Defining the relationship of salivary gland malignancies to novel cell subpopulations in human salivary glands using single nucleus RNA-sequencing.

Salivary glands have essential roles in maintaining oral health, mastication, taste and speech, by secreting saliva. Salivary glands are composed of several types of cells, and each cell type is predicted to be involved in the carcinogenesis of different types of cancers including adenoid cystic carcinoma (ACC), acinic cell carcinoma (AciCC), salivary duct carcinoma (SDC), myoepithelial carcinoma (MECA) and other histology. In our study, we performed single nucleus RNA-seq on three human salivary gland samples to clarify the gene expression profile of each complex cellular component of the salivary glands and related these expression patterns to expression found in salivary gland cancers (SGC) to infer cell of origin. By single nucleus RNA-seq, salivary gland cells were stratified into four clusters: acinar cells, ductal cells 1, ductal cells 2 and myoepithelial cells/stromal cells. The localization of each cell group was verified by IHC of each cluster marker gene, and one group of ductal cells was found to represent intercalated ductal cells labeled with HES1. Furthermore, in comparison with SGC RNA-seq data, acinar cell markers were upregulated in AciCC, but downregulated in ACC and ductal cell markers were upregulated in SDC but downregulated in MECA, suggesting that markers of origin are highly expressed in some SGC. Cell type expressions in specific SGC histology are similar to those found in normal salivary gland populations, indicating a potential etiologic relationship.

A Network Landscape of HPVOPC Reveals Methylation Alterations as Significant Drivers of Gene Expression via an Immune-Mediated GPCR Signal.

HPV-associated oropharynx carcinoma (HPVOPC) tumors have a relatively low mutational burden. Elucidating the relative contributions of other tumor alterations, such as DNA methylation alterations, alternative splicing events (ASE), and copy number variation (CNV), could provide a deeper understanding of carcinogenesis drivers in this disease. We applied network propagation analysis to multiple classes of tumor alterations in a discovery cohort of 46 primary HPVOPC tumors and 25 cancer-unaffected controls and validated our findings with TCGA data. We identified significant overlap between differential gene expression networks and all alteration classes, and this association was highest for methylation and lowest for CNV. Significant overlap was seen for gene clusters of G protein-coupled receptor (GPCR) pathways. HPV16-human protein interaction analysis identified an enriched cluster defined by an immune-mediated GPCR signal, including CXCR3 cytokines CXCL9, CXCL10, and CXCL11. CXCR3 was found to be expressed in primary HPVOPC, and scRNA-seq analysis demonstrated CXCR3 ligands to be highly expressed in M2 macrophages. In vivo models demonstrated decreased tumor growth with antagonism of the CXCR3 receptor in immunodeficient but not immunocompetent mice, suggesting that the CXCR3 axis can drive tumor proliferation in an autocrine fashion, but the effect is tempered by an intact immune system. In conclusion, methylation, ASE, and SNV alterations are highly associated with network gene expression changes in HPVOPC, suggesting that ASE and methylation alterations have an important role in driving the oncogenic phenotype. Network analysis identifies GPCR networks, specifically the CXCR3 chemokine axis, as modulators of tumor-immune interactions that may have proliferative effects on primary tumors as well as a role for immunosurveillance; however, CXCR3 inhibition should be used with caution, as these agents may both inhibit and stimulate tumor growth considering the competing effects of this cytokine axis. Further investigation is needed to explore opportunities for targeted therapy in this setting.

Acute Pneumonitis Associated With the Inhalation of Pyrethroid-Based Domestic Insecticides.

We report a 72-year-old female who presented to our hospital with a worsening cough and dyspnea that had emerged a week earlier following the accidental inhalation of a significant quantity of spray-type imiprothrin (a synthetic pyrethroid)-based insecticide in her bathroom. She exhibited acute respiratory failure necessitating 4 L/minute of nasal oxygen at maximum. Chest CT images showed diffuse centrilobular ground-glass opacities with mosaic attenuation and consolidation areas in the lower lobes of both lungs. The patient was diagnosed with acute pneumonitis due to insecticide inhalation, and her symptoms improved following methylprednisolone pulse and alpha-tocopherol therapy. Generally, the accidental inhalation of aerosolized pyrethroids does not induce significant respiratory symptoms, and case reports on pulmonary toxicity related to pyrethroid inhalation are scarce. This case report underscores the need to include inhaled pyrethroid insecticides in the differential diagnosis of patients with acute pneumonitis and suggests that methylprednisolone and alpha-tocopherol therapy can be beneficial for treating this condition.

An Unusual Case of Bilateral Lower Extremity Edema in the Elderly: Immunoglobulin A (IgA) Vasculitis.

We report a case of a 74-year-old male who exhibited bilateral lower extremity edema over three days. Examination revealed no signs of heart, renal, or hepatic failure, and hypothyroidism was also ruled out. An outpatient regimen of 40 mg furosemide was initiated. At a 12-day follow-up, although the edema had improved, the patient had developed pain in both lower limbs, especially ankles, accompanied by numerous petechiae and erythemas, some of which had formed papules. Skin biopsy of the rash displayed leukocytoclastic vasculitis with immunoglobulin A (IgA) deposition within the vascular walls, leading to a diagnosis of IgA vasculitis. Given the rarity of IgA vasculitis in elderly patients and the broad spectrum of potential diagnoses related to bilateral lower extremity edema in this population, IgA vasculitis can be easily overlooked. While this case did not present with glomerulonephritis, regular renal function monitoring is recommended due to the prognostic implications of renal involvement in adult-onset IgA vasculitis.

Relationship of maternal inflammatory response and fetal inflammatory response to duration and intensity of intra-amniotic infection and inflammation.

INTRODUCTION: We aimed to use two indices, amniotic fluid interleukin-6 (IL-6) concentration at diagnosis and diagnosis-to-delivery interval, to clarify the frequencies of maternal inflammatory response (MIR) and fetal inflammatory response (FIR) in the placenta of patients with intra-amniotic infection and intra-amniotic inflammation (IAI). METHODS: This is a single-center retrospective cohort study. From August 2014 to April 2020, participants were diagnosed with IAI with or without microbial invasion of the amniotic cavity (MIAC) using amniocentesis. IAI was defined as concentrations of amniotic IL-6 ≥ 2.6 ng/mL. MIAC was defined as a positive amniotic fluid culture. IAI with MIAC was defined as an intra-amniotic infection. We calculated the cut-off values for IL-6 concentration in the amniotic fluid at diagnosis and the diagnosis-to-delivery interval for MIR-positive cases among those with intra-amniotic infection. RESULTS: The amniotic fluid IL-6 concentration at diagnosis and diagnosis-to-delivery interval were 15.8 ng/mL and 12 h, respectively. Among cases with intra-amniotic infection, MIR was 98% (52/53) positive, i.e., when either of the two cut-off values was exceeded. There were no significant differences between the frequencies of MIR and FIR. In cases with IAI but no MIAC, the frequencies of MIR and FIR were significantly lower than those with intra-amniotic infection, except when neither of the two cut-off values was exceeded. DISCUSSION: We clarified the MIR- and FIR-positive cases in intra-amniotic infection and cases with IAI but no MIAC according to condition, including the diagnosis-to-delivery interval.

Contribution of Fetal Inflammatory Response Syndrome (FIRS) with or without Maternal-Fetal Inflammation in The Placenta to Increased Risk of Respiratory and Other Complications in Preterm Neonates.

This study classifies fetal inflammatory response syndrome (FIRS) based on the presence or absence of maternal-fetal inflammation in the placenta and clarifies the association of FIRS with neonatal morbidities. Women (330) who delivered at gestational ages of 22w0d-33w6d were enrolled and grouped into four based on FIRS and maternal/fetal inflammatory response (MIR/FIR) statuses: Group A: without FIRS and MIR/FIR (reference group); Group B: MIR/FIR alone; Group C: FIRS and MIR/FIR; and Group D: FIRS without MIR/FIR. The associations between bronchopulmonary dysplasia (BPD), adverse neonatal outcomes, extremely low gestational age and Groups B, C, and D were investigated after adjustment for potential confounders. Among patients with FIRS, 29% were in Group D. The risk of BPD was increased in Groups C (adjusted odds ratio (aOR): 3.36; 95% confidence interval (CI): 1.14-9.89) and D (aOR: 4.17; 95% CI: 1.03-16.9), as was the risk of adverse neonatal outcomes (Group C: aOR: 7.17; 95% CI: 2.56-20.1; Group D: aOR: 6.84; 95% CI: 1.85-25.2). The risk of extremely low gestational age was increased in Group D (aOR: 3.85; 95% CI: 1.56-9.52). Therefore, FIRS without MIR/FIR is not rare and may be associated with neonatal morbidities more than FIRS and MIR/FIR.

Tumorigenic activation around HPV integrated sites in head and neck squamous cell carcinoma.

Human papillomavirus (HPV) is causally involved in the development of head and neck squamous cell carcinoma (HNSCC). The integration of HPV drives tumorigenesis through expression of oncogenic viral genes as well as genomic alterations in surrounding regions. To elucidate involvement of epigenetic dysregulation in tumorigenesis, we here performed integrated analyses of the epigenome, transcriptome and interactome using ChIP-seq, RNA-seq and Hi-C and 4C-seq for HPV(+) HNSCCs. We analyzed clinical HNSCC using The Cancer Genome Atlas data and found that genes neighboring HPV integration sites were significantly upregulated and were correlated with oncogenic phenotypes in HPV(+) HNSCCs. While we found four HPV integration sites in HPV(+) HNSCC cell line UPCI-SCC-090 through target enrichment sequencing, 4C-seq revealed 0.5 to 40 Mb of HPV-interacting regions (HPVIRs) where host genomic regions interacted with integrated HPV genomes. While 9% of the HPVIRs were amplified and activated epigenetically forming super-enhancers, the remaining non-amplified regions were found to show a significant increase in H3K27ac levels and an upregulation of genes associated with GO terms, for example, Signaling by WNT and Cell Cycle. Among those genes, ITPR3 was significantly upregulated, involving UPCI-SCC-090-specific super-enhancer formation around the ITPR3 promoter and in the 80-kb-downstream region. The knockdown of ITPR3 by siRNA or CRISPR deletions of the distant enhancer region led to a significant suppression of cell proliferation. The epigenetic activation of HPVIRs was also confirmed in other cell lines, UM-SCC-47 and UM-SCC-104. These data indicate that epigenetic activation in HPVIRs contributes, at least partially, to genesis of HPV(+) HNSCC.

Repression of DERL3 via DNA methylation by Epstein-Barr virus latent membrane protein 1 in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is Epstein-Barr virus (EBV)-associated invasive malignancy. Increasing evidence indicates that epigenetic abnormalities, including DNA methylation, play important roles in the development of NPC. In particular, the EBV principal oncogene, latent membrane protein 1 (LMP1), is considered a key factor in inducing aberrant DNA methylation of several tumour suppressor genes in NPC, although the mechanism remains unclear. Herein, we comprehensively analysed the methylome data of Infinium BeadArray from 51 NPC and 52 normal nasopharyngeal tissues to identify LMP1-inducible methylation genes. Using hierarchical clustering analysis, we classified NPC into the high-methylation, low-methylation, and normal-like subgroups. We defined high-methylation genes as those that were methylated in the high-methylation subgroup only and common methylation genes as those that were methylated in both high- and low-methylation subgroups. Subsequently, we identified 715 LMP1-inducible methylation genes by observing the methylome data of the nasopharyngeal epithelial cell line with or without LMP1 expression. Because high-methylation genes were enriched with LMP1-inducible methylation genes, we extracted 95 high-methylation genes that overlapped with the LMP1-inducible methylation genes. Among them, we identified DERL3 as the most significantly methylated gene affected by LMP1 expression. DERL3 knockdown in cell lines resulted in significantly increased cell proliferation, migration, and invasion. Lower DERL3 expression was more frequently detected in the advanced T-stage NPC than in early T-stage NPC. These results indicate that DERL3 repression by DNA methylation contributes to NPC tumour progression.

Clinical response in metastatic castration-resistant prostate cancer (mCRPC) cases treated with supra-physiological doses of testosterone: Bipolar androgen therapy.

Androgen deprivation therapy is a standard of care for metastatic prostate cancer. A paradoxical approach utilizing high doses of testosterone in castration-resistant prostate cancer patients demonstrated clinical responses. Here, we report on four heavily pretreated Japanese patients (including one patient on hemodialysis) successfully treated with supra-physiological doses of testosterone.

Novel prognostic value and potential utility of opioid receptor gene methylation in liquid biopsy for oral cavity cancer.

Opioids are a class of recreational drugs and prescription medications that bind to a group of G-protein-coupled receptors known as opioid receptors (ORs). ORs are involved in the development of many types of cancer; however, their role in head and neck squamous cell carcinoma (HNSCC) is complex and poorly understood. Here, we analyzed the methylation status of five OR genes in verification (301 HNSCC primary samples) and validation (five circulating tumor DNA [ctDNA] samples) studies using quantitative methylation-specific PCR (Q-MSP). OPRL1 and OPRM1 methylation levels were significantly higher in HNSCC tissues than in corresponding normal tissues from the same individuals (P = 0.001 and P < 0.001, respectively). In Kaplan-Meier estimate and multivariate Cox proportional hazard analyses, two genes (OPRL1 and OPRM1) were significantly associated with increased recurrence in the methylation group with oral cavity cancer. Furthermore, a validation study of ctDNA demonstrated that OPRL1 genes exhibited predictive performance as emerging biomarkers and were each capable of discriminating the plasma from tumor-free individuals. We characterized the relationship between OR gene methylation status and outcomes in oral cavity cancer. Our results highlight the potential utility of ctDNA methylation-based detection in the clinical management of oral cavity cancer.

Deliberation on Deferred Cytoreductive Nephrectomy and Postoperative Treatment for Advanced Renal Cell Carcinoma: A Case Report.

In a rare case, free from systemic therapy, deferred cytoreductive nephrectomy was implemented in treating an advanced renal cell carcinoma with liver, lung, and splenic colon metastases. A 59-year-old man diagnosed with advanced renal cell carcinoma underwent deferred cytoreductive nephrectomy due to a partial response to systemic treatment after a period of 1 year. After the surgery, no additional treatment was implemented. Furthermore, after 10 months, the patient had no recurrence of renal cell carcinoma. Through a review of this case and deferred cases in the current literature, we could emphasize the importance of image evaluation and pathological findings as an indication for surgery and subsequent treatment options. However, there is room for debate with regards to the indications for deferred cytoreductive nephrectomy as well as a therapeutic strategy after the surgery. This report discusses the significance of deferred cytoreductive nephrectomy in terms of prognosis and quality-of-life improvement in advanced renal cancer.

Extrachromosomal DNA in HPV-Mediated Oropharyngeal Cancer Drives Diverse Oncogene Transcription.

PURPOSE: Human papillomavirus (HPV) plays a major role in oncogenesis and circular extrachromosomal DNA (ecDNA) is found in many cancers. However, the relationship between HPV and circular ecDNA in human cancer is not understood. EXPERIMENTAL DESIGN: Forty-four primary tumor tissue samples were obtained from a cohort of patients with HPV-positive oropharynx squamous cell carcinoma (OPSCC). Twenty-eight additional HPV oropharyngeal cancer (HPVOPC) tumors from The Cancer Genome Atlas (TCGA) project were analyzed as a separate validation cohort. Genomic, transcriptomic, proteomic, computational, and functional analyses of HPVOPC were applied to these datasets. RESULTS: Our analysis revealed circular, oncogenic DNA in nearly all HPVOPC, with circular human and human-viral hybrid ecDNA present in over a third of HPVOPC and viral circular DNA in remaining tumors. Hybrid ecDNA highly express fusion transcripts from HPV promoters and HPV oncogenes linked to downstream human transcripts that drive oncogenic transformation and immune evasion, and splice multiple, diverse human acceptors to a canonical SA880 viral donor site. HPVOPC have high E6*I expression with specific viral oncogene expression pattern related to viral or hybrid ecDNA composition. CONCLUSIONS: Nonchromosomal circular oncogenic DNA is a dominant feature of HPVOPC, revealing an unanticipated link between HPV and ecDNA that leverages the power of extrachromosomal inheritance to drive HPV and somatic oncogene expression.

DNA Methylation and HPV-Associated Head and Neck Cancer.

Head and neck squamous cell carcinoma (HNSCC), especially oropharyngeal squamous cell carcinoma (OPSCC), has recently been found to be significantly associated with human papillomavirus (HPV) infection. The incidence of OPSCC has been increasing and surpassed the number of cervical cancer cases in the United States. Although HPV-associated OPSCC has a relatively better prognosis than HPV-negative cancer, approximately 20% of HPV-associated HNSCC patients show a poor prognosis or therapeutic response, and the molecular mechanism behind this outcome in the intermediate-risk group is yet to be elucidated. These biological differences between HPV-associated HNSCC and HPV-negative HNSCC are partly explained by the differences in mutation patterns. However, recent reports have revealed that epigenetic dysregulation, such as dysregulated DNA methylation, is a strikingly common pathological feature of human malignancy. Notably, viral infections can induce aberrant DNA methylation, leading to carcinogenesis, and HPV-associated HNSCC cases tend to harbor a higher amount of aberrantly methylated DNA than HPV-negative HNSCC cases. Furthermore, recent comprehensive genome-wide DNA-methylation analyses with large cohorts have revealed that a sub-group of HPV-associated HNSCC correlates with increased DNA methylation. Accordingly, in this review, we provide an overview of the relationship between DNA methylation and HPV-associated HNSCC.

Long interspersed nuclear element 1 hypomethylation has novel prognostic value and potential utility in liquid biopsy for oral cavity cancer.

BACKGROUND: New biomarkers are urgently needed to improve personalized treatment approaches for head and neck squamous cell carcinoma (HNSCC). Global DNA hypomethylation has wide-ranging functions in multistep carcinogenesis, and the hypomethylation of long interspersed nucleotide element-1 (LINE-1) is related to increased retrotransposon activity and induced genome instability. However, little information is available regarding LINE-1 hypomethylation and its prognostic implications in HNSCC. METHODS: In this study, we analyzed LINE-1 hypomethylation levels in a well-characterized dataset of 317 primary HNSCC tissues and 225 matched pairs of normal mucosa tissues, along with five oral cavity cancer (OCC) circulating tumor DNA (ctDNA) samples using quantitative real-time methylation and unmethylation PCR. The analysis was performed according to various clinical characteristics and prognostic implications. RESULTS: The results demonstrated that LINE-1 hypomethylation levels were significantly higher in the HNSCC tissues than in corresponding normal tissues from the same individuals (P < 0.001). Univariate analysis revealed that high levels of LINE-1 hypomethylation were correlated with poor disease-free survival (DFS; log-rank test, P = 0.038), whereas multivariate analysis demonstrated that they were significant independent prognostic factor for DFS (hazard ratio: 2.10, 95% confidence interval: 1.02-4.36; P = 0.045). Moreover, samples with high LINE-1 hypomethylation levels exhibited the greatest decrease in 5-hydroxymethylcytosine (5-hmC) levels and increase in tumor-suppressor gene methylation index (P = 0.006 and P < 0.001, respectively). Further, ctDNA studies also showed that LINE-1 hypomethylation had high predictive ability in OCC. CONCLUSIONS: LINE-1 hypomethylation is associated with a higher risk of early OCC relapse, and is hence, a potential predictive biomarker for OCC. Furthermore, 5-hmC levels also exhibited predictive potential in OCC, based on their inverse correlation with LINE-1 hypomethylation levels. LINE-1 hypomethylation analysis, therefore, has applications in determining patient prognosis and real-time surveillance of disease recurrence, and could serve as an alternative method for OCC screening. SUPPLEMENTARY INFORMATION: Supplementary information accompanies this paper at 10.1186/s40364-020-00235-y.

Identification of novel methylation markers in HPV-associated oropharyngeal cancer: genome-wide discovery, tissue verification and validation testing in ctDNA.

Human papilloma virus (HPV)-associated oropharyngeal cancer (OPC) is an independent tumour type with regard to cellular, biological, and clinical features. The use of non-invasive biomarkers such as circulating tumour DNA (ctDNA) may be relevant in early diagnosis and eventually improve the outcomes of patients with head and neck squamous cell carcinoma (HNSCC). Genome-wide discovery using RNA sequencing and reduced representation bisulfite sequencing yielded 21 candidates for methylation-targeted genes. A verification study (252 HNSCC patients) using quantitative methylation-specific PCR (Q-MSP) identified 10 genes (ATP2A1, CALML5, DNAJC5G, GNMT, GPT, LY6D, LYNX1, MAL, MGC16275, and MRGPRF) that showed a significant increase recurrence in methylation groups with OPC. Further study on ctDNA using Q-MSP in HPV-associated OPC showed that three genes (CALML5, DNAJC5G, and LY6D) had a high predictive ability as emerging biomarkers for a validation set, each capable of discriminating between the plasma of the patients from healthy individuals. Among the 42 ctDNA samples, methylated CALML5, DNAJC5G, and LY6D were observed in 31 (73.8%), 19 (45.2%), and 19 (45.2%) samples, respectively. Among pre-treatment ctDNA samples, methylated CALML5, DNAJC5G, and LY6D were observed in 8/8 (100%), 7/8 (87.5%), and 7/8 (87.5%) samples, respectively. Methylated CALML5, DNAJC5G, and LY6D were found in 2/8 (25.0%), 0/8 (0%), and 1/8 (12.5%) of the final samples in the series, respectively. Here, we present the relationship between the methylation status of three specific genes and cancer recurrence for risk classification of HPV-associated OPC cases. In conclusion, ctDNA analysis has the potential to aid in determining patient prognosis and real-time surveillance for disease recurrences and serves as an alternative method of screening for HPV-associated OPC.

Overexpression of Sal-like protein 4 in head and neck cancer: epigenetic effects and clinical correlations.

BACKGROUND: Sal-like protein 4 (SALL4), an embryonic stem cell factor, has been reported to play an essential role in embryogenesis and oncogenesis. As yet, however, the expression and role of this transcription factor in head and neck squamous cell carcinoma (HNSCC) has not been established. METHODS: We assessed SALL4 mRNA expression in a well-characterised dataset of 230 HNSCC samples (test cohort 110 cases and validation cohort 120 cases). We also transfected HNSCC cells (FaDu and UM-SCC-6) with SALL4 siRNA and assessed its effects on proliferation and expression of specific epigenetic factors in order to uncover the role of SALL4 in HNSCC. RESULTS: Overexpression of SALL4 was detected in tumour samples of both cohorts. HNSCC cells treated with SALL4 siRNA showed a reduction in growth and a decrease in DNA methyltransferase 3 alpha (DNMT3A) expression. In the patient cohorts, SALL4 overexpression was found to significantly correlate with disease recurrence (p < 0.001) and SALL4 methylation status (p = 0.002). We also found that DNMT3A was significantly upregulated upon SALL4 upregulation (p < 0.001). High expression levels of SALL4 correlated with decreases in disease-free survival (DFS) rates (log-rank test, p < 0.001). Multivariate analysis revealed that SALL4 expression served as an independent prognostic factor for DFS (hazard ratio: 2.566, 95% confidence interval: 1.598-4.121; p < 0.001). CONCLUSIONS: Our findings indicate that SALL4 upregulation correlates with HNSCC tumour aggressiveness and an adverse patient outcome. Our findings also indicate that DNMT3A may synergistically contribute to the regulatory effects of SALL4. Our findings provide insight into SALL4-mediated HNSCC development via epigenetic modulation.

Establishment of epigenetic markers to predict irradiation efficacy against oropharyngeal cancer.

Irradiation, or chemoradiotherapy, is a curative treatment for oropharyngeal squamous cell carcinoma (OPSCC). Its invasiveness, however, can often negate its efficacy. Therefore, developing methods to predict which patients would benefit from irradiation is urgent. Promoter DNA hypermethylation was recently reported to correlate with favorable OPSCC prognosis. It is still unclear, however, whether there is an association between promoter DNA methylation and response to irradiation. In this study, we analyzed DNA methylation in the specimens from 40 OPSCC patients who had undergone irradiation, using the Infinium assay. Our results showed significant correlation between high levels of promoter DNA methylation and better response to treatment (P < 0.01). We used the 10 most differentially-methylated genes between responders and non-responders to develop a panel of predictive markers for efficacy. Our panel had high sensitivity, specificity and accuracy (92%, 93% and 93%, respectively). We conducted pyrosequencing to quantitatively validate the methylation levels of 8 of the 10 marker genes (ROBO1, ULK4P3, MYOD1, LBX1, CACNA1A, IRX4, DPYSL3 and ELAVL2) obtained by Infinium. The validation by pyrosequencing showed that these 8 genes had a high prediction performance for the training set of 40 specimens and for a validation set of 35 OPSCC specimens, showing 96% sensitivity, 89% specificity and 94% accuracy. Methylation of these markers correlated significantly with better progression-free and overall survival rates, regardless of human papillomavirus status. These results indicate that increased DNA methylation is associated with better responses to irradiation therapy and that DNA methylation can help establish efficacy prediction markers in OPSCC.

Stratification of HPV-associated and HPV-negative oropharyngeal squamous cell carcinomas based on DNA methylation epigenotypes.

While the incidence of oropharyngeal squamous cell carcinoma (OPSCC) has been increasing in these two decades, primarily due to human papillomavirus (HPV), stratification of OPSCC into molecular subgroups showing different clinicopathological features has not been fully investigated. We performed DNA methylome analysis using Infinium 450k for 170 OPSCC cases, including 89 cases in our cohort and 81 cases reported by The Cancer Genome Atlas, together with targeted exon sequencing analysis. We stratified OPSCC by hierarchical clustering analysis using methylome data. Methylation levels of classifier markers were validated quantitatively using pyrosequencing, and area under the curve (AUC) values of receiver operating characteristics (ROC) curves were calculated. OPSCC was stratified into four epigenotypes: HPV(+) high-methylation (OP1), HPV(+) intermediate-methylation (OP2), HPV(-) intermediate-methylation (OP3) and HPV(-) low-methylation (OP4). Ten methylation marker genes were generated: five to classify HPV(+) cases into OP1 and OP2, and five to classify HPV(-) cases into OP3 and OP4. AUC values of ROC curves were 0.969 and 0.952 for the two marker panels, respectively. While significantly higher TP53 mutation and CCND1 copy number gains were observed in HPV(-) than in HPV(+) groups (p < 0.01), no significant difference of genomic aberrations was observed between OP1 and OP2, or OP3 and OP4. The four epigenotypes showed significantly different prognosis (p = 0.0006), distinguishing the most favorable OPSCC subgroup (OP1) among generally favorable HPV(+) cases, and the most unfavorable OPSCC subgroup (OP3) among generally unfavorable HPV(-) cases. HPV(+) and HPV(-) OPSCC are further divided into distinct DNA methylation epigenotypes, showing significantly different prognosis.

Neuropeptide receptor genes GHSR and NMUR1 are candidate epigenetic biomarkers and predictors for surgically treated patients with oropharyngeal cancer.

Pathological staging and histological grading systems are useful, but imperfect, predictors of recurrence in head and neck squamous cell carcinoma (HNSCC). Aberrant promoter methylation is the main type of epigenetic modification that plays a role in the inactivation of tumor suppressor genes. To identify new potential prognostic markers, we investigated the promoter methylation status of five neuropeptide receptor genes. The methylation status of the target genes was compared with clinical characteristics in 278 cases; 72 hypopharyngeal cancers, 54 laryngeal cancers, 75 oropharyngeal cancers, and 77 oral cavity cancers were studied. We found that the NTSR1, NTSR2, GHSR, MLNR, and NMUR1 promoters were methylated in 47.8%, 46.8%, 54.3%, 39.2%, and 43.5% of the samples, respectively. GHSR and NMUR1 promoter methylation independently predicted recurrence in HNSCC. In patients with oropharyngeal cancer (n = 75), GHSR and NMUR1 promoter methylation significantly correlates with survival in surgically treated patients. We classified our patients as having a low, intermediate, or high-risk of death based on three factors: HPV status, and GHSR and NMUR1 promoter methylation. The disease-free survival (DFS) rates were 87.1%, 42.7%, and 17.0%, respectively. Combined data analysis of the methylation status of ten-eleven translocation (TET) family genes indicated a trend toward greater methylation indices as the number of TET methylation events increased. In the current study, we presented the relationship between the methylation status of the GHSR and NMUR1 genes and recurrence in HNSCC, specifically in risk classification of oropharyngeal carcinomas cases with HPV status.

5-Hydroxymethylcytosine and ten-eleven translocation dioxygenases in head and neck carcinoma.

Ten-eleven translocation (TET) enzymes are implicated in DNA demethylation through dioxygenase activity, which converts 5-methylcytosine to 5-hydroxymethylcytosine (5-hmC). However, the specific roles of TET enzymes and 5-hmC levels in head and neck squamous cell carcinoma (HNSCC) have not yet been evaluated. In this study, we analyzed 5-hmC levels and TET mRNA expression in a well-characterized dataset of 117 matched pairs of HNSCC tissues and normal tissues. 5-hmC levels and TET mRNA expression were examined via enzyme-linked immunosorbent assay and quantitative real-time PCR, respectively. 5-hmC levels were evaluated according to various clinical characteristics and prognostic implications. Notably, we found that 5-hmC levels were significantly correlated with tumor stage (P = 0.032) and recurrence (P = 0.018). Univariate analysis revealed that low levels of 5-hmC were correlated with poor disease-free survival (DFS; log-rank test, P = 0.038). The expression of TET family genes was not associated with outcomes. In multivariate analysis, low levels of 5-hmC were evaluated as a significant independent prognostic factor of DFS (hazard ratio: 2.352, 95% confidence interval: 1.136-4.896; P = 0.021). Taken together, our findings showed that reduction of TET family gene expression and subsequent low levels of 5-hmC may affect the development of HNSCC.