Effect of serpinE1 overexpression on the primary tumor and lymph node, and lung metastases in head and neck squamous cell carcinoma

Serpin peptidase inhibitor, clade E, member 2 is associated with malignant progression and clinical prognosis in oral squamous cell carcinoma

Background/purpose

The serpin peptidase inhibitor, clade E, member 2 (SERPINE2), is upregulated in breast cancer, prostate cancer, and urothelial carcinoma; however, limited information exists regarding its expression in oral cancer. Therefore, this study aimed to analyze the association between SERPINE2 expression and oral squamous cell carcinoma (OSCC) outcomes.

Materials and methods

SERPINE2 mRNA and protein expression in patients with head and neck squamous cell carcinoma and OSCC were investigated using online databases and tissue-array analysis. Its relationship with clinicopathological characteristics, OSCC prognosis and its biological function in OSCC cells were explored.

Results

Analysis using online databases revealed higher SERPINE2 expression in tumor tissues and its role as a prognostic factor. High SERPINE2 protein levels were significantly correlated with adverse pathological parameters, including advanced clinical stage and tumor status (P < 0.001), lymph nodes (P = 0.014), and distant metastases (P = 0.013). High SERPINE2 expression was associated with worse overall survival (P < 0.001) and was identified as an independent prognostic factor for OSCC. In vitro studies revealed that SERPINE2 knockdown significantly reduced cell proliferation, migration, and invasion in OSCC cell lines.

Conclusion

This study suggests that SERPINE2 may serve as a prognostic biomarker and potential therapeutic target for oral cancer.

Leveraging diverse cell-death patterns to predict the prognosis, immunotherapy and drug sensitivity of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) poses clinical challenges due to its varied prognosis, tumor microenvironment attributes, and responses to immunotherapy. We established a novel Programmed Cell Death-related Signature (PRS) for ccRCC assessment, derived through the Least Absolute Shrinkage and Selection Operator (LASSO) regression method. We validated PRS using the E-MTAB-1980 dataset and created PCD-related clusters via non-negative matrix factorization (NMF). Our investigation included an in-depth analysis of immune infiltration scores using various algorithms. Additionally, we integrated data from the Cancer Immunome Atlas (TCIA) for ccRCC immunotherapy insights and leveraged the Genomics of Drug Sensitivity in Cancer (GDSC) database to assess drug sensitivity models. We complemented our findings with single-cell sequencing data and employed the Clinical Proteomic Tumor Analysis Consortium (CPTAC) and qRT-PCR to compare gene expression profiles between cancerous and paracancerous tissues. PRS serves as a valuable tool for prognostication, immune characterization, tumor mutation burden estimation, immunotherapy response prediction, and drug sensitivity assessment in ccRCC. We identify five genes with significant roles in cancer promotion and three genes with cancer-suppressive properties, further validated by qRT-PCR and CPTAC analyses, showcasing gene expression differences in ccRCC tissues. Our study introduces an innovative PCD model that amalgamates diverse cell death patterns to provide accurate predictions for clinical outcomes, mutational profiles, and immune characteristics in ccRCC. Our findings hold promise for advancing personalized treatment strategies in ccRCC patients.

High-fat diet induces C-reactive protein secretion, promoting lung adenocarcinoma via immune microenvironment modulation

To understand the effects of a high-fat diet (HFD) on lung cancer progression and biomarkers, we here used an inducible mutant epidermal growth factor receptor (EGFR)-driven lung cancer transgenic mouse model fed a regular diet (RD) or HFD. The HFD lung cancer (LC-HFD) group exhibited significant tumor formation and deterioration, such as higher EGFR activity and proliferation marker expression, compared with the RD lung cancer (LC-RD) group. Transcriptomic analysis of the lung tissues revealed that the significantly changed genes in the LC-HFD group were highly enriched in immune-related signaling pathways, suggesting that an HFD alters the immune microenvironment to promote tumor growth. Cytokine and adipokine arrays combined with a comprehensive analysis using meta-database software indicated upregulation of C-reactive protein (CRP) in the LC-HFD group, which presented with increased lung cancer proliferation and metastasis; this was confirmed experimentally. Our results imply that an HFD can turn the tumor growth environment into an immune-related pro-tumorigenic microenvironment and demonstrate that CRP has a role in promoting lung cancer development in this microenvironment.

Bioinformatic analysis identifies HPV-related tumor microenvironment remodeling prognostic biomarkers in head and neck squamous cell carcinoma

Head and neck squamous cell carcinomas (HNSCCs) are highly aggressive tumors with rapid progression and poor prognosis. Human papillomavirus (HPV) infection has been identified as one of the most important carcinogens for HNSCC. As an early event in HNSCC, infection with HPV leads to altered immune profiles in the tumor microenvironment (TME). The TME plays a key role in the progression and transformation of HNSCC. However, the TME in HNSCC is a complex and heterogeneous mix of tumor cells, fibroblasts, different types of infiltrating immune cells, and extracellular matrix. Biomarkers relevant to the TME, and the biological role of these biomarkers, remain poorly understood. To this end, we performed comprehensive analysis of the RNA sequencing (RNA-Seq) data from tumor tissue of 502 patients with HNSCC and healthy tissue of 44 control samples. In total, we identified 4,237 differentially expressed genes, including 2,062 upregulated and 2,175 downregulated genes. Further in-depth bioinformatic analysis suggested 19 HNSCC tumor tissue-specific genes. In the subsequent analysis, we focused on the biomarker candidates shown to be significantly associated with unfavorable patient survival: ITGA5, PLAU, PLAUR, SERPINE1, TGFB1, and VEGFC. We found that the expression of these genes was negatively regulated by DNA methylation. Strikingly, all of these potential biomarkers are profoundly involved in the activation of the epithelial-mesenchymal transition (EMT) pathway in HNSCCs. In addition, these targets were found to be positively correlated with the immune invasion levels of CD4+ T cells, macrophages, neutrophils, and dendritic cells, but negatively correlated with B-cell infiltration and CD8+ T-cell invasion. Notably, our data showed that the expression levels of ITGA5, PLAU, PLAUR, SERPINE1, and TGFB1 were significantly overexpressed in HPV-positive HNSCCs compared to normal controls, indicating the potential role of these biomarkers as transformation and/or malignant progression markers for HNSCCs in patients with HPV infection. Taken together, the results of our study propose ITGA5, PLAU, PLAUR, SERPINE1, and TGFB1 as potential prognostic biomarkers for HNSCCs, which might be involved in the HPV-related TME remodeling of HNSCC. Our findings provide important implications for the development and/or improvement of patient stratification and customized immunotherapies in HNSCC.

Association between cancer stem cell gene expression signatures and prognosis in head and neck squamous cell carcinoma

Background

Various cancer stem cell (CSC) biomarkers and the genes encoding them in head and neck squamous cell carcinoma (HNSCC) have been identified and evaluated. However, the validity of these factors in the prognosis of HNSCC has been questioned and remains unclear. In this study, we examined the clinical significance of CSC biomarker genes in HNSCC, using five publicly available HNSCC cohorts.

Methods

To predict the prognosis of patients with HNSCC, we developed and validated the expression signatures of CSC biomarker genes whose mRNA expression levels correlated with at least one of the four CSC genes (CD44, MET, ALDH1A1, and BMI1).

Results

Patients in The Cancer Genome Atlas (TCGA) HNSCC cohort were classified into CSC gene expression-associated high-risk (CSC-HR; n = 285) and CSC gene expression-associated low-risk (CSC-LR; n = 281) subgroups. The 5-year overall survival and recurrence-free survival rates were significantly lower in the CSC-HR subgroup than in the CSC-LR subgroup (p = 0.04 and 0.02, respectively). The clinical significance of the CSC gene expression signature was validated using four independent cohorts. Analysis using Cox proportional hazards models showed that the CSC gene expression signature was an independent prognostic factor of non-oropharyngeal HNSCC which mostly indicates HPV (–) status. Furthermore, the CSC gene expression signature was associated with the prognosis of HNSCC patients who received radiotherapy.

Conclusion

The CSC gene expression signature is associated with the prognosis of HNSCC and may help in personalized treatments for patients with HNSCC, especially in cases with HPV (–) status who were classified in more detail.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10184-4.

A Four-Gene Signature Associated with Radioresistance in Head and Neck Squamous Cell Carcinoma Identified by Text Mining and Data Analysis

Purpose

Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cancer globally, and radiotherapy plays a crucial part in its treatment. This study was designed to identify potential genes related to radiation resistance in HNSCC.

Method

We first used text mining to obtain common genes related to radiotherapy resistance and HNSCC in published articles. Functional enrichment analyses were conducted to identify the significantly enriched pathways and genes. Protein and protein interactions were performed, and the most significant gene modules were determined; then, genes in the gene modules were validated at transcriptional levels and overall survival. Gene set variation analysis (GSVA) score was calculated, and the association between GSVA score and survival/pathway was estimated. Immune cell infiltration, methylation, and genetic alteration analysis of these genes was conducted in HNSCC patients. Finally, potential sensitive anticancer drugs related to target genes were obtained.

Result

We identified 583 common genes through text mining. After further validation, a four-gene signature (EPHB2, SPP1, SERPINE1, and VEGFC) was constructed. The patients with higher GSVA scores have a worse prognosis than those with lower GSVA scores. Differences in methylation of these four genes in HNSCC tumor tissue and normal tissue were compared, with higher methylation levels of EBPH2 and SPP1 in normal tissue and higher methylation levels of SERPINE1 in the tumor. Immune cell infiltration revealed that the increased expression of these genes was closely related to the infiltration level of CD4+ T cell, neutrophil, macrophage, and dendritic cell. Thirty drugs, including 22 positively and eight negatively correlated drugs that most correlated with related genes, were available for treating HNSCC.

Conclusion

In this study, we identified four potential genes as well as corresponding drugs that might be related to radioresistance in HNSCC patients. These candidate genes may provide a promising avenue to further elevate radiotherapy efficacy.

Circ_0058063 contributes to oral squamous cell carcinoma development by sponging miR-145-5p and upregulating SERPINE1

BACKGROUND

We aimed to demonstrate the effects circ_0058063 exerted on oral squamous cell carcinoma (OSCC) and its downstream mechanism associated with miR-145-5p and SERPINE1.

METHODS

The relevant contents of miR-145-5p, circ 0058063, and SERPINE1 mRNAs in OSCC were evaluated using RT-qPCR. Functional experiments including CCK-8, Transwell, Western blot and in vivo experiment were implemented to investigate the biological impacts on OSCC cells. Using dual-luciferase reporter, RIP, and RNA pull-down assays, the direct binding relationship between miR-145-5p, circ 0058063, and SERPINE1, SMAD3, CYR61, and IGF1R mRNAs was verified.

RESULTS

In OSCC, Circ 0058063 was significantly overexpressed. Knockdown of circ_0058063 suppressed OSCC cell migration and proliferation, but enhanced cell apoptosis. Functionally and mechanistically, circ_0058063 could specifically bind with miR-145-5p and thus up-regulated expression of downstream target SERPINE1, which together contributed to the progression of OSCC.

CONCLUSION

Circ_0058063 could promote malignant behavior of OSCC by upregulating SERPINE1 through sponging miR-145-5p.

Identification of Tumor-Suppressive miR-30e-3p Targets: Involvement of SERPINE1 in the Molecular Pathogenesis of Head and Neck Squamous Cell Carcinoma

Recently, our studies revealed that some passenger strands of microRNAs (miRNAs) were closely involved in cancer pathogenesis. Analysis of miRNA expression signatures showed that the expression of miR-30e-3p (the passenger strand of pre-miR-30e) was significantly downregulated in cancer tissues. In this study, we focused on miR-30e-3p (the passenger strand of pre-miR-30e). We addressed target genes controlled by miR-30e-3p that were closely associated with the molecular pathogenesis of head and neck squamous cell carcinoma (HNSCC). Ectopic expression assays demonstrated that the expression of miR-30e-3p attenuated cancer cell malignant phenotypes (e.g., cell proliferation, migration, and invasive abilities). Our analysis of miR-30e-3p targets revealed that 11 genes (ADA, CPNE8, C14orf126, ERGIC2, HMGA2, PLS3, PSMD10, RALB, SERPINE1, SFXN1, and TMEM87B) were expressed at high levels in HNSCC patients. Moreover, they significantly predicted the short survival of HNSCC patients based on 5-year overall survival rates (p < 0.05) in The Cancer Genome Atlas (TCGA). Among these targets, SERPINE1 was found to be an independent prognostic factor for patient survival (multivariate Cox regression; hazard ratio = 1.6078, p < 0.05). Aberrant expression of SERPINE1 was observed in HNSCC clinical samples by immunohistochemical analysis. Functional assays by targeting SERPINE1 expression revealed that the malignant phenotypes (e.g., proliferation, migration, and invasion abilities) of HNSCC cells were suppressed by the silencing of SERPINE1 expression. Our miRNA-based approach will accelerate our understanding of the molecular pathogenesis of HNSCC.

Human α-defensin 6 (HD6) suppresses CRC proliferation and metastasis through abolished EGF/EGFR signaling pathway

The incidence of colorectal cancer (CRC) has increased significantly in the past decade. Early diagnosis and new therapeutics are still urgently needed for CRC in clinical practice. Human α-defensin 6 (HD6) plays a defense role against microbes in the gastrointestinal tract. However, the role and mechanism of HD6 in CRC is still unresolved. Specimens from CRC patients with higher HD6 showed better outcomes. Overexpressed HD6 in CRC cells caused a reduction of cell proliferative, migratory, and invasive ability in vitro and in vivo. HD6-overexpressed caused S phase arrest through changes in cyclin-A and B and CDK2 levels. In addition, serpine-1 may be negatively regulated by HD6 altering the translocation of c-Jun N-terminal kinases (JNK), extracellular regulated protein kinases (ERK), and p38. Higher HD6 and lower serpine-1 levels in CRC patients reflected better outcomes. Finally, we found that HD6 interacts directly with epidermal growth factor receptor (EGFR) by co-immunoprecipitated assay. EGF treatment caused an increase of the level of serpine-1 and pEGFR levels and then increased growth activity in HD6 overexpressing cells. Together, our study shows that HD6 may compete with EGF to bind to EGFR and interrupt cancer progression in CRC. We believe these findings may give new insights for HD6 in CRC therapy.

Identification of pivotal genes associated with the prognosis of gastric carcinoma through integrated analysis

PURPOSE

Detecting and diagnosing gastric cancer (GC) during its early period remains greatly difficult. Our analysis was performed to detect core genes correlated with GC and explore their prognostic values.

METHODS

Microarray datasets from the Gene Expression Omnibus (GEO) (GSE54129) and The Cancer Genome Atlas (TCGA)-stomach adenocarcinoma (STAD) datasets were applied for common differentially co-expressed genes using differential gene expression analysis and Weighted Gene Co-expression Network Analysis (WGCNA). Functional enrichment analysis and protein-protein interaction (PPI) network analysis of differentially co-expressed genes were performed. We identified hub genes via the CytoHubba plugin. Prognostic values of hub genes were explored. Afterward, Gene Set Enrichment Analysis (GSEA) was used to analyze survival-related hub genes. Finally, the tumor-infiltrating immune cell (TIC) abundance profiles were estimated.

RESULTS

Sixty common differentially co-expressed genes were found. Functional enrichment analysis implied that cell-cell junction organization and cell adhesion molecules were primarily enriched. Hub genes were identified using the degree, edge percolated component (EPC), maximal clique centrality (MCC), and maximum neighborhood component (MNC) algorithms, and serpin family E member 1 (SERPINE1) was highly associated with the prognosis of GC patients. Moreover, GSEA demonstrated that extracellular matrix (ECM) receptor interactions and pathways in cancers were correlated with SERPINE1 expression. CIBERSORT analysis of the proportion of TICs suggested that CD8+ T cell and T-cell regulation were negatively associated with SERPINE1 expression, showing that SERPINE1 may inhibit the immune-dominant status of the tumor microenvironment (TME) in GC.

CONCLUSIONS

Our analysis shows that SERPINE1 is closely correlated with the tumorigenesis and progression of GC. Furthermore, SERPINE1 acts as a candidate therapeutic target and prognostic biomarker of GC.

A signature of 24 aging‑related gene pairs predict overall survival in gastric cancer

Background

Aging is the major risk factor for most human cancers. We aim to develop and validate a reliable aging-related gene pair signature (ARGPs) to predict the prognosis of gastric cancer (GC) patients.

Methods

The mRNA expression data and clinical information were obtained from two public databases, The Cancer Genome Atlas (TCGA) dataset, and Gene Expression Omnibus (GEO) dataset, respectively. The best prognostic signature was established using Cox regression analysis (univariate and least absolute shrinkage and selection operator). The optimal cut-off value to distinguish between high- and low-risk patients was found by time-dependent receiver operating characteristic (ROC). The prognostic ability of the ARGPS was evaluated by a log‐rank test and a Cox proportional hazards regression model.

Results

The 24 ARGPs were constructed for GC prognosis. Using the optimal cut-off value − 0.270, all patients were stratified into high risk and low risk. In both TCGA and GEO cohorts, the results of Kaplan–Meier analysis showed that the high-risk group has a poor prognosis (P < 0.001, P = 0.002, respectively). Then, we conducted a subgroup analysis of age, gender, grade and stage, and reached the same conclusion. After adjusting for a variety of clinical and pathological factors, the results of multivariate COX regression analysis showed that the ARGPs is still an independent prognostic factor of OS (HR, 4.919; 95% CI 3.345–7.235; P < 0.001). In comparing with previous signature, the novel signature was superior, with an area under the receiver operating characteristic curve (AUC) value of 0.845 vs. 0.684 vs. 0.695. The results of immune infiltration analysis showed that the abundance of T cells follicular helper was significantly higher in the low-risk group, while the abundance of monocytes was the opposite. Finally, we identified and incorporated independent prognostic factors and developed a superior nomogram to predict the prognosis of GC patients.

Conclusion

Our study has developed a robust prognostic signature that can accurately predict the prognostic outcome of GC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12938-021-00871-x.

Integrated Analysis Reveals ENDOU as a Biomarker in Head and Neck Squamous Cell Carcinoma Progression

Background

Head and neck squamous cell carcinoma (HNSCC) is a leading cancer with high morbidity and mortality worldwide. The aim is to identify genes with clinical significance by integrated bioinformatics analysis and investigate their function in HNSCC.

Methods

We downloaded and analyzed two gene expression datasets of GSE6631 and GSE107591 to screen differentially expressed genes (DEGs) in HNSCC. Common DEGs were functionally analyzed by Gene ontology and KEGG pathway enrichment analysis. Protein-protein interaction (PPI) network was constructed with STRING database and Cytoscape. ENDOU was overexpressed in FaDu and Cal-27 cell lines, and cell proliferation and migration capability were evaluated with MTT, scratch and transwell assay. The prognostic performance of ENDOU and expression correlation with tumor infiltrates in HNSCC were validated with TCGA HNSCC datasets.

Results

Ninety-eight genes shared common differential expression in both datasets, with core functions like extracellular matrix organization significantly enriched. 15 genes showed prognostic significance, and COBL and ENDOU serve as independent survival markers in HNSCC. In-vitro ENDOU overexpression inhibited FaDu and Cal-27 cells proliferation and migration, indicating its tumor-suppressing role in HNSCC progression. GSEA analysis indicated ENDOU down-stream pathways like DNA replication, mismatch repair, cell cycle and IL-17 signaling pathway. ENDOU showed relative lower expression in HNSCC, especially HPV-positive HNSCC samples. At last, ENDOU showed negative correlation with tumor purity and tumor infiltrating macrophages, especially M2 macrophages.

Conclusion

This study identified ENDOU as a biomarker with prognostic significance in HNSCC progression.

Down-Regulation of MiR-181c-5p Promotes Epithelial-to-Mesenchymal Transition in Laryngeal Squamous Cell Carcinoma via Targeting SERPINE1

Laryngeal squamous cell carcinoma (LSCC) arises from the squamous epithelium of the larynx and is associated with a high incidence of cervical lymph node metastasis. MicroRNAs (miRNAs) play a crucial role in the epigenetic regulation of cellular biological processes, including cancer metastasis. However, the molecular mechanisms of specific miRNAs responsible for LSCC metastasis and their clinical significance have yet to be fully elucidated. In this study, LSCC cohort datasets from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were downloaded and examined by comprehensive bioinformatics analysis, which revealed that upregulation of mRNA SERPINE1 and downregulation of miR-181c-5p were associated with unfavorable overall survival. Our analysis showed that SERPINE1 expression negatively correlated with the expression level of miR-181c-5p in our LSCC patient samples. Silencing of miR-181c-5p expression promoted cell migration and invasion in cell lines, whereas the overexpression of miR-181c-5p suppressed cell migration and epithelial-to-mesenchymal transition (EMT) through the downregulation of SERPINE1. Further analysis showed that the enhancement effect on EMT and metastasis induced by silencing miR-181c-5p could be rescued through knockdown of SERPINE1 expression in vitro. Collectively, our findings indicated that miR-181c-5p acted as an EMT suppressor miRNA by downregulation of SERPINE1 in LSCC and offers novel strategies for the prevention of metastasis in LSCC.

Long noncoding RNA MAFG-AS1 facilitates bladder cancer tumorigenesis via regulation of miR-143-3p/SERPINE1 axis

Background

Numerous studies have shown that long noncoding RNAs (lncRNAs) act as key regulators of bladder cancer progression. While lncRNA MAFG-AS1 has been confirmed as an oncogenic molecule in various cancers and tumorigenesis, in present study, we investigated its function and role in the tumorigenesis of bladder cancer.

Methods

The expression of MAFG-AS1, miR-143-3p and SERPINE1 in bladder cancer tissues was detected by qRT-PCR methods. The relationship between MAFG-AS1 expression and clinicopathologic characteristics of bladder cancer was analyzed. The effects of MAFG-AS1 depletion on cell proliferation, migration, invasion and apoptosis were investigated. The binding relationship of MAFG-AS1, miR-143-3p and SERPINE1 was examined by luciferase reporter analysis and RNA immunoprecipitation (RIP) assay.

Results

MAFG-AS1 was upregulated in bladder cancer tissues and cell lines. High MAFG-AS1 expression was associated with bladder cancer histological grade, TNM stage and lymph node metastasis, and patients with high expression showed poor overall survival. Cell function experiments showed that MAFG-AS1 silencing markedly suppressed bladder cancer cell proliferation, migration, invasion and increased cell apoptosis. Moreover, our results demonstrated that MAFG-AS1 functioned as a competing endogenous RNA for miR-143-3p to modulate SERPINE1 levels. Further analysis showed that miR-143-3p inhibition or SERPINE1 overexpression alleviated the suppressive effects of MAFG-AS1 silencing on malignant features.

Conclusions

Our findings indicated that MAFG-AS1 facilitates tumorigenesis via regulation of the miR-143-3p/SERPINE1 axis and also provides a novel insight into tumorigenesis and identify a promising therapeutic target for bladder cancer.

TP53/miR-34a-associated signaling targets SERPINE1 expression in human pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a disease of aging. The TP53 gene product regulates cell growth, aging, and cancer. To determine the important targets of TP53 in PDAC, we examined the expression of 440 proteins on a reverse phase protein array (RPPA) in PDAC-derived MIA-PaCa-2 cells which either had WT-TP53 or lacked WT-TP53. MIA-PaCa-2 cells have a TP53 mutation as well as mutant KRAS and represent a good in vitro model to study PDAC. RPPA analysis demonstrated expression of tumor promoting proteins in cells that lacked WT-TP53; and this feature could be reversed significantly when the cells were transfected with vector encoding WT-TP53 or treated with berberine or a modified berberine (BBR). Expression of miR-34a-associated signaling was elevated in cells expressing WT-TP53 compared to cells expressing mTP53. Results from in vivo studies using human PDAC specimens confirmed the in vitro results as the expression of miR-34a and associated signaling was significantly decreased in PDAC specimens compared to non-cancerous tissues. This study determined SERPINE1 as a miR-34a target with relevance to the biology of PDAC. Thus, we have identified a key target (SERPINE1) of the TP53/miR-34a axis that may serve as a potential biomarker for early detection of pancreatic cancer.

Integrin α-5 as a potential biomarker of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignant tumors that endanger human health. In recent years, the incidence of HNSCC has been increasing, without any significant improvement in the prognosis. Therefore, increased knowledge on the molecular mechanism underlying HNSCC development will allow the development of new strategies for therapy. The present study attempted to identify key genes involved in HNSCC development. Expression profiles of HNSCC and normal samples were downloaded from The Cancer Genome Atlas database. Differentially expressed genes (DEGs) between the HNSCC and normal samples were identified and subjected to Gene Oncology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis. A protein-protein interaction (PPI) network was constructed, and Cytoscape CentiScape and Gene Expression Profiling Interactive Analysis were used to identify key DEGs. Finally, expression profiles of HNSCCs, including 500 HNSCCs and 44 normal samples, were included in the analysis. A total of 1,181 DEGs were screened, among which 354 genes were upregulated and 827 genes were downregulated in HNSCC compared with normal tissues. The GO enrichment analysis showed that the DEGs were mainly involved in chloride transmembrane transporter, metalloendopeptidase and substrate-specific channel activities. The KEGG pathway analysis revealed that the DEGs were mainly associated with ‘protein digestion and absorption’, as well as ‘extracellular matrix-receptor interaction’. Integrin α-5 (ITGA5) was identified as a hub gene, based on the PPI network complex, and was confirmed to be significantly associated with the overall survival rate. Moreover, ITGA5 was overexpressed specifically in HNSCC. The genes found, notably ITGA5, are potential diagnostic biomarkers and therapeutic targets in HNSCC.