotherapy and chemotherapy. However, traditional treatment methods suffer from some limitations, such as systemic toxicity, limited therapeutic effect and drug resistance. With the rapid development of nanotechnology, nanodrug delivery systems (DDSs) and intelligent DDSs have been widely used in targeted therapy for OSCC. Meanwhile, the newly developed therapeutic techniques such as immunotherapy, gene therapy and bionic technology provide the possibility to realize the active targeted therapy. Here, the latest advances of target therapy for OSCC are reviewed, and their therapeutic remarks, current limits and future prospects are also systematically interpreted. It is believed that active and passive targeted therapies have great potentials for clinical transformation and application of OSCC, which will greatly improve human quality of life.