Surrogates of immunologic cell death (ICD) and chemoradiotherapy outcomes in head and neck squamous cell carcinoma (HNSCC)

Role and clinical significance of immunogenic cell death biomarkers in chemoresistance and immunoregulation of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignancies in the whole world, with little improvement in the 5-year survival rate due to the occurrence of chemoresistance. With the increasing interests in tumor immune microenvironment, immunogenic cell death (ICD)-induced chemotherapy has shown promising results in enhancing sensitivity to immune checkpoint inhibitors (ICI) and improving the efficiency of tumor immunotherapy. This review summarizes the role of key ICD biomarkers and their underlying molecular mechanisms in HNSCC chemoresistance. The results showed that ICD initiation could significantly improve the survival and prognosis of patients. ICD and its biomarker could also serve as molecular markers for tumor diagnosis and prognosis. Moreover, key components of DAMPs including CALR, HGMB1, and ATP are involved in the regulation of HNSCC chemo-sensitivity, confirming that the key biomarkers of ICD can also be developed into new targets for regulating HNSCC chemoresistance. This review clearly illustrates the theoretical basis for the hypothesis that ICD biomarkers are therapeutic targets involved in HNSCC progression, chemoresistance, and even immune microenvironment regulation. The compilation and investigation may provide new insights into the molecular therapy of HNSCC.

Identification of immunogenic cell death-related signature on prognosis and immunotherapy in kidney renal clear cell carcinoma

Background

Immunogenic cell death (ICD) is considered a particular cell death modality of regulated cell death (RCD) and plays a significant role in various cancers. The connection between kidney renal clear cell carcinoma (KIRC) and ICD remains to be thoroughly explored.

Methods

We conducted a variety of bioinformatics analyses using R software, including cluster analysis, prognostic analysis, enrichment analysis and immune infiltration analysis. In addition, we performed Quantitative Real-time PCR to evaluate RNA levels of specific ICD genes. The proliferation was measured through Cell Counting Kit-8 (CCK-8) assay and colony-formation assay in RCC cell lines.

Results

We determined two ICD subtypes through consensus clustering analysis. The two subtypes showed significantly different clinical outcomes, genomic alterations and tumor immune microenvironment. Moreover, we constructed the ICD prognostic signature based on TF, FOXP3, LY96, SLC7A11, HSP90AA1, UCN, IFNB1 and TLR3 and calculated the risk score for each patient. Kaplan-Meier survival analysis and ROC curve demonstrated that patients in the high-risk group had significantly poorer prognosis compared with the low-risk group. We then validated the signature through external cohort and further evaluated the relation between the signature and clinical features, tumor immune microenvironment and immunotherapy response. Given its critical role in ICD, we conducted further analysis on LY96. Our results indicated that downregulation of LY96 inhibited the proliferation ability of RCC cells.

Conclusions

Our research revealed the underlying function of ICD in KIRC and screened out a potential biomarker, which provided a novel insight into individualized immunotherapy in KIRC.

Clinical Significance of PD-L1 Status in Circulating Tumor Cells for Cancer Management during Immunotherapy

The approval of monoclonal antibodies against programmed death-ligand 1 (PD-L1) and programmed cell death protein (PD1) has changed the landscape of cancer treatment. To date, many immune checkpoint inhibitors (ICIs) have been approved by the FDA for the treatment of metastatic cancer as well as locally recurrent advanced cancer. However, immune-related adverse events (irAEs) of ICIs highlight the need for biomarker analysis with strong predictive value. Liquid biopsy is an important tool for clinical oncologists to monitor cancer patients and administer or change appropriate therapy. CTCs frequently express PD-L1, and this constitutes a clinically useful and non-invasive method to assess PD-L1 status in real-time. This review summarizes all the latest findings about the clinical significance of CTC for the management of cancer patients during the administration of immunotherapy and mainly focuses on the assessment of PD-L1 expression in CTCs.

Targeting toll-like receptor 7/8 for immunotherapy: recent advances and prospectives

Toll-like receptors (TLRs) are a large family of proteins that are expressed in immune cells and various tumor cells. TLR7/8 are located in the intracellular endosomes, participate in tumor immune surveillance and play different roles in tumor growth. Activation of TLRs 7 and 8 triggers induction of a Th1 type innate immune response in the highly sophisticated process of innate immunity signaling with the recent research advances involving the small molecule activation of TLR 7 and 8. The wide range of expression and clinical significance of TLR7/TLR8 in different kinds of cancers have been extensively explored. TLR7/TLR8 can be used as novel diagnostic biomarkers, progression and prognostic indicators, and immunotherapeutic targets for various tumors. Although the mechanism of action of TLR7/8 in cancer immunotherapy is still incomplete, TLRs on T cells are involved in the regulation of T cell function and serve as co-stimulatory molecules and activate T cell immunity. TLR agonists can activate T cell-mediated antitumor responses with both innate and adaptive immune responses to improve tumor therapy. Recently, novel drugs of TLR7 or TLR8 agonists with different scaffolds have been developed. These agonists lead to the induction of certain cytokines and chemokines that can be applied to the treatment of some diseases and can be used as good adjutants for vaccines. Furthermore, TLR7/8 agonists as potential therapeutics for tumor-targeted immunotherapy have been developed. In this review, we summarize the recent advances in the development of immunotherapy strategies targeting TLR7/8 in patients with various cancers and chronic hepatitis B.

Tumor-Promoting Activity and Proteomic Profiling of Cisplatin/Oxaliplatin-Derived DAMPs in Cholangiocarcinoma Cells

Damage-associated molecular patterns (DAMPs) are well recognized as the molecular signature of immunogenic cell death (ICD). The efficacy of drug-induced ICD function may be impacted by the precise ratio between immunostimulatory and immunoinhibitory DAMPs. Tumor-derived DAMPs can activate tumor-expressed TLRs for the promotion of tumor cell motility, invasion, metastatic spread and resistance to chemotherapeutic treatment. Herein, drug-induced DAMPs’ expression and their role in tumor progression are utilized as one crucial point of evaluation regarding chemotherapeutic treatment efficacy in our study. Cisplatin and oxaliplatin, the conventional anticancer chemotherapy drugs, are emphasized as a cause of well-known DAMPs’ release from cholangiocarcinoma (CCA) cells (e.g., HSP family, S100, CRT and HMGB1), whereby they trigger Akt, ERK and Cyclin-D1 to promote tumor activities. These findings strengthen the evidence that DAMPs are not only involved in immunomodulation but also in tumor promotion. Therefore, DAMP molecules should be considered as either targets of cancer treatment or biomarkers to evaluate treatment efficacy and tumor recurrence.

Association of Cell Death Markers With Tumor Immune Cell Infiltrates After Chemo-Radiation in Cervical Cancer

Irradiation induces distinct cellular responses such as apoptosis, necroptosis, iron-dependent cell death (a feature of ferroptosis), senescence, and mitotic catastrophe. Several of these outcomes are immunostimulatory and may represent a potential for immunogenic type of cell death (ICD) induced by radiotherapy triggering abscopal effects. The purpose of this study is to determine whether intra-tumoral ICD markers can serve as biomarkers for the prediction of patient's outcomes defined as the metastasis status and survival over a 5-year period. Thirty-eight patients with locally advanced cervical cancer, treated with neoadjuvant chemoradiotherapy using cisplatin were included in this study. Pre-treatment tumor biopsy and post-treatment hysterectomy samples were stained for cell death markers and danger associated molecular patterns (DAMPs): cleaved caspase-3 (apoptosis), phosphorylated mixed lineage kinase domain like pseudokinase (pMLKL; necroptosis), glutathione peroxidase 4 (GPX4; ferroptosis) and 4-hydroxy-2-noneal (4-HNE; ferroptosis), high mobility group box 1 (HMGB1) and calreticulin. Although these markers could not predict the patient's outcome in terms of relapse or survival, many significantly correlated with immune cell infiltration. For instance, inducing ferroptosis post-treatment seems to negatively impact immune cell recruitment. Measuring ICD markers could reflect the impact of treatment on the tumor microenvironment with regard to immune cell recruitment and infiltration.

One Sentence Summary

Cell death readouts during neoadjuvant chemoradiation in cervical cancer.

Prognostic impact of indoleamine 2,3-dioxygenase 1 (IDO1) mRNA expression on circulating tumour cells of patients with head and neck squamous cell carcinoma

Background

We sought to determine the prognostic role of indoleamine 2,3-dioxygenase 1 (IDO1) by evaluating IDO1 expression in circulating tumour cells (CTCs) at baseline and after completion of chemoradiotherapy in patients with locally advanced (LA) head and neck squamous cell carcinoma (HNSCC) treated with curative intent.

Methods

In a prospective cohort of 113 patients with LA HNSCC, we evaluated expression of IDO1 in the EpCAM+ CTC fraction at baseline and after cisplatin chemoradiation. The prognostic value of combined programmed cell death ligand-1 (PDL-1) and IDO1 expression was assessed.

Results

IDO1 was significantly overexpressed at baseline compared with the post-treatment counterparts (p=0.007). IDO1 messenger RNA (mRNA) expression at baseline was associated with better survival in terms of progression-free survival (PFS) (HR=0.19, p=0.017). Post-treatment IDO1 mRNA levels were correlated with unfavourable prognosis in terms of overall survival (OS) (HR=3.27, p=0.008). Patients with combined decreased expression levels of PDL-1 and IDO1 after treatment exhibited superior PFS (p=0.043) and OS (p=0.021).

Conclusions

Our results strongly suggest that IDO1 mRNA expression is an independent prognostic factor for clinical outcome. Our study provides useful information for future trials combining chemoradiation with immune checkpoint inhibitors and IDO1 inhibitors.

Prognostic Value of a Ten-Gene Signature in HNSCC Patients Based on Tumor-Associated Macrophages Expression Profiling

Tumor-associated macrophages (TAMs) are regarded as the most abundantly infiltrating immune cells around the tumor microenvironment (TME) in head and neck squamous cell carcinoma (HNSCC), which plays an essential role in immunosuppression and tumorigenesis. In the TCGA HNSCC cohort, 500 patients with clinical-pathological information and RNA sequence expression were randomly assigned to training for lasso regression and validation for verification, respectively. A TAM-based ten-gene signature (TBGs) was constructed, which divided the patients into high-risk and low-risk groups, could predict overall survival (OS) of HNSCC patients in the training dataset (p = 3.527e^-05) and validation dataset (p = 3.785e^-02). The result of Cox univariate and multivariate regression analyses showed that the risk score of TBGs could be an independent prognostic factor in HNSCC. ROC curve confirmed that the risk score of TBGs has good sensitivity and specificity for prognosis prediction (AUC = 0.659) and was also verified by the validation dataset (AUC = 0.621). We obtained key risk transcription factors (TFs)-EHF and SNAI2-by correlation analysis with TBGs. Moreover, we ran a gene set enrichment analysis (GSEA) to speculate that TBGs act on interstitial remodeling, tumor killing, metabolic reprogramming, and tumor immune-related pathways. Finally, we combined clinical-pathological features and risk score of TBGs to establish clinical nomograms, and calibration curves verified the accuracy of long-term clinical prognosis in the two datasets (C-index of 5-year OS = 0.721 and 0.716). In general, the TBGs we obtained may accurately predict the prognosis of HNSCC patients to provide personalized treatment.

Circulating Tumour Cell Expression of Immune Markers as Prognostic and Therapeutic Biomarkers in Head and Neck Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

Rates of loco-regional recurrence and distant metastasis remain high among head and neck squamous cell carcinoma (HNSCC) patients, despite advancing cancer treatment modalities and therapeutic agents. One area that has generated considerable interest is the immune landscape of the tumour, heralding a wave of immune checkpoint inhibitors with notable efficacy in recurrent/metastatic HNSCC patients. However, HNSCC remains poorly served by biomarkers that can direct treatment in a personalised fashion to target the tumour heterogeneity seen between patients. Detection and analysis of circulating tumour cells (CTCs) in HNSCC has provided a previously unseen view of the metastasis forming cells that are potentially contributing to poor clinical outcomes. In particular, identifying CTC expression of phenotypic and druggable protein markers has allowed CTC sub-populations to be defined that hold prognostic value or are potential therapeutic targets themselves. The aim of this systematic review was to examine the role of CTC immune-marker expression as prognostic/therapeutic biomarkers in HNSCC by evaluating progress to date and discussing areas for future research. Our results highlight how few studies have been able to demonstrate prognostic significance of immune-marker expression in CTCs. As expected, the immune checkpoint PD-L1 was the most widely investigated marker. However, no studies evaluated CTC target immune marker expression in immunotherapy cohorts. Despite these findings, the data presented demonstrate promise that CTCs may be a source of future biomarkers for immunotherapy and will provide valuable information regarding the potential immune evasion of these metastasis forming cells.

Nonthermal plasma as part of a novel strategy for vaccination

Vaccination has been one of the most effective health intervention mechanisms to reduce morbidity and mortality associated with infectious diseases. Vaccines stimulate the body's protective immune responses through controlled exposure to modified versions of pathogens that establish immunological memory. However, only a few diseases have effective vaccines. The biological effects of nonthermal plasma on cells suggest that plasma could play an important role in improving efficacy of existing vaccines and overcoming some of the limitations and challenges with current vaccination strategies. This review summarizes the opportunities for nonthermal plasma for immunization and therapeutic purposes.

Circulating tumor cells as Trojan Horse for understanding, preventing, and treating cancer: a critical appraisal

Circulating tumor cells (CTCs) are regarded as harbingers of metastases. Their ability to predict response to therapy, relapse, and resistance to treatment has proposed their value as putative diagnostic and prognostic indicators. CTCs represent one of the zeniths of cancer evolution in terms of cell survival; however, the triggers of CTC generation, the identification of potentially metastatic CTCs, and the mechanisms contributing to their heterogeneity and aggressiveness represent issues not yet fully deciphered. Thus, prior to enabling liquid biopsy applications to reach clinical prime time, understanding how the above mechanistic information can be applied to improve treatment decisions is a key challenge. Here, we provide our perspective on how CTCs can provide mechanistic insights into tumor pathogenesis, as well as on CTC clinical value. In doing so, we aim to (a) describe how CTCs disseminate from the primary tumor, and their link to epithelial-mesenchymal transition (EMT); (b) trace the route of CTCs through the circulation, focusing on tumor self-seeding and the possibility of tertiary metastasis; (c) describe possible mechanisms underlying the enhanced metastatic potential of CTCs; (d) discuss how CTC could provide further information on the tissue of origin, especially in cancer of unknown primary origin. We also provide a comprehensive review of meta-analyses assessing the prognostic significance of CTCs, to highlight the emerging role of CTCs in clinical oncology. We also explore how cell-free circulating tumor DNA (ctDNA) analysis, using a combination of genomic and phylogenetic analysis, can offer insights into CTC biology, including our understanding of CTC heterogeneity and tumor evolution. Last, we discuss emerging technologies, such as high-throughput quantitative imaging, radiogenomics, machine learning approaches, and the emerging breath biopsy. These technologies could compliment CTC and ctDNA analyses, and they collectively represent major future steps in cancer detection, monitoring, and management.

Combination of Gas Plasma and Radiotherapy Has Immunostimulatory Potential and Additive Toxicity in Murine Melanoma Cells in Vitro

Despite continuous advances in therapy, malignant melanoma is still among the deadliest types of cancer. At the same time, owing to its high plasticity and immunogenicity, melanoma is regarded as a model tumor entity when testing new treatment approaches. Cold physical plasma is a novel anticancer tool that utilizes a plethora of reactive oxygen species (ROS) being deposited on the target cells and tissues. To test whether plasma treatment would enhance the toxicity of an established antitumor therapy, ionizing radiation, we combined both physical treatment modalities targeting B16F10 murine melanoma cell in vitro. Repeated rather than single radiotherapy, in combination with gas plasma-introduced ROS, induced apoptosis and cell cycle arrest in an additive fashion. In tendency, gas plasma treatment sensitized the cells to subsequent radiotherapy rather than the other way around. This was concomitant with increased levels of TNFα, IL6, and GM-CSF in supernatants. Murine JAWS dendritic cells cultured in these supernatants showed an increased expression of cell surface activation markers, such as MHCII and CD83. For PD-L1 and PD-L2, increased expression was observed. Our results are the first to suggest an additive therapeutic effect of gas plasma and radiotherapy, and translational tumor models are needed to develop this concept further.