Cancer stem cells of head and neck squamous cell carcinoma; distance towards clinical application; a systematic review of literature

Head and neck squamous cell carcinoma (HNSCC) is the major pathological type of head and neck cancer (HNC). The disease ranks sixth among the most common malignancies worldwide, with an increasing incidence rate yearly. Despite the development of therapy, the prognosis of HNSCC remains unsatisfactory, which may be attributed to the resistance to traditional radio-chemotherapy, relapse, and metastasis. To improve the diagnosis and treatment, the targeted therapy for HNSCC may be successful as that for some other tumors. Nanocarriers are the most effective system to deliver the anti-cancerous agent at the site of interest using passive or active targeting approaches. The system enhances the drug concentration in HCN target cells, increases retention, and reduces toxicity to normal cells. Among the different techniques in nanotechnology, quantum dots (QDs) possess multiple fluorescent colors emissions under single-source excitation and size-tunable light emission. Dendrimers are the most attractive nanocarriers, which possess the desired properties of drug retention, release, unaffecting by the immune system, blood circulation time enhancing, and cells or organs specific targeting properties. In this review, we have discussed the up-to-date knowledge of the Cancer Stem Cells of Head and Neck Squamous Cell Carcinoma. Although a lot of data is available, still much more efforts remain to be made to improve the treatment of HNSCC.

ETV5 facilitates tumor progression in head-neck squamous cell carcinoma

OBJECTIVE

E26 transformation-specific (ETS) factors have emerged as key mediators underlying human tumorigenesis. Here, we sought to characterize the expression pattern, biological roles, and clinical significance of ETS Variant Transcription Factor 5 (ETV5) in head neck squamous cell carcinoma (HNSCC).

SUBJECTS AND METHODS

ETV5 expression pattern in HNSCC was determined by bioinformatics interrogations and immunohistochemical staining in primary samples. The associations between its abundance with clinicopathological parameters, and patient survival were evaluated. Colony formation, CCK-8, flow cytometry, wound healing, and Transwell invasion assays, as well as xenograft models, were utilized to determine the phenotypic changes after ETV5 silencing in vitro and vivo. The potential binding of ETV5 in the Slug promoter was determined by ChIP-qPCR.

RESULTS

ETV5 was significantly overexpressed in HNSCC samples. Its overexpression is significantly associated with aggressiveness features and reduced survival. ETV5 knockdown significantly inhibited cell proliferation, migration, invasion, and induced apoptosis in vitro, and impaired tumor growth in vivo. Moreover, ETV5-activated Slug transcription by binding its promoter region in HNSCC cells. Patients with ETV5high Slughigh had the worst survival across multiple HNSCC cohorts.

CONCLUSIONS

Our findings reveal that ETV5 serves as a novel prognostic biomarker and putative oncogene for HNSCC progression likely by activating Slug transcription.

Development of a novel prognostic signature derived from enhancer RNA-regulated genes in head neck squamous cell carcinoma

BACKGROUND

Enhancer RNAs (eRNAs) are increasingly recognized as prognostic biomarkers-across human cancers. Here, we sought to develop a novel eRNA-regulated genes (ERGs)-derived prognostic signature for head neck squamous cell carcinoma (HNSCC).

METHODS

Candidate ERGs were identified via co-expression between individual survival-related eRNAs and their putative targets by Spearman's correlation analyses. The ERG signature was developed by univariate Cox regression, Kaplan-Meier survival analysis and maximum AUC in 1000 iterations of LASSO-penalized multivariate Cox regression. An ERG nomogram incorporating ERG signature and selected clinicopathological parameters were constructed by multivariate Cox regression. Biological roles of eRNA of interest were further explored in vitro.

RESULTS

The ERG signature successfully stratified patients into subgroups with distinct survival in multiple cohorts. An ERG nomogram was developed with satisfactory performance in prognostication. Inhibition of ENSR00000165816 significantly reduced transcript level of SLC2A9 and impaired cell proliferation and invasion.

CONCLUSION

Our results establish ERG signature and nomogram as powerful prognostic predictors for HNSCC.

Postoperative Delirium after Reconstructive Surgery in the Head and Neck Region

Postoperative delirium (POD) is an acute and serious complication following extended surgery. The aim of this study was to identify possible risk factors and scores associated with POD in patients undergoing reconstructive head and neck surgery. A collective of 225 patients was retrospectively evaluated after receiving reconstructive surgery in the head and neck region, between 2013 to 2018. The incidence of POD was examined with regards to distinct patient-specific clinical as well as perioperative parameters. Uni- and multivariate statistics were performed for data analysis. POD occurred in 49 patients (21.8%) and was strongly associated with an increased age-adjusted Charlson Comorbidity Index (ACCI) and a prolonged stay in the ICU (p = 0.009 and p = 0.000, respectively). Analogous, binary logistic regression analysis revealed time in the ICU (p < 0.001), an increased ACCI (p = 0.022) and a Nutritional Risk Screening (NRS) score ≠ 0 (p = 0.005) as significant predictors for a diagnosis of POD. In contrast, the extent of reconstructive surgery in terms of parameters such as type of transplant or duration of surgery did not correlate with the occurrence of POD. The extension of reconstructive interventions in the head and neck region is not decisive for the development of postoperative delirium, whereas patient-specific parameters such as age and comorbidities, as well as nutritional parameters, represent predictors of POD occurrence.

Is there any correlation between tumor infiltrating lymphocytes and expression of EGFR in squamous cell carcinoma of head and neck? A retrospective observational study

BACKGROUND

: The dismal survival of one of the commonest malignancies of the world, head neck squamous cell carcinomas (HNSCC), has prompted researchers to probe into its various characteristics, especially those which reflect the outcome. Over the years, even though epidermal growth factor receptor (EGFR) and tumor-infiltrating lymphocytes (TIL) have emerged as useful biomarkers of the disease, the two parameters have rarely been considered in conjunction.

AIMS AND OBJECTIVES

The study aimed to assess if there is any correlation between TIL levels (both stromal and intratumoral) and site, grade, stage, and EGFR score of HNSCC.

MATERIALS AND METHODS

A retrospective observational study was conducted in which histopathologically confirmed cases of HNSCC were included. The site of tumor, grade, stage, stromal and intratumoral TIL levels, and EGFR score were noted for each case. The data were analyzed using standard statistical tests.

RESULTS

The study population consisted of 122 patients with a mean age of 53.8 ± 9.2 years. The oral cavity was the commonest site of tumor (109 cases, 89.3%). Most cases were moderately differentiated (75, 61.5%). Pathological staging showed 66 cases (54%) to be in pT1, and 92 cases (75.4%) to be in pN0. In 68 cases (55.7%), stromal TIL level was high, and intratumoral TIL was low in 102 cases (83.6%). A statistically significant correlation was found between TIL levels and site, grade, pathological stage, and EGFR score of HNSCC.

CONCLUSION

This pioneering study is unique in its exploration of the correlation between two significant biomarkers of HNSCC - TIL and EGFR score.

Human papillomavirus elevated genetic biomarker signature by statistical algorithm

Head and neck squamous cell carcinoma (HNSCC) is the one of the most frequently found cancers in the world. The aim of the study was to find the genes responsible and enriched pathways associated with HNSCC using bioinformatics and survival analysis methods. A total of 646 patients with HNSCC based on clinical information were considered for the study. HNSCC samples were grouped according to the parameters (RFS, DFS, PFS, or OS). The probe ID of these 11 genes was retrieved by Affymetrix using the NetAffx Query algorithm. The protein-protein interaction (PPI) network and Kaplan-Meier curve were used to find associations among the genes' expression data. We found that among these 11 genes, nine genes, CCNA1, MMP3, FLRT3, GJB6, ZFR2, PITX2, SYCP2, MEI1, and UGT8 were significant (p < .05). A survival plot was drawn between the p value and gene expression. This study helped us find the nine significant genes which play vital roles in HNSCC along with their key pathways and their interaction with other genes in the PPI network. Finally, we found the biomarker index for relapse time and risk factors for HNSCC in cancer patients.

Significance of the Neutrophil-to-Lymphocyte Ratio in p16-Negative Squamous Cell Carcinoma of Unknown Primary in Head and Neck

Objective: The neutrophil-to-lymphocyte ratio (NLR) has been reported to be associated with survival in solid malignancies. The main goal was to evaluate the prognostic significance of the NLR in patients with p16-negative squamous cell carcinoma of unknown primary (SCCUP) in head and neck.

Methods: The association between the NLR and clinical pathologic variables was evaluated by the chi-square test. The primary endpoint of interest was disease-specific survival (DSS). Univariate and Coxmodel analyses were used to evaluate prognostic factors.

Results: A total of 153 patients were included in the analysis. Cancer cachexia was noted in 10 patients. The mean NLR value was 3.9 (range: 1.4–8.3). A high NLR was significantly associated with cancer cachexia development. The 5-year DSS rate was 58%. In patients with NLRs varying from 1.4 to 3.7, the 5-year DSS rate was 71%; in patients with NLRs varying from 3.7 to 6.0, the 5-year DSS rate was 57%; in patients with NLRs varying from 6.0 to 8.3, the 5-year DSS rate was 39%, and the difference was significant (p = 0.001). Further Cox model analysis confirmed the independence of the NLR in predicting survival.

Conclusions: In patients with p16-negative SCCUP, an NLR ≥ 6.0 is significantly associated with worse prognosis.

Prognostic Value of a Family History of Oral Tongue Squamous Cell Carcinoma: A Matched-Pair Study

OBJECTIVES/HYPOTHESIS

To analyze the prognostic value of a family cancer history for predicting survival in patients with oral tongue squamous cell carcinoma (SCC).

STUDY DESIGN

Retrospective case series.

METHODS

Each patient with a family history was paired with one patient with sporadic oral tongue SCC without a family history. The primary endpoint was disease-specific survival (DSS).

RESULTS

In total, 124 patients were enrolled as participants with a family cancer history, and the 5-year DSS rate was 51%. In the matched group, the 5-year DSS rate was 40%. The difference was significant (P = .032). In the smoking patients with a family history, the 5-year DSS rate was 43%. In the smoking patients from the matched group, the 5-year DSS rate was 17%; the difference was significant (P = .028). In nonsmoking patients with a history of cancer, the 5-year DSS rate was 51%; in nonsmoking patients in the matched group, the 5-year DSS rate was 40%; the difference was not significant (P = .141).

CONCLUSIONS

A family cancer history is associated with improved DSS in surgically treated oral tongue SCC patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:E605-E610, 2020.

Overexpression of ZEB2-AS1 promotes epithelial-to-mesenchymal transition and metastasis by stabilizing ZEB2 mRNA in head neck squamous cell carcinoma

The long noncoding RNAs (lncRNAs) have been increasingly appreciated as key players underlying tumourigenesis and hold great potentials as prognostic biomarkers and therapeutic targets. However, their roles in head neck squamous cell carcinoma (HNSCC) have remained incompletely known. Here, we sought to reveal the oncogenic roles and clinical significance of a tumour‐associated lncRNA, zinc finger E‐box binding homeobox 2 antisense RNA 1 (ZEB2‐AS1), in HNSCC. ZEB2‐AS1 was aberrantly overexpressed in a fraction of HNSCC samples. Its overexpression significantly associated with large tumour size, cervical node metastasis and reduced overall and disease‐free survival. Antisense oligonucleotides (ASO)‐mediated ZEB2‐AS1 depletion markedly inhibited cell proliferation, migration and invasion while triggered apoptosis in HNSCC cells in part via modulating ZEB2 mRNA stability. Enforced overexpression of ZEB2 largely attenuated the phenotypic changes resulted from ZEB2‐AS1 inhibition except the impaired cell proliferation. In addition, ZEB2‐AS1 was required for TGF‐β1‐induced epithelial‐mesenchymal transition (EMT) in vitro. Significantly reduced tumour growth and lung metastasis were observed in ZEB2‐AS1‐depleted cells in HNSCC xenograft animal models. Taken together, our findings reveal that overexpression of ZEB2‐AS1 associates with tumour aggressiveness and unfavourable prognosis by serving as a putative oncogenic lncRNA and a novel prognostic biomarker in HNSCC.

Therapeutic Targeting of BRD4 in Head Neck Squamous Cell Carcinoma

The bromodomain and extraterminal family members are epigenetic readers and transcriptional coactivators which are critically involved in various biological processes including tumorigenesis. BRD4 has been increasingly appreciated as a key oncogene and promising anticancer target. Here, we sought to characterize the expression of BRD4 and its tumorigenic roles as well as therapeutic targeting in HNSCC.

Methods: Expression of BRD4 mRNA and protein was determined by bioinformatics interrogation of publically available databases, primary HNSCC samples and 4NQO-induced HNSCC animal model. The tumorigenic roles of BRD4 in HNSCC were evaluated by genetic and pharmacological approach in vitro and in vivo. Therapeutic efficiency of BRD4 targeting by JQ1 was assessed in three preclinical models including xenograft model, 4NQO-induced model and patients-derived xenograft model. Gene candidates responsible for therapeutic effects of JQ1 were identified by transcriptional profiling in HNSCC cells after JQ1 exposure.

Results: Significant upregulation of BRD4 was found in primary HNSCC samples and 4NQO-induced HNSCC model. Its overexpression associated with aggressive clinicopathological features and inferior overall and disease-free survival. BRD4 depletion by genetic silencing or pharmacological inhibition impaired cell proliferation, migration and invasion and reduced tumor growth and metastasis in vivo. Transcriptional profiling of HNSCC cells following JQ1 exposure identified hundreds of genes which might mediated its antitumor effects and enriched in cancer-relevant pathways. A novel prognostic risk score derived from JQ1-regulated genes was developed to stratify patients into subgroups with favorable or inferior prognosis.

Conclusions: Our findings reveal that BRD4 serves as a novel and critical mediator underlying tumorigenesis and a robust prognostic biomarker in HNSCC. Therapeutic targeting of BRD4 represents a potent and promising strategy against HNSCC.

Co-inhibitory immune checkpoints in head and neck squamous cell carcinoma

The upregulation of co-inhibitory immune checkpoints hampers the immune response toward tumor cells and facilitates the tumor cells ability to evade immunosurveillance. Specific inhibitory immune checkpoint delivers inhibitory signals to T cells using multiple mechanisms. More in-depth understanding of the co-inhibitory immune checkpoints could be exploited for head and neck squamous cell carcinoma (HNSCC) treatment. In this review, we summarize the expression and the mechanism of partial co-inhibitory immune checkpoint signals and discuss targeting co-inhibitory immune checkpoints as an immunotherapeutic target for cancer therapy. This review may provide a better understanding of the co-inhibitory immune checkpoints and could promote applications of immunotherapy.

STAT3 blockade enhances the efficacy of conventional chemotherapeutic agents by eradicating head neck stemloid cancer cell

Signaling transducer and activator 3 (STAT3) and cancer stem cells (CSCs) have garnered huge attention as a therapeutic focus, based on evidence that they may represent an etiologic root of tumor initiation and radio-chemoresistance. Here, we investigated the high phosphorylation status of STAT3 (p-STAT3) and its correlation with self-renewal markers in head neck squamous cell carcinoma (HNSCC). Over-expression of p-STAT3 was found to have increased in post chemotherapy HNSCC tissue. We showed that blockade of p-STAT3 eliminated both bulk tumor and side population (SP) cells with characteristics of CSCs in vitro. Inhibition of p-STAT3 using small molecule S3I-201 significantly delayed tumorigenesis of spontaneous HNSCC in mice. Combining blockade of p-STAT3 with cytotoxic drugs cisplatin, docetaxel, 5-fluorouracil (TPF) enhanced the antitumor effect in vitro and in vivo with decreased tumor sphere formation and SP cells. Taken together, our results advocate blockade of p-STAT3 in combination with conventional chemotherapeutic drugs enhance efficacy by improving CSCs eradication in HNSCC.

A combined lymphokine-activated killer (LAK) cell immunotherapy and adenovirus-p53 gene therapy for head and neck squamous cell carcinoma

BACKGROUND

The antitumor activity of lymphokine activated killer (LAK) cells immunotherapy is not always effective in all patients, especially when used alone. In this study, we investigated the in vitro antitumor activities of a combination of LAK immunotherapy and gene therapy employing an adenovirus carrying the p53 gene (Ad-p53) in human head and neck squamous cell carcinoma.

MATERIALS AND METHODS

The in vitro cytotoxicity of LAK cells was tested in H891 cells infected with or without Ad-p53, and the mRNA expression levels of natural killer group 2D ligands (UL16 binding protein (ULBP) 1 to 5) and tumor necrosis factor (TNF-α) in these cells were measured by real-time reverse transcription polymerase chain reaction.

RESULTS

Ad-p53 infection increased the cytotoxicity of LAK cells against H891 cells, and also increased the mRNA expression levels of the ULBPs in H891 cells and TNF-α in the LAK cells.

CONCLUSION

The antitumor activities of LAK cells in H891 cells were enhanced by Ad-p53.

CONCLUSION

The combinational therapy of LAK immunotherapy and Ad-p53 gene therapy may represent a new paradigm for the treatment of head and neck cancer.