Fibroblast activation protein (FAP) as a prognostic biomarker in multiple tumors and its therapeutic potential in head and neck squamous cell carcinoma

Background:Fibroblast activation protein(FAP),a cell surface serine protease,plays roles in tumor invasion and immune regulation.However,there is currently no pan-cancer analysis of FAP.Objective:We aimed to assess the pan-cancer expression profile of FAP,its molecular function,and its potential role in head and neck squamous cell carcinoma(HNSC).Methods:We analyzed gene expression,survival status,immune infiltration,and molecular functional pathways of FAP in The Cancer Genome Atlas(TCGA)and Genotype Tissue Expression(GTEx)tumors.Furthermore,to elucidate the role of FAP in HNSC,we performed proliferation,migration,and invasion assays post-FAP overexpression or knock-down.Results:FAP expression was elevated in nine tumor types and was associated with poor survival in eight of them.In the context of immune infiltration,FAP expression negatively correlated with CD8+T-cell infiltration infive tumor types and positively with regulatory T-cell infiltration in four tumor types.Our enrichment analysis highlighted FAP’s involvement in the PI3K-Akt signaling pathway.In HNSC cells,FAP overexpression activated the PI3K-Akt pathway,promoting tumor proliferation,migration,and invasion.Conversely,FAP knockdown showed inhibitory effects.Conclusion:Our study unveils the association of FAP with poor tumor prognosis across multiple cancers and highlights its potential as a therapeutic target in HNSC.

PPP1R14A is Associated with Immunotherapy Resistance in Head and Neck Squamous Cell Carcinoma Identified by Single-Cell and Bulk RNA-Sequencing

Objective To identify nivolumab resistance-related genes in patients with head and neck squamous cell carcinoma(HNSCC)using single-cell and bulk RNA-sequencing data.Methods The single-cell and bulk RNA-sequencing data downloaded from the Gene Expression Omnibus database were analyzed to screen out differentially expressed genes(DEGs)between nivolumab resistant and nivolumab sensitive patients using R software.The Least Absolute Shrinkage Selection Operator(LASSO)regression and Recursive Feature Elimination(RFE)algorithm were performed to identify key genes associated with nivolumab resistance.Functional enrichment of DEGs was analyzed with Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses.The relationships of key genes with immune cell infiltration,differentation trajectory,dynamic gene expression profiles,and ligand-receptor interaction were explored.Results We found 83 DEGs.They were mainly enriched in T-cell differentiation,PD-1 and PD-L1 checkpoint,and T-cell receptor pathways.Among six key genes identified using machine learning algorithms,only PPP1R14A gene was differentially expressed between the nivolumab resistant and nivolumab sensitive groups both before and after immunotherapy(P<0.05).The high PPP1R14A gene expression group had lower immune score(P<0.01),higher expression of immunosuppressive factors(such as PDCD1,CTLA4,and PDCD1LG2)(r>0,P<0.05),lower differentiation of infiltrated immune cells(P<0.05),and a higher degree of interaction between HLA and CD4(P<0.05).Conclusions PPP1R14A gene is closely associated with resistance to nivolumab in HNSCC patients.Therefore,PPP1R14A may be a target to ameliorate nivolumab resistance of HNSCC patients.

Nanomaterials for refining tumor microenvironment and enhancing therapy in head and neck squamous cell carcinoma: a review

Head and neck squamous cell carcinoma (HNSCC) is a prevalent and lethal solid tumor with a high mortality rate. Conventional cancertreatments, including surgery, radiotherapy, and chemotherapy, primarily target cancer cell eradication. However, uncontrolled proliferation and metabolic activities of these cells result in abnormalities in nutrient levels, hypoxia, and immunosuppression within the tumor microenvironment (TME). These factors constrain the efficacy of traditional treatments by promoting drug resistance, recurrence, and metastasis. Nanomaterials (NMs), such as nanozymes, can exhibit enzymatic activity similar to that of natural enzymes and offer a promising avenuefor the direct modification of the TME through catalytic oxidation-reduction processes. Moreover, they can serve as sensitizers or drug deliverycarriers, enhancing the efficacy of traditional treatment methods. Recently, NMs have garnered significant attention from oncologists. Thisreview begins with an overview of the composition and unique characteristics of the TME. Subsequently, we comprehensively exploredthe application of NMs in the treatment of HNSCC. Finally, we discuss the potential prospects and challenges associated with usingNMs in biomedical research.

PTEN as a Novel Diagnostic and Prognostic Biomarker of Head and Neck Squamous Cell Carcinoma

This review article explores phosphatase and tensin homolog(PTEN)’s role in head and neck squamous cell carcinoma(HNSCC)through comprehensive expression and methylation examinations,genetic mutation investigation,and prognostic evaluation.Using the UALCAN informational collection,PTEN expression examination uncovered a critical over-expression in HNSCC cells isolated from normal control samples,proposing its role in HNSCC multiplication.Further,analysis of PTEN expression across various clinical limits has shown critical up-regulation in different cancer development stages,racial groups,gender,and age classes within the context of HNSCC patients,suggesting its major role in cancer duplication.PTEN expression was validated by utilizing the GEPIA2.0 online tool,which showed PTEN expression was particularly significantly expressed in HNSCC cancer improvement when it appeared differently from normal control samples.Accordingly,examining PTEN validation across different phases of cancer advancement showed dysregulation in each of the four phases with the most raised expression in stage I and the least expression in stage IV.Thus,this study investigated the promoter methylation level of PTEN,figuring out a basic relationship between HNSCC samples and normal control samples.Analyzing promoter methylation across various clinical limits uncovered massive variations,with specific methylation patterns seen across malignant growth stages,race groups,gender,and age groups.Overall survival and disease-free survival(OS and DFS)utilizing the KM plotter tool showed a critical relationship between PTEN expression levels in HNSCC patients,showing high PTEN expression exhibited good overall survival when showed up distinctively comparable to low PTEN expression levels.In addition,in disease-free survival(DFS)evaluation HNSCC patients showing low PTEN expression experienced great DFS relative to HNSCC patients with high PTEN expression.Moreover,to validate PTEN expression against survival,the study examined the HNSCC patients into low and high-expression groups of PTEN.In HNSCC,low PTEN expression was connected with great overall survival(OS)when it appeared contrastingly relative to the high PTEN expression.In like manner,the study found that low PTEN expression level was connected with great DFS in HNSCC when it appeared contrastingly related to the high PTEN expression group.Genetic mutation analysis via cBioPortal identifies a minimal proportion of PTEN mutations in HNSCC,predominantly in-frame mutation,missense mutation,splice mutation,truncating mutation,and structural variant,indicating their basal significance in PTEN dysregulation within HNSCC.Further investigation of PTEN molecular components and their exchange inside the HNSCC microenvironment might disclose novel roads for designated treatment and accurate medication approaches in battling this harmful disease.

ATM is a Prognostic Biomarker of Survival in Head and Neck Squamous Cell Carcinoma Patients

This review examines the role of ATM expression in head and neck squamous cell carcinoma(HNSCC).Analysis revealed significant overexpression of ATM in HNSCC cells compared to normal control samples,suggesting its involvement in cancer proliferation.ATM expression was notably upregulated across various clinical parameters,including different stages of cancer,racial groups,genders,and age groups,highlighting its role in cancer progression.Validation using the GEPIA2 tool confirmed strong ATM expression throughout all four stages of HNSCC,with the highest levels in stage II and the lowest in stage I.Promoter methylation analysis of ATM showed distinct patterns across different demographics and cancer stages,reinforcing its significance.The study also explored the relationship between ATM expression and patient outcomes using the KM plotter tool,finding that high ATM expression was associated with better overall survival(OS),while low ATM expression correlated with better disease-free survival(DFS).Genetic mutation analysis via cBioPortal identified minimal ATM mutations in HNSCC,including in-frame,splice,truncating,and missense mutations,suggesting their role in ATM dysregulation.The STRING tool was used to construct a protein-protein interaction(PPI)network,revealing that the ATM gene interacts with ten key genes(NBN,ATR,CHEK2,MDC1,MSH2,MSH6,MRE11,TP53,TP53BP1,BRCA1),indicating its involvement in various biological functions.Functional annotation of differentially expressed genes(DEGs)through the DAVID web server revealed their participation in critical biological processes,including double-strand break repair,cellular response to DNA damage,and DNA damage checkpoints.KEGG pathway analysis further linked DEGs to cellular senescence,platinum drug resistance,homologous recombination,p53 signaling,and the cell cycle,underscoring ATM’s multifaceted role in HNSCC.

Application of single-cell RNA sequencing in head and neck squamous cell carcinoma

Single-cell RNA sequencing has been broadly applied to head and neck squamous cell carcinoma(HNSCC) for characterizing the heterogeneity and genomic mutations of HNSCC benefiting from the advantage of single-cell resolution. We summarized most of the current studies and aimed to explore their research methods and ideas, as well as how to transform them into clinical applications. Through single-cell RNA sequencing, we found the differences in tumor cells’ expression programs and differentiation tracks. The studies of immune microenvironment allowed us to distinguish immune cell subpopulations, the extensive expression of immune checkpoints, and the complex crosstalk network between immune cells and non-immune cells. For cancerassociated fibroblasts(CAFs), single-cell RNA sequencing had made an irreplaceable contribution to the exploration of their differentiation status, specific CAFs markers, and the interaction with tumor cells and immune cells. In addition, we demonstrated in detail how single-cell RNA sequencing explored the HNSCC epithelial-tomesenchymal transition(EMT) model and the mechanism of drug resistance, as well as its clinical value.

Glucocorticoid reduces the efficacy of afatinib on the head and neck squamous cell carcinoma

Glucocorticoids(GC)are widely used to counter the adverse events during cancer therapy;nonetheless,previous studies pointed out that GC may reduce the efficacy of chemotherapy on cancer cells,especially in epidermal growth factor receptor(EGFR)-targeted therapy of head and neck squamous cell carcinoma(HNSCC)remaining to be elucidated.The primary aim of the present study was to probe into the GC-induced resistance of EGFR-targeted drug afatinib and the underlying mechanism.HNSCC cell lines(HSC-3,SCC-25,SCC-9,and H-400)and the human oral keratinocyte(HOK)cell lines were assessed for GC receptor(GR)expression.The promoting tumor growth effect of GC was evaluated by the CCK-8 assay and flow cytometry.Levels of signaling pathways participants GR,mTOR,and EGFR were determined by quantitative polymerase chain reaction and western blotting.GC increased the proliferation of HNSCC cells in a GR-dependent manner and promoted AKT/mTOR signaling.But GC failed in counteracting the inhibition of rapamycin in the mTOR signaling pathway.Besides,GC also induced resistance to EGFR-targeted drug afatinib through AKT/mTOR instead of the EGFR/ERK signaling pathway.Thus,GCs reduce the efficacy of afatinib on HNSCC,implicating a cautious use of glucocorticoids in clinical practice.

Neoadjuvant Immunotherapy for Head and Neck Squamous Cell Carcinoma:Expecting Its Application in Temporal Bone Squamous Cell Carcinoma

Temporal bone malignant tumors are characterized by atypical clinical symptoms,and easy recurrence and metastasis.They account for 0.2%of head and neck tumors,and the most common pathological type is squamous cell carcinoma.Patients with squamous cell carcinoma of the temporal bone are often at advanced stages when diagnosed,and lose the chance for surgery.Neoadjuvant immunotherapy has recently been approved as the first-line treatment for refractory recurrent/metastatic squamous cell carcinoma of the head and neck.However,it remains to be determined whether neoadjuvant immunotherapy can be used as the first-line treatment for temporal bone squamous cell carcinoma to reduce the tumor stage before surgery,or as a palliative treatment for patients with unresectable advanced stage carcinoma.The present study reviews the development of immunotherapy and its clinical application in head and neck squamous cell carcinoma,summarizes the treatment of temporal bone squamous cell carcinoma,and prospects the neoadjuvant immunotherapy as the first-line treatment for temporal bone squamous cell carcinoma.

Comprehensive bioinformatics analysis and experimental validation:An anoikis-related gene prognostic model for targeted drug development in head and neck squamous cell carcinoma

We analyzed RNA-sequencing(RNA-seq)and clinical data from head and neck squamous cell carcinoma(HNSCC)patients in The Cancer Genome Atlas(TCGA)Genomic Data Commons(GDC)portal to investigate the prognostic value of anoikis-related genes(ARGs)in HNSCC and develop new targeted drugs.Differentially expressed ARGs were screened using bioinformatics methods;subsequently,a prognostic model including three ARGs(CDKN2A,BIRC5,and PLAU)was constructed.Our results showed that the model-based risk score was a good prognostic indicator,and the potential of the three ARGs in HNSCC prognosis was validated by the TISCH database,the model’s accuracy was validated in two independent cohorts of the Gene Expression Omnibus database.Immune correlation analysis and half-maximal inhibitory concentration were also performed to reveal the different landscapes of TIME between risk groups and to predict immuno-and chemo-therapeutic responses.Potential small-molecule drugs for HNSCC were subsequently predicted using the L1000FWD database.Finally,in vitro experiments were used to verify the database findings.The relative ARG mRNA expression levels in HNSCC and surrounding normal tissues remained consistent with the model results.BIRC5 knockdown inhibited anoikis resistance in WSU-HN6 and CAL-27 cells.Molecular docking,real-time PCR,cell counting kit-8(CCK-8),plate clone,and flow cytometry analyses showed that small-molecule drugs predicted by the database may target the ARGs in the prognostic model,inhibit HNSCC cells survival rate,and promote anoikis in vitro.Therefore,we constructed a new ARG model for HNSCC patients that can predict prognosis and immune activity and identify a potential small-molecule drug for HNSCC,paving the way for clinically targeting anoikis in HNSCC.

Regulation of RNA methylation and immune infiltration patterns by m5C regulators in head and neck squamous cell carcinoma

5-Methylcytosine(m5C)methylation contributes to the development and progression of various malignant tumors.This study aimed to explore the potential role of m5C methylation regulators(m5CMRs)in head and neck squamous cell carcinoma(HNSCC).Methods:The transcription data of HNSCC samples were obtained from The Cancer Genome Atlas(TCGA)and the Gene Expression Omnibus(GEO)databases.Subsequently,the m5C patterns in HNSCC were evaluated based on 14 m5CMRs.Then,the m5Cscore was developed to quantify m5C patterns by using principal component analysis(PCA)algorithms.Two single-cell RNA sequencing datasets and various methods were employed to assess the prognostic value and sensitivity to immunotherapy.Finally,key prognostic m5CMRs were identified using univariate COX regression analysis,and their clinical significance was validated based on the Human Protein Atlas(HPA)database and by using immunohistochemistry.Results:Two distinct m5C clusters were identified.m5C cluster A is characterized by an immune-activated microenvironment and is associated with a favorable prognosis.Notable differences were observed in prognosis,immune infiltration,and immunotherapy response between the high-and low-m5Cscore groups.Patients in the high-m5Cscore group exhibited high TMB,which is correlated with poor prognosis.The m5Cscore of epithelial cells in HNSCC was higher than that in other cells.Key prognostic m5CMRs,including NSUN2,DNMT3B,ALKBH1,and Y-Box Binding Protein 1(YBX1),were associated with poor prognosis.Conclusion:Our research indicates that in head and neck squamous cell carcinoma,the m5C modification profoundly affects the TME’s diversity and complexity,influencing prognosis and the success of immunotherapy.Targeting m5C regulatory elements may be a new method for enhancing the efficacy of immunotherapy in HNSCC.

Optimization of Culture Medium and Transfection Method for Head and Neck Squamous Cell Carcinoma Organoids

[Objectives] To optimize the culture medium for head and neck squamous cell carcinoma patient-derived organoid and screen suitable cytokines;compare the transfection efficiency of direct transfection and short-term suspension transfection for organoid in matrigel. [Methods] Advanced DMEM/F12 medium, GlutaMax and HEPES buffer, nicotinamide, N-acetylcysteine, B27, A83-01, EGF, Y-27632 and Primocin primary cell antibiotics were prepared. On this basis, fibroblast growth factor 10(FGF10), Neuregulin 1, Noggin and R-spondin-1 were added in turn to prepare the selection medium, and the organoid diameter was used as the evaluation index to evaluate the effect of organoid medium. Using lentivirus, mCherry red fluorescent protein was transfected into HNSCC—PDO in different ways, and the transfection effect was evaluated by the fluorescence intensity of organoid sphere. [Results] Nrg1 Noggin and R-Spondin-1 promoted the growth of head and neck squamous cell carcinoma sphere(P<0.05) while FGF10 did not significantly promote the growth of head and neck squamous cell carcinoma sphere(P>0.05). Compared with direct transfection, short-term suspension transfection had higher transfection efficiency for HNSCC—PDO in matrigel. [Conclusions] R-Spondin-1 Nrg1 and Noggin may be the key cytokines in culture of HNSCC—PDO whereas FGF10 played an insignificant role in this study. Short-term suspension transfection could improve the transfection efficiency of lentivirus to HNSCC—PDO.

Clinical impact of surveillance for head and neck cancer in patients with esophageal squamous cell carcinoma

To evaluate the clinical impact of surveillance for head and neck (HN) region with narrow band imaging (NBI) in patients with esophageal squamous cell carcinoma (ESCC).METHODSSince 2006, we introduced the surveillance for HN region using NBI for all patients with ESCC before treatment, and each follow-up. The patients with newly diagnosed stage I to III ESCC were enrolled and classified into two groups as follows: Group A (no surveillance for HN region); between 1992 and 2000), and Group B (surveillance for HN region with NBI; between 2006 and 2008). We comparatively evaluated the detection rate of superficial head and neck squamous cell carcinoma (HNSCC), and the serious events due to metachronous advanced HNSCC during the follow-up.RESULTSA total 561 patients (group A: 254, group B: 307) were enrolled. Synchronous superficial HNSCC was detected in 1 patient (0.3%) in group A, and in 12 (3.9%) in group B (P = 0.008). During the follow up period, metachronous HNSCC were detected in 10 patients (3.9%) in group A and in 30 patients (9.8%) in group B (P = 0.008). All metachronous lesions in group B were early stage, and 26 patients underwent local resection, however, 6 of 10 patients (60%) in group A lost their laryngeal function and died with metachronous HNSCC.CONCLUSIONSurveillance for the HN region by using NBI endoscopy increase the detection rate of early HNSCC in patients with ESCC, and led to decrease serious events related to advanced metachronous HNSCC.

Downregulation of iASPP Expression Suppresses Proliferation, Invasion and Increases Chemosensitivity to Paclitaxel of Head and Neck Squamous Cell Carcinoma In Vitro

Objective Our previous study has revealed that iASPP is elevated in human head and neck squamous cell carcinoma(HNSCC)and iASPP overexpression signifcantly correlates with tumor malignant progression and poor survival of HNSCC.This study investigated the function of iASPP playing in proliferation and invasion of HNSCC in vitro.Methods HNSCC cell line Tu686 transfected with Lentiviral vector-mediated iASPP-specific shRNA and control shRNA were named the shRNA-iASPP group and shRNA-NC group,respectively.The non-infected Tu686 cells were named the CON group.CCK-8 assay,flow cytometry,transwell invasion assay were performed to detect the effects of iASPP inhibition in vitro.Results Our results demonstrated that the proliferation of shRNA-iASPP cells at the time of 72 h(F=32.459,P=0.000),96 h(F=51.407,P=0.000),120 h(F=35.125,P=0.000)post-transfection,was significantly lower than that of shRNANC cells and CON cells.The apoptosis ratio of shRNA-iASPP cells was 9.42%±0.39%(F=299.490,P=0.000),which was significantly higher than that of CON cells(2.80%±0.42%)and shRNA-NC cells(3.18%±0.28%).The percentage of shRNA-iASPP cells in G0/G1 phase was 74.65%±1.09%(F=388.901,P=0.000),which was strikingly increased,compared with that of CON cells(55.19%±1.02%)and shRNA-NC cells(54.62%±0.88%).The number of invading cells was 56±4 in the shRNA-iASPP group(F=84.965,P=0.000),which decreased significantly,compared with the CON group(111±3)and the shRNA-NC group(105±8).The survival rate of shRNA-iASPP cells administrated with paclitaxel was highly decreased,compared with CON cells and shRNA-NC cells(F=634.841,P=0.000).Conclusion These results suggest iASPP may play an important role in progression and aggressive behavior of HNSCC and may be an efficient chemotherapeutic target for the treatment of HNSCC.

The prognostic value of Tiaml proteinexpression in head and neck squamous cellcarcinoma： a retrospective study

Introduction Head and neck squamous cell carcinoma （HNSCC） is a common cancer worldwide and has a poorprognosis. A biomarker predicting the clinical outcome of HNSCC patients could be useful in guiding treatment planning.Overexpression of theT lymphoma invasion and metastasis 1 （Tiaml） protein has been implicated in the migrationand invasion of neoplasms. However, its role in HNSCC progression needs to be further validated. We detectedthe expression of Tiaml in normal and tumor tissues and determined its association with clinical outcomes in patientswith HNSCCMethods： We measured the expression of Tiaml in normal and cancerous tissue samples from the patients withHNSCC treated at Sun Yat-sen University Cancer Center between 2001 and 2008. The Tiaml expression was scoredfrom 0 to 12 based on the percentage of positively stained cells and the staining intensity. We then determined thediagnostic performance of this score in predicting overall survival （OS） and disease-free survival （DFS）.Results： Of the 194 evaluable patients, those with advanced disease, lymph node metastasis at diagnosis, and recurrenceor metastasis during follow-up had a highertendency of having high Tiaml expression as compared with theircounterparts （P 〈 0.05）. The proportion of samples with high Tiaml expression was also higher in cancerous tissuesthan in non-cancerous tissues （57.7% vs. 13.9%, P 〈 0.001）. Cox proportional hazards regression analysis revealed thatTiaml expression scores of 5 and greater independently predicted short OS and DFS.Conclusion： TheTiaml expression is shown as a promising biomarker of clinical outcomes in patients with HNSCCand should be evaluated in prospective trials.

Association of microRNA polymorphisms with the risk of head and neck squamous cell carcinoma in a Chinese population:a case-control study

Background:MicroRNA(miRNA) polymorphisms may alter miRNA-related processes,and they likely contribute to cancer susceptibility.Various studies have investigated the associations between genetic variants in several key miRNAs and the risk of human cancers;however,few studies have focused on head and neck squamous cell carcinoma(HNSCC) risk.This study aimed to evaluate the associations between several key miRNA polymorphisms and HNSCC risk in a Chinese population.Methods:In this study,we genotyped five common single-nucleotide polymorphisms(SNPs) in several key miRNAs(miR-149 rs2292832,miR-146 a rs2910164,miR-605 rs2043556,miR-608 rs4919510,and miR-196a2 rs11614913) and evaluated the associations between these SNPs and HNSCC risk according to cancer site with a case-control study including 576 cases and 1552 controls,which were matched by age and sex in a Chinese population.Results:The results revealed that miR-605 rs2043556[dominant model:adjusted odds ratio(OR) 0.71,95%confidence interval(CI) 0.58-0.88;additive model:adjusted OR 0.74,95%CI 0.62-0.89]and miR-196a2 rs11614913(dominant model:adjusted OR 1.36,95%C11.08-1.72;additive model:adjusted OR 1.28,95%C11.10-1.48) were significantly associated with the risk of oral squamous cell carcinoma(OSCC).Furthermore,when these two loci were evaluated together based on the number of putative risk alleles(rs2043556 A and rs11614913 G),a significant locus-dosage effect was noted on the risk of OSCC(P_(trend) < 0.001).However,no significant association was detected between the other three SNPs(miR-149 rs2292832,miR- 146 a rs2910164,and miR-608 rs4919510) and HNSCC risk.Conclusion:Our study provided the evidence that miR-605 rs2043556 and miR-196a2 rs11614913 may have an impact on genetic susceptibility to OSCC in Chinese population.

Re-expression of DIRAS3 and P53 induces apoptosis and impaired autophagy in head and neck squamous cell carcinoma

Background:p53 and DIRAS3 are tumor suppressors that are frequently silenced in tumors.In this study,we sought to determine whether the concurrent re-expression of p53 and DIRAS3 could effectively induce head and neck squamous cell carcinoma(HNSCC)cell death.Methods:CAL-27 and SCC-25 cells were treated with Ad-DIRAS3 and rAd-p53 to induce re-expression of DIRAS3 and p53 respectively.The effects of DIRAS3 and p53 re-expression on the growth and apoptosis of HNSCC cells were examined by TUNEL assay,flow cytometric analysis and MTT.The effects of DIRAS3 and p53 re-expression on Akt phosphorylation,oncogene expression,and the interaction of 4 E-BP1 with eIF4 E were determined by real-time PCR,Western blotting and immunoprecipitation analysis.The ability of DIRAS3 and p53 re-expression to induce autophagy was evaluated by transmission electron microscopy,LC3 fluorescence microscopy and Western blotting.The effects of DIRAS3 and p53 re-expression on HNSCC growth were evaluated by using an orthotopic xenograft mouse model.Results:TUNEL assay and flow cytometric analysis showed that the concurrent re-expression of DIRAS3 and p53 significantly induced apoptosis(P<0.001).MTT and flow cytometric analysis revealed that DIRAS3 and p53 reexpression significantly inhibited proliferation and induced cell cycle arrest(P<0.001).Mechanistically,the concurrent re-expression of DIRAS3 and p53 down-regulated signal transducer and activation of transcription 3(STAT3)and upregulated p21WAF1/CIP1 and Bax(P<0.001).DIRAS3 and p53 re-expression also inhibited Akt phosphorylation,increased the interaction of eIF4 E with 4 E-BP1,and reduced the expression of c-Myc,cyclin D1,vascular endothelial growth factor(VEGF),fibroblast growth factor(FGF),epidermal growth factor receptor(EGFR)and Bcl-2(P<0.001).Moreover,the concurrent re-expression of DIRAS3 and p53 increased the percentage of cells with GFP-LC3 puncta compared with that in cells treated with control adenovirus(50.00%±4.55%vs.4.67%±1.25%,P<0.001).LC3 fluorescence microscopy and Western blotting further showed that DIRAS3 and p53 re-expression significantly promoted autophagic activity but also inhibited autophagic flux,resulting in overall impaired autophagy.Finally,the concurrent re-expression of DIRAS3 and p53 significantly decreased the tumor volume compared with the control group in a HNSCC xenograft mouse model[(3.12±0.75)mm^(3) vs.(189.02±17.54)mm^(3),P<0.001].Conclusions:The concurrent re-expression of DIRAS3 and p53 is a more effective approach to HNSCC treatment than current treatment strategies.

Molecular signaling in cancer stem cells of tongue squamous cell carcinoma:Therapeutic implications and challenges

Head and neck squamous cell carcinoma is the seventh most common cancer worldwide with high mortality rates.Amongst oral cavity cancers,tongue carcinoma is a very common and aggressive oral cavity carcinoma.Despite the implementation of a multimodality treatment regime including surgical intervention,chemo-radiation as well as targeted therapy,tongue carcinoma shows a poor overall 5-year survival pattern,which is attributed to therapy resistance and recurrence of the disease.The presence of a rare population,i.e.,cancer stem cells(CSCs)within the tumor,are involved in therapy resistance,recurrence,and distant metastasis that results in poor survival patterns.Therapeutic agents targeting CSCs have been in clinical trials,although they are unable to reach into therapy stage which is due to their failure in trials.A more detailed understanding of the CSCs is essential for identifying efficient targets.Molecular signaling pathways,which are differentially regulated in the CSCs,are one of the promising targets to manipulate the CSCs that would provide an improved outcome.In this review,we summarize the current understanding of molecular signaling associated with the maintenance and regulation of CSCs in tongue squamous cell carcinoma in order to emphasize the need of the hour to get a deeper understanding to unravel novel targets.

Sustained complete response to erlotinib in squamous cell carcinoma of the head and neck:A case report

BACKGROUND Squamous cell carcinoma of head and neck(SCCHN) is the fifth most common cancer worldwide. Inhibition of epidermal growth factor receptor signaling has been shown to be a critical component of therapeutic option. Herein, we report a case of durable complete response to erlotinib.CASE SUMMARY An 81-year-old Caucasian male who presented with metastatic poorly differentiated squamous cell carcinoma of right cervical lymph nodes(levels 2 and 3). Imaging studies including(18)F-fluorodeoxyglucose positron emission tomography/computed tomography(CT) and contrast-enhanced CT scan of neck and chest did not reveal any other disease elsewhere. Panendoscopic examination with random biopsy did not reveal malignant lesion in nasopharynx,oropharynx, and larynx. He underwent modified neck dissection and postoperative radiation. Within 2 mo after completion of radiation, he developed local recurrence at right neck, which was surgically removed. Two mo after the salvage surgery, he developed a second recurrence at right neck. Due to suboptimal performance status and his preference, he started erlotinib treatment.He achieved partial response after first 2 mo of erlotinib treatment, then complete response after total 6 mo of erlotinib treatment. He developed sever skin rash and diarrhea including Clostridium difficile infection during the course of erlotinib treatment requiring dose reduction and eventual discontinuation. He remained in complete remission for more than two years after discontinuation of erlotinib.CONCLUSION We report a case of metastatic SCCHN achieving durable complete response from erlotinib. Patient experienced skin rash and diarrhea toxicities which were likely predictors of his treatment response.

Boron neutron capture therapy: moving towards targeted therapy for locally recurrent head and neck squamous cell carcinoma

Locally recurrent head and neck squamous cell carcinoma(HNSCC)is often unresectable,and a repeat course of radiotherapy is associated with incremental toxicities.Boron neutron capture therapy(BNCT)is a novel targeted radiotherapy modality that can achieve a high dose gradient between cancerous and adjacent normal tissues.However,the relationships among the dose resulting from BNCT,tumor response to BNCT,and survival are not completely understood.Recently,a study published in Radiotherapy and Oncology investigated the efficacy of BNCT in the treatment of patients with locally recurrent HNSCC and the factors associated with favorable treatment response and survival.In this article,the findings,strengths and limitations of this study are discussed in depth,and the significance of the study and motivations for future research are highlighted.

Biomarkers of cetuximab resistance in patients with head and neck squamous cell carcinoma

Objective:In patients with head and neck squamous cell carcinoma(HNSCC),cetuximab[a monoclonal antibody targeting epidermal growth factor receptor(EGFR)]has been shown to improve overall survival when combined with radiotherapy in the locally advanced setting or with chemotherapy in first-line recurrent and/or metastatic(R/M)setting,respectively.While biomarkers of resistance to cetuximab have been identified in metastatic colorectal cancer,no biomarkers of efficacy have been identified in HNSCC.Here,we aimed to identify biomarkers of cetuximab sensitivity/resistance in HNSCC.Methods:HNSCC patients treated with cetuximab at the Curie Institute,for whom complete clinicopathological data and formalin-fixed paraffin-embedded(FFPE)tumor tissue collected before cetuximab treatment were available,were included.Immunohistochemistry analyses of PTEN and EGFR were performed to assess protein expression levels.PIK3 CA and H/N/KRAS mutations were analyzed using high-resolution melting(HRM)and Sanger sequencing.We evaluated the predictive value of these alterations in terms of progression-free survival(PFS).Results:Hot spot activating PIK3 CA and KRAS/HRAS mutations were associated with poor PFS among HNSCC patients treated with cetuximab in the first-line R/M setting,but not among HNSCC patients treated with cetuximab in combination with radiotherapy.Loss of PTEN protein expression had a negative predictive value among HNSCC patients treated with cetuximab and radiotherapy.High EGFR expression did not predict cetuximab sensitivity in our patient population.Conclusions:Hot spot activating PIK3 CA and RAS mutations predicted cetuximab resistance among HNSCC patients in the firstline R/M setting,whereas loss of PTEN protein expression predicted resistance to cetuximab when combined to radiotherapy.