The Cancer Genome Atlas Head And Neck Squamous Cell Carcinoma Research Articles

Abstract 1727: Silencing of novel m6A reader PRRC2A as a therapeutic strategy for oral cancer

Abstract Background: Oral squamous cell carcinoma (OSCC) poses a substantial global health challenge characterized by limited treatment options and unfavorable prognoses. Recent research has illuminated the pivotal role of N6-methyladenosine (m6A) modification and its regulators in cancer biology. However, the precise involvement of a novel m6A regulator (m6A reader), PRCC2A in OSCC remains inadequately understood. Objective: This study aims to unravel the role of PRCC2A in OSCC and ascertain its potential as both a diagnostic biomarker and a therapeutic target. Methods: We collected 76 OSCC tumor samples and 38 adjacent non-tumor samples from OSCC patients. Comprehensive analyses, including RT-qPCR, western blotting, histopathological examination, and associations with clinicopathological features, were performed to assess PRRC2A expression in cancer tissues. Furthermore, we explored its links with key factors like metastasis and its implications for patient prognosis. In vitro experiments were conducted using OSCC cell lines and human normal oral keratinocytes (NOKs). PRCC2A knockdown in OSCC cell lines was assessed for its effects on cell proliferation, apoptosis, cell cycle, migration, invasion, and sphere-forming abilities. The study also delved into its impact on immune cell infiltration and involvement in biological pathways. Results: Our investigation unveiled significant overexpression of PRCC2A in OSCC tissue samples and cell lines, relative to adjacent non-tumor tissues and NOKs (P < 0.001). These findings were further validated by the Cancer Genome Atlas - Head and Neck Squamous Cell Carcinoma (TCGA-HNSC) dataset. PRCC2A expression displayed significant correlations with nodal metastasis, higher tumor grades, and advanced cancer stages in OSCC samples, suggesting its crucial role in driving cancer progression and aggressiveness. Silencing PRCC2A in vitro led to reduced metastasis, diminished tumor colony formation, and increased apoptosis in oral cancer cell lines. Furthermore, the study uncovered PRCC2A intricate connections with immune regulatory genes, highlighting its potential to influence the tumor immune microenvironment. Conclusion: PRCC2A emerges as a promising candidate for both diagnosis and therapeutic intervention in OSCC. Its pronounced overexpression in oral cancer tissues, coupled with its associations with metastasis and intricate interactions with immune regulatory networks, underscores its significance in the context of oral cancer malignancies. This research offers valuable insights into the multifaceted role of PRCC2A in OSCC and lays the groundwork for future investigations and potential clinical applications. Citation Format: Balachander Kannan, Vijayashree Priyadharsini Jayaseelan, Senthil MuruganM, Paramasivam Arumugam. Silencing of novel m6A reader PRRC2A as a therapeutic strategy for oral cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1727.

Constructing a T-Cell Receptor-Related Gene Signature for Prognostic Stratification and Therapeutic Guidance in Head and Neck Squamous Cell Carcinoma

Backgroud: The stratification of head and neck squamous cell carcinoma (HNSCC) patients based on prognostic differences is critical for therapeutic guidance. This study was designed to construct a predictive signature derived from T-cell receptor-related genes (TCRRGs) to forecast the clinical outcomes in HNSCC. Methods: We sourced gene expression profiles from The Cancer Genome Atlas (TCGA) HNSCC dataset, GSE41613, and GSE65858 datasets. Utilizing consensus clustering analysis, we identified two distinct HNSCC clusters according to TCRRG expression. A TCRRG-based signature was subsequently developed and validated across diverse independent HNSCC cohorts. Moreover, we established a nomogram model based on TCRRGs. We further explored differences in immune landscapes between high- and low-risk groups. Results: The TCGA HNSCC dataset was stratified into two clusters, displaying marked variations in both overall survival (OS) and immune cell infiltration. Furthermore, we developed a robust prognostic signature based on TCRRG utilizing the TCGA HNSCC train cohort, and its prognostic efficacy was validated in the TCGA HNSCC test cohort, GSE41613, and GSE65858. Importantly, the high-risk group was characterized by a suppressive immune microenvironment, in contrast to the low-risk group. Our study successfully developed a robust TCRRG-based signature that accurately predicts clinical outcomes in HNSCC, offering valuable strategies for improved treatments.

PHF5A regulates the expression of the DOCK5 variant to promote HNSCC progression through p38 MAPK activation

BackgroundPreviously, we identified an oncogenic splicing variant of DOCK5 in head and neck squamous cell carcinoma (HNSCC); however, the mechanism for the generation of this specific DOCK5 variant remains unknown. This study aims to explore the potential spliceosome genes involved in the production of the DOCK5 variant and validate its role in regulating the progression of HNSCC.MethodsThe differentially expressed spliceosome genes involved in the DOCK5 variant were analysed in The Cancer Genome Atlas (TCGA), and the correlation between the DOCK5 variant and the potential spliceosome gene PHF5A was verified by qRT-PCR. The expression of PHF5A was detected in HNSCC cells, TCGA data and a separate primary tumour cohort. The functional role of PHF5A was examined using CCK-8, colony formation, cell scratch and Transwell invasion assays in vitro and validated in vivo in xenograft models of HNSCC. Western blot analysis was used to explore the potential mechanism of PHF5A in HNSCC.ResultsPHF5A was one of the top upregulated spliceosome genes in TCGA HNSCC samples with highly expressed DOCK5 variants. Knockdown or overexpression of PHF5A in HNSCC cells correspondingly altered the level of the DOCK5 variant. PHF5A was highly expressed in tumour cells and tissues and correlated with a worse prognosis of HNSCC. Loss- and gain-of-function experiments demonstrated that PHF5A could promote the proliferation, migration and invasion of HNSCC cells in vitro and in vivo. Moreover, PHF5A inhibition reversed the oncogenic effect of the DOCK5 variant in HNSCC. Western blot analysis showed that PHF5A activated the p38 MAPK pathway, and inhibition of p38 MAPK further reversed the effect of PHF5A on the proliferation, migration and invasion of HNSCC cells.ConclusionPHF5A regulates the alternative splicing of DOCK5 to promote HNSCC progression through p38 MAPK activation, which provides potential therapeutic implications for HNSCC patients.

Exploration of prognostic biomarkers in head and neck squamous cell carcinoma microenvironment from TCGA database.

Immune checkpoint blockade (ICB) therapies have redefined human cancer treatment, including for head and neck squamous cell carcinoma (HNSCC). However, clinical responses to various immune checkpoint inhibitors are often accompanied by immune-related adverse events (irAEs). Therefore, it is crucial to obtain a comprehensive understanding of the association between different immune tumor microenvironments (TMEs) and the immunotherapeutic response. The research data were obtained from The Cancer Genome Atlas (TCGA) database. We applied RNA-seq genomic data from tumor biopsies to assess the immune TME in HNSCC. As the TME is a heterogeneous system that is highly associated with HNSCC progression and clinical outcome, we relied on the Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) algorithm to calculate immune and stromal scores that were evaluated based on the immune or stromal components in the TME. Then, the Tumor Immune Dysfunction and Exclusion algorithm (TIDE) was used to predict the benefits of ICB to each patient. Finally, we identified specific prognostic tumor-infiltrating immune cells (TIICs) by quantifying the cellular composition of the immune response in HNSCC and its association to survival outcome, using the CIBERSORT algorithm. Utilizing the HNSCC cohort of the TCGA database and TIDE and ESTIMATE algorithm-derived immune scores, we obtained a list of microenvironment-associated lncRNAs that predicted different clinical outcomes in HNSCC patients. We validated these correlations in a different HNSCC cohort available from the TCGA database and provided insight into the prediction of response to ICB therapies in HNSCC. This study confirmed that CD8+ T cells were significantly associated with better survival in HNSCC and verified that the top five significantly mutated genes (SMGs) in the TCGA HNSCC cohort were TP53, TTN, FAT1, CDKN2A, and MUC16. A high level of CD8+ T cells and high immune and stroma scores corresponded to a better survival probability in HNSCC.

Novel prognostic matrisome-related gene signature of head and neck squamous cell carcinoma.

Background: Head and neck squamous cell carcinoma (HNSCC) is a common malignancy of the mucosal epithelium of the oral cavity, pharynx, and larynx. Laryngeal squamous cell carcinoma (LSCC) and oral squamous cell carcinoma are common HNSCC subtypes. Patients with metastatic HNSCC have a poor prognosis. Therefore, identifying molecular markers for the development and progression of HNSCC is essential for improving early diagnosis and predicting patient outcomes. Methods: Gene expression RNA-Seq data and patient clinical traits were obtained from The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HNSC) and Gene Expression Omnibus databases. Differentially expressed gene (DEG) screening was performed using the TCGA-HNSC dataset. Intersection analysis between the DEGs and a list of core matrisome genes obtained from the Matrisome Project was used to identify differentially expressed matrisome genes. A prognostic model was established using univariate and multivariate Cox regression analyses, least absolute shrinkage, and selection operator (LASSO) regression analysis. Immune landscape analysis was performed based on the single-sample gene set enrichment analysis algorithm, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, prognostic value, receiver operating characteristic curve analysis, and gene mutation analyses. Immunohistochemical results regarding prognostic protein levels were obtained from the Human Protein Atlas. Single-gene RNA-sequencing data were obtained from GSE150321 and GSE172577 datasets. CCK-8 and Transwell assays were used to confirm cell proliferation and migration. Results: A total of 1,779 DEGs, including 939 upregulated and 840 downregulated genes, between tumor and normal samples were identified using the TCGA-HNSC microarray data. Intersection analysis revealed 52 differentially expressed matrisome-related genes. After performing univariate and multivariate Cox regression and LASSO analyses, a novel prognostic model based on six matrisome genes (FN1, LAMB4, LAMB3, DMP1, CHAD, and MMRN1) for HNSCC was established. This risk model can successfully predict HNSCC survival. The high-risk group had worse prognoses and higher enrichment of pathways related to cancer development than the low-risk group. Silencing LAMB4 in HNSCC cell lines promoted cell proliferation and migration. Conclusion: This study provides a novel prognostic model for HNSCC. Thus, FN1, LAMB4, LAMB3, DMP1, CHAD, and MMRN1 may be the promising biomarkers for clinical practice.

T cell repertoire in peripheral blood as a potential biomarker for predicting response to concurrent cetuximab and nivolumab in head and neck squamous cell carcinoma

BackgroundT cell receptor (TCR) signaling profile is a fundamental property that underpins both adaptive and innate immunity in the host. Despite its potential clinical relevance, the TCR repertoire in peripheral...

A Transcriptomic Analysis of Head and Neck Squamous Cell Carcinomas for Prognostic Indications.

Survival analysis of the Cancer Genome Atlas (TCGA) dataset is a well-known method for discovering gene expression-based prognostic biomarkers of head and neck squamous cell carcinoma (HNSCC). A cutoff point is usually used in survival analysis for patient dichotomization when using continuous gene expression values. There is some optimization software for cutoff determination. However, the software’s predetermined cutoffs are usually set at the medians or quantiles of gene expression values. There are also few clinicopathological features available in pre-processed datasets. We applied an in-house workflow, including data retrieving and pre-processing, feature selection, sliding-window cutoff selection, Kaplan–Meier survival analysis, and Cox proportional hazard modeling for biomarker discovery. In our approach for the TCGA HNSCC cohort, we scanned human protein-coding genes to find optimal cutoff values. After adjustments with confounders, clinical tumor stage and surgical margin involvement were found to be independent risk factors for prognosis. According to the results tables that show hazard ratios with Bonferroni-adjusted p values under the optimal cutoff, three biomarker candidates, CAMK2N1, CALML5, and FCGBP, are significantly associated with overall survival. We validated this discovery by using the another independent HNSCC dataset (GSE65858). Thus, we suggest that transcriptomic analysis could help with biomarker discovery. Moreover, the robustness of the biomarkers we identified should be ensured through several additional tests with independent datasets.

Abstract 2422: Genetic aberrations of Anaplastic Lymphoma Kinase (ALK) are functional drivers in head and neck squamous cell carcinoma (HNSCC)

Abstract Head and neck squamous carcinoma (HNSCC) is a cancer with high genetic heterogeneity. Fusions of Anaplastic Lymphoma Kinase (ALK) have been widely described as a functional driver for lung cancer. Yet, mutations and amplification of ALK are found in HNSCC as well as many other human cancers. Their biological impacts on cancer cell growth are underexplored. Using the Cancer Genome Atlas (TCGA) HNSCC dataset (Firehose Legacy; N=510), we identified a subset of HNSCC patients harboring ALK aberrations (4%), including 0.4% cases with gene amplification and 3.5% with somatic mutations. Transcriptome analysis showed significant tumor-specific ALK upregulation in 43 adjacent normal-HNSCC tumor pairs (2-fold, p=0.001***, TCGA HNSCC Firehose Legacy). Interestingly, clinical analysis revealed that ~94% HNSCC patients with ALK amplification and mutations have advanced diseases (stage III or IV). Among the HNSCC-associated ALK aberrations, ALK amplification, as well as ALK p.R401L mutations are recurrent events. Thus, we sought to investigate their biological functions by ectopic expressions into an HNSCC cell line, FaDu, via retroviral infection. We found that overexpression of ALK WT gene (mimicking gene amplification) and ALK p.R401L significantly promoted cell proliferation vs. EGFP-control (p=0.0004***, 0.01*, respectively). Clonogenic assay also demonstrated both events to be drivers for colony survival vs. EGFP-control by 120%, 150% (p=0.02*, 0.0025**, respectively). Lastly, both events markedly increase FaDu cells invasiveness by Matrigel invasion assay by 67%, 58% (vs. EGFP-control, p<0.0001****, 0.0001****, respectively). In conclusion, ALK aberrations are functional drivers promoting HNSCC aggressiveness. Acknowledgements: This study is funded by General Research Fund, Research Grant Council, Hong Kong Government, Hong Kong SAR (#17121616 ). VWYL also receives funding supports from General Research Fund, Research Grant Council, Hong Kong Government, Hong Kong SAR (#17121616, #14168517), Research Impact Fund (#R4015-19F, R4017-18), the Health and Medical Research Fund (HMRF#15160691) from the Health and Medical Research Fund, the Food and Health Bureau, the Government of the Hong Kong Special Administrative Region), University-Industry Collaboration Programme (UIM/329; Innovation and Technology Fund, Hong Kong Government, Hong Kong SAR), and the Hong Kong Cancer Fund, Hong Kong SAR. Citation Format: Lan Wang, Thomas Chun Kit Yeung, Hoi-Lam Ngan, Peony Hiu Yan Poon, Vivian Wai Yan Lui. Genetic aberrations of Anaplastic Lymphoma Kinase (ALK) are functional drivers in head and neck squamous cell carcinoma (HNSCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2422.

Unraveling most abundant mutational signatures in head and neck cancer.

Genomic alterations are a driving force in the multistep process of head and neck cancer (HNC) and result from the interaction of exogenous environmental exposures and endogenous cellular processes. Each of these processes leaves a characteristic pattern of mutations on the tumor genome providing the unique opportunity to decipher specific signatures of mutational processes operative during HNC pathogenesis and to address their prognostic value. Computational analysis of whole exome sequencing data of the HIPO-HNC (Heidelberg Center for Personalized Oncology-head and neck cancer) (n = 83) and TCGA-HNSC (The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma) (n = 506) cohorts revealed five common mutational signatures (Catalogue of Somatic Mutations in Cancer [COSMIC] Signatures 1, 2, 3, 13 and 16) and demonstrated their significant association with etiological risk factors (tobacco, alcohol and HPV16). Unsupervised hierarchical clustering identified four clusters (A, B, C1 and C2) of which Subcluster C2 was enriched for cases with a higher frequency of signature 16 mutations. Tumors of Subcluster C2 had significantly lower p16INK4A expression accompanied by homozygous CDKN2A deletion in almost one half of cases. Survival analysis revealed an unfavorable prognosis for patients with tumors characterized by a higher mutation burden attributed to signature 16 as well as cases in Subcluster C2. Finally, a LASSO-Cox regression model was applied to prioritize clinically relevant signatures and to establish a prognostic risk score for head and neck squamous cell carcinoma patients. In conclusion, our study provides a proof of concept that computational analysis of somatic mutational signatures is not only a powerful tool to decipher environmental and intrinsic processes in the pathogenesis of HNC, but could also pave the way to establish reliable prognostic patterns.

The Prognostic Significance of Immune-Related Metabolic Enzyme MTHFD2 in Head and Neck Squamous Cell Carcinoma.

Metabolic dysregulation has emerged as a crucial determinant of the clinical responses to immunotherapy. The aim of this study was to determine the clinical significance of the candidate immune-related metabolic enzymes (IRMEs) methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 2 (MTHFD2) in head and neck squamous cell carcinoma (HNSCC). The gene expression profile of HNSCC cohort and the corresponding clinical information were downloaded from The Cancer Genome Atlas (TCGA). The differentially expressed IRMEs were identified, and then, the prognosis-associated IRMEs were revealed by univariate cox regression analysis. The prognostic significance of MTHFD2 in HNSCC as well as the association between MTHFD2 and immune cell infiltration were further analyzed. A total of 121 significantly altered IRMEs were identified between HNSCC and normal tissues, and 21 IRMEs were found to be strongly associated with overall survival of HNSCC. Upregulation of MTHFD2 was positively correlated with adverse clinicopathological factors in TCGA HNSCC cohort, which was further validated with our own cohort using immunohistochemical analysis. Interestingly, bioinformatic analysis further revealed that increased MTHFD2 expression was negatively associated with NK cells activation, while positively correlated with mast cells activation. In conclusion, MTHFD2 overexpression is closely correlated with unfavorable prognosis of HNSCC, and it might play an important role in modulating the tumor immune microenvironment.

RUVBL1 is an amplified epigenetic factor promoting proliferation and inhibiting differentiation program in head and neck squamous cancers.

Mutations in histone modifying enzymes and histone variants were identified in multiple cancers in The Cancer Genome Atlas (TCGA) studies. However, very little progress and understanding has been made in identifying the contribution of epigenetic factors in head and neck squamous cell carcinoma (HNSCC). Here, we report the identification of RUVBL1 (TIP49a), a component of the TIP60 histone modifying complex as being amplified and overexpressed in HNSCC. RUVBL1 plays a key role in incorporating histone variant H2AZ in chromatin thereby regulating transcription of key genes involved in differentiation, cancer cell proliferation and invasion. H2AZ is also overexpressed in HNSCC tumors thereby regulating RUVBL1/H2AZ dependent transcriptional programs. Patient data analysis of multiple cohorts including TCGA and single cell HNSCC data indicated RUVBL1 overexpression as a poor prognostic marker and predicts poor survival. In vitro experiments indicate a pro-proliferative role for RUVBL1/H2AZ in HNSCC cells. RUVBL1 inversely correlates with differentiation program and positively correlates with oncogenic programs, making it a key contributor to tumorigenesis and a vulnerable therapeutic target in HNSCC patients.

Computational analysis of TP53 mutational landscape unveils key prognostic signatures and distinct pathobiological pathways in head and neck squamous cell cancer

BackgroundMutations of the tumour-suppressor gene TP53 are the most frequent somatic genomic alterations in head and neck squamous cell carcinoma (HNSCC). However, it is not yet clear whether specific TP53 mutations bear distinct clinical and pathophysiological significance in different HNSCC subgroups.MethodsA systematic bioinformatics appraisal of TP53 mutations was performed on 415 HNSCC cases available on The Cancer Genome Atlas (TCGA). The following features were analysed and correlated with known clinicopathological variables: mutational profile of TP53, location (within secondary structure and predicted domains of p53 protein) and well-known hotspot mutations. Interactome–genome–transcriptome network analysis highlighted different gene networks. An algorithm was generated to develop a new prognostic classification system based on patients’ overall survival.ResultsTP53 mutations in HNSCCs exhibited distinct differences in different anatomical sites. The mutational profile of TP53 was an independent prognostic factor in HNSCC. High risk of death mutations, identified by our novel classification algorithm, was an independent prognostic factor in TCGA HNSCC database. Finally, network analysis suggested that distinct p53 molecular pathways exist in a site- and mutation-specific manner.ConclusionsThe mutational profile of TP53 may serve as an independent prognostic factor in HNSCC patients, and is associated with distinctive site-specific biological networks.

Abstract PR02: Mutational analysis of head and neck squamous cell carcinoma stratified by smoking status

Abstract Smoking has historically been recognized as a negative prognostic factor in head and neck squamous cell carcinoma (HNSCC). This study aimed to assess the mutational differences between heavy smokers (>20 pack-years) and never smokers among the HNSCC patients within The Cancer Genome Atlas (TCGA). Single nucleotide variation (SNV) and copy number aberration (CNA) differences between heavy smokers and never smokers were compared within HPV-positive (n=67) and negative (n=431) TCGA HNSCC cohorts, and the impact of these mutations on survival was assessed. No genes were differentially mutated between smoking and never smoking patients with HPV-positive tumors. By contrast, in HPV-negative tumors, NSD1 and COL1A11 were found to be more frequently mutated in heavy smokers, while CASP8 was more frequently altered in never smokers. HPV-negative patients with NSD1 mutations experienced significantly improved overall survival compared with NSD1 wild-type patients. This improved prognosis was validated in an independent cohort of 77 oral cavity cancers and a meta-analysis that included two additional datasets (688 total patients, hazard ratio for death 0.44, 95% CI 0.30-0.65). NSD1 mutations are more common in HPV-negative heavy smokers and define a cohort with favorable prognosis, and may represent a clinically useful biomarker to guide treatment deintensification for HPV-negative patients. Citation Format: Farhad Ghasemi, Stephenie D. Prokopec, Danielle MacNeil, Neil Mundi, Christopher Howlett, William Stecho, Kevin Fung, John Yoo, Eric Winquist, Steven Gameiro, Axel Sahovaler, Paul Plantinga, Joe S. Mymryk, John W. Barrett, Paul C. Boutros, Anthony C. Nichols. Mutational analysis of head and neck squamous cell carcinoma stratified by smoking status [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr PR02.

Gene signature for prediction of radiosensitivity in human papillomavirus-negative head and neck squamous cell carcinoma.

PurposeThe probability of recurrence of cancer after adjuvant or definitive radiotherapy in patients with human papillomavirus-negative (HPV(–)) head and neck squamous cell carcinoma (HNSCC) varies for each patient. This study aimed to identify and validate radiation sensitivity signature (RSS) of patients with HPV(–) HNSCC to predict the recurrence of cancer after radiotherapy.Materials and MethodsClonogenic survival assays were performed to assess radiosensitivity in 14 HNSCC cell lines. We identified genes closely correlated with radiosensitivity and validated them in The Cancer Genome Atlas (TCGA) cohort. The validated RSS were analyzed by ingenuity pathway analysis (IPA) to identify canonical pathways, upstream regulators, diseases and functions, and gene networks related to radiosensitive genes in HPV(–) HNSCC.ResultsThe survival fraction of 14 HNSCC cell lines after exposure to 2 Gy of radiation ranged from 48% to 72%. Six genes were positively correlated and 35 genes were negatively correlated with radioresistance, respectively. RSS was validated in the HPV(–) TCGA HNSCC cohort (n = 203), and recurrence-free survival (RFS) rate was found to be significantly lower in the radioresistant group than in the radiosensitive group (p = 0.035). Cell death and survival, cell-to-cell signaling, and cellular movement were significantly enriched in RSS, and RSSs were highly correlated with each other.ConclusionWe derived a HPV(–) HNSCC-specific RSS and validated it in an independent cohort. The outcome of adjuvant or definitive radiotherapy in HPV(–) patients with HNSCC can be predicted by analyzing their RSS, which might help in establishing a personalized therapeutic plan.

Computational discovery of non-mutational tumor-restricted antigens reveals evidence of immunoediting in head and neck squamous cell carcinoma.

6564 Background: We previously identified 107 expression-based tumor antigens (EbTAgs) defined as genes with negligible expression in healthy tissue and overexpression in cancer. EbTAgs present novel targets for the adaptive anti-tumor immune response and exhibit evidence of immunoediting in highly immune infiltrated oral cavity tumors. To detail the landscape of EbTAgs in head and neck squamous cell carcinoma (HNSC) and further elucidate EbTAg immunoediting, we compared the expression EbTAgs in the context of tumor immune infiltration among four HNSCC subtypes: oral cavity (OC), HPV+ oropharyngeal (HPV+OP), HPV- oropharyngeal (HPV-OP), and laryngeal/hypopharyngeal (LH). Methods: Upper quartile FPKM gene expression values of all protein coding genes were calculated for all HNSC samples using RNAseq data from The Cancer Genome Atlas (TCGA). TCGA HNSC tumors were divided into subtypes and analyzed for EbTAg expression. Individual tumor sample immune infiltrate was determined using unsupervised clustering of 14 immune cell signature ssGSEA scores for the HNSC dataset as a whole and for each subtype. Results: LH tumors expressed significantly more EbTAgs than other subtypes (p=0.0014), specifically HPV+OP (p=0.0008, Tukey’s test). Immune clustering analysis showed that LH tumors were significantly more likely to be in the low than the high immune cluster whereas the reverse was true for HPV+OP tumors (p<0.0001). Hypothesizing that EbTAg expression was a function of tumor immune infiltration rather than HNSC subtype, we compared EbTAg expression between tumors in low and high immune clusters of the entire HNSC dataset as well as of each HNSC subtype. Significantly more EbTAgs were expressed in low immune tumors compared to high immune tumors of the HNSC dataset (p<0.0001). Similarly, significantly more EbTAgs were expressed in low immune tumors compared to high immune tumors of the OC, OP-all tumors, and HPV+OP datasets (p=0.0003, p<0.0001, p=0.0006) with a trend of more EbTAgs in the immune low versus high tumors in the HPV-OP and LH datasets (p=0.12, p=0.095). Conclusions: EbTAg expression in TCGA HNSC samples correlates with tumor immune infiltration resulting in lower expression under greater immunological pressure. These results reinforce the hypothesis that EbTAgs undergo immunoediting and are immunologically relevant. Exploration of EbTAgs as antigenic targets of modular vaccines or adoptive T-cell therapy as well as biomarkers of immune checkpoint inhibition therapy response is warranted.

A robust six-miRNA prognostic signature for head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) remains a major health problem worldwide. We aimed to identify a robust microRNA (miRNA)-based signature for predicting HNSCC prognosis. The miRNA expression profiles of HNSCC were obtained from The Cancer Genome Atlas (TCGA) database. The TCGA HNSCC cohort was randomly divided into the discovery and validation cohort. A miRNA-based prognostic signature was built up based on TGCA discovery cohort, and then further validated. The downstream targets of prognostic miRNAs were subjected to functional enrichment analyses. The role of miR-1229-3p, a prognosis-related miRNA, in tumorigenesis of HNSCC was further evaluated. A total of 305 significantly differentially expressed miRNAs were found between HNSCC samples and normal tissues. A six-miRNA prognostic signature was constructed, which exhibited a strong association with overall survival (OS) in the TCGA discovery cohort. In addition, these findings were successfully confirmed in TCGA validation cohort and our own independent cohort. The miRNA-based signature was demonstrated as an independent prognostic indicator for HNSCC. A risk signature-based nomogram model was constructed and showed good performance for predicting the OS for HNSCC. The functional analyses revealed that the downstream targets of these prognostic miRNAs were closely linked to cancer progression. Mechanistically, in vitro analysis revealed that miR-1229-3p played a tumor promoting role in HNSCC. In conclusion, our study has developed a robust miRNA-based signature for predicting the prognosis of HNSCC with high accuracy, which will contribute to improve the therapeutic outcome.

SEMA3A Exon 9 Expression Is a Potential Prognostic Marker of Unfavorable Recurrence-Free Survival in Patients with Tongue Squamous Cell Carcinoma.

This study tried to assess the prognostic value of semaphorin (SEMA) family genes in patients with tongue squamous cell carcinoma (TSCC) and the potential epigenetic alterations of the genes. The part of third-level TSCC data in The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HNSC) was extracted using the UCSC Xena browser for analysis. Among 20 SEMA genes examined, 7 were markedly upregulated, while 8 were substantially decreased in TSCC tissues compared with adjacent normal tissues. SEMA3A was the only gene with independent prognostic value in terms of recurrence-free survival (RFS) in multivariate analysis (hazard ratio [HR]: 1.697, 95% CI: 1.228-2.345, p = 0.001). Among the individual exons of SEMA3A, the exon 9 had a better prognostic value in terms of recurrence than total SEMA3A expression and its expression also independently predicted shorter RFS (HR: 2.193, 95% CI: 1.463-3.290, p < 0.001). The methylation levels of two CpG sites (cg06144675 and cg13988052) were moderately correlated with SEMA3A expression. Interestingly, cg06144675, which locates at the promoter region, showed a negative correlation with SEMA3A expression, whereas cg13988052, which is in the intron of SEMA3A gene body showed a positive correlation with SEMA3A expression. In conclusion, SEMA3A expression is aberrantly upregulated in TSCC tissues. Its exon 9 expression is a potentially valuable prognostic marker of unfavorable RFS in TSCC patients. Both promoter hypomethylation and gene body hypermethylation might contribute to the dysregulation.

Prognostic value of trafficking of regulatory T cells to tumors in head and neck cancer patients.

104 Background: The prognostic value of regulatory T cells (Tregs) in head and neck squamous cell carcinoma (HNSCC) remains unknown. We analyzed the prognostic effect of Tregs in HNSCC with immune activity scores, which reflect the activity status of the seven-step cancer-immunity cycle. Methods: We correlated the 23 immune activity scores and clinicopathologic features of The Cancer Genome Atlas (TCGA) HNSCC using multivariate Cox regression analyses and Kaplan-Meier survival curves. The processed data of immune activity scores were obtained from TIP online tool and the clinicopathologic data were downloaded from TCGA HNSCC database. Results: Immune activity scores of “trafficking of Tregs to tumors” was significantly associated with overall survival (OS) and progression-free survival (PFS). Low activity scores of “trafficking of Tregs to tumors” resulted in shorter OS and PFS. In multivariate analysis, low scores predicted poor OS (adjusted HR = 1.87, 95% CI 1.34-2.60 ; P &lt; 0.001) and were related with unfavorable PFS (adjusted HR = 2.04, 95% CI 1.45-2.86 ; P &lt; 0.001). Conclusions: Immune activity scores of “trafficking of Tregs to tumors” was independent significant prognostic factor in HNSCC. Therefore, assessment of immune activity scores may be useful tools for predicting prognosis in these patients.

1139P - Sensitizing HRAS overexpressing head and neck squamous cell carcinoma (HNSCC) to chemotherapy

BackgroundHRAS is mutated or overexpressed in various cancers. Although numerous studies have demonstrated that HRAS mutations (HRASmut) promote chemoresistance in HNSCC, the effect of wild type HRAS overexpression (wtHRASov) on chemotherapy has not yet been studied. We sought: i. to investigate the repair capacity of wtHRASov tumors in cisplatin- induced damage and ii. to explore the cisplatin sensitizing effect of HRAS inhibitor tipifarnib. MethodsMutation/RNA and cisplatin IC50 data were retrieved from the Cancer Genome Atlas (TCGA) and COSMIC Cell Lines Project respectively. Modified Z-score was used to define HRAS overexpression. Patient derived xenografts (PDXs) were generated from treatment naïve HNSCC patients. Mutational and expression profile of tumor grafts was identified by whole exome sequencing, IHC, qRT-PCR and western blot analysis. Cisplatin or cisplatin combined with tipifarnib was used for PDX’s treatment. Therapy response was monitored by sequential tumor volume measurements over time. ResultsOur analysis of available RNA and cisplatin IC50 data from HNSCC cell lines demonstrated that wild type HRAS levels are positively correlated with cisplatin resistance. To identify resistance signatures in wtHRASov tumors, we compared the TCGA HNSCC transcriptomes of HRAS-altered (HRASmut or wtHRASov) and HRAS- unaltered tumors. Approximately 6% of HNSCCs were overexpressing HRAS, and there was only partial overlap with the 6% of HRASmut tumors. Moreover, ERCC1 was found highly upregulated in HRAS altered group and especially among wtHRASov subcluster. To further study the resistance of wtHRASov tumors, we generated a cohort of HNSCC PDXs and acquired their mutational, expression and chemosensitivity profile. PDX tumors harboring a profile similar to wtHRASov TCGA cluster exhibited a strong chemoresistant squamous phenotype associated with high ERCC1 levels. Interestingly, these tumors were resensitized to cisplatin when subjected to cisplatin/tipifarnib combinatorial treatment. ConclusionsERCC1 expression is a well-established biomarker for cisplatin resistance. Our study demonstrates that wtHRASov tumours represent a distinctive entity that strongly express ERCC1 and can be resensitized to cisplatin by tipifarnib. Legal entity responsible for the studyThe authors. FundingKura Oncology. DisclosureT. Rampias: Research grant / Funding (institution): Kura Oncology Company. All other authors have declared no conflicts of interest.

A nomogram based on a gene signature for predicting the prognosis of patients with head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is one of the most common malignant tumors. The purpose of this study was to establish and validate a gene-expression-based prognostic signature in non-metastatic patients with HNSCC. All the patients were retrieved from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. We randomly divided the GSE65858 samples into 70% (training cohort, n = 190) and 30% (internal validation cohort, n = 72). A total of 36 samples collected from the TCGA HNSCC databases were selected as an independent external validation cohort. The oligo package in R was used to normalize the raw data before analysis. Data characteristics were extracted, and a gene signature was built via the least absolute shrinkage and selection operator regression model. The predictive model was developed by multivariable Cox regression analysis. T stage, N stage, human papilloma virus status, and the gene signature were incorporated in this predictive model, which was shown as a nomogram. Calibration and discrimination were performed to assess the performance of the nomogram. The clinical utility of this nomogram was assessed by the decision curve analysis. Overall, 2001 significant messenger RNAs in HNSCC samples were identified compared with normal samples. The gene signature contained seven genes and significantly correlated with overall survival. The gene signature was also significant in subgroup analysis of the primary cohort. The calibration was plotted in the external cohort (C-index 0.90, 95% CI 0.85, 0.95) compared with the training (C-index 0.76, 95% CI 0.73, 0.79) and internal (C-index 0.71, 95% CI 0.66, 0.77) cohorts. In clinic, a decision curve analysis demonstrated that the model including the prognostic gene signature score status was better than that without it. This study developed and validated a predictive model, which can promote the individualized prediction of overall survival in non-metastatic patients with HNSCC.