Immunotherapy for Head and Neck Squamous Cell Carcinoma

Construction of a Ferroptosis-Related Gene Signature for Head and Neck Squamous Cell Carcinoma Prognosis Prediction

Background

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignant cancers, and few studies have demonstrated the value of ferroptosis-related genes in prognosis.

Methods

The original counts of RNA sequencing data and clinicopathological data were obtained from TCGA and GSE65858 datasets. Common ferroptosis-related genes related to prognosis were identified from the training set and were included in LASSO to determine the best prognosis. To evaluate the efficacy, time-dependent ROC and Kaplan–Meier (KM) survival analyses were applied. Moreover, univariate and multivariate Cox regression analyses were used to screen independent parameters of prognosis and build a nomogram. Eventually, possible biological pathways were proposed based on GSEA.

Results

Among 242 ferroptosis-related genes, we identified that the FLT3, IL6, Keap1, NQO1, SOCS1 and TRIB3 genes were significantly connected with HNSCC patient prognosis as a six-gene signature. After, the patients were divided into high- and low-risk groups based on the six-gene signature. The KM survival curves demonstrated that the high-risk group had worse OS (p < 0.0001) and higher AUC values (0.654, 0.735, and 0.679 for 1-, 3-, and 5-year survival, respectively) for the prognostic signature of the six genes compared with other genes, which were also validated in the GSE65858 dataset. Moreover, GSEA suggested that the epithelial mesenchymal transition pathway was abundant and that the mesenchymal status in the high-risk group was substantially higher than that in the low-risk group. Finally, the immune microenvironment and differences in the content of immune cell types were demonstrated.

Conclusion

We established a six-ferroptosis-related-gene model crossing clinical prognostic parameters that can predict HNSCC patient prognosis and provide a reliable prognostic evaluation tool to assist clinical treatment decisions.

Profiles of immune cell infiltration in head and neck squamous carcinoma

Tumor immune infiltration cells (TIICs) are highly heterogeneous, not only in different cancer subtypes but also within different cancer regions. We conducted the Cell-type Identification using Estimating Relative Subsets Of RNA Transcripts (CIBERSORT) method. We assessed the relative proportions of 22 TIICs in HNSC using publicly available TCGA transcriptional datasets, analyzed the proportions of TIICs between HNSC tissues and normal tissues, along with accompanying clinicopathological data, and the impact of TIICs on clinical outcome. After the filter criteria, a total of 395 patients were included in the analysis. We found significant differences in naïve B cells, monocytes, resting mast cells, activated mast cells, CD8⁺ T cells, and M0 macrophages between HNSC tissues and adjacent non-cancer tissues. We also found that some TIIC subgroups were significantly associated with clinical parameters. Moreover, the patients with low Tregs fraction had worse OS and DFS than those with high Tregs fraction. However, low M0 macrophages fraction was associated with better OS and DFS in HNSC patients. Moreover, Tregs and M0 macrophages are likely to be important determinants of prognosis, which may serve as a potential immunotherapy target for HNSC. Then, we screened the immune-related differentially expressed genes (DEGs), performed the GO and KEGG enrichment analysis, constructed the protein–protein interaction network, and screened the prognosis-related hub genes in HNSC. However, further clinical investigation and basic experiments are needed to validate our results, and uncover the molecular mechanisms interlinking TIICs in HNSC and their roles in prognosis and therapy.

EGFR modulates complement activation in head and neck squamous cell carcinoma

Background

The epidermal growth factor receptor (EGFR) is pivotal for growth of epithelial cells and is overexpressed in several epithelial cancers like head and neck squamous cell carcinoma (HNSCC). EGFR signalling is also involved in diverse innate immune functions in epithelia. We previously found a role for EGFR in modulating the complement system in skin, this prompted an investigation into EGFR role in complement modulation in HNSCC.

Methods

We used patient derived HNSCC cell lines with varying sensitivities to EGFR inhibitors, and generated EGFR inhibition resistant cell lines to study the role of EGFR in modulating complement in HNSCC.

Results

We found that HNSCC cell lines activate the complement system when incubated with human serum. This complement activation was increased in cell lines sensitive to EGFR inhibition following the use of the tyrosine kinase inhibitor Iressa. Sensitive cell line made resistant to EGFR-inhibitors displayed complement activation and a decrease in complement regulatory proteins even in the absence of EGFR-inhibitors. Complement activation did not cause lysis of HNSCC cells, and rather led to increased extracellular signal-regulated kinase (ERK) phosphorylation in one cell line.

Conclusion

These data indicate that EGFR has a complement modulatory role in HNSCC, and that a prolonged EGFR-inhibition treatment in sensitive cancer cells increases complement activation. This has implications in understanding the response to EGFR inhibitors, in which resistance and inflammatory skin lesions are two major causes for treatment cessation.

Could the endocrine disruptor bisphenol-A be implicated in the pathogenesis of oral and oropharyngeal cancer? Metabolic considerations and future directions

Bisphenol-A (BPA), a prototype endocrine disrupting molecule, has been associated with many disease entities such as diabetes mellitus, obesity, polycystic ovarian disease, cardiovascular disease, reproductive and neurodevelopmental disorders. BPA has also been associated mainly with not only hormone sensitive cancers such as breast, prostate, endometrial, ovarian, testicular and thyroid cancers but also non-hormonal sensitive cancers such as cervical and lung cancers, osteosarcoma and meningioma. Recent research has investigated the sources of contamination which are responsible for higher BPA concentrations in the oral cavity and oropharyngeal space, representing the first site of BPA exposure after ingestion. Besides growing awareness and case registration, the incidence and prevalence of oral (OC) and oropharyngeal cancer (OPC) have increased during the last decades correlating with the increased production of BPA worldwide. So far, no study in the medical literature has explored the association of BPA with OC and OPC. BPA may be linked to the etiopathogenesis of OC and OPC through a multitude of mechanisms encompassing and interconnecting genetic, epigenetic, inflammatory, immune, metabolic, hormonal and oxidative stress alterations as well as modulation of oral microbiome. Hence, it is not possible to rule out a potential role of BPA exposure in oral and oropharyngeal tissue carcinogenesis, especially knowing its potential to participate in other non-hormonal sensitive malignancies and to deregulate signaling pathways implicated in OC and OPC. This perspective aims at outlining evidence and proposing for the first time a potential link between BPA with OC and OPC, the most frequent subtypes of head and neck malignancies.

Prognostic and predictive values of immune infiltrate in patients with head and neck squamous cell carcinoma

This study sought to determine whether the in situ tumor-infiltrating immune lymphocytes, as a novel companion to the Immunoscore analysis, could be a promising, valuable prognostic and predictive marker in patients with head and neck squamous cell carcinoma (HNSCC). Total (CD3+) and cytotoxic (CD8+) T lymphocytes were assessed using immunohistochemistry in tumor nests and stroma obtained from patient surgical specimens. The "Immunoscore" methodology has been defined to quantify the amount of in situ immune infiltrate (from I0 to I4). Survival curves were measured using the Kaplan-Meier method, and differences in survival and response to therapy between the groups were estimated using the log-rank test. The prognostic value of the Immunoscore was determined using Cox multivariate analysis. The density and location of CD3+ and CD8+ lymphocytes and the associated Immunoscore correlated significantly with differences in disease-free survival (DFS) and overall survival (OS) (all P < .005). Compared with tumor-node-metastasis (TNM) staging, the Immunoscore was found to have an advantage in predicting survival (P = .000). In addition, a high Immunoscore was associated with the tumors of advanced-stage patients who underwent different treatment regimens. The Immunoscore could be a useful prognostic marker. The measurement of CD3+ and CD8+ cell infiltration may be beneficial in HNSCC patients and may help determine which patients may benefit most from definitive chemoradiotherapy.

Role of Nrf2 signaling pathway in the radiation tolerance of patients with head and neck squamous cell carcinoma: an in vivo and in vitro study

We aimed to investigate the relationship between the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway and the radiation tolerance of patients with head and neck squamous cell carcinoma (HNSCC). From January 2015 to January 2016, 117 patients with HNSCC were enrolled in our study and assigned into the sensitive and tolerance groups based on curative effect. Immunohistochemistry (IHC) was conducted to measure protein expressions of Nrf2, heme oxygenase-1 (HO1), NADPH quinine oxidoreductase 1 (NQO1) and glutathione S-transferase (GST). Human squamous cell carcinoma cell line, HSC-4, was induced by radiation to construct the HSC-4-radiation resistance (RR) cell line. HSC-4 and HSC-4-RR were also assigned into the blank, negative control (NC) and Nrf2 siRNA groups. Cell Counting Kit-8 (CCK-8), quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were employed to detect cell viability, mRNA expression and protein expression, respectively, of Nrf2, HO1, NQO1 and GST. A total of 40 nude mice were equally assigned into the untreated, Nrf2 siRNA, radiation therapy (RT) and RT + Nrf2 siRNA groups. Compared with the sensitive group, patients in the tolerance group had upregulated Nrf2, HO1, NQO1 and GST expressions. HSC-4-RR cell line had improved cell viability and higher protein and mRNA expressions of Nrf2, HO1, NQO1 and GST compared with HSC-4 cell line. Compared with the HSC-4-NC and HSC-4-blank groups, the HSC-4-Nrf2 siRNA group had downregulated cell viability. Compared with the HSC-4-RR-NC and HSC-4-RR-blank groups, the HSC-4-RR-Nrf2 siRNA group had lower cell viability. However, the HSC-4-RR-Nrf2 siRNA group had elevated cell viability than the HSC-4-Nrf2 siRNA group. Tumor volume and tumor weight in the RT and RT + Nrf2 siRNA groups decreased evidently. The RT + Nrf2 siRNA group exhibited decreased tumor volume and tumor weight in comparison with the RT group. Our data demonstrated that downregulation of HO1, NQO1 and GST via inhibiting Nrf2 signaling pathway reduces the radiation tolerance of patients with HNSCC.