An update: emerging drugs to treat squamous cell carcinomas of the head and neck

Targeted radionuclide therapy for head and neck squamous cell carcinoma: a review

Head and neck squamous cell carcinoma (HNSCC) is a type of head and neck cancer that is aggressive, difficult to treat, and often associated with poor prognosis. HNSCC is the sixth most common cancer worldwide, highlighting the need to develop novel treatments for this disease. The current standard of care for HNSCC usually involves a combination of surgical resection, radiation therapy, and chemotherapy. Chemotherapy is notorious for its detrimental side effects including nausea, fatigue, hair loss, and more. Radiation therapy can be a challenge due to the anatomy of the head and neck area and presence of normal tissues. In addition to the drawbacks of chemotherapy and radiation therapy, high morbidity and mortality rates for HNSCC highlight the urgent need for alternative treatment options. Immunotherapy has recently emerged as a possible treatment option for cancers including HNSCC, in which monoclonal antibodies are used to help the immune system fight disease. Combining monoclonal antibodies approved by the US Food and Drug Administration, such as cetuximab and pembrolizumab, with radiotherapy or platinum-based chemotherapy for patients with locally advanced, recurrent, or metastatic HNSCC is an accepted first-line therapy. Targeted radionuclide therapy can potentially be used in conjunction with the first-line therapy, or as an additional treatment option, to improve patient outcomes and quality of life. Epidermal growth factor receptor is a known molecular target for HNSCC; however, other targets such as human epidermal growth factor receptor 2, human epidermal growth factor receptor 3, programmed cell death protein 1, and programmed death-ligand 1 are emerging molecular targets for the diagnosis and treatment of HNSCC. To develop successful radiopharmaceuticals, it is imperative to first understand the molecular biology of the disease of interest. For cancer, this understanding often means detection and characterization of molecular targets, such as cell surface receptors, that can be used as sensitive targeting agents. The goal of this review article is to explore molecular targets for HNSCC and dissect previously conducted research in nuclear medicine and provide a possible path forward for the development of novel radiopharmaceuticals used in targeted radionuclide therapy for HNSCC, which has been underexplored to date.

Pharmacological inhibition of MYC to mitigate chemoresistance in preclinical models of squamous cell carcinoma

Rationale: Cisplatin-based chemotherapy is the first-line treatment for late-stage head and neck squamous cell carcinoma (HNSCC). However, resistance to cisplatin has become a major obstacle for effective therapy. Cancer stem cells (CSCs) are critical for tumor initiation, growth, metastasis, and chemoresistance. How to effectively eliminate CSCs and overcome chemoresistance remains a key challenge. Herein, we confirmed that MYC plays critical roles in chemoresistance, and explored targeting MYC to overcome cisplatin resistance in preclinical models. Methods: The roles of MYC in HNSCC cisplatin resistance and cancer stemness were tested in vitro and in vivo. The combined therapeutic efficiency of MYC targeting using the small molecule MYC inhibitor MYCi975 and cisplatin was assessed in a 4‑nitroquinoline 1-oxide-induced model and in a patient-derived xenograft model. Results: MYC was highly-expressed in cisplatin-resistant HNSCC. Targeting MYC using MYCi975 eliminated CSCs, prevented metastasis, and overcame cisplatin resistance. MYCi975 also induced tumor cell-intrinsic immune responses, and promoted CD8+ T cell infiltration. Mechanistically, MYCi975 induced the DNA damage response and activated the cGAS-STING-IRF3 signaling pathway to increase CD8+ T cell-recruiting chemokines. Conclusions: Our findings suggested that targeting MYC might eliminate CSCs, prevent metastasis, and activate antitumor immunity to overcome cisplatin resistance in HNSCC.

Bioactive phytocompounds for oral cancer prevention and treatment: A comprehensive and critical evaluation

The high incidence of oral cancer combined with excessive treatment cost underscores the need for novel oral cancer preventive and therapeutic options. The value of natural agents, including plant secondary metabolites (phytochemicals), in preventing carcinogenesis and representing expansive source of anticancer drugs have been established. While fragmentary research data are available on antioral cancer effects of phytochemicals, a comprehensive and critical evaluation of the potential of these agents for the prevention and intervention of human oral malignancies has not been conducted according to our knowledge. This study presents a complete and critical analysis of current preclinical and clinical results on the prevention and treatment of oral cancer using phytochemicals. Our in-depth analysis highlights anticancer effects of various phytochemicals, such as phenolics, terpenoids, alkaloids, and sulfur-containing compounds, against numerous oral cancer cells and/or in vivo oral cancer models by antiproliferative, proapoptotic, cell cycle-regulatory, antiinvasive, antiangiogenic, and antimetastatic effects. Bioactive phytochemicals exert their antineoplastic effects by modulating various signaling pathways, specifically involving the epidermal growth factor receptor, cytokine receptors, toll-like receptors, and tumor necrosis factor receptor and consequently alter the expression of downstream genes and proteins. Interestingly, phytochemicals demonstrate encouraging effects in clinical trials, such as reduction of oral lesion size, cell growth, pain score, and development of new lesions. While most phytochemicals displayed minimal toxicity, concerns with bioavailability may limit their clinical application. Future directions for research include more in-depth mechanistic in vivo studies, administration of phytochemicals using novel formulations, investigation of phytocompounds as adjuvants to conventional treatment, and randomized clinical trials.

Theranostic Potential of EFNB2 for Cetuximab Resistance in Head and Neck Cancer

Only 13% of head and neck cancer (HNC) patients respond to cetuximab therapy despite its target (EGFR) is expressed in about 80-90% of HNC patients. However, this problem remained unresolved till date despite of numerous efforts. Thus, the current study aimed to establish hub genes involved in cetuximab resistance via series of bioinformatics approach. The GSE21483 dataset was analysed for differentially expressed genes (DEGs) using GEO2R and enrichment analysis was carried out using DAVID. STRING 11.5 and Cytoscape 3.7.2 were used for protein-protein interactions and hub genes respectively. The significant hub genes (p < 0.05) were validated using ULCAN and Human protein atlas. Validated genes were further queried for tumor infiltration using TIMER2.0. Out of total 307 DEGs, 38 hub genes were identified of which IL1A, EFNB2, SPRR1A, ROBO1 and SOCS3 were the significant hub genes associated with both mRNA expression and overall survival. IL1A, ROBO1, and SOCS3 were found to be downregulated whereas EFNB2 and SPRR1A were found to be upregulated in our study. However, using UALCAN, we found that high expression of IL1A, EFNB2, SOCS3 negatively affects overall survival whereas high expression of SPRR1A and ROBO1 positively affects overall survival. Protein level for EFNB2 and SPRR1A expression was significant in tumor HNC tissue as compared to normal HNC tissue. EFNB2 was found to be a key regulator of CTX resistance among HNC patients. Targeting EFNB2 and associated PPI circuits might improve the response rate to CTX. Thus, EFNB2 has potential to be theranostic marker for CTX resistance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03739-9.

Epidemiology, Risk Factors, and Prevention of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a group of malignancies, involving the oral cavity, pharynx, hypopharynx, larynx, nasal cavity, and salivary glands, that together compose the seventh most common cancer diagnosis worldwide. With 890,000 new cases and 450,000 deaths annually per GLOBOCAN estimates, HNSCC accounts for roughly 4.5% of cancer diagnoses and deaths. In the developing world, the incidence of HNSCC is growing with increasing consumption of tobacco (smoked or chewed), alcohol, and areca nut (betel quid). Alcohol and tobacco have a synergistic effect, with the heavy consumption of both increasing HNSCC risk 40-fold. In developed nations, HPV-related HNSCC surpasses tobacco- and alcohol-related disease. HPV-related HNSCC more commonly affects the oropharynx, hypopharynx, and larynx than the oral cavity, and is associated with a significantly longer median survival (130 months vs. 20 months). Discrepancies in etiology as well as disparities in lifestyle choices and access to healthcare may account for the greater incidence and poorer survival of HNSCC among minority and lower-socioeconomic-status communities in developed nations. Pharmacotherapy and counseling together have been shown to be effective in promoting smoking and alcohol cessation. Education on cancer risk and community engagement have reduced areca nut consumption in Asia as well as in diaspora communities. HPV vaccination, starting at age 11-12 for both sexes, has been shown to reduce the prevalence of high-risk HPV serologies and prevent pre-cancerous lesions of the cervix, vagina, and vulva. As of 2020, 58.6% of eligible adolescents in the US have received the full two-vaccine series. Increased adoption of vaccination, education on safe sex practices, and routine visual oral screening for high-risk patients would curb growing HNSCC incidence in developed nations.

SN-38, an active metabolite of irinotecan, enhances anti-PD-1 treatment efficacy in head and neck squamous cell carcinoma

Anti-programmed cell death 1 (anti-PD-1) therapy shows definite but modest activity in patients with advanced/metastatic head and neck squamous cell carcinoma (HNSCC). Preliminary evidence suggests that SN-38, an activated form of irinotecan that increases expression of the transcription factor FoxO3a, can suppress programmed cell death ligand-1 (PD-L1) expression in breast and ovarian tumor models. We analyzed the SN-38-mediated activation of natural killer cells in vitro and explored the efficacy of SN-38 in combination with anti-PD-1 for treatment in vivo. In vitro, SN-38 enhanced the expression of FoxO3a and reduced the expression of c-Myc and PD-L1 dose-dependently in tumor cells. Low-dose SN-38 increased interferon-γ secretion by NK cells and promoted NK cell-mediated cytotoxicity in tumor cells. In vivo studies revealed that at non-cytotoxic drug concentrations, SN-38 significantly enhanced anti-PD-1 activity in suppressing murine tumor growth. We found increased NK cell and CD8⁺ T-cell infiltration in post-treatment tumors. RNA-seq analysis indicated that SN-38 increased the enrichment of immune cells and biological function genes related to the immune responses. SN-38 is a potentially beneficial adjunct to checkpoint inhibitor therapy in HNSCC. Further studies exploring its mechanism of action and possible applications are necessary. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Therapeutic Targeting of MYC in Head and Neck Squamous Cell Carcinoma

MYC plays critical roles in tumorigenesis and is considered an attractive cancer therapeutic target. Small molecules that directly target MYC and are well tolerated in vivo represent invaluable anti-cancer therapeutic agents. Here, we aimed to investigate the therapeutic effect of MYC inhibitors in head and neck squamous cell carcinoma (HNSCC). The results showed that pharmacological and genetic inhibition of MYC inhibited HNSCC proliferation and migration. MYC inhibitor 975 (MYCi975), inhibited HNSCC growth in both cell line-derived xenograft and syngeneic murine models. MYC inhibition also induced tumor cell-intrinsic immune responses, and promoted CD8⁺ T cell infiltration. Mechanistically, MYC inhibition increased CD8⁺ T cell-recruiting chemokines by inducing the DNA damage related cGAS-STING pathway. High expression of MYC combined with a low level of infiltrated CD8⁺ T cell in HNSCC correlated with poor prognosis. These results suggested the potential of small-molecule MYC inhibitors as anti-cancer therapeutic agents in HNSCC.

Simultaneously targeting ErbB family kinases and PI3K in HPV-positive head and neck squamous cell carcinoma

OBJECTIVES

To identify the most effective PI3K and EGFR inhibitors in HPV-positive head and neck squamous cell carcinoma (HNSCC) and investigate the efficacy of a combination of an ErbB family kinase inhibitor and a PI3K inhibitor to inhibit cell proliferation of HPV-positive HNSCC.

MATERIALS AND METHOD

HPV-positive HNSCC cell lines were treated with the FDA approved ErbB kinase inhibitor, Afatinib or FDA-approved PI3K inhibitor, Copanlisib, alone or in combination, and phosphorylation and total protein levels of cells were assessed by Western blot analysis.Cell proliferation and apoptosis were examined by MTS assay, flow cytometry, and Western blots, respectively.

RESULTS

Copanlisib more effectively inhibited cell proliferation in comparison to other PI3K inhibitors tested. HPV-positive HNSCC cells differentially responded to cisplatin, Afatinib, or Copanlisib. The combination of Afatinib and Copanlisib more effectively suppressed cell proliferation and induced apoptosis compared to either treatment alone. Mechanistically, the combination of Afatinib and Copanlisib completely blocked phosphorylation of EGFR, HER2, HER3, and Akt as well as significantly decreased the HPV E7 expression compared to either treatment alone.

CONCLUSION

Afatinib and Copanlisib more effectively suppress cell proliferation and survival of HPV-positive HNSCC in comparison to either treatment alone.

Targeting Wee1 kinase to suppress proliferation and survival of cisplatin-resistant head and neck squamous cell carcinoma

PURPOSE

We investigated the role of Wee1 kinase in cisplatin-resistant head and neck squamous cell carcinoma (HNSCC) in multiple cisplatin-resistant HNSCC cell lines and determined the efficacy of either Wee1 inhibitor, AZD1775 alone, or in combination with cisplatin, on cisplatin-resistant HNSCC inhibition.

METHODS

Phosphorylation and total protein levels of cells were assessed by Western blot analysis. Cell viability and apoptosis were examined by MTS assay and flow cytometry, respectively.

RESULTS

Wee1 kinase protein expression levels in five cisplatin-resistant HNSCC cell types were higher than those in their parental cisplatin-sensitive partners. Importantly, Wee1 knockdown inhibited cell proliferation and re-sensitized cells to cisplatin treatment. Interestingly, previous studies have also shown that Wee1 inhibitor AZD1775 synergizes with cisplatin to suppress cell proliferation of cisplatin-sensitive HNSCC. We found that AZD1775 inhibited both cisplatin-sensitive and resistant HNSCC with similar IC₅₀ values, which suggested that AZD1775 could overcome cisplatin resistance in cisplatin-resistant HNSCC. Mechanistically, AZD1775 and cisplatin cooperatively induced DNA damage and apoptosis.

CONCLUSION

Wee1 inhibitor, AZD1775, and cisplatin coordinately suppressed proliferation and survival of HNSCC.

SSTP1, a Host Defense Peptide, Exploits the Immunomodulatory IL6 Pathway to Induce Apoptosis in Cancer Cells

While the immunomodulatory pathways initiated in immune cells contribute to therapeutic response, their activation in cancer cells play a role in cancer progression. Also, many of the aberrantly expressed immunomodulators on cancer cells are considered as therapeutic targets. Here, we introduce host defense peptide (HDP), a known immuomodulator, as a therapeutic agent to target them. The cationic host defense peptides (HDPs), an integral part of the innate immune system, possess membranolytic activity, which imparts antimicrobial and antitumor efficacy to it. They act as immunomodulators by activating the immune cells. Though their antimicrobial function has been recently reassigned to immunoregulation, their antitumor activity is still attributed to its membranolytic activity. This membrane pore formation ability, which is proportional to the concentration of the peptide, also leads to side effects like hemolysis, limiting their therapeutic application. So, despite the identification of a variety of anticancer HDPs, their clinical utility is limited. Though HDPs are shown to exert the immunomodulatory activity through specific membrane targets on immune cells, their targets on cancer cells are unknown. We show that SSTP1, a novel HDP identified by shotgun cloning, binds to the active IL6/IL6Rα/gp130 complex on cancer cells, rearranging the active site residues. In contrast to the IL6 blockers inhibiting JAK/STAT activity, SSTP1 shifts the proliferative IL6/JAK/STAT signaling to the apoptotic IL6/JNK/AP1 pathway. In IL6Rα-overexpressing cancer cells, SSTP1 induces apoptosis at low concentration through JNK pathway, without causing significant membrane disruption. We highlight the importance of immunomodulatory pathways in cancer apoptosis, apart from its established role in immune cell regulation and cancer cell proliferation. Our study suggests that identification of the membrane targets for the promising anticancer HDPs might lead to the identification of new drugs for targeted therapy.

Integrative Analysis of Metabolomics and Transcriptomics Data Identifies Prognostic Biomarkers Associated With Oral Squamous Cell Carcinoma

Background

Oral squamous cell carcinoma (OSCC) is the most malignant neoplasm in oral cancer. There is growing evidence that its progression involves altered metabolism. The current method of evaluating prognosis is very limited, and metabolomics may provide a new approach for quantitative evaluation. The aim of the study is to evaluate the use of metabolomics as prognostic markers for patients with OSCC.

Methods

An analytical platform, Ultra-Performance Liquid Chromatography-Quadrupole/Orbitrap High Resolution Mass Spectrometry (UHPLC-Q-Orbitrap HRMS), was used to acquire the serum fingerprinting profiles from a total of 103 patients of OSCC before and after the operation. In total, 103 OSCC patients were assigned to either a training set (n = 73) or a test set (n = 30). The potential biomarkers and the changes of serum metabolites were profiled and correlated with the clinicopathological parameters and survival of the patients by statistical analysis. To further verify our results, we linked them to gene expression using data from the Kyoto Encyclopedia of Genes and Genomes (KEGG).

Results

In total, 14 differential metabolites and five disturbed pathways were identified between the preoperative group and postoperative group. Succinic acid change-low, hypoxanthine change-high tumor grade, and tumor stage indicated a trend towards improved recurrence-free survival (RFS), whether in a training set or a test set. In addition, succinic acid change-low, hypoxanthine change-high, and tumor grade provided the highest predictive accuracy of the patients with OSCC. KEGG enrichment analysis showed that the imbalance in the amino acid and purine metabolic pathway may affect the prognosis of OSCC.

Conclusions

The changes of metabolites before and after operation may be related to the prognosis of OSCC patients. UHPLC-Q-Orbitrap HRMS serum metabolomics analysis could be used to further stratify the prognosis of patients with OSCC. These results can better understand the mechanisms related to early recurrence and help develop more effective therapeutic targets.

Epitope Mapping of the Anti-CD44 Monoclonal Antibody (C44Mab-46) Using Alanine-Scanning Mutagenesis and Surface Plasmon Resonance

CD44 is a type I transmembrane protein expressed in various kinds of normal cancer cells, including pancreatic, breast, and oral cancers. CD44 is associated with cancer progression, metastases, and treatment resistance. CD44 consists of 20 exons, and various isoforms exist due to alternative splicing of the central 10 exons. Some splicing variants show cancer-specific expression patterns and are related to prognosis of patients with cancer. Therefore, CD44 targeting therapy has been attracting attention. In a previous study, we established an anti-CD44 monoclonal antibody, C₄₄Mab-46 (IgG₁, kappa), useful for flow cytometry, Western blotting, and immunohistochemistry by immunizing mice with CD44v3-10 ectodomain. This study investigated the binding epitope of C₄₄Mab-46 using enzyme-linked immunosorbent assay (ELISA) and the surface plasmon resonance (SPR) with the synthesized peptide. ELISA results using deletion mutants showed that C₄₄Mab-46 reacted with the amino acids (aa) of 161-180 aa of CD44. Further examination of the C₄₄Mab-46 epitope using ELISA with point mutants in 161-180 aa of CD44 demonstrates that the C₄₄Mab-46 epitope comprised Thr174, Asp177, and Val178. The SPR with point mutants in 161-180 aa of CD44 demonstrated that the C₄₄Mab-46 epitope comprises Thr174, Asp175, Asp176, Asp177, and Val178. Together, the C₄₄Mab-46 epitope was determined to be located in exon 5 of CD44.

Kinectin1 depletion promotes EGFR degradation via the ubiquitin-proteosome system in cutaneous squamous cell carcinoma

Depletion of kinectin1 (KTN1) provides a potential strategy for inhibiting tumorigenesis of cutaneous squamous cell carcinoma (cSCC) via reduction of epidermal growth factor receptor (EGFR) protein levels. Yet, the underlying mechanisms of KTN1 remain obscure. In this study, we demonstrate that KTN1 knockdown induces EGFR degradation in cSCC cells by promoting the ubiquitin-proteasome system, and that this effect is tumor cell-specific. KTN1 knockdown increases the expression of CCDC40, PSMA1, and ADRM1 to mediate tumor suppressor functions in vivo and in vitro. Mechanistically, c-Myc directly binds to the promoter region of CCDC40 to trigger the CCDC40-ADRM1-UCH37 axis and promote EGFR deubiquitination. Furthermore, KTN1 depletion accelerates EGFR degradation by strengthening the competitive interaction between PSMA1 and ADRM1 to inhibit KTN1/ADRM1 interaction at residues Met1-Ala252. These results are supported by studies in mouse xenografts and human patient samples. Collectively, our findings provide novel mechanistic insight into KTN1 regulation of EGFR degradation in cSCC.

A phase II study of poziotinib in patients with recurrent and/or metastatic head and neck squamous cell carcinoma

Background

In phase I studies, poziotinib has shown meaningful efficacy against various types of cancers. This phase 2 study aimed to investigate the efficacy and safety of poziotinib in recurrent and/or metastatic head and neck squamous cell carcinoma (R/M‐HNSCC).

Methods

Overall, 49 patients were enrolled (median age, 62 years; age range, 21–78 years). Patients received a median of two prior treatments including chemotherapy and others and received 12 mg poziotinib orally once daily as part of a 28‐day cycle. The primary endpoint was objective response rate (ORR), and the secondary endpoints were progression‐free survival (PFS) and overall survival (OS). Targeted capture sequencing was performed using available tissues to identify translational biomarkers related to clinical response.

Results

ORR was 22.4%, median PFS was 4.0 months (95% confidence interval [CI], 1.8–6.2 months), and median OS was 7.6 months (95% CI, 4.4–10.8 months). The most common treatment‐related adverse events were acneiform rash (85%) and mucositis (77%). A grade 3 or higher adverse event was acneiform rash (3%). Targeted capture sequencing was performed in 30 tissue samples. TP53 and PIK3CA were the most frequently mutated genes (43%), followed by CCND1 (33%) and EGFR (30%). Mutations in ERBB2, ERBB3, and ERBB4, which are HER family genes, were observed in 17%, 13%, and 10% samples, respectively. There was no difference in the frequency of somatic mutations in the HER family genes between the clinically benefitted and non‐benefitted groups.

Conclusion

Compared to other pan‐HER inhibitors, poziotinib showed clinically meaningful efficacy in heavily treated R/M‐HNSCC.

Clinical trial registration number.

NCT02216916.

The combinatorial inhibition of Wnt signaling and Akt kinase is beneficial for reducing the survival and glycolytic activity of tongue cancer cells

BACKGROUND

Wnt signaling is important in the development of head and neck squamous cell carcinomas (HNSCC); however, Wnt pathway inhibitors lack satisfactory potency when used in monotherapy. The aim of this study was to assess the effects of the combinations of Wnt-signaling inhibitors and the inhibitor of Akt kinase on the survival and glycolytic activity of tongue carcinoma cells.

METHODS

CAL27, SCC-25, and BICR22 tongue cancer cell lines were used. Cells were treated with Wnt signaling (PRI-724 and IWP-O1) and Akt-kinase inhibitors. The effect of the chemicals on cell viability and cytotoxicity were evaluated by MTS and CellTox Green assays, respectively. Cell cycle distribution was analyzed cytometrically after propidium iodide staining. Annexin V binding to externalized phosphatidylserine and analysis of mitochondrial potential allowed the assessment of apoptosis. Glucose uptake and lactate release were evaluated luminometrically. Additionally, the viability of cells in spheroids was analyzed based on ATP content.

RESULTS

The Akt-kinase inhibitor showed significant cytotoxicity toward primary cancer cells. Moreover, its pro-apoptotic effects were enhanced by Wnt-pathway inhibitors. The activity of Akt inhibitor was even higher (by twofold) in 3D spheroids in comparison to cells grown in monolayer. The synergistic reduction in the growth of spheroids was observed between Akt inhibitor and IWP-O1. Reduced glucose consumption may play a part in the combinatorial effects of these chemicals.

CONCLUSION

The results point to the therapeutic potential of the combinatorial use of Wnt inhibitors together with Akt inhibitors in HNSCC.

circFAT1 Promotes Cancer Stemness and Immune Evasion by Promoting STAT3 Activation

Cancer stemness and immune evasion are closely associated, and play critical roles in tumor development and resistance to immunotherapy. However, little is known about the underlying molecular mechanisms that coordinate this association. Here, it is reported that elevated circular RNA FAT1 (circFAT1) in squamous cell carcinoma (SCC) unifies and regulates the positive association between cancer stemness and immune evasion by promoting STAT3 activation. circFAT1 knockdown (KD) reduces tumorsphere formation of SCC cells in vitro and tumor growth in vivo. Bioinformatic analysis reveals that circFAT1 KD impairs the cancer stemness signature and activates tumor cell-intrinsic immunity. Mechanistically, circFAT1 binding to STAT3 in the cytoplasm prevents STAT3 dephosphorylation by SHP1 and promotes STAT3 activation, resulting in inhibition of STAT1-mediated transcription. Moreover, circFAT1 KD significantly enhances PD1 blockade immunotherapy by promoting CD8+ cell infiltration into tumor microenvironment. Taken together, the results demonstrate that circFAT1 is an important regulator of cancer stemness and antitumor immunity.

Dermatologic Toxicities of Targeted Therapy and Immunotherapy in Head and Neck Cancers

Treatment of head and neck cancers requires multidisciplinary collaboration to reduce morbidity and mortality associated with the tumor burden, as well as to preserve function of organs and structures. With the use of various new targeted therapies come new adverse events including dermatologic toxicities, which may consist of xerosis, nail and hair changes, morbilliform or papulopustular rashes, to more severe eruptions such as Stevens–Johnson syndrome. We describe the dermatologic toxicities and corresponding grades of severity and associated pathophysiology resulting from seven therapeutics used to treat head and neck cancers: cetuximab, trastuzumab, pembrolizumab, nivolumab, lentatinib, larotrectinib, and entrectinib. Being familiar with these dermatologic toxicities allows clinicians to provide comprehensive counseling for patients, encourage preventative measures, and to know when it is appropriate to hold therapy or permanently stop treatment.

Programmed Death-1/Programmed Death-Ligand 1-Axis Blockade in Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma Stratified by Human Papillomavirus Status: A Systematic Review and Meta-Analysis

Background

Programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors have provided clinical benefit to head and neck squamous cell carcinoma (HNSCC) patients in recent clinical trials. However, it remains unclear as to whether human papillomavirus (HPV) status is associated with improved clinical outcome of anti-PD-1 or anti-PD-L1 immunotherapy in HNSCC.

Methods

PubMed, EMBASE, Cochrane Library, and Web of Science were systematically searched up to February 28, 2021. Published clinical trials of HNSCC patients treated with only PD-1 or PD-L1 inhibitors were selected. The primary or secondary outcome of these studies included objective response rate (ORR) stratified by HPV status. The pooled odds ratio (OR) and hazard ratio (HR) were estimated using a fixed-effect model.

Results

A total of seven eligible studies comprising 814 patients were included. The ORR of HPV positive HNSCC patients was significantly higher than that of HPV negative HNSCC patients (OR = 1.77; 95%CI = 1.14-2.74; P = 0.01), and this favorable effect occurred in pooled anti-PD-L1 trials (OR = 2.66; 95%CI = 1.16-6.11; P = 0.02). In comparison, the pooled OR was 1.51 in anti-PD-1 trials (95%CI = 0.90-2.54; P = 0.12). Survival analysis indicated that HPV positive HNSCC patients had a lower risk of overall death as compared to HPV negative HNSCC patients (HR = 0.77; 95%CI = 0.60–0.99; P = 0.04).

Conclusions

HPV positive HNSCC patients display improved outcomes with PD-1/PD-L1 axis blockade as compared to HPV negative HNSCC patients. These improved outcomes are likely driven to a greater extent by anti-PD-L1 inhibitors. However, randomized controlled trials with greater numbers of patients are needed for validation of these early findings.

Improved local control in p16 negative oropharyngeal cancers with hypermethylated MGMT

INTRODUCTION

Patients with oropharyngeal cancers that are p16 negative (p16-) have worse outcomes than those who are p16 positive (p16+) and there is an unmet need for prognostic markers in this population. O6-Methylguanine (O6-MG)-DNA-methyltransferase (MGMT) gene methylation has been associated with response to chemoradiotherapy (CRT) in glioblastoma. We sought to find if MGMT promoter methylation was associated with outcomes of locally advanced oropharyngeal and oral cavity squamous cell carcinoma (OOSCC) in patients treated with definitive concurrent CRT.

METHODS

Patients were identified with primary OOSCC, known p16 status, retrievable pre-treatment biopsies, and at least 6 months of follow-up who received definitive concurrent CRT from 2004 to 2015. Biopsies were tested for MGMT hypermethylation (MGMT+) using a Qiagen pyrosequencing kit (Catalog number 970061). Outcomes were subsequently recorded and analyzed.

RESULTS

Fifty-eight patients were included with a median follow up of 78 (range 6-196) months. Fourteen patients (24.1%) had oral cavity cancer and 44 (75.9%) had oropharyngeal cancer. A significant difference was found for local recurrence free survival (LRFS) by combined MGMT and p16 status (p = 0.0004). Frequency of LR in MGMT+/p16+, MGMT+/p16-, MGMT-/p16+, and MGMT-p16- patients was 14.3%, 14.3%, 13.0%, and 69.2%, respectively (p = 0.0019). A significant difference was not found for distant recurrence free survival (p = 0.6165) or overall survival (p = 0.1615). LRFS remained significant on analysis restricted to oropharyngeal cancer patients (p-value = 0.0038).

CONCLUSION

Patients who are p16- and MGMT+ with oropharyngeal and oral cavity squamous cell carcinoma have significantly better LC with definitive CRT than those who are p16- and MGMT-. Prospective studies are needed to verify these findings.

Improved therapeutic efficacy of unmodified anti-tumor antibodies by immune checkpoint blockade and kinase targeted therapy in mouse models of melanoma

The use of specific anti-tumor antibodies has transformed the solid cancer therapeutics landscape with the relative successes of therapies such as anti-HER2 in breast cancer, and anti-EGFR in HNSCC and colorectal cancer. However, these therapies result in toxicity and the emergence of resistant tumors. Here, we showed that removing immune suppression and enhancing stimulatory signals increased the anti-tumor activity of unmodified TA99 antibodies (anti-TYRP1) with a significant reduction of growth of solid tumors and lung metastases in mouse models of melanoma. Immune checkpoint blockade enhanced the efficacy of TA99, which was associated with greater CD8⁺/Foxp3⁺, NK1.1⁺ and dendritic cell infiltrates, suggestive of an increased anti-tumor innate and adaptive immune responses. Further, MEK inhibition in melanoma cell lines increased the expression of melanosomal antigens in vitro, and combining TA99 and MEKi in vivo resulted in enhanced tumor control. Moreover, we found an improved therapeutic effect when YUMM tumor-bearing mice were treated with TA99 combined with MEKi and immune checkpoint blockade (anti-PD1 and anti-CTLA4). Our findings suggest that MEKi induced an increased expression of tumor-associated antigens, which in combination with anti-tumor antibodies, generated a robust adaptive anti-tumor response that was sustained by immune checkpoint inhibition therapy. We postulate that combining anti-tumor antibodies with standard-of-care strategies such as immune checkpoint blockade or targeted therapy, will improve therapeutic outcomes in cancer.

Inhibition of Lysosomal Function Mitigates Protective Mitophagy and Augments Ceramide Nanoliposome-Induced Cell Death in Head and Neck Squamous Cell Carcinoma

Therapies for head and neck squamous cell carcinoma (HNSCC) are, at best, moderately effective, underscoring the need for new therapeutic strategies. Ceramide treatment leads to cell death as a consequence of mitochondrial damage by generating oxidative stress and causing mitochondrial permeability. However, HNSCC cells are able to resist cell death through mitochondria repair via mitophagy. Through the use of the C6-ceramide nanoliposome (CNL) to deliver therapeutic levels of bioactive ceramide, we demonstrate that the effects of CNL are mitigated in drug-resistant HNSCC via an autophagic/mitophagic response. We also demonstrate that inhibitors of lysosomal function, including chloroquine (CQ), significantly augment CNL-induced death in HNSCC cell lines. Mechanistically, the combination of CQ and CNL results in dysfunctional lysosomal processing of damaged mitochondria. We further demonstrate that exogenous addition of methyl pyruvate rescues cells from CNL + CQ-dependent cell death by restoring mitochondrial functionality via the reduction of CNL- and CQ-induced generation of reactive oxygen species and mitochondria permeability. Taken together, inhibition of late-stage protective autophagy/mitophagy augments the efficacy of CNL through preventing mitochondrial repair. Moreover, the combination of inhibitors of lysosomal function with CNL may provide an efficacious treatment modality for HNSCC.

Identification and Clinical Validation of 4-lncRNA Signature for Predicting Survival in Head and Neck Squamous Cell Carcinoma

Background

The prognosis of patients with head and neck squamous cell carcinoma (HNSCC) is still poor due to the lack of effective prognostic biomarkers. lncRNA is an important survival prognostic indicator and has important biological functions in tumorigenesis.

Methods

RNA-seq was re-annotated, and comprehensive clinical information was obtained from the GEO database. Univariate and multivariate Cox regression analyses were used to construct the lncRNA prognosis signature. Gene set enrichment analysis (GSEA) enrichment analysis method is used to explore the possible mechanism of the selected lncRNA influencing HNSCC development. The rms package was used to calculate the C-index to evaluate the overall prediction performance between different signature. PCR is used to detect the expression of selected lncRNA in cancer and adjacent tissues.

Results

In the GSE65858 training cohort, 124 probes significantly related to prognosis were identified, 11 significant lncRNAs were further selected by rbsurv dimensionality reduction analysis. Finally, 4-lncRNA signature was constructed by multivariate Cox analysis. This signature was associated with tumor-associated pathway and is an independent factor of the patient’s prognosis. 4-lncRNA signature has strong robustness and can exert stable prediction performance in different cohorts. A nomogram comprising the prognostic model to predict the overall survival was established. The 4-lncRNA signature was significantly upregulated in HNSCC samples.

Conclusion

The predictive model and nomogram will enable patients to be more accurately managed in trials and clinical practices and could be applied as a new prognostic model for predicting survival of HNSCC patients.

BMI1 Inhibition Eliminates Residual Cancer Stem Cells after PD1 Blockade and Activates Antitumor Immunity to Prevent Metastasis and Relapse

PD1 blockade-based combination therapy has been approved as a first-line treatment for head and neck squamous cell carcinoma (HNSCC). However, the response rate remains relatively low, and patients with HNSCC eventually relapse. Here, we show that the combination treatment of anti-PD1 and cisplatin enriched BMI1⁺ CSCs in HNSCC while inhibiting HNSCC growth. In contrast, the pharmacological and genetic inhibition of BMI1 eliminated BMI1⁺ CSCs and enabled PD1 blockade therapy, resulting in the inhibition of metastatic HNSCC and prevention of HNSCC relapses. BMI1 inhibition strongly induced tumor cell-intrinsic immune responses by recruiting and activating CD8⁺ T cells in addition to eliminating BMI1⁺ CSCs. Mechanistically, BMI1 inhibition induced CD8⁺ T cell-recruiting chemokines by stimulating IRF3-mediated transcription and erasing repressive H2A ubiquitination. Our results suggest that targeting BMI1 may enable immune checkpoint blockade to inhibit metastatic tumor growth and prevent tumor relapse by activating cell-intrinsic immunity, in addition to purging CSCs.

Biological Determinants of Chemo-Radiotherapy Response in HPV-Negative Head and Neck Cancer: A Multicentric External Validation

Purpose: Tumor markers that are related to hypoxia, proliferation, DNA damage repair and stem cell-ness, have a prognostic value in advanced stage HNSCC patients when assessed individually. Here we aimed to evaluate and validate this in a multifactorial context and assess interrelation and the combined role of these biological factors in determining chemo-radiotherapy response in HPV-negative advanced HNSCC. Methods: RNA sequencing data of pre-treatment biopsy material from 197 HPV-negative advanced stage HNSCC patients treated with definitive chemoradiotherapy was analyzed. Biological parameter scores were assigned to patient samples using previously generated and described gene expression signatures. Locoregional control rates were used to assess the role of these biological parameters in radiation response and compared to distant metastasis data. Biological factors were ranked according to their clinical impact using bootstrapping methods and multivariate Cox regression analyses that included clinical variables. Multivariate Cox regression analyses comprising all biological variables were used to define their relative role among all factors when combined. Results: Only few biomarker scores correlate with each other, underscoring their independence. The different biological factors do not correlate or cluster, except for the two stem cell markers CD44 and SLC3A2 (r = 0.4, p < 0.001) and acute hypoxia prediction scores which correlated with T-cell infiltration score, CD8⁺ T cell abundance and proliferation scores (r = 0.52, 0.56, and 0.6, respectively with p < 0.001). Locoregional control association analyses revealed that chronic (Hazard Ratio (HR) = 3.9) and acute hypoxia (HR = 1.9), followed by stem cell-ness (CD44/SLC3A2; HR = 2.2/2.3), were the strongest and most robust determinants of radiation response. Furthermore, multivariable analysis, considering other biological and clinical factors, reveal a significant role for EGFR expression (HR = 2.9, p < 0.05) and T-cell infiltration (CD8⁺T-cells: HR = 2.2, p < 0.05; CD8⁺T-cells/Treg: HR = 2.6, p < 0.01) signatures in locoregional control of chemoradiotherapy-treated HNSCC. Conclusion: Tumor acute and chronic hypoxia, stem cell-ness, and CD8⁺ T-cell parameters are relevant and largely independent biological factors that together contribute to locoregional control. The combined analyses illustrate the additive value of multifactorial analyses and support a role for EGFR expression analysis and immune cell markers in addition to previously validated biomarkers. This external validation underscores the relevance of biological factors in determining chemoradiotherapy outcome in HNSCC.

Genome-Wide Identification of a Novel Eight-lncRNA Signature to Improve Prognostic Prediction in Head and Neck Squamous Cell Carcinoma

Objectives: LncRNAs are essential survival prognostic indicators with important biological functions in tumorigenesis and tumor progression. This study aimed to establish a long non-coding RNA (lncRNA) signature that can effectively predict the prognosis of patients with head and neck squamous cell carcinoma (HNSCC) and explore the potential functions of these lncRNAs.

Materials and Methods: We re-annotated RNA sequencing and obtained exhaustive RNA-seq data of 269 patients with comprehensive clinical information from the GEO database. Then an 8-lncRNA signature capable of predicting the survival prognosis of HNSCC patients and a nomogram containing this signature were established. Weighted Co-expression Network Construction (WGCNA), Gene Set Enrichment Analysis (GSEA), and Gene Ontology (GO) enrichment were then applied to predict the possible biological functions of the signature and each individual lncRNA.

Results: Eight lncRNAs associated with survival in HNSCC patients, including AC010624.1, AC130456.4, LINC00608, LINC01300, MIR99AHG, AC008655.1, AC055758.2, and AC118553.1, were obtained by univariate regression, cox LASSO regression, and multivariate regression. Functionally, patients with high signature scores had abnormal immune functions via GSEA. AC010624.1 and AC130456.4 may participate in epidermal cell differentiation and skin development, and MIR99AHG in the formation of cellular structures. Other lncRNAs in the signature may also participate in important biological processes.

Conclusions: Therefore, we established an 8-lncRNA signature that can effectively guide clinical prediction of the prognosis of patients with HNSCC, and individuals with high signature scores may have abnormal immune function.