Enhancer infestation drives tumorigenic activation of inactive B compartment in Epstein-Barr virus-positive nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated malignant epithelial tumor endemic to Southern China and Southeast Asia. While previous studies have revealed a low frequency of gene mutations in NPC, its epigenomic aberrations are not fully elucidated apart from DNA hypermethylation. Epigenomic rewiring and enhancer dysregulation, such as enhancer hijacking due to genomic structural changes or extrachromosomal DNA, drive cancer progression.

METHODS

We conducted Hi-C, 4C-seq, ChIP-seq, and RNA-seq analyses to comprehensively elucidate the epigenome and interactome of NPC using C666-1 EBV(+)-NPC cell lines, NP69T immortalized nasopharyngeal epithelial cells, clinical NPC biopsy samples, and in vitro EBV infection in HK1 and NPC-TW01 EBV(-) cell lines.

FINDINGS

In C666-1, the EBV genome significantly interacted with inactive B compartments of host cells; the significant association of EBV-interacting regions (EBVIRs) with B compartment was confirmed using clinical NPC and in vitro EBV infection model. EBVIRs in C666-1 showed significantly higher levels of active histone modifications compared with NP69T. Aberrant activation of EBVIRs after EBV infection was validated using in vitro EBV infection models. Within the EBVIR-overlapping topologically associating domains, 14 H3K4me3(+) genes were significantly upregulated in C666-1. Target genes of EBVIRs including PLA2G4A, PTGS2 and CITED2, interacted with the enhancers activated in EBVIRs and were highly expressed in NPC, and their knockdown significantly reduced cell proliferation.

INTERPRETATION

The EBV genome contributes to NPC tumorigenesis through "enhancer infestation" by interacting with the inactive B compartments of the host genome and aberrantly activating enhancers.

FUNDING

The funds are listed in the Acknowledgements section.

Pan-cancer assessment of antineoplastic therapy-induced interstitial lung disease in patients receiving subsequent therapy immediately following immune checkpoint blockade therapy

BACKGROUND

Drug-induced interstitial lung disease (DIILD) is a serious adverse event potentially induced by any antineoplastic agent. Whether cancer patients are predisposed to a higher risk of DIILD after receiving immune checkpoint inhibitors (ICIs) is unknown.

METHODS

This study retrospectively assessed the cumulative incidence of DIILD in consecutive cancer patients who received post-ICI antineoplastic treatment within 6 months from the final dose of ICIs. There was also a separate control cohort of 55 ICI-naïve patients with non-small cell lung cancer (NSCLC) who received docetaxel.

RESULTS

Of 552 patients who received ICIs, 186 met the inclusion criteria. The cohort predominantly comprised patients with cancer of the lung, kidney/urinary tract, or gastrointestinal tract. The cumulative incidence of DIILD in the entire cohort at 3 and 6 months was 4.9% (95% confidence interval [CI] 2.4%-8.7%) and 7.2% (95% CI 4.0%-11.5%), respectively. There were significant differences according to cancer type (Gray's test, P = .04), with the highest cumulative incidence of DIILD in patients with lung cancer being 9.8% (95% CI 4.3%-18.0%) at 3 months and 14.2% (95% CI 7.3%-23.3%) at 6 months. DIILD was caused by docetaxel in six of these 11 lung cancer patients (54.5%). After matching, the cumulative incidence of docetaxel-induced ILD in patients with NSCLC in the post-ICI setting was higher than that in the ICI-naïve setting: 13.0% (95% CI 3.3%-29.7%) vs 4.3% (95% CI 0.3%-18.2%) at 3 months; and 21.7% (95% CI 7.9%-39.9%) vs 4.3% (95% CI 0.3%-18.2%) at 6 months. However, these were not significant differences (hazard ratio, 5.37; 95% CI 0.64-45.33; Fine-Gray P = .12).

CONCLUSIONS

Patients with lung cancer were at high risk of developing DIILD in subsequent regimens after ICI treatment. Whether NSCLC patients are predisposed to additional risk of docetaxel-induced ILD by prior ICIs warrants further study.

Impact of Radiation Dose on Treatment of Maxillary Cancer With Superselective Intra-arterial Cisplatin With Radiotherapy

BACKGROUND/AIM

Maxillary sinus cancer is a relatively rare disease, and treatment is still evolving. We compared the efficacy of superselective intra-arterial infusion of high-dose cisplatin (CDDP) with concomitant radiotherapy (RADPLAT) using three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) and analyzed the relationship between the total radiation dose and the treatment outcome in localized maxillary sinus cancer.

PATIENTS AND METHODS

We reviewed the cases of 58 patients with localized maxillary sinus cancer treated with RADPLAT at our institution from March 2004 to November 2020. These 58 patients included 34 who received 3DCRT and 24 who received IMRT.

RESULTS

The median follow-up period was 38.4 months. The median prescribed dose to the local lesion was 66 Gy in the 3DCRT group and 70 Gy in the IMRT group. CDDP (100-120 mg/m²) was administered once a week for a median of 6 cycles. The 5-year local control rate and overall survival rate were 69.9% and 72.2%, respectively. The patients treated with 70 Gy had a significantly higher local control rate (87.7%) than those treated with 60 Gy or less (41.0%) (p=0.011). No late grade 3 or higher eye disorders except for cataracts developed in the IMRT group, while grade 4 eye disorders occurred in four patients receiving 3DCRT.

CONCLUSION

IMRT can escalate radiation dose safely with acceptable toxicities. The total dose may have an impact on the local control rate in RADPLAT.

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.

Association between human papillomavirus particle production and the severity of recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis (RRP) has a wide range of severity. We investigate the relationship between human papillomavirus (HPV) particle production and severity of RRP. From September 2005 to June 2021, 68 RRP samples (from 29 patients) were included. HPV type was determined. HPV viral load, physical status, and demographic and clinical characteristics were assessed. Immunohistochemistry (IHC) was performed for p16, Ki-67, L1, and E4. We used NanoSuit-CLEM (correlative light and electron microscopy) and transmission electron microscopy (TEM) to examine the samples. The total number of surgeries in HPV-positive and HPV-negative cases were 3.78 (n = 55/68, range: 1-16) and 1.30 (n = 13/68, range: 1-3), respectively (p = 0.02). IHC showed that L1 and E4 were correlated and expressed on the tumour surface. NanoSuit-CLEM and TEM revealed HPV particles in L1-positive nuclei. L1 IHC-positive cases had a shorter surgical interval (p < 0.01) and more frequent surgeries (p = 0.04). P16 IHC, viral load, and physical status were not associated with disease severity. This study visualised HPV particle production in RRP for the first time. Persistent HPV particle infection was associated with severity. We suggest L1 IHC for evaluating RRP severity in addition to the Derkay score.

Analysis of Speech Fundamental Frequencies for Different Tasks in Japanese

PURPOSE

Speech fundamental frequency (SFF) assessment is essential for all dysphonia patients to effectively evaluate the therapeutic effects of voice therapy, especially in patients with disturbances in their voice pitch due to mutational dysphonia, Reinke's edema, or as side effects of hormone therapy. A standard method of SFF measurement remains unknown. Speech tasks such as sustained vowel phonation, counting, reading passage, and spontaneous speech have generally been used for SFF measurements. Ideally, spontaneous speech best reflects SFF; however, this task has not yet been clearly defined and is limited with regard to its adaptation to a clinical setting. A reliable task for SFF measurement in Japanese, which corresponds to a speech task that most closely reflects the value that would be observed with typical spontaneous speech, has not been investigated. This study aimed to identify a reliable speech task by measuring the SFF values elicited by different widely used speech tasks in Japanese, and assess its reliability and coefficient of determination (R²).

METHODS

Sixty healthy volunteers (30 men and 30 women; aged 19-30 years; mean age 22.5 years) were enrolled. All experimental procedures were performed in Japanese. The SFF values for the speech tasks were determined through the voice samples recorded using a Pulse Code Modulation (PCM) recorder. Each task, except spontaneous speech, was repeated five times, and the average fundamental frequency in each task was determined as the SFF. To assess the reliability of the SFF values across daily variations within individual speakers, the SFF measurements were repeated on two different days, separated by at least 1 week.

RESULTS

The SFF values of sustained /a/ phonation, sustained vowel-average, counting, reading passage, and spontaneous speech had excellent reliability, in terms of their reproduction based on intraclass correlation. Significantly high SFF values were observed, in decreasing order, for sustained vowels-average, counting, reading passage, and spontaneous speech in both males and females. The highest R² for spontaneous speech was that of reading passage in both males (R² = 0.771) and females (R² = 0.806) (P < 0.01).

CONCLUSION

When spontaneous speech was presented as a task most reflective of daily conversation, reading passage was determined to be the reliable task to assess the therapeutic effect of voice therapy in Japanese.

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.

Update on Findings about Sudden Sensorineural Hearing Loss and Insight into Its Pathogenesis

Sudden sensorineural hearing loss (SSNHL) is routinely encountered and is one of the most common emergent diseases in otolaryngology clinics. However, the etiology of SSNHL remains unclear. Due to the inaccessibility of the living human inner ear for biopsy, studies investigating the etiology of SSNHL have been performed by analyzing data obtained from examinations using peripheral blood or imaging. We updated the findings obtained from serological, magnetic resonance imaging, genetic, and viral examinations to reveal the etiology of SSNHL. Regarding viral examination, we focused on sensorineural hearing loss associated with coronavirus disease (COVID-19) because the number of correlated reports has been increasing after the outbreak. The updated findings revealed the following three possible mechanisms underlying the development of SSNHL: thrombosis and resulting vascular obstruction in the cochlea, asymptomatic viral infection and resulting damage to the cochlea, and cochlear inflammation and resulting damage to the cochlea. Thrombosis and viral infection are predominant, and cochlear inflammation can be secondarily induced through viral infection or even thrombosis. The findings about sensorineural hearing loss associated with COVID-19 supported the possibility that asymptomatic viral infection is one of the etiologies of SSNHL, and the virus can infect inner ear tissues and directly damage them.

Auditory and Vestibular Characteristics of NLRP3 Inflammasome Related Autoinflammatory Disorders: Monogenic Hearing Loss Can Be Improved by Anti-interleukin-1 Therapy

Inflammasomes are large multimeric protein complexes which regulate the activation of the proinflammatory cytokines interleukins-1β and−18 and inflammatory cell death called pyroptosis. NLRP1, NLRP3, NLRC4, AIM2, and pyrin can induce the formation of inflammasomes. Of these, the NLRP3 inflammasome is the most well-characterized. Recent studies revealed that variants of the NLRP3 gene cause genetic diseases, including systemic inflammatory syndrome called cryopyrin-associated periodic syndrome (CAPS) and non-syndromic sensorineural hearing loss DFNA34. NLRP3 variants cause CAPS and DFNA34 by constitutively activating the NLRP3 inflammasome and increasing IL-1β release. Patients with CAPS show systemic inflammatory symptoms, and hearing loss is a characteristic feature. Patients with CAPS and DFNA34 show progressive bilateral sensorineural hearing loss. Hearing loss has unique characteristics that can be improved or stabilized by anti-interluekin-1 therapy, although it is usually difficult to alleviate genetic hearing loss by drugs. However, it should be noted that there is a window of opportunity to respond to treatment, and younger patients are most likely to respond. It is important to know the characteristics of CAPS and DFNA34 for early diagnosis, and mutation analysis of NLRP3 will lead to a definite diagnosis. In this review, we summarize the current understanding of the mechanisms of the NLRP3 inflammasome and characteristics of patients with CAPS and DFNA34, especially focused on auditory and vestibular findings.

Diagnosis of Ion-Exchange Resin Depositions in Paraffin Sections Using Corrective Light and Electron Microscopy-NanoSuit Method

Ion-exchange resins are commonly used to treat complications such as hyperkalemia, hyperphosphatemia, and hypercholesterolemia. Gastrointestinal complications may occur as side effects of such treatments. Sodium and calcium polystyrene sulfonate (PS-Ca) are cation-exchange resins comprising an insoluble structure that binds to potassium ions in the digestive tract and exchanges them with sodium and calcium ions, respectively, to promote their elimination. PS crystals are rhomboid, refractive, and basophilic in hematoxylin and eosin staining. To differentiate PS crystals from other ion-exchange resin crystals such as sevelamer and cholestyramine, periodic acid-Schiff, Ziehl-Neelsen, and Congo red staining are usually performed. Here, correlative light and electron microscopy (CLEM)-energy-dispersive X-ray spectroscopy and the NanoSuit method (CENM) was applied to perform a definitive identification of ion-exchange resins. CENM could detect sulfur in PS crystals without destroying the glass slides. Notably, PS retained its ion-exchange ability to bind potassium in paraffin sections. Differential diagnosis of anion-exchange resins, such as sevelamer and cholestyramine, was possible using these characteristics. The phosphorus:carbon ratio was higher in sevelamer than in cholestyramine after soaking paraffin sections in a phosphate solution. Therefore, CENM may be used for the differential pathological diagnosis of ion-exchange resins in paraffin sections.

Identification and characterization of primary cilia-positive salivary gland tumours exhibiting basaloid/myoepithelial differentiation

Primary cilia (PC) are non-motile, antenna-like structures on the cell surface. Many types of neoplasms exhibit PC loss, whereas in some neoplasms PC are retained and involved in tumourigenesis. To elucidate the PC status and characteristics of major salivary gland tumours (SGTs), we examined 100 major SGTs encompassing eight histopathological types by immunohistochemical analysis. PC were present in all (100%) of the pleomorphic adenomas (PAs), basal cell adenomas (BCAs), adenoid cystic carcinomas (AdCCs), and basal cell adenocarcinomas (BCAcs) examined, but absent in all (0%) of the Warthin tumours, salivary duct carcinomas, mucoepidermoid carcinomas, and acinic cell carcinomas examined. PC were also detected by electron-microscopic analysis using the NanoSuit method. It is worthy of note that the former category and latter category of tumours contained and did not contain a basaloid/myoepithelial differentiation component, respectively. The four types of PC-positive SGTs showed longer PC than normal and exhibited a characteristic distribution pattern of the PC in the ductal and basaloid/neoplastic myoepithelial components. Two PC-positive carcinomas (AdCC and BCAc) still possessed PC in their recurrent/metastatic sites. Interestingly, activation of the Hedgehog signalling pathway, shown by predominantly nuclear GLI1 expression, was significantly more frequently observed in PC-positive SGTs. Finally, we identified tau tubulin kinase 2 (TTBK2) as being possibly involved in the production of PC in SGTs. Taken together, our findings indicate that SGTs that exhibit basaloid/myoepithelial differentiation (PA, BCA, AdCC, and BCAc) are ciliated, and their PC exhibit tumour-specific characteristics, are involved in activation of the Hedgehog pathway, and are associated with TTBK2 upregulation, providing a significant and important link between SGT tumourigenesis and PC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

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.

Telomere shortening in head and neck cancer: association between DNA demethylation and survival

A growing body of evidence indicates that telomere dysfunction is a biological marker of progression in several types of cancer. However, the association between head and neck squamous cell carcinoma (HNSCC) and telomere length (TL) remains unknown. We measured the absolute TL levels in a well-characterised dataset of 211 tumoral vs normal tissues obtained from the same patients by quantitative polymerase chain reaction assay. Normalised TL levels were significantly lower in tumour samples than in normal tissue (P < 0.001) and there was a positive correlation between tumour tissue and normal mucosal tissue (R² = 0.176, P < 0.001). We were able to distinguish two classes, one with a tumour/normal TL ratio ≤ 0.3 (38.4%), which showed clear telomere erosion, and the other with a tumour/normal TL ratio > 0.3 (61.6%), in which the TL was slightly shorter or longer than that in normal tissue. Notably, the tumour/normal TL ratio was correlated with the likelihood of disease recurrence (P = 0.002), the 5-hydroxymethylcytosine level (P = 0.043), and expression of the ten-eleven translocation (TET) gene (P = 0.043). Our findings show that TL shortening and subsequent low levels of 5-hydroxymethylcytosine and TET expression may contribute to development of 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.

G Protein-Coupled Receptor Genes, PTGDR1, PTGDR2, and PTGIR, Are Candidate Epigenetic Biomarkers and Predictors for Treated Patients with HPV-Associated Oropharyngeal Cancer

Differences in the biology of human papillomavirus (HPV)-associated oropharyngeal cancers (OPCs) and HPV-negative OPCs may have implications in patient management. Early detection is imperative to reduce HPV-associated OPC mortality. Circulating tumor DNA (ctDNA) can potentially serve as a biomarker for monitoring clinically relevant cancer-related genetic and epigenetic modifications. We analyzed the methylation status of 24 G protein-coupled receptor (GPCR) genes in verification (85 OPC primary samples) and validation (8 OPC ctDNA samples) studies using quantitative methylation-specific polymerase chain reaction (Q-MSP). The Q-MSP-based verification study with 85 OPC primary samples revealed the GPCR genes that were significantly associated with recurrence in high methylation groups (≥14 methylated genes) with OPC and HPV-associated OPC (p < 0.001). In the Kaplan–Meier estimate and multivariate Cox proportional hazard analyses, 13 GPCR genes were significantly related to increased recurrence in the methylation group. Furthermore, the validation study on ctDNA showed that three of these genes (Prostaglandin D2 receptor 1: PTGDR1, Prostaglandin D2 receptor 2: PTGDR2, and Prostaglandin I2 Receptor: PTGIR) had a prediction performance as emerging biomarkers. We characterized the relationship between the methylation status of GPCR genes and outcomes in HPV-associated OPC. Our results highlight the potential utility of ctDNA methylation-based detection for the clinical management of HPV-associated OPC.

Primary Lymphangiosarcoma of the Urinary Bladder in a Dog

Abdominal ultrasonographical and computed tomography examinations of a 12-year-old neutered female toy poodle revealed a protruding mass, approximately 2 cm in diameter, at the apex of the bladder. The mass was firm and haemorrhagic with a homogeneously brownish-yellow cut surface. Microscopically, it was unencapsulated and located in the muscle layer with invasion of the extra-muscular layer. It was composed of spindloid to oval neoplastic cells that formed irregular clefts and diffuse sheets that dissected bundles of collagen. Immunohistochemically, the neoplastic cells were positive for vimentin and lymphatic vessel endothelial hyaluronan receptor 1 antigens, but negative for cytokeratin AE1/AE3, factor VIII-related antigen, CD31, CD34, Prox-1, S100, desmin, α-smooth muscle actin and MyoD1. Negative immunolabelling for laminin antigen supported the absence of evidence of a basal lamina on ultrastructural examination. Based on these findings, this tumour was identified as a lymphangiosarcoma. To the best of our knowledge, this case is the first report of lymphangiosarcoma arising from the bladder in a dog.

Assessment of Dysphonia Using the Japanese Version of the Voice Handicap Index and Determination of Cutoff Points for Screening

INTRODUCTION

The Voice Handicap Index (VHI) is recognized as a useful subjective assessment method for dysphonia. The original VHI has been translated into numerous other languages, including Japanese (J-VHI). Although the reliability and validity of the J-VHI have already been established, the cutoff point has not been determined. The aims of this study were to investigate the relationship between the J-VHI and other voice laboratory measurements, and determine the cutoff point.

METHOD

This study included 167 dysphonic patients and 55 healthy volunteers. All patients and volunteers completed the J-VHI at the initial visit, and the following outcomes were determined: VHI scores of patients with dysphonia and healthy volunteers, VHI scores according to disease, cutoff point, and correlations between VHI scores and other voice laboratory measurements.

RESULTS

Both the total VHI (VHI-T) and individual domain (functional domain [VHI-F], emotional domain [VHI-E], physical domain [VHI-P]) scores were significantly higher in the dysphonia group compared to the healthy volunteer group. VHI-T, VHI-F, and VHI-E scores were significantly lower in the benign mucosal lesion subgroup, compared to the other disease subgroups. The G scale and B scale of the grade-roughness-breathiness-asthenia-strain scale showed a significant association with VHI-T, VHI-F, and VHI-P scores. Similarly, the A scale showed a significant association with VHI-T, VHI-F, and VHI-E scores. The cutoff point (12) for VHI-T was chosen from the receiver operating characteristic curve to maximize sensitivity and specificity. Similarly, the cutoff points for VHI-F (5), VHI-P (5), and VHI-E (3) were also obtained. Significant differences in maximum phonation time, pitch range, G scale, and B scale were observed between the VHI-T negative (VHI ≤ 12) and positive (VHI-T > 13) groups.

CONCLUSION

These findings suggest that self-evaluation using the VHI could serve as an independent assessment and screening tool for patients with dysphonia.

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.

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.

Prostanoid receptor genes confer poor prognosis in head and neck squamous cell carcinoma via epigenetic inactivation

Background

Chronic inflammation is a risk factor for head and neck squamous cell carcinoma (HNSCC) and other diseases. Prostanoid receptors are clearly involved in the development of many types of cancer. However, their role is not simple and is poorly understood in HNSCC.

Methods

Methylation profiles of prostanoid receptor family genes were generated for tumour samples obtained from 274 patients with HNSCC, including 69 hypopharynx, 51 larynx, 79 oral cavity, and 75 oropharynx tumour samples, by quantitative methylation-specific PCR. Promoter methylation was then evaluated with respect to various clinical characteristics and patient survival.

Results

The mean number of methylated genes per sample was 2.05 ± 2.59 (range 0 to 9). Promoters of PTGDR1, PTGDR2, PTGER1, PTGER2, PTGER3, PTGER4, PTGFR, PTGIR, and TBXA2R were methylated in 43.8%, 18.2%, 25.5%, 17.5%, 41.2%, 8.0%, 19.3%, 20.4%, and 11.3% of the samples, respectively. Methylation indices for prostanoid receptor family genes tended to be higher as the number of TET methylation events increased. Patients with 5–9 methylated genes had a significantly lower survival rate than that of patients with 0–4 methylated genes (log-rank test, P= 0.007). In multivariate analyses, PTGDR1 methylation was most highly correlated with recurrence in patients with hypopharyngeal cancer (P = 0.014). A similar correlation was observed for PTGER4 in patients with laryngeal cancer (P = 0.046). Methylation of the PTGIR and TBXA2R promoters was positively correlated with recurrence in oropharyngeal cancer (P = 0.028 and P = 0.006, respectively). Moreover, Patients with 5–9 methylated genes were extremely lower of 5hmC levels (P = 0.035) and was correlated with increasing expression of DNMT3A and DNMT3B (P < 0.05 and P < 0.05, respectively).

Conclusion

We characterised the relationship between the methylation status of prostanoid receptor genes and recurrence in HNSCC. These results provide new perspectives for the development of molecular targeted treatment approaches.

Utility of Scanning Electron Microscopy Elemental Analysis Using the 'NanoSuit' Correlative Light and Electron Microscopy Method in the Diagnosis of Lanthanum Phosphate Deposition in the Esophagogastroduodenal Mucosa

BACKGROUND

We have recently developed the correlative light and electron microscopy of hematoxylin and eosin (H&E)-stained glass slides using the 'NanoSuit' method. The aim of this study is to explore the utility of the new NanoSuit-correlative light and electron microscopy method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy elemental analysis for the diagnosis of lanthanum phosphate deposition in the H&E-stained glass slides.

METHODS

Nine H&E-stained glass slides of the upper gastrointestinal tract mucosa containing the brown pigmented areas by light microscopic observation, which were suspected as lanthanum phosphate deposition, were observed and analyzed by scanning electron microscopy-energy dispersive X-ray spectroscopy using the NanoSuit-correlative light and electron microscopy method.

RESULTS

In all nine slides, the new NanoSuit-correlative light and electron microscopy method combined with scanning electron microscopy-energy dispersive X-ray spectroscopy revealed the accumulation of both lanthanum and phosphorus in the tissue area corresponding to the brown pigment deposition. In addition to the existence of lanthanum phosphate in the stomach and duodenum, known target organs, we observed deposition in the esophagus for the first time. Furthermore, we observed lanthanum phosphate deposition in the background mucosa of stomach containing primary adenocarcinoma.

CONCLUSIONS

Scanning electron microscopy-energy dispersive X-ray spectroscopy analysis using the NanoSuit-correlative light and electron microscopy method is useful for the diagnosis of lanthanum phosphate deposition in the H&E-stained glass slides. Lanthanum phosphate deposition occurs not only in the stomach and duodenum but also in the esophagus.

Randomized clinical trial of extensive intraoperative peritoneal lavage versus standard treatment for resectable advanced gastric cancer (CCOG 1102 trial)

BACKGROUND

A survival benefit of extensive intraoperative peritoneal lavage (EIPL) has been reported in patients with gastric cancer with positive peritoneal cytology. The hypothesis of this study was that EIPL may reduce peritoneal recurrence in patients with advanced gastric cancer who undergo surgery with curative intent.

METHODS

This was an open-label, multi-institutional, randomized, phase 3 trial to assess the effects of EIPL versus standard treatment after curative gastrectomy for resectable gastric cancer of T3 status or above. The primary endpoint was disease-free survival (DFS); secondary endpoints were overall survival, peritoneal recurrence-free survival and incidence of adverse events.

RESULTS

Between July 2011 and January 2014, 314 patients were enrolled from 15 institutions and 295 patients were analysed (145 and 150 in the EIPL and no-EIPL groups respectively). The 3-year DFS rate was 63·9 (95 per cent c.i. 55·5 to 71·2) per cent in the EIPL group and 59·7 (51·3 to 67·1) per cent in the control group (hazard ratio (HR) 0·81, 95 per cent c.i. 0·57 to 1·16; P = 0·249). The 3-year overall survival rate was 75·0 (67·1 to 81·3) per cent in the EIPL group and 73·7 (65·9 to 80·1) per cent in the control group (HR 0·91, 0·60 to 1·37; P = 0·634). Peritoneal recurrence-free survival was not significantly different between the two groups (HR 0·92, 0·62 to 1·36; P = 0·676). No intraoperative complications related to EIPL were observed.

CONCLUSION

EIPL did not improve survival or peritoneal recurrence in patients who underwent gastrectomy for advanced gastric cancer. Registration number: 000005907 (http://www.umin.ac.jp/ctr/index.htm).

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.

SALL2 Is a Novel Prognostic Methylation Marker in Patients with Oral Squamous Carcinomas: Associations with SALL1 and SALL3 Methylation Status

Staging and pathological grading systems are convenient, but imperfect predictors of recurrence of head and neck squamous cell carcinoma. Therefore, to identify potential alternative prognostic markers, we investigated the methylation status of the promoter of Sal-like protein 2 (SALL2). SALL2 mRNA expression was absent in 8/9 (88.9%) University of Michigan squamous cell carcinoma cell lines, whereas two nonmalignant cell lines had stable expression. The normalized methylation value of SALL2 in cancer cell lines was significantly higher than in normal cell lines. SALL2 methylation found in 74 of 233 (31.8%) tumor specimens was correlated with the methylation status of both SALL1 and SALL3. SALL2 methylation was not associated with any difference in disease-free survival (DFS). Therefore, the presence of SALL2 methylation was statistically correlated with a decrease in DFS in patients with oral cancer (log-rank test, p = 0.032). Furthermore, it was associated with disease recurrence in 36.2% of oral cancer cases, with an odds ratio of 2.922 (95% confidence interval = 1.198-7.130; p = 0.018) by multivariate Cox proportional hazard regression analysis. This study suggests that cytosine-phosphate- guanosine (CpG) hypermethylation is a likely mechanism of SALL2 inactivation and supports the hypothesis that SALL2 could serve as an important clinical risk assessment.

An Ameloblastoma in the Middle Ear

An ameloblastoma is a locally aggressive odontogenic tumour that commonly develops from the odontogenic epithelium within the jawbone. Here we present for the first time a case of a rare primary ameloblastoma in the middle ear cavity, along with some consideration of its treatment and a new classification. A 65-year-old woman presented with a left middle ear cavity tumour. Pathological examination led to the diagnosis of an ameloblastoma. We resected the tumour along with an extensive part of the middle ear mucosa, which made it difficult to have an adequate margin. It is recommended that the remaining bone be ground 2-3 mm beyond the visible margin after resecting the gross tumour. Therefore, several cases are treated with conservative surgery, including physicochemical treatment. This factor should be considered when designing treatment strategies as good alternatives in cases where resection with an adequate margin is difficult.

Genes Located on 18q23 Are Epigenetic Markers and Have Prognostic Significance for Patients with Head and Neck Cancer

Loss of heterozygosity (LOH) on chromosome 18q23 is associated with significantly decreased survival in head and neck cancer. In agreement with such tumor suppressive roles, the loss of function of genes located in this region can be achieved through LOH and promotor hypermethylation. In this study, the methylation status of promoters of 18q23 genes in 243 head and neck cancer patients was assessed by quantitative methylation-specific PCR. Promoter methylation was then compared to various clinical characteristics and patient survival. GALR1 and SALL3 promoter methylation correlated with reduced disease-free survival (log-rank test, p = 0.018 and p = 0.013, respectively). Furthermore, based on multivariate Cox proportional hazards analysis, these methylation events were associated with poor disease-free survival, with hazard ratios of 1.600 (95% confidence interval: CI, 1.027–2.493; p = 0.038) and 1.911 (95% CI, 1.155–3.162; p = 0.012), respectively. By comparison, GALR1 and SALL3 methylation were not prognostic for overall survival in The Cancer Genome Atlas (TCGA) cohort. Our findings suggest that the methylation status of 18q23 genes could serve as important biomarkers for the prediction of clinical outcomes in well-annotated head and neck squamous cell carcinoma cohorts. GALR1 and SALL3 methylation could thus help to facilitate risk stratification for individualized treatment.

Defective repair capacity of variant proteins of the DNA glycosylase NTHL1 for 5-hydroxyuracil, an oxidation product of cytosine

The NTHL1 gene encodes DNA glycosylase, which is involved in base excision repair, and biallelic mutations of this gene result in NTHL1-associated polyposis (NAP), a hereditary disease characterized by colorectal polyposis and multiple types of carcinomas. However, no proper functional characterization of variant NTHL1 proteins has been done so far. Herein, we report functional evaluation of variant NTHL1 proteins to aid in the accurate diagnosis of NAP. First, we investigated whether it would be appropriate to use 5-hydroxyuracil (5OHU), an oxidation product of cytosine, for the evaluation. In the supF forward mutation assay, 5OHU caused an increase of the mutation frequency in human cells, and the C→T mutation was predominant among the 5OHU-induced mutations. In addition, in DNA cleavage activity assay, 5OHU was excised by NTHL1 as well as four other DNA glycosylases (SMUG1, NEIL1, TDG, and UNG2). When human cells overexpressing the five DNA glycosylases were established, it was found that each of the five DNA glycosylases, including NTHL1, had the ability to suppress 5OHU-induced mutations. Based on the above results, we performed functional evaluation of eight NTHL1 variants using 5OHU-containing DNA substrate or shuttle plasmid. The DNA cleavage activity assay showed that the variants of NTHL1, Q90X, Y130X, R153X, and Q287X, but not R19Q, V179I, V217F, or G286S, showed defective repair activity for 5OHU and two other oxidatively damaged bases. Moreover, the supF forward mutation assay showed that the four truncated-type NTHL1 variants showed a reduced ability to suppress 5OHU-induced mutations in human cells. These results suggest that the NTHL1 variants Q90X, Y130X, R153X, and Q287X, but not R19Q, V179I, V217F, or G286S, were defective in 5OHU repair and the alleles encoding them were considered to be pathogenic for NAP.

Promoter methylation of galanin receptors as epigenetic biomarkers for head and neck squamous cell carcinomas

INTRODUCTION

While remarkable progress has been made in standard treatments for head and neck squamous cell carcinomas (HNSCCs), the long-term survival remains at an unsatisfactory 40-50%. To improve the survival rate, biomarkers for optimal treatment selection and prognostic prediction, as well as novel, low-toxicity treatment strategies, are required. Galanin receptor (GALR) 1 and GALR2 are well-studied tumor suppressors in HNSCCs. Compared with other clinicopathological factors, the epigenetic variants of GALRs have been found to be the most powerful markers to predict the prognosis of HNSCC patients. Areas covered: This review outlines the functions and signaling pathways of GALRs and explains the potential of GALR promoter methylation as a biomarker for HNSCC prognosis. We also summarize recent developments in promoter methylation studies in HNSCC and indicate future directions for GALR promoter methylation studies. Expert commentary: GALR studies have highlighted two major aspects with implications in HNSCC - that G-protein coupled receptors (GPCRs) act as tumor suppressor genes and that GALR promoter methylation is significantly related to the carcinogenesis of HNSCC. The findings of GALR studies can be applied to studies on other GPCRs and further in-depth DNA methylation studies. Deeper insights into GPCR epigenetics are expected to markedly improve HNSCC treatment.

Aberrant Epigenetic Regulation in Head and Neck Cancer Due to Distinct EZH2 Overexpression and DNA Hypermethylation

Enhancer of Zeste homologue 2 (EZH2) overexpression is associated with tumor proliferation, metastasis, and poor prognosis. Targeting and inhibition of EZH2 is a potentially effective therapeutic strategy for head and neck squamous cell carcinoma (HNSCC). We analyzed EZH2 mRNA expression in a well-characterized dataset of 230 (110 original and 120 validation cohorts) human head and neck cancer samples. This study aimed to investigate the effects of inhibiting EZH2, either via RNA interference or via pharmacotherapy, on HNSCC growth. EZH2 upregulation was significantly correlated with recurrence (p < 0.001) and the methylation index of tumor suppressor genes (p < 0.05). DNMT3A was significantly upregulated upon EZH2 upregulation (p = 0.043). Univariate analysis revealed that EZH2 upregulation was associated with poor disease-free survival (log-rank test, p < 0.001). In multivariate analysis, EZH2 upregulation was evaluated as a significant independent prognostic factor of disease-free survival (hazard ratio: 2.085, 95% confidence interval: 1.390–3.127; p < 0.001). Cells treated with RNA interference and DZNep, an EZH2 inhibitor, showed the most dramatic changes in expression, accompanied with a reduction in the growth and survival of FaDu cells. These findings suggest that EZH2 upregulation is correlated with tumor aggressiveness and adverse patient outcomes in HNSCC. Evaluation of EZH2 expression might help predict the prognosis of HNSCC patients.

Abstract 3318: Frequent promoter hypermethylation correlates with better prognosis in pharyngeal cancer

The incidence of Human Papilloma Virus (HPV) associated oropharyngeal cancer is dramatically increasing in developed countries, due to mainly HPV 16. Whereas viral infection status could affect molecular subtypes in other cancers, molecular features of HPV(+) and HPV(-) OPSCCs including epigenetic aberrations are not fully clarified. We here performed genome-wide DNA methylation analysis of OPSCC. We identified 144 candidate methylation-associated silencing genes using Infinium 450k analysis of 13 OPSCC samples, 4 normal mucosal samples and two HNSCC cell lines with/without 5Aza/TSA. Re-expression of the hypermethylated genes by 5-aza-2-deoxycytidine was confirmed by RNA-seq. Among the 144 candidate genes, 9 genes were selected and their methylation status was analyzed in 70 pharyngeal SCC cases including 55 OPSCC and 15 hypopharyngeal SCC cases using pyrosequencing. HPV(+) samples showed higher methylation level within all the samples (P=0.0002, t-test) and within OPSCC (P=0.001, t-test). While HPV infection significantly correlated with positive staining of p16 in immunohistochemistry, HPV(+) as well as p16(+) status significantly correlated with better prognosis (P = 0.005 and 0.002, log-rank test). The aberrant hypermethylation of an identified marker gene also correlated with better prognosis significantly when all the cases were analyzed (P = 0.04). Interestingly, the its hypermethylation status also correlated with better prognosis within p16(-) cases (P = 0.03). Our data suggest that aberrant DNA methylation might be involved in genesis of OPSCC, that DNA methylation might associate with HPV infection, and that methylation marker might work as prognostic marker. To elucidate the correlation between DNA methylation and OPSCC including HPV(+) and HPV(-) OPSCCs, we additionally performed genome-wide DNA methylation analysis of OPSCC using Infinium 450k analysis of 83 OPSCC samples, and integrated our data with 81 OPSCC data from the Cancer Genome Atlas (TCGA). HPV(+) and HPV(-) OPSCCs were mainly classified into two epigenotypes, respectively. Analyzing the correlation with clinicopathological data, we created a new classification strategy for OPSCC.

Citation Format: Takuya Nakagawa, Keisuke Matsusaka, Kiyoshi Misawa, Masaki Fukuyo, Kiyoko Takane, Toyoyuki Hanazawa, Hisahiro Matsubara, Yoshitaka Okamoto, Atsushi Kaneda. Frequent promoter hypermethylation correlates with better prognosis in pharyngeal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3318.

Abstract 5332: Prognostic value of aberrant promoter hypermethylation of tumor-related genes in early-stage head and neck cancer

Staging and pathological grading are useful, but imperfect predictors of recurrence in head and neck squamous cell carcinoma (HNSCC). Accordingly, molecular biomarkers that predict the risk of recurrence are necessary to improve clinical outcomes. The ability to distinguish between low- and high-risk HNSCCs at an early stage may reduce follow-up costs. We hypothesized that the quantitative methylation specific PCR (Q-MSP) assay could be used to define patterns of DNA methylation that differentiate low- and high-risk HNSCCs. The methylation statuses of the promoters of 11 tumor-related genes (p16, RASSF1A, E-cadherin, H-cadherin, MGMT, DAPK, DCC, COL1A2, TAC1, SST, and GALR1) were analyzed in 133 HNSCC cases using quantitative methylation-specific PCR. Frequent methylation of p16 (44%), RASSF1A (18%), E-cadherin (53%), H-cadherin (35%), MGMT (35%), DAPK (53%), DCC (42%), COL1A2 (44%), TAC1 (61%), SST (64%), and GALR1 (44%) in HNSCC were detected. Disease-free survival was lower in patients with 6-11 methylated genes than in those with 0-5 methylated genes (log-rank test, P = 0.001). In a multivariate Cox proportional hazards analysis, the methylation of E-cadherin, COL1A2, TAC1, and GALR1 was associated with poor survival, with hazard ratios of 4.474 (95% CI, 1.241-16.124). In a joint analysis of these four genes, patients with 2-4 methylated genes had a significantly lower survival rate than those with 0-1 methylated genes in early-stage HNSCC. Importantly, the methylation of some genes was closely related to poor prognosis in early-stage HNSCC, providing strong evidence that these hypermethylated genes are valuable biomarkers for prognostic evaluation. In conclusion, the methylation profiles of E-cadherin, COL1A2, TAC1, and GALR1 were the most powerful combination for predicting early-stage HNSCC. This demonstrates that molecular stratification may predict cancer progression. These findings can benefit HNSCC screening and surveillance algorithms. Although our study was retrospective, was conducted at a single institution, and the number of patients was small, it serves as a platform to establish optimal therapeutic strategies for early-stage HNSCC.

Citation Format: Atsushi Imai, Kiyoshi Misawa, Daiki Mochizuki, Hiroyuki Mineta, Takeharu Kanazawa. Prognostic value of aberrant promoter hypermethylation of tumor-related genes in early-stage head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5332.

Abstract 5337: The epigenetic feedback loop of the CpG demethylase TET family genes in head and neck cancers

Purpose: The aim of this study is that clarifying the epigenetic regulation of TET family genes can provide insights into the mechanisms of tumorigenesis and the risk of disease recurrence in HNSCC.

Experimental Design: We generated methylation profiles of TET family genes in tumor samples obtained from 233 patients with head and neck squamous cell carcinoma (HNSCC); these included 57 hypopharynx, 44 larynx, 69 oral cavity, and 63 oropharynx tumor samples. TET family genes mRNA expression and promoter DNA methylation were examined via quantitative reverse transcription (Q-RT-PCR) and methylation-specific PCR (Q-MSP), respectively. Promoter methylation was compared with various clinical characteristics and methylation index.

Results: The TET methylation index (TE-MI) as the number of TET family genes methylation events was positively correlated with alcohol consumption (P = 0.004), HPV status (P = 0.004) and disease recurrence (P = 0.002). Simultaneous methylation analysis of TET family genes significantly correlated with reduced disease-free survival in unfavorable event groups (log-rank test, P = 0.026). In the multivariate Cox proportional hazards analysis, TET3 methylation of T1/2 patients, oropharyngeal cancer patients and oral cancer patients exhibited the high association with poor survival (hazard ratio: 2.64, P = 0.014; 3.55, P = 0.048; 2.63, P = 0.028, respectively). Joint analysis of tumor suppressor genes methylation index (TS-MI) showed a significant trend toward higher TE-MI increased.

Conclusions: TET family genes methylation status was independently associated with aggressive tumor behavior and forming a DNA methylation feedback loop in patients with HNSCC.

Citation Format: Kiyoshi Misawa, Atsushi Imai, Daiki Mochizuki, Takeharu Kanazawa. The epigenetic feedback loop of the CpG demethylase TET family genes in head and neck cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5337.

Abstract 3317: Genes encoding neuropeptide receptors are epigenetic markers in patients with head and neck cancer: A site-specific analysis

Staging and pathological grading systems are useful but imperfect predictors of recurrence in head and neck squamous cell carcinoma (HNSCC). The aim of this study was to determine the methylation status of eight GPCR-encoding genes in HNSCCs and its relationship to recurrence, survival, and clinical characteristics (e.g., tumor location and lymph node metastasis). All eight genes (NPFFR1, NPFFR2, HCRTR1, HCRTR2, NPY1R, NPY2R, NPY4R, and NPY5R) encode neuropeptide receptors and are in the Class A β subgroup. This study is the first to implicate neuropeptide receptors in the genesis of HNSCC. To identify potential prognostic markers, we examined the methylation status of eight neuropeptide receptor gene promoters in 231 head and neck squamous cell carcinomas. The NPFFR1, NPFFR2, HCRTR1, HCRTR2, NPY1R, NPY2R, NPY4R, and NPY5R promoters were methylated in 80.5%, 79.2%, 67.1%, 73.2%, 35.1%, 36.4%, 38.5%, and 35.9% of the samples, respectively. In a multivariate Cox proportional hazards analysis, the odds ratio for recurrence was 2.044 (95% confidence interval [CI], 1.323-3.156; P = 0.001) when the NPY2R promoter was methylated. In patients without lymph node metastasis (n = 100), methylation of NPY2R (compared with methylation of the other seven genes) best correlated with poor disease-free survival (DFS) (odds ratio, 2.492; 95% CI, 1.190-5.215; P = 0.015). In patients with oral cancer (n = 69), methylated NPY1R and NPY2R were independent prognostic factors for poor DFS, both individually and, even more so, in combination (odds ratio, 3.90; 95% CI, 1.523-9.991; P = 0.005). Similar findings were observed for NPY2R and NPY4R in patients with oropharyngeal cancer (n = 162) (odds ratio, 5.663; 95% CI, 1.507- 21.28; P = 0.010). The present study suggests that the methylation status of the NPY1R, NPY2R, and NPY4R genes is an independent indicator of DFS in patients with oral and/or oropharyngeal cancers. Our findings support the use of methylation markers in patient selection for adjuvant therapy after initial surgical treatment and may aid oropharyngeal cancer screening and surveillance programs. However, they are preliminary and hence need to be validated in larger and more homogeneous HNSCC patient cohorts.

Citation Format: Daiki Mochizuki, Kiyoshi Misawa, Atsushi Imai, Takeharu Kanazawa, Hiroyuki Mineta. Genes encoding neuropeptide receptors are epigenetic markers in patients with head and neck cancer: A site-specific analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3317.

Association of TET3 epigenetic inactivation with head and neck cancer

The aim of this study was to clarify the epigenetic regulation of ten eleven translocation protein (TET) family genes, which can provide insights into the mechanisms of tumorigenesis and the risk of disease recurrence in head and neck squamous cell carcinoma (HNSCC). We generated methylation profiles of TET1, TET2 and TET3 genes in tumor samples obtained from 233 patients with HNSCC; these included 57 hypopharynx, 44 larynx, 69 oral cavity, and 63 oropharynx tumor samples. The mRNA expression and promoter DNA methylation of TET family genes were examined via quantitative RT-PCR and methylation-specific PCR, respectively. Promoter methylation was compared with various clinical characteristics and the TET methylation index (TE-MI). The TE-MI, representing the number of methylation events in TET family genes, was positively correlated with alcohol consumption (P = 0.004), high-risk human papilloma virus (HPV) status (P = 0.004) and disease recurrence (P = 0.002). The simultaneous methylation analysis of TET family genes was correlated with reduced disease-free survival in unfavorable event groups (log-rank test, P = 0.026). In the multivariate Cox proportional hazards analysis, TET3 methylation in T1 and T2 tumor stages, oropharyngeal cancer, and oral cancer patients exhibited high association with poor survival (hazard ratio: 2.64, P = 0.014; 3.55, P = 0.048; 2.63, P = 0.028, respectively). A joint analysis of the tumor suppressor gene methylation index showed a significant trend toward a higher TE-MI. The methylation status of TET3 was independently associated with aggressive tumor behavior and a global effect on DNA methylation status in HNSCC.

Epigenetic inactivation of galanin receptors in salivary duct carcinoma of the parotid gland: Potential utility as biomarkers for prognosis

Salivary duct carcinoma (SDC) constitutes one of the most aggressive cancers in the salivary gland and is associated with a poor prognosis; however, no established systemic therapy options are available. SDC exhibits biological similarity to prostate and breast cancers, therefore anti-hormone therapy and molecular target therapies are available, however with limited beneficial effects. Galanin and galanin receptors (GALRs) are well established as molecular biomarkers to predict the survival rate and risk of recurrence of head and neck squamous cell carcinoma. The present study investigated the clinicopathological features of patients with SDC and the methylation status of their galanin and GALR genes to demonstrate the prognostic value for this disease. The median overall survival (OS) was 37.2 months. T-stage, N-stage, disease stage, tumor size, and preoperative facial paralysis were significantly associated with OS, whereas human epidermal growth factor receptor 2 (HER2) overexpression was not. GALR1 and GALR2 methylation rates in tumor tissues were significantly increased compared with normal tissues with 9.85- and 4.49-fold increase, respectively. p27^kip1 and p57^kip2 expression significantly inversely correlated with the methylation rate of GALR1 and GALR2. In addition, the observed GALR1 and/or GALR2 methylation rates were significantly correlated with a decrease in OS. These results suggest that GALR1 and GALR2 may serve as potential prognostic factors and therapeutic targets in SDC.

The neuropeptide genes SST, TAC1, HCRT, NPY, and GAL are powerful epigenetic biomarkers in head and neck cancer: a site-specific analysis

Background

Staging and pathological grading systems are convenient but imperfect predictors of recurrence in head and neck squamous cell carcinoma (HNSCC). Identifying biomarkers for HNSCC that will progress and cause death is a critical research area, particularly if the biomarker can be linked to selection of patients. Therefore, to identify potential alternative prognostic markers, we investigated the methylation status of five neuropeptide gene promoters. The promoter methylation status was determined by quantitative methylation-specific PCR in 230 cases of HNSCC; 58 hypopharynx, 45 larynx, 56 oropharynx, and 71 oral cavity tumor samples were studied.

Results

The somatostatin (SST), tachykinin precursor 1 (TAC1), hypocretin neuropeptide precursor (HCRT), neuropeptide Y (NPY), and galanin (GAL) promoters were methylated in 84.3, 63.5, 32.6, 28.3, and 20.0%, respectively, of the samples. The mean number of methylated genes per sample was 2.29 (range, 0–5). Disease-free survival was lower in patients with 3–5 methylated genes than in those with 0–2 methylated genes (log-rank test, P = 0.007). In multivariate Cox proportional hazards analysis, TAC1 and GAL promoter methylation independently predicted recurrence (odds ratios 1.620, 95% confidence interval [CI] 1.018–2.578, P = 0.042, and odds ratios 1.692, 95% CI 1.063–2.694, P = 0.027, respectively). In patients with oral cancer, TAC1 methylation showed the best correlation with poor survival (odds ratio 4.427, 95% CI 1.634–12.00, P = 0.003). Similar findings were observed for HCRT and GAL in patients with laryngeal cancer and oropharyngeal cancer, respectively.

Conclusion

In this study, we demonstrated the methylation status of the neuropeptide-encoding genes SST, TAC1, HCRT, NPY, and GAL and its relationship with recurrence and survival in HNSCC. These methylation changes may serve as potential molecular markers for defining the risk and prognosis of HNSCC.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0485-0) contains supplementary material, which is available to authorized users.

Epigenetic modification of SALL1 as a novel biomarker for the prognosis of early stage head and neck cancer

This study examined Sal-like protein (SALL)1 methylation profiles in head and neck squamous-cell carcinoma (HNSCC) patients at diagnosis and follow-up, and evaluated their prognostic significance and value as a biomarker. SALL1 expression was examined in a panel of cell lines by quantitative reverse transcription PCR (qRT-PCR). Promoter methylation was determined by quantitative methylation-specific polymerase chain reaction (qMSP) and was compared to the clinical characteristics of 205 samples. SALL1 promoter methylation was associated with transcriptional inhibition and was correlated with disease recurrence in 31.7% of cases, with an odds ratio of 1.694 (95% confidence interval: 1.093-2.626; P = 0.018) by multivariate Cox proportional hazard regression analysis. SALL1 promoter hypermethylation showed highly discriminatory receiver operator characteristic curve profiles that clearly distinguished HNSCC from adjacent normal mucosal tissue, and was correlated with reduced disease-free survival in early stage T1 and T2 patients (log-rank test, P < 0.001). SALL1 methylation was significantly correlated with the methylation status of both SALL3 and CDH1. This study suggests that CpG hypermethylation is a likely mechanism of SALL1 gene inactivation, supporting the hypothesis that SALL1 might play a role in HNSCC tumorigenesis and could serve as an important biomarker.

Prognostic value of aberrant promoter hypermethylation of tumor-related genes in early-stage head and neck cancer

Staging and pathological grading are useful, but imperfect predictors of recurrence in head and neck squamous cell carcinoma (HNSCC). Accordingly, molecular biomarkers that predict the risk of recurrence are necessary to improve clinical outcomes. The methylation statuses of the promoters of 11 tumor-related genes (p16, RASSF1A, E-cadherin, H-cadherin, MGMT, DAPK, DCC, COL1A2, TAC1, SST, and GALR1) were analyzed in 133 HNSCC cases using quantitative methylation-specific PCR. We detected frequent methylation of p16 (44%), RASSF1A (18%), E-cadherin (53%), H-cadherin (35%), MGMT (35%), DAPK (53%), DCC (42%), COL1A2 (44%), TAC1 (61%), SST (64%), and GALR1 (44%) in HNSCC. Disease-free survival was lower in patients with 6–11 methylated genes than in those with 0–5 methylated genes (log-rank test, P = 0.001). In a multivariate Cox proportional hazards analysis, the methylation of E-cadherin, COL1A2, TAC1, and GALR1 was associated with poor survival, with hazard ratios of 4.474 (95% CI, 1.241–16.124). In a joint analysis of these four genes, patients with 2–4 methylated genes had a significantly lower survival rate than those with 0–1 methylated genes in early-stage HNSCC. Importantly, the methylation of some genes was closely related to poor prognosis in early-stage HNSCC, providing strong evidence that these hypermethylated genes are valuable biomarkers for prognostic evaluation.

Analysis of Site-Specific Methylation of Tumor-Related Genes in Head and Neck Cancer: Potential Utility as Biomarkers for Prognosis

Clarifying the epigenetic regulation of tumor-related genes (TRGs) can provide insights into the mechanisms of tumorigenesis and the risk for disease recurrence in HPV-negative head and neck cancers, originating in the hypopharynx, larynx, and oral cavity. We analyzed the methylation status of the promoters of 30 TRGs in 178 HPV-negative head and neck cancer patients using a quantitative methylation-specific PCR. Promoter methylation was correlated with various clinical characteristics and patient survival. The mean number of methylated TRGs was 14.2 (range, 2-25). In the multivariate Cox proportional hazards analysis, the methylation of COL1A2 and VEGFR1 was associated with poor survival for hypopharyngeal cancer, with hazard ratios: 3.19; p = 0.009 and 3.07; p = 0.014, respectively. The methylation of p16 and COL1A2 were independent prognostic factors for poor survival in laryngeal cancer (hazard ratio: 4.55; p = 0.013 and 3.12; p = 0.035, respectively). In patients with oral cancer, the methylation of TAC1 and SSTR1 best correlated with poor survival (hazard ratio: 4.29; p = 0.005 and 5.38; p = 0.029, respectively). Our findings suggest that methylation status of TRGs could serve as important site-specific biomarkers for prediction of clinical outcomes in patients with HPV-negative head and neck cancer.

Indwelling voice prosthesis insertion after total pharyngolaryngectomy with free jejunal reconstruction

Objectives

Total pharyngolaryngectomy with free jejunal reconstruction is often performed in patients with hypopharyngeal carcinoma. However, postoperative speechlessness significantly decreases patient quality of life. We investigated whether Provox® insertion could preserve speech after total pharyngolaryngectomy with free jejunal reconstruction.

Study Design

Retrospective chart review.

Methods

A total of 130 cases of secondary Provox® insertions after total pharyngolaryngectomy with free jejunal reconstruction were analyzed. Communication outcomes were compared using the Head and Neck Cancer Understandability of Speech Subscale. Outcomes and complications associated with insertion site (jejunal insertion vs. esophageal insertion) and adjuvant irradiation therapy were also evaluated.

Results

Provox® insertion had favorable communication outcomes in 102 cases (78.4%). Neither the insertion site nor irradiation affected the communication outcome. Complications were observed in 20 cases (15.4%). Local infection was the most common complication. Free jejunal insertion, in which the resection range was enlarged, had a lower complication rate than did esophageal insertion, and its complication rate was unaffected by previous irradiation. For all patients, the hospitalization duration and duration of speechlessness were 13.4 days and 14.6 months, respectively. Patients receiving jejunal insertions had a significantly shorter hospitalization duration than did those receiving esophageal insertions. Unlike Provox®2, Provox®Vega significantly reduced the complication rate to zero.

Conclusion

For jejunal inserson of a Provox® prosthetic, a sufficient margin can be maintained during total pharyngolaryngectomy and irradiation can be performed, and satisfactory communication outcomes were observed. Provox® insertion after total pharyngolaryngectomy with free jejunal reconstruction should be considered the standard therapy for voice restoration.

Level of Evidence

4.

Injection of basic fibroblast growth factor for unilateral vocal cord paralysis. Acta Otolaryngol 2017;137:962-967. [PMID: 28434284 DOI: 10.1080/00016489.2017.1314550]

OBJECTIVE

Unilateral vocal cord paralysis (UVCP) not only induces severe dysphonia, but aspiration as well. Although laryngeal framework surgery is usually performed to treat this condition, the procedure is not tolerated by some patients. In the previous study, basic fibroblast growth factor (bFGF) injections for vocal cord scarring and sulcus have been reported to provide favorable outcomes while being minimally invasive. In this study, the authors retrospectively investigated phonological outcomes after bFGF injection in patients with UVCP.

METHODS

This study was registered in University hospital Medical Information Network - Clinical Trials Registry (UMIN000019347). Nineteen patients with unilateral cord paralysis were treated with bFGF injection. The treatment regimen involved a single injection of 50 μg of bFGF into the muscle layer. More than six months after the injection, aerodynamic and acoustic outcomes were examined.

RESULTS

The voice handicap index, maximum phonation time, mean airflow rate, and pitch range improved significantly after injection of bFGF. No sex-related differences were observed in any phonological parameter.

CONCLUSION

bFGF injection, an easy method and suitable as an office procedure, significantly improved the hoarseness caused by UVCP. It is expected to be widely adopted and effective adjunctive drugs, and procedures are anticipated to be developed.