A review on the advances and challenges of immunotherapy for head and neck cancer

Microbiome and cancer: from mechanistic implications in disease progression and treatment to development of novel antitumoral strategies

Cancer is a very aggressive disease and one of mankind's most important health problems, causing numerous deaths each year. Its etiology is complex, including genetic, gender-related, infectious diseases, dysbiosis, immunological imbalances, lifestyle, including dietary factors, pollution etc. Cancer patients also become immunosuppressed, frequently as side effects of chemotherapy and radiotherapy, and prone to infections, which further promote the proliferation of tumor cells. In recent decades, the role and importance of the microbiota in cancer has become a hot spot in human biology research, bringing together oncology and human microbiology. In addition to their roles in the etiology of different cancers, microorganisms interact with tumor cells and may be involved in modulating their response to treatment and in the toxicity of anti-tumor therapies. In this review, we present an update on the roles of microbiota in cancer with a focus on interference with anticancer treatments and anticancer potential.

Harnessing adenovirus in cancer immunotherapy: evoking cellular immunity and targeting delivery in cell-specific manner

Recombinant adenovirus (rAd) regimens, including replication-competent oncolytic adenovirus (OAV) and replication-deficient adenovirus, have been identified as potential cancer therapeutics. OAV presents advantages such as selective replication, oncolytic efficacy, and tumor microenvironment (TME) remodeling. In this perspective, the principles and advancements in developing OAV toolkits are reviewed. The burgeoning rAd may dictate efficacy of conventional cancer therapies as well as cancer immunotherapies, including cancer vaccines, synergy with adoptive cell therapy (ACT), and TME reshaping. Concurrently, we explored the potential of rAd hitchhiking to adoptive immune cells or stem cells, highlighting how this approach facilitates synergistic interactions between rAd and cellular therapeutics at tumor sites. Results from preclinical and clinical trials in which immune and stem cells were infected with rAd have been used to address significant oncological challenges, such as postsurgical residual tumor tissue and metastatic tissue. Briefly, rAd can eradicate tumors through various mechanisms, resulting from tumor immunogenicity, reprogramming of the TME, enhancement of cellular immunity, and effective tumor targeting. In this context, we argue that rAd holds immense potential for enhancing cellular immunity and synergistically improving antitumor effects in combination with novel cancer immunotherapies.

The dynamic role of immune checkpoint molecules in diagnosis, prognosis, and treatment of head and neck cancers

Head and neck cancer (HNC) is the sixth most common cancer type, accounting for approximately 277,597 deaths worldwide. Recently, the Food and Drug Administration (FDA) has approved immune checkpoint blockade (ICB) agents targeting programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) as a treatment regimen for head and neck squamous cell carcinomas (HNSCC). Studies have reported the role of immune checkpoint inhibitors as targeted therapeutic regimens that unleash the immune response against HNSCC tumors. However, the overall response rates to immunotherapy vary between 14-32% in recurrent or metastatic HNSCC, with clinical response and treatment success being unpredictable. Keeping this perspective in mind, it is imperative to understand the role of T cells, natural killer cells, and antigen-presenting cells in modulating the immune response to immunotherapy. In lieu of this, these immune molecules could serve as prognostic and predictive biomarkers to facilitate longitudinal monitoring and understanding of treatment dynamics. These immune biomarkers could pave the path for personalized monitoring and management of HNSCC. In this review, we aim to provide updated immunological insight on the mechanism of action, expression, and the clinical application of immune cells' stimulatory and inhibitory molecules as prognostic and predictive biomarkers in HNC. The review is focused mainly on CD27 and CD137 (members of the TNF-receptor superfamily), natural killer group 2 member D (NKG2D), tumor necrosis factor receptor superfamily member 4 (TNFRSF4 or OX40), S100 proteins, PD-1, PD-L1, PD-L2, T cell immunoglobulin and mucin domain 3 (TIM-3), cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), lymphocyte-activation gene 3 (LAG-3), indoleamine-pyrrole 2,3-dioxygenase (IDO), B and T lymphocyte attenuator (BTLA). It also highlights the importance of T, natural killer, and antigen-presenting cells as robust biomarker tools for understanding immune checkpoint inhibitor-based treatment dynamics. Though a comprehensive review, all aspects of the immune molecules could not be covered as they were beyond the scope of the review; Further review articles can cover other aspects to bridge the knowledge gap.

TS-2021, a third-generation oncolytic adenovirus that carried Ki67 promoter, TGF-β2 5'UTR, and IL-15 against experimental glioblastoma

Oncolytic virotherapy is a promising therapeutic approach for glioblastoma (GBM) treatment, although the outcomes are partially satisfactory. Hence, more effective strategies are needed urgently to modify therapeutic viruses to enhance their efficiency and safety in killing tumor cells and improve the survival rate of GBM patients. This study generated a new-generation oncolytic adenovirus Ad5 KT-E1A-IL-15 (TS-2021) and evaluated its antitumor efficacy. Ex vivo analyses revealed Ki67 and TGF-β2 co-localized in GBM cells. In addition, TS-2021 selectively replicated in GBM cells, which was dependent on the expression of Ki67 and TGF-β2. The immunocompetent mice model of GBM demonstrated the in vivo efficacy of TS-2021 by inhibiting tumor growth and improving survival proficiently. Notably, TS-2021 effectively reduced MMP3 expression by inactivating the MKK4/JNK pathway, thereby reducing tumor invasiveness. Altogether, the findings of the present study highlight that TS-2021 can effectively target GBM cells expressing high levels of Ki67 and TGF-β2, exerting potent antitumor effects. Additionally, it can improve efficacy and suppress tumor invasiveness by inhibiting the MKK4/JNK/MMP3 pathway. Thus our study demonstrates the efficiency of the novel TS-2021 in the mouse model and provides a potential therapeutic option for patients with GBM.

Deciphering the immune landscape of head and neck squamous cell carcinoma: A single-cell transcriptomic analysis of regulatory T cell responses to PD-1 blockade therapy

Immunotherapy is changing the Head and Neck Squamous Cell Carcinoma (HNSCC) landscape and improving outcomes for patients with recurrent or metastatic HNSCC. A deeper understanding of the tumor microenvironment (TME) is required in light of the limitations of patients' responses to immunotherapy. Here, we aimed to examine how Nivolumab affects infiltrating Tregs in the HNSCC TME. We used single-cell RNA sequencing data from eight tissues isolated from four HNSCC donors before and after Nivolumab treatment. Interestingly, the study found that Treg counts and suppressive activity increased following Nivolumab therapy. We also discovered that changes in the CD44-SSP1 axis, NKG2C/D-HLA-E axis, and KRAS signaling may have contributed to the increase in Treg numbers. Furthermore, our study suggests that decreasing the activity of the KRAS and Notch signaling pathways, and increasing FOXP3, CTLA-4, LAG-3, and GZMA expression, may be mechanisms that enhance the killing and suppressive capacity of Tregs. Additionally, the result of pseudo-temporal analysis of the HNSCC TME indicated that after Nivolumab therapy, the expression of certain inhibitory immune checkpoints including TIGIT, ENTPD1, and CD276 and LY9, were decreased in Tregs, while LAG-3 showed an increased expression level. The study also found that Tregs had a dense communication network with cluster two, and that certain ligand-receptor pairs, including SPP1/CD44, HLA-E/KLRC2, HLA-E/KLRK1, ANXA1/FPR3, and CXCL9/FCGR2A, had notable changes after the therapy. These changes in gene expression and cell interactions may have implications for the role of Tregs in the TME and in response to Nivolumab therapy.

Enhancing prognostic accuracy in head and neck squamous cell carcinoma chemotherapy via a lipid metabolism-related clustered polygenic model

OBJECTIVE

Systemic chemotherapy is the first-line therapeutic option for head and neck squamous cell carcinoma (HNSCC), but it often fails. This study aimed to develop an effective prognostic model for evaluating the therapeutic effects of systemic chemotherapy.

METHODS

This study utilized CRISPR/cas9 whole gene loss-of-function library screening and data from The Cancer Genome Atlas (TCGA) HNSCC patients who have undergone systemic therapy to examine differentially expressed genes (DEGs). A lipid metabolism-related clustered polygenic model called the lipid metabolism related score (LMRS) model was established based on the identified functionally enriched DEGs. The prediction efficiency of the model for survival outcome, chemotherapy, and immunotherapy response was evaluated using HNSCC datasets, the GEO database and clinical samples.

RESULTS

Screening results from the study demonstrated that genes those were differentially expressed were highly associated with lipid metabolism-related pathways, and patients receiving systemic therapy had significantly different prognoses based on lipid metabolism gene characteristics. The LMRS model, consisting of eight lipid metabolism-related genes, outperformed each lipid metabolism gene-based model in predicting outcome and drug response. Further validation of the LMRS model in HNSCCs confirmed its prognostic value.

CONCLUSION

In conclusion, the LMRS polygenic prognostic model is helpful to assess outcome and drug response for HNSCCs and could assist in the timely selection of the appropriate treatment for HNSCC patients. This study provides important insights for improving systemic chemotherapy and enhancing patient outcomes.

Immunotherapy in Head and Neck Cancer: Where Do We Stand?

PURPOSEOF REVIEW

Head and neck cancer (HNC) comprises a group of malignancies, amongst which squamous cell carcinoma accounts for more than 90% of the cases. HNC has been related to tobacco use, alcohol consumption, human papillomavirus, Epstein-Barr virus, air pollution, and previous local radiotherapy. HNC has been associated with substantial morbidity and mortality. This review aims to summarize the recent findings regarding immunotherapy in HNC.

RECENT FINDINGS

The recent introduction of immunotherapy, with the use of programmed death 1 (PD-1) inhibitors pembrolizumab and nivolumab, which have been FDA approved for the treatment of metastatic or recurrent head and neck squamous cell carcinoma, has changed the field in metastatic or recurrent disease. There are many ongoing trials regarding the use of novel immunotherapeutic agents, such as durvalumab, atezolizumab, avelumab, tremelimumab, and monalizumab. In this review, we focus on the therapeutic potential of novel immunotherapy treatment modalities, such as combinations of newer immune-checkpoint inhibitors; the use of tumor vaccines such as human papillomavirus-targeted vaccines; the potential use of oncolytic viruses; as well as the latest advances regarding adoptive cellular immunotherapy. As novel treatment options are still emerging, a more personalized approach to metastatic or recurrent HNC therapy should be followed. Moreover, the role of the microbiome in immunotherapy, the limitations of immunotherapy, and the various diagnostic, prognostic, and predictive biomarkers based on genetics and the tumor microenvironment are synopsized.

Human Immunodeficiency Virus Is Associated With Poor Overall Survival Among Patients With Head and Neck Cancer

BACKGROUND

Head and neck squamous cell cancer (HNSCC) occurs at higher rates among persons with HIV (PWH). This study compares the impact of sociodemographic and clinicopathologic characteristics on outcomes among PWH-HNSCC compared with HNSCC patients without HIV.

METHODS

Patient data from HNSCC individuals were collected at a single academic hospital center between 2002 and 2018. Forty-eight patients with HIV (HIV-HNSCC) and 2894 HNSCC patients without HIV were included. Multivariate analysis determined predictors of survival using Cox proportional hazards regression model. HIV-positive and -negative tumors were analyzed by quantitative immunofluorescence for expression of CD4, CD8, CD20 and PD-L1.

RESULTS

HIV-HNSCC patients had a lower median overall survival than HNSCC patients without HIV (34 [18-84] vs 94 [86-103] months; P < .001). In multivariate analysis that included age, sex, race/ethnicity, stage, site, tobacco use, time to treatment initiation, and insurance status, HIV was an independent predictor of poorer survival, with a hazard ratio of 1.98 (95% CI: 1.32-2.97; P < .001). PWH with human papillomavirus (HPV)-positive oropharyngeal tumors also had worse prognosis than HPV-positive oropharyngeal tumors in the population without HIV (P < .001). The tumor microenvironment among HIV-HNSCC patients revealed lower intratumoral CD8 infiltration among HIV+ HPV+ tumors compared with HIV- HPV+ tumors (P = .04).

CONCLUSIONS

HIV-HNSCC patients had worse prognosis than the non-HIV population, with HIV being an independent predictor of poor clinical outcomes when accounting for important sociodemographic and clinicopathologic factors. Our findings highlight differences in tumor biology that require further detailed characterization in large cohorts and increased inclusion of PWH in immunotherapy trials.

Correlations between the severity of radiation-induced oral mucositis and salivary epidermal growth factor as well as inflammatory cytokines in patients with head and neck cancer

BACKGROUND

This study aimed to investigate correlations of the severity of radiation-induced oral mucositis (RIOM) with epidermal growth factor (EGF) and inflammatory cytokines in patients with head and neck cancer (HNC).

METHODS

Levels of inflammatory cytokines and EGF in saliva of HNC patients were measured. Correlations of inflammatory cytokines and EGF levels with RIOM severity and pain degree, and their diagnostic values on RIOM severity were determined.

RESULTS

Elevated IFN-γ, TNF-α, IL-2, and IL-6 levels, and reduced IL-4, IL-10, and EGF levels were found in patients with severe RIOM. IFN-γ, TNF-α, IL-2, and IL-6 were positively correlated with RIOM severity, while IL-10, IL-4, and EGF were negatively correlated with it. All factors were effective in predicting the severity of RIOM.

CONCLUSION

IFN-γ, TNF-α, IL-2, and IL-6 in saliva of patients with HNC are positively correlated with the severity of RIOM, and IL-4, IL-10, and EGF were negatively correlated with it.

Potential Alternative Therapeutic Modalities for Management Head and Neck Squamous Cell Carcinoma: A Review

Head and neck squamous cell carcinoma (HNSCC) includes malignancies of the lip and oral cavity, oropharynx, nasopharynx, larynx, and hypopharynx. It is among the most common malignancy worldwide, affecting nearly 1 million people annually. The traditional treatment options for HNSCC include surgery, radiotherapy, and conventional chemotherapy. However, these treatment options have their specific sequelae, which produce high rates of recurrence and severe treatment-related disabilities. Recent technological advancements have led to tremendous progress in understanding tumor biology, and hence the emergence of several alternative therapeutic modalities for managing cancers (including HNSCC). These treatment options are stem cell targeted therapy, gene therapy, and immunotherapy. Therefore, this review article aims to provide an overview of these alternative treatments of HNSCC.

Decoding the influence of the immune system and immunotherapy targets on carcinomas: A hidden prism in oral cancer therapy

In recent decades, understanding tumorigenesis and the complex interaction between the host and the immune system has been the pillar for significant advances in anticancer therapy. Conventional anticancer therapy (e.g., cut, burn, and cytotoxic drugs) involves multiple targeting of tumor cells. However, the tumor tissue microenvironment can present a dysregulated, stimulating, or subverted immune response which, in turn, reveals pro-tumor activities favoring tumor expansion and progression. Recently, new potential targets have been identified based on immunomodulatory therapies, which are crafted to re-establish the host anti-tumoral immune response. Clinicians should fully understand the intricate interactions between carcinogens, the tumor milieu, the immune system, and traditional anticancer therapies in order to progress and to overcome the refractory/recurrent challenges and morbidity of the disease. Thus, in this article, we highlight the complex milieu of the oral cancer immune response, pointing out potential therapeutic immunotargets for oral squamous cell carcinomas. The impact of traditional anticancer therapy on the immune system is also outlined.

Current status and novel insights into the role of metastasectomy in the era of immunotherapy

INTRODUCTION

New perspectives on the role of metastasectomy have emerged along with the advances in cancer immunotherapy. Despite accumulating evidence that encourages the use of immunotherapy in the metastatic setting, current data regarding its combination with surgical resection of secondary lesions, as well as the best timeline and sequence of such a therapeutic approach is limited.

AREAS COVERED

We review the currently available literature on the role of metastasectomy in the era of novel immunotherapeutic agents and provide comprehensive evidence from ongoing trials about the available treatment strategies. In metastatic melanoma, immune checkpoint inhibitors (ICIs) play a key role both in the neoadjuvant and adjuvant setting to achieve long-term disease control. In metastatic renal cell carcinoma, investigation is ongoing regarding the emerging role of ICIs before metastasectomy. ICIs have improved outcomes in patients with metastatic colorectal and head and neck cancer.

EXPERT OPINION

In the neoadjuvant setting, the high response rates and the durability of responses to immunotherapy may enable the resectability of metastatic lesions. In the adjuvant setting post metastasectomy, immunotherapy constitutes a safe and efficacious approach to support immune tumor surveillance and delay or even prevent disease relapse. Patient participation in relevant clinical trials should be encouraged.

Identification of the Immune Cell Infiltration Landscape in Head and Neck Squamous Cell Carcinoma (HNSC) for the Exploration of Immunotherapy and Prognosis

It is generally believed that the majority of head and neck cancers develop in the mucosal epithelial cells of the mouth, pharynx, and larynx, which is collectively known as head and neck squamous cell carcinoma (HNSC). As a complex pathological process, HNSC develops through a variety of cellular and molecular events. Cancerous cells and immune cells infiltrating tumors are the main components of the tumor microenvironment. However, infiltration of HNSCs by the immune system has not been determined to date. In this work, we proposed computational algorithms to identify different immune subtypes. An analysis of the Cancer Genome Atlas (TCGA) database revealed gene expression profiles and corresponding clinical information. In HNSC patients, two immune-related genes (ZAP70 and IGKV2D-40) may be targets for immunotherapy, and these genes appear to be closely related to the prognosis. Several immunological subtypes were associated with immune function, immune checkpoints, and prognostic factors in HNSCs. Furthermore, ZAP70 is closely related to the overall survival (OS), progress-free interval (PFI), and disease-specific survival (DSS) of HNSC patients. The potential pathways that are associated with ZAP70 were found to have included adaptive immune response, response to oxidative stress, DNA replication, and lipid binding. This study provides a theoretical foundation for developing immunotherapy drugs for HNSC patients. By evaluating larger cohorts, we can gain a deeper understanding of immunotherapy and provide direction for current research on immunotherapy strategies in HNSCs.

Smoking Cessation after Cancer Diagnosis and Enhanced Therapy Response: Mechanisms and Significance

The adverse effects of smoking on human health have been recognized for several decades, especially in the context of cancer. The ability of tobacco smoke components, including tobacco-specific carcinogens and additive compounds such as nicotine, to initiate or promote tumor growth have been described in hundreds of studies. These investigations have revealed the tumor-promoting activities of nicotine and other tobacco smoke components and have also recognized the ability of these agents to suppress the efficacy of cancer therapy; it is now clear that smoking can reduce the efficacy of most of the widely used therapeutic modalities, including immunotherapy, radiation therapy, and chemotherapy. Several studies examined if continued smoking after cancer diagnosis affected therapy response; it was found that while never smokers or non-smokers had the best response to therapy, those who quit smoking at the time of diagnosis had higher overall survival and reduced side-effects than those who continued to smoke. These studies also revealed the multiple mechanisms via which smoking enhances the growth and survival of tumors while suppressing therapy-induced cell death. In conclusion, smoking cessation during the course of cancer therapy markedly increases the chances of survival and the quality of life.

Oncolytic Adenovirus, a New Treatment Strategy for Prostate Cancer

Prostate cancer is the most common cancer and one of the leading causes of cancer mortality in males. Androgen-deprivation therapy (ADT) is an effective strategy to inhibit tumour growth at early stages. However, 10~50% of cases are estimated to progress to metastatic castration-resistant prostate cancer (mCRPC) which currently lacks effective treatments. Clinically, salvage treatment measures, such as endocrine therapy and chemotherapy, are mostly used for advanced prostate cancer, but their clinical outcomes are not ideal. When the existing clinical therapeutic methods can no longer inhibit the development of advanced prostate cancer, human adenovirus (HAdV)-based gene therapy and viral therapy present promising effects. Pre-clinical studies have shown its powerful oncolytic effect, and clinical studies are ongoing to further verify its effect and safety in prostate cancer treatment. Targeting the prostate by HAdV alone or in combination with radiotherapy and chemotherapy sheds light on patients with castration-resistant and advanced prostate cancer. This review summarizes the advantages of oncolytic virus-mediated cancer therapy, strategies of HAdV modification, and existing preclinical and clinical investigations of HAdV-mediated gene therapy to further evaluate the potential of oncolytic adenovirus in prostate cancer treatment.

Current Insights and Progress in the Clinical Management of Head and Neck Cancer

Head and neck cancer (HNC), also known as the cancer that can affect the structures between the dura mater and the pleura, is the 6th most common type of cancer. This heterogeneous group of malignancies is usually treated with a combination of surgery and radio- and chemotherapy, depending on if the disease is localized or at an advanced stage. However, most HNC patients are diagnosed at an advanced stage, resulting in the death of half of these patients. Thus, the prognosis of advanced or recurrent/metastatic HNC, especially HNC squamous cell carcinoma (HNSCC), is notably poorer than the prognosis of patients diagnosed with localized HNC. This review explores the epidemiology and etiologic factors of HNC, the histopathology of this heterogeneous cancer, and the diagnosis methods and treatment approaches currently available. Moreover, special interest is given to the novel therapies used to treat HNC subtypes with worse prognosis, exploring immunotherapies and targeted/multi-targeted drugs undergoing clinical trials, as well as light-based therapies (i.e., photodynamic and photothermal therapies).

Transcriptomic discovery of a theranostic signature (SERPINE1/MMP3/COL1A1/SPP1) for head and neck squamous cell carcinomas and identification of antrocinol as a candidate drug

Head and neck squamous cell carcinomas (HNSCC) are prevalent malignancies with a disappointing prognosis, necessitating the search for theranostic biomarkers for better management. Based on a meta-analysis of transcriptomic data containing ten clinical datasets of HNSCC and matched nonmalignant samples, we identified SERPINE1/MMP3/COL1A1/SPP1 as essential hub genes as the potential theranostic biomarkers. Our analysis suggests these hub genes are associated with the extracellular matrix, peptidoglycans, cell migration, wound-healing processes, complement and coagulation cascades, and the AGE-RAGE signaling pathway within the tumor microenvironment. Also, these hub genes were associated with tumor-immune infiltrating cells and immunosuppressive phenotypes of HNSCC. Further investigation of The Cancer Genome Atlas (TCGA) cohorts revealed that these hub genes were associated with staging, metastasis, and poor survival in HNSCC patients. Molecular docking simulations were performed to evaluate binding activities between the hub genes and antrocinol, a novel small-molecule derivative of an anticancer phytochemical antrocin previously discovered by our group. Antrocinol showed high affinities to MMP3 and COL1A1. Notably, antrocinol presented satisfactory drug-like and ADMET properties for therapeutic applications. These results hinted at the potential of antrocinol as an anti-HNSCC candidate via targeting MMP3 and COL1A1. In conclusion, we identified hub genes: SERPINE1/MMP3/COL1A1/SPP1 as potential diagnostic biomarkers and antrocinol as a potential new drug for HNSCC.

Tumor microenvironment and immunotherapy of oral cancer

Oral cancer is one of the most common malignant tumors of the head and neck, not only affects the appearance, but also affects eating and even endangers life. The clinical treatments of oral cancer mainly include surgery, radiotherapy, and chemotherapy. However, unsatisfactory therapeutic effect and toxic side effects are still the main problems in clinical treatment. Tumor microenvironment (TME) is not only closely related to the occurrence, growth, and metastasis of tumor but also works in the diagnosis, prevention, and treatment of tumor and prognosis. Future studies should continue to investigate the relationship of TME and oral cancer therapy. This purpose of this review was to analyze the characteristics of oral cancer microenvironment, summarize the traditional oral cancer therapy and immunotherapy strategies, and finally prospect the development prospects of oral cancer immunotherapy. Immunotherapy targeting tumor microenvironment is expected to provide a new strategy for clinical treatment of oral cancer.

Engineered extracellular vesicles: A novel platform for cancer combination therapy and cancer immunotherapy

Extracellular vesicles (EVs), phospholipid membrane-bound vesicles, produced by most cells, contribute to cell-cell communication. They transfer several proteins, lipids, and nucleic acids between cells both locally and systemically. Owing to the biocompatibility and immune activity of EVs, therapeutic approaches using these vesicles as drug delivery systems are being developed. Different methods are used to design more effective engineered EVs, which can serve as smart tools in cancer therapy and immunotherapy. Recent progress in the field of targeted-cancer therapy has led to the gradual use of engineered EVs in combinational therapy to combat heterogeneous tumor cells and multifaceted tumor microenvironments. The high plasticity, loading ability, and genetic manipulation capability of engineered EVs have made them the ideal platforms to realize numerous combinations of cancer therapy approaches. From the combination therapy view, engineered EVs can co-deliver chemotherapy with various therapeutic agents to target tumor cells effectively, further taking part in immunotherapy-related cancer combination therapy. However, a greater number of studies were done in pre-clinical platforms and the clinical translation of these studies needs further scrutiny because some challenges are associated with the application of engineered EVs. Given the many therapeutic potentials of engineered EVs, this review discusses their function in various cancer combination therapy and immunotherapy-related cancer combination therapy. In addition, this review describes the opportunities and challenges associated with the clinical application of engineered EVs.

Immunotherapy in Head and Neck Cancer When, How, and Why?

Head and neck cancer (HNC) is one of the most common cancers worldwide. Alcohol and tobacco consumption, besides viral infections, are the main risk factors associated with this cancer. When diagnosed in advanced stages, HNC patients present a higher probability of recurrence or metastasising. The complexity of therapeutic options and post-treatment surveillance is associated with poor prognosis and reduced overall survival (OS). This review aims to explore immunotherapy (immune checkpoint inhibitors (ICI), therapeutic vaccines, and oncolytic viruses) in HNC patients’ treatment, and to explore when, how, and why patients can benefit from it. The monotherapy with ICI or in combination with chemotherapy (QT) shows the most promising results. Compared to standard therapy, ICI are able to increase OS and patients’ quality of life. QT in combination with ICI demonstrates significant response rates and considerable long-term clinical benefits. However, the toxicity associated with this approach is still a hurdle to overcome. In parallel, the therapeutic vaccines directed to the Human Papilloma Virus are also efficient in increasing the antitumour response, inducing cellular and humoral immunity. Although these results demonstrate clinical benefits compared to standard therapy, it is also important to unravel the resistance mechanisms in order to predict the clinical benefit of immunotherapy.

Immunotherapy for the Treatment of Squamous Cell Carcinoma: Potential Benefits and Challenges

Melanoma and nonmelanoma skin cancers (NMSCs) are recognized as among the most common neoplasms, mostly in white people, with an increasing incidence rate. Among the NMSCs, squamous cell carcinoma (SCC) is the most prevalent malignancy known to affect people with a fair complexion who are exposed to extreme ultraviolet radiation (UVR), have a hereditary predisposition, or are immunosuppressed. There are several extrinsic and intrinsic determinants that contribute to the pathophysiology of the SCC. The therapeutic modalities depend on the SCC stages, from actinic keratosis to late-stage multiple metastases. Standard treatments include surgical excision, radiotherapy, and chemotherapy. As SCC represents a favorable tumor microenvironment with high tumor mutational burden, infiltration of immune cells, and expression of immune checkpoints, the SCC tumors are highly responsive to immunotherapies. Until now, there are three checkpoint inhibitors, cemiplimab, pembrolizumab, and nivolumab, that are approved for the treatment of advanced, recurrent, or metastatic SCC patients in the United States. Immunotherapy possesses significant therapeutic benefits for patients with metastatic or locally advanced tumors not eligible for surgery or radiotherapy to avoid the potential toxicity caused by the chemotherapies. Despite the high tolerability and efficiency, the existence of some challenges has been revealed such as, resistance to immunotherapy, less availability of the biomarkers, and difficulty in appropriate patient selection. This review aims to accumulate evidence regarding the genetic alterations related to SCC, the factors that contribute to the potential benefits of immunotherapy, and the challenges to follow this treatment regime.

Complete remission of an early-stage laryngeal cancer under combined pembrolizumab and chemotherapy treatment of a synchronous lung adenocarcinoma

BACKGROUND

Anti-PD1-Checkpoint inhibition (CI) is an established treatment of recurrent and/or metastatic head and neck cancer. A potential benefit from CI in early-stage disease that is usually treated by radiation or surgery has not been investigated so far and is currently not addressed in clinical trials.

CASE PRESENTATION

A 58-year-old man was diagnosed with a cT2 supraglottic laryngeal cancer and a synchronous metastasized adenocarcinoma of the lung. As the patient refused any treatment of his laryngeal cancer, he received combined immune-chemotherapy according to the KEYNOTE-189 protocol. After 4 cycles of pembrolizumab/carboplatin/pemetrexed, the patient showed a complete remission of his laryngeal cancer with a clear shrinkage of the mediastinal and hilar lung cancer metastases. After 21 cycles of maintenance therapy, the lung adenocarcinoma shows a stable disease status with no signs of any residual or recurrent laryngeal cancer.

CONCLUSIONS

Anti-PD1-CI may be a treatment option also for early-stage HNSCC with excellent functional outcome when established therapies are not available.

Polymeric Systems for Cancer Immunotherapy: A Review

Immunotherapy holds enormous promise to create a new outlook of cancer therapy by eliminating tumors via activation of the immune system. In immunotherapy, polymeric systems play a significant role in improving antitumor efficacy and safety profile. Polymeric systems possess many favorable properties, including magnificent biocompatibility and biodegradability, structural and component diversity, easy and controllable fabrication, and high loading capacity for immune-related substances. These properties allow polymeric systems to perform multiple functions in immunotherapy, such as immune stimulants, modifying and activating T cells, delivery system for immune cargos, or as an artificial antigen-presenting cell. Among diverse immunotherapies, immune checkpoint inhibitors, chimeric antigen receptor (CAR) T cell, and oncolytic virus recently have been dramatically investigated for their remarkable success in clinical trials. In this report, we review the monotherapy status of immune checkpoint inhibitors, CAR-T cell, and oncolytic virus, and their current combination strategies with diverse polymeric systems.

Preclinical efficacy and involvement of mTOR signaling in the mechanism of Orf virus against nasopharyngeal carcinoma cells

AIMS

Orf virus (ORFV) is a parapoxvirus causing contagious ecthyma in sheep and goats. With inhibitory role of ORFV reported by previous studies, ORFV can be a candidate of oncolytic virus. However, few studies reported the application and mechanism of ORFV in nasopharyngeal carcinoma (NPC). We aimed to elucidate the anti-tumor mechanism of ORFV against NPC cells.

MATERIALS AND METHODS

The anti-tumor effect of ORFV in NPC cells was confirmed by cell counting kit 8 (CCK-8) assay, flow cytometry and Western blot. In vitro and in vivo experiments were adopted to evaluate the inhibitory effect of ORFV in NPC cells. Western blot was used to determine the down-regulation of rapamycin (mTOR) signaling and autophagy enhancement induced by ORFV. To explore the mechanism of ORFV on NPC cells, mTOR signaling agonist and autophagy inhibitors were used to rescue the effects of ORFV.

KEY FINDINGS

The results indicated that ORFV replicates in NPC cells, thus induces the apoptosis of NPC cells. Moreover, ORFV can effectively inhibit NPC cell growth in vivo. ORFV infection in NPC cells leads to the mTOR signaling inhibition and up-regulated autophagy, which might be the specific mechanism of ORFV in killing tumor cells. As to safety confirmation, normal nasopharyngeal epithelial cells NP69 are insensitive to ORFV. More importantly, ORFV would not cause organ damage in vivo.

SIGNIFICANCES

Our data clarified that ORFV induces autophagy of NPC cells via inhibiting mTOR signaling, thus further inducing apoptosis. The anti-tumor role of ORFV might provide a preclinical strategy for NPC treatment.

Current Trends in Precision Medicine and Next-Generation Sequencing in Head and Neck Cancer

OPINION STATEMENT

As the field of oncology enters the era of precision medicine and targeted therapies, we have come to realize that there may be no single "magic bullet" for patients with head and neck cancer. While immune check point inhibitors and some targeted therapeutics have shown great promise in improving oncologic outcomes, the current standard of care in most patients with head and neck squamous cell carcinoma (HNSCC) remains a combination of surgery, radiation, and/or cytotoxic chemotherapy. Nevertheless, advances in precision medicine, next-generation sequencing (NGS), and targeted therapies have a potential future in the treatment of HNSCC. These roles include increased patient treatment stratification based on predictive biomarkers or targetable mutations and novel combinatorial regimens with existing HNSCC treatments. There remain challenges to precision medicine and NGS in HNSCC, including intertumor and intratumor heterogeneity, challenging targets, and need for further trials validating the utility of NGS and precision medicine. Additionally, there is a need for evidence-based practice guidelines to assist clinicians on how to appropriately incorporate NGS in care for HNSCC. In this review, we describe the current state of precision medicine and NGS in HNSCC and opportunities for future advances in this challenging but important field.

Pan-cancer analysis reveals NUP37 as a prognostic biomarker correlated with the immunosuppressive microenvironment in glioma

Nucleoporin 37 kDa (NUP37), a member of the nucleoporin family, has been reported to regulate the proliferation and apoptosis of several tumor types. However, its role in the tumor immune microenvironment is unclear. Here, we evaluated the expression, methylation, copy number alteration, and prognostic significance of NUP37 using RNA-seq and clinical data from The Cancer Genome Atlas. We observed higher expression of NUP37 in 28 of 29 tumor types, and high NUP37 expression predicted worse survival status of patients in 15 tumors. Using data from the cBioportal database, we described the gene variation of NUP37 in glioma and pan-cancer. We further assessed the role of NUP37 in the tumor immune microenvironment using immune infiltration data. NUP37 expression was positively associated with the infiltration levels of immunosuppressive cells, such as nTregs, iTregs, and tumor-associated macrophages, and negatively correlated with immune killer cells, such as CD8+ T and NK cells across cancers. Furthermore, NUP37 expression was associated with immune checkpoints and immune regulation-related genes. The half-maximal inhibitory concentrations of anti-cancer drugs were obtained from the Genomics of Drug Sensitivity in the Cancer database. The correlation between half-maximal inhibitory concentration and NUP37 expression was evaluated. The patients with the evaluated expression of NUP37 were resistant to several anti-cancer drugs. These results suggest that NUP37 is a potential oncogene and prognostic biomarker in glioma and pan-cancer. Tumor tissues with high NUP37 expression exist in a relatively immunosuppressive microenvironment and are resistant to several anti-cancer drugs.

Immunotherapy and Targeted Therapy in the Management of Oral Cancers

Oral cancers (OCs), being one of the frequent malignancies in the head and neck region, need prompt diagnosis and treatment. Apart from basic therapeutic modalities, immunotherapy has now been utilized as a novel approach to combat the disease. With the comprehension of the strategies adopted by cancer cells to evade the immune elimination by the body's immune system, targeted immunotherapies have now become the core area of research. The immune expression of epidermal growth factor receptor (EGFR), programmed cell death protein ligand-1 (PDL-1), etc., are enhanced in OC and have been associated with evasion of the immune system. Targeted immunotherapies now include monoclonal antibodies targeting EGFR like cetuximab and panitumumab, programmed cell death-1 (PD-1) inhibitors like pembrolizumab, cemiplimab, and nivolumab, and PD-L1 inhibitors like atezolizumab, avelumab, and durvalumab. Targeted immunotherapies like chimeric antigen receptor T-cell treatment and small molecule inhibitors are in several clinical trials tried as monotherapy and adjuvant immunotherapy and have shown promising results. Other immunothera-peutic approaches such as cytokines like interferons or interleukins, vaccines, and gene therapy have also been an area of research for the management of OC. However, the cautious selection of appropriate patients with specific immune characteristics as a candidate for immunotherapeutic agents is a crucial component of targeted immunotherapy. This article elaborates on the immune contexture of oral cancer cells, the mechanism of immune evasion by cancer cells, targets for immunotherapies, existent immunotherapeutic agents, and prospects in the field of immunotherapy.