Multicenter clinical trial on functional evaluation of transoral laser microsurgery for supraglottic laryngeal carcinomas.

BACKGROUND: Transoral laser microsurgery (TLM) is an accepted and effective treatment strategy for supraglottic carcinomas. Data on oncologic and to a lesser extent functional outcomes have been published by mainly European specialized single institutions. TLM for supraglottic carcinomas has never been tested in a multicenter trial on its applicability as surgical standard at every hospital. OBJECTIVES: To test the efficacy of TLM supraglottic laryngectomy (TLM-SGL) in terms of swallowing function, oncologic outcome parameters, morbidity, complications of treatment, and quality of life in a multicenter setting. METHODS: The study is designed as a multicenter (approximately 25 centers), non-randomized, single-arm study with a targeted number of 200 previously untreated patients with squamous cell carcinomas (SCC) of the supraglottic larynx T2/T3 N0-3 M0; UICC stage II-IVa. The surgical treatment consists of TLM-SGL and elective or therapeutic uni- or bilateral selective neck dissection (SND). After pathologic risk stratification adjuvant radio- (RT) or radiochemotherapy (RCT) is indicated. Patients are followed-up for 2 years post surgically. Swallowing function is assessed by fibreoptic endoscopic evaluation of swallowing (FEES). The primary endpoint is aspiration-free swallowing at 12 months as established using FEES and defined as grade < 6 of penetration-aspiration scale (PAS). Secondary endpoints include local control, larynx preservation, overall and disease-free survival, complications and side effects of treatment, prevalence of tracheostomy and percutaneous endoscopic gastrostomy (PEG)-tube-feeding, and dysphagia-specific quality of life (QoL) assessed by the MD Anderson Dysphagia Inventory (MDADI) as well as voice-related QoL assessed by the Voice Handicap Index (VHI).

[Retrocochlear diagnostics for acute hearing loss and successful therapy]. / Retrocochleäre Diagnostik im Rahmen der Hörsturzuntersuchung und erfolgreiche Therapie.

A 41-year-old female patient presented due to acute onset of unilateral hearing loss 3 months previously and persistent since then. Systemic therapy with oral glucocorticoids in decreasing doses had been performed beforehand, but did not lead to any improvement. In the course of audiological diagnostics, based on subjective and objective methods, a retrocochlear hearing disorder was suspected. A meningioma was diagnosed by diagnostic imaging. Subsequent surgical removal achieved a significant hearing improvement.

Facilitation properties in electrically evoked compound action potentials depending on spatial location and on threshold.

Spiral ganglion neurons (SGNs) facilitation properties can be recorded utilizing electrically evoked compound action potential (ECAP). While intracochlear variation of the ECAP threshold in relation to its electrode channel is reported, no study investigated its impact on facilitation. In this study, we quantified intracochlear variation of the facilitation properties in cochlear implants (CI) using ECAPs. We hypothesized that the facilitation effect is dependent on the electrode channel and its ECAP threshold. Therefore, ECAPs were recorded in 23 CI subjects. For each subject, five default (channel-derived) and up to two additional (threshold-derived) stimulation sites were defined. Facilitation was quantified by the paradigm introduced by (Hey et al., 2017) with optimized parameter settings. For each channel the maximum facilitated amplitude was determined by a series of ECAP measurements. A linear mixed-effects model was used to investigate the impact of the electrode channel and ECAP threshold on the maximum facilitated amplitude. The maximum facilitated amplitude was found to be dependent on the ECAP threshold and independent on the electrode channel. We conclude that the facilitation paradigm is a useful and feasible tool to gain local information on the SGNs temporal processing patterns.

Effect of postoperative systemic prednisolone on short-term and long-term outcomes in chronic rhinosinusitis with nasal polyps: A multi-centered randomized clinical trial.

Introduction: The objective of this study was to determine whether postoperative additive systemic steroid administration in chronic rhinosinusitis with nasal polyps (CRSwNP) impacted selected endoscopic, subjective and objective outcome measures. Methods: This was a prospective, randomized, double-blind, placebo-controlled, noninferiority multicenter trial of n=106 patients with CRSwNP. All patients underwent primary functional endoscopic sinus surgery (FESS) followed by topical nasal steroids. Patients were randomized to a systemic steroid or placebo for 1 month. Patients were followed up for 2 years over 9 time points. The primary outcome measures were the differences between groups with respect to the nasal polyp score (NPS) and sinonasal quality of life (SNQoL). Secondary outcome measures included interactions with respect to the Lund-Kennedy score (LKS), sinonasal symptoms, general quality of life (GQoL), 16-item odor identification test scores, recurrence rates, need for revision surgery and mucus biomarker levels. Results: 106 patients were randomized to either the placebo or the systemic steroid group (n=53 per group). Postoperative systemic steroids were not superior to placebo with respect to all primary (p= 0.077) and secondary outcome measures (p>0.05 for all). Reported adverse events were similar between the two groups. Conclusion: In conclusion, the addition of postoperative systemic steroids after primary FESS did not confer a benefit over topical steroid nasal spray alone with respect to NPS, SNQOL, LKS, GQOL, sinonasal symptoms, smell scores, recurrence rates, the need for revision surgery or biomarkers over a short-term follow-up of up to 9 months and a long-term follow-up of up to 24 months in CRSwNP patients. Functional endoscopic surgery did, however, show a strong effect on all outcome measures, which remained relatively stable up to the endpoint at 2 years.

Tonsillar swabs and sputum predict SLPI- and AnxA2 expression in tonsils: A prospective study on smoking dependent SLPI- and AnxA2-expression, and tonsillar HPV infection.

Previous retrospective studies have elucidated a correlation between secretory leucocyte protease inhibitor (SLPI) and Annexin A2 (AnxA2), patient smoking status and tonsillar human papilloma virus (HPV) status. The current study assessed these parameters prospectively and to the best of our knowledge, analyzed SLPI-/AnxA2-expression for the first time in tonsillar swabs and sputum. Samples were obtained from 52 patients with tonsillar squamous cell carcinoma and 163 patients with tonsillar hyperplasia (H; n=56) and chronic or recurrent tonsillitis (CRT; n=107). HPV-DNA, SLPI and AnxA2 gene expression was analyzed in sputum, tonsillar swabs and tissue by performing reverse transcription-quantitative PCR. Results were compared with smoking status, revealing that smoking resulted in significantly increased SLPI gene expression in all biomaterials of all cases. SLPI-gene expression was significantly decreased in all HPV-DNA-positive samples (tissue/swab/sputum), while AnxA2 was significantly increased in all HPV-DNA-positive samples. Results from swabs and sputum were able to predict SLPI- and AnxA2 gene expression of the corresponding tonsil. The current prospective study confirmed previous retrospective results underlining this hypothesis: Smoking enhances SLPI-expression, preventing HPV-binding to AnxA2. HPV-binding to AnxA2 appears essential for successful cell-entry. SLPI/AnxA2-gene expression in swabs and sputum reflect their expression in tonsillar tissue. Accordingly, a positive AnxA2/SLPI-ratio in sputum/swabs could possibly be used to reduce HPV-associated carcinogenesis, by performing tonsillectomy or HPV-vaccination in patients with positive AnxA2/SLPI-ratios.

The interaction of smoking habit, SLPI and AnxA2 in HPV associated head and neck and other cancers.

Six own studies confirm a correlation between smoking, expression of the secretory leukocyte protease inhibitor (SLPI, an antileukoproteinase) and expression of Annexin A2 (AnxA2), and their influence on human papilloma virus (HPV)-infections. SLPI and HPV are ligands of AnxA2. This correlation was tested on 928 tissue samples from 892 patients in six independent studies [squamous cell carcinoma of the head and neck (HNSCC), n = 522; non-neoplastic tonsils n = 214; clinically normal mucosa, n = 93 (of these n = 57 were obtained from patients treated for non-malignant diseases and n = 36 were obtained from HNSCC-patients) and vulvar squamous cell carcinoma (VSCC) n = 99]. HPV-DNA-status was determined by GP5+/GP6+-PCR, followed in case of HPV-positivity by Sanger sequencing and RT-PCR using HPV-type specific primers. SLPI- and AnxA2-gene-expression was determined by RT-q-PCR; SLPI-protein-expression was additionally determined by immunohistochemistry (IHC); the data were correlated with each other and with patient characteristics. Smoking results in increased SLPI-gene- and protein- and AnxA2-gene-expression with significantly higher SLPI- than AnxA2-gene-expression. SLPI is decreased in non-smokers with a continuous AnxA2-surplus. HPV-status correlates with smoking habit, with smokers being mostly HPV-negative and non-smokers HPV-positive. We hypothesize that smoking leads to SLPI-overexpression with SLPI-binding to AnxA2. Thus, HPV cannot bind to AnxA2 but this seems pivotal for HPV-cell-entry. Smoking favors SLPI-expression resulting in HPV-negative carcinomas, while HPV-positive carcinomas are more common in non-smokers possibly due to a surplus of unbound AnxA2. In addition, the hypothesis may contribute to understand why smokers show increased oral HPV-prevalence in natural history studies but do not necessarily develop HPV-associated lesions.

HPV DNA/RNA detection in various oral and oropharyngeal biomaterials identifies active HPV infections also in non-neoplastic tonsils.

Previous studies describe a correlation between HPV-positivity and non-smoking in TSCC; p16INK4A-expression as surrogate-marker for HPV-DNA/RNA-positivity is discussed controversially. In the present study, these parameters are assessed prospectively. HPV-status of sputum and tonsillar-swabs was analyzed to determine their validity as surrogate-marker for tissue-HPV-status. TSCC- (n = 52) and non-neoplastic tonsillar tissue (n = 163) were analyzed. HPV-DNA- and HPV-RNA-status of total sputum, cellular fraction and supernatants, tonsillar-swabs and -tissue was determined by (RT)-PCR. Immunohistochemistry determined p16INK4A-expression. 23/163 (14.2%) non-neoplastic tonsils were HPV-DNA-positive; five patients (3 HPV16, 2 HPV11) had active HPV-infections (HPV-RNA-positive), in all biomaterials. 140/163 (85.9%) patients were either HPV-DNA-positive or HPV-DNA-negative in all samples. 21/52 (40.4%) TSCC-tonsils were HPV-DNA-positive; 17 patients were HPV-RNA-positive (14 HPV16; 4 HPV18). 40/52 (76.9%) TSCC-patients were congruent in all biomaterials. p16INK4A-expression alone would have misclassified the HPV-status of 14/52 (26.2%) TSCC-patients. This prospective study confirms the discrepancy between HPV-status and p16INK4A-expression and the significant correlation between non-smoking and HPV-DNA-positivity. HPV-sputum- and/or swab-results do not consistently match tissue-results, possibly having (detrimental) consequences if those were used to assess tissue-HPV-status. In the 5 patients with active HPV infection in the non-neoplasitic tonsils, tonsillectomy likely prevented subsequent development of TSCC.

Transoral laser microsurgery for glottic cancer in the elderly: Efficacy and safety.

BACKGROUND: Data about the results of transoral laser microsurgery (TLM) in elderly patients are limited. METHODS: A retrospective study of 72 consecutive cases of glottic carcinoma (63 pT1 and 9 pT2 cases) in elderly patients (≥70 years old, mean 76 years) treated with TLM was made. A systematic review of the literature was performed. RESULTS: Six patients (8%) had postoperative complications, but no treatment-related deaths were observed. Local recurrences occurred in 12 patients (16.5%): nine with pT1 (14%) and three with pT2 (33%) tumors. Five-year disease-specific survival (DSS), overall survival, and laryngectomy-free survival were 95%, 68%, and 88%, respectively. The literature review indicated that TLM is safe and effective treatment for these patients, with few complications and good local control (>85%) and DSS (>90%) rates. CONCLUSIONS: Our results and the information from the literature show that TLM for glottic cancer in elderly patients can lead to satisfactory treatment results.

Transoral Laser Microsurgery for Supraglottic Cancer.

INTRODUCTION: Transoral laser microsurgery (TLM) is an accepted and effective treatment strategy for supraglottic carcinomas. Early supraglottic carcinoma has excellent outcomes independently of the treatment approach. The role of TLM for the treatment of locally advanced tumors is debated. Particularly, the functional outcomes after TLM have to be proven by functional assessment of large cohorts of patients. This study analyzes the oncologic and functional outcomes after TLM for supraglottic carcinomas. PATIENTS AND METHODS: Ninety-one patients with pT1-pT4a supraglottic carcinomas treated between January 2002 and December 2012 were analyzed. Distribution of tumors (UICC 2010) was 11 patients with pT1, 31 patients with pT2, 36 patients with pT3, and 13 patients with pT4a tumors. Node status was positive in 40 (43.6%) patients; 61 (67.1%) patients had stage III or IVa disease. Local control and survival were estimated using the Kaplan-Meier method. For the assessment of functional outcomes, the MD Anderson Dysphagia Inventory (MDADI), the Voice Handicap Index-10 (VHI-10), and the performance status scale for head and neck cancer [Performance Status Scale for Head and Neck (PSS-HN)] were used. RESULTS: The median age was 62 years (range, 33-88 years). Fourteen (15.4%) patients developed a local or locoregional recurrence. The 5-year local control rate and 5-year ultimate local control rate were 72 and 92%, respectively. The 5-year overall survival rate was 63%. Twelve (13.2%) patients needed temporary tracheostomy. Sixty-eight (74.0%) patients had a nasogastric feeding tube post-operatively. At 1-year post-operative follow-up, only three patients were PEG dependent. The median VHI-10 score was 35, the median MDADI composite score was 80, and the median score of the domain "normalcy of diet" in the PSS-HN was 91. CONCLUSION: The oncologic outcomes are comparable to the results of open surgery for early and advanced supraglottic carcinomas. Functional swallowing outcome is superior to open surgery and to concomitant chemoradiation. Patients treated with TLM perceive low levels of voice- and swallowing-related quality of life impairment.

Influence of HPV-status on survival of patients with tonsillar carcinomas (TSCC) treated by CO2-laser surgery plus risk adapted therapy - A 10 year retrospective single centre study.

The positive prognostic value of HPV-infections in oropharyngeal squamous cell cancer (OSCC) patients has led to the initiation of prospective clinical trials testing the value of treatment de-escalation. It is unclear how to define patients potentially benefiting from de-escalated treatment, whether a positive smoking history impacts survival data and what kind of de-escalation might be best. Here, we investigate the effect of HPV-status, smoking habit and treatment design on overall survival (OS) and progression free survival (PFS) of 126 patients with tonsillar SCC (TSCC) who underwent CO2-laser-surgery and risk adapted adjuvant treatment. HPV-DNA-, HPV-mRNA-, and p16INK4A-expression were analysed and results were correlated to OS and PFS. Factors tested for prognostic value included HPV-status, p16INK4A-protein expression, therapy and smoking habit. Log rank test and p-values ≤0.05 defined significant differences between groups. The highest accuracy of data with highest significance in this study is given when the HPV-RNA-status is considered. Using p16INK4A-expression alone or in combination with HPV-DNA-status, would have misclassified 23 and 7 patients, respectively. Smoking fully abrogates the positive impact of HPV-infection in TSCC on survival. Non-smoking HPV-positive TSCC patients show 10-year OS of 100% and 90.9% PFS when treated with adjuvant RCT. The presented data show that high-precision HPV-detection methods are needed, specifically when treatment decisions are based on the results. Furthermore, smoking habit should be included in all studies and clinical trials testing HPV-associated survival. Adjuvant RCT especially for HPV-positive non-smokers may help to avoid distant failure.

miRNA-expression in tonsillar squamous cell carcinomas in relation to HPV infection and expression of the antileukoproteinase SLPI.

The aim of this study was to determine if micro-(mi-)RNAs are involved in the previously reported inverse correlation between the antileukoproteinase SLPI, HPV, and smoking habit of head and neck squamous cells carcinoma (HNSCC) patients. HPV-status and SLPI-protein expression were determined in tonsillar SCC (TSCC; n=126). Differentially expressed miRNAs dependent on HPV-status and SLPI-expression were detected by microarray; possible binding-sites in SLPI- and HPVE6-mRNAs were determined in silico. Survival rates were estimated testing prognostic values of HPV-status, SLPI- and miRNA-expression. miRNA-array identified 24 up-regulated and 10 down-regulated miRNAs in HPV-positive versus HPV-negative TSCC (p<0.01; HPV-positivity: 42.1%). HPV-positivity resulted in two up-regulated miRNAs in SLPI-positive TSCC. Of 16 further miRNAs, eight miRNAs were up- and eight were down-regulated in SLPI-negative TSCC. RT-q-PCR-validation of the four most differentially expressed miRNAs showed that miR-363 is expressed strongest in SLPI-negative/HPV-positive TSSC. In silico-analysis of all differentially expressed miRNAs identified miR-363, miR-210, miR-130a, and miR-181a with possible binding sites in the HPV16-E6-mRNA, but none were predicted in the SLPI-mRNA. HPV-positivity, low SLPI-levels and high miR-363-levels are significantly associated with better survival rates. The data presented here show that miR-363 is associated with HPV-positive/SPLI-negative TSCC. The prognostic value of miR-363 suggests a role in the assumed inverse correlation of smoking and SPLI-expression in the mode of HPV-infections in tonsillar but possibly also other HNSCC.

Lysyl oxidase like-4 monoclonal antibody demonstrates therapeutic effect against head and neck squamous cell carcinoma cells and xenografts.

A new member of the lysyl oxidase (LOX) family, lysyl oxidase-like 4 (LOXL4), is overexpressed in head and neck squamous cell carcinoma (HNSCC) compared to normal squamous epithelium. A monoclonal antibody (mAb) derived from fusion of Balb/c mouse splenocytes immunized with LOXL4 specific peptide was used to evaluate its therapeutic efficacy in 15 HNSCC cell lines associated with LOXL4 overexpression. For xenograft experiments 41 severe combined immunodeficient (SCID) mice were used to analyze LOXL4-mAb mediated tumor regression. Cell viability was analyzed using cytotoxicity-, and clonogenic-assays. Significant suppression of tumor cell growth was observed in 12 out of 15 (80%) tumor cell lines after 48 hr exposure to the mAb (LD50 of 15 µg/ml to 45 µg/ml). The effect induced by the antibody could be blocked by pre-incubation of the antibody with the peptide used for immunization of the mice and antibody generation, indicating that the effect of the antibody is specific. In mice inoculated with HNSCC cells, i.v. injections of the LOXL4-mAb resulted within 70 days in extensive tumor destruction in all treated animals whereas no tumor regression occurred in control animals. In mice pre-immunized i.v. with LOXL4-mAb and subsequently injected with HNSCC cells, tumor development was considerably delayed in contrast to non LOXL4-mAb pre-immunized animals. These results demonstrate that the LOXL4-mAb has potent antitumor activity and suggest its suitability as a therapeutic immune agent applicable to HNSCC exhibiting tumor specific upregulation of LOXL4.

Manifestation of eosinophilic granulomatosis with polyangiitis in head and neck.

INTRODUCTION: Besides an obvious clinical involvement of the ear, nose and throat (ENT)-region in Eosinophilic Granulomatosis with Polyangiitis (EGPA), systematic data is sparse. Only a few case series and case reports are available that particularly describe rhinological, otological or other manifestations of EGPA in the ENT-region. Therefore, the objective of this study is to systematically describe data on ENT-region involvement in a large series of EGPA patients. METHOD: EGPA patients examined in the Department of Otorhinolaryngology of the Christian-Albrechts-University of Kiel between 1990 and 2010 were included in the study. Criteria for ENT-manifestation were assigned to five subgroups (history, ENT examination, audiological and rhinological diagnostic findings and cranial MRI) and documented cumulatively. EGPA patients were examined in a standardized way based on the validated Ear Nose and Throat Activity Score (ENTAS) or its precursor, including audiological and rhinological diagnostic findings. MRI scans were analysed to further evaluate ENT involvement. RESULTS: A total of 95 EGPA patients were included in the study. In approximately 80% of them, ENT-involvement was documented and the assumption of a frequent rhinological manifestation in patients with EGPA was confirmed. Moreover, the data reveals remarkable evidence for an otological manifestation. A missing correlation between the rhinological and the otological manifestation indicates an independent autoimmune-inflammatory process for this manifestation. CONCLUSION: The data of the largest monocentric study presented here confirms the hypothesis of a frequent ENT involvement in EGPA patients, in whom rhinological and otological manifestations are most common. Therefore, treatment should include long term follow-up and should be managed interdisciplinary.

Geographical and anatomical influences on human papillomavirus prevalence diversity in head and neck squamous cell carcinoma in Germany.

The increased knowledge regarding HPV-infections in head and neck squamous cell carcinoma (HNSCC) has unexpectedly contributed to several uncertainties related to i) prevalence diversities depending on tumour site and geographical origin of the patients, ii) proportion of HPV-driven tumours among HPV-DNA-positive cases, and iii) identification of patients with HPV-attributed survival benefit. To investigate this heterogeneity, we analysed 307 HNSCC cases (tonsillar, n=135; non-tonsillar, n=172) from eight health care centers mostly from Northern Germany and determined HPV-DNA/mRNA and p16INK4A-status and combined results with the patient outcome. Overall HPV-DNA prevalence rate was 23.5% (72/307); attributed to: 43.7% (59/135) and 7.6% (13/172) tonsillar and non-tonsillar cases, respectively. Among these, 96.6% tonsillar and 38.5% non-tonsillar SCC were HPV-mRNA-positive. Although the study cohort was composed of patients from regions of rather close proximity, prevalence rates showed diversities of up to 40% in HNSCC subsite analysis with the lowest prevalence for tonsillar SCC in metropolitan areas (22.2%) vs. 50.9% in rural areas. Survival analysis identified p16INK4A alone as strongest predictor, followed by HPV-DNA-status alone or in combination with p16INK4A. This survival benefit was shown for tonsillar and non-tonsillar cases. Smoking significantly correlated with HPV-status, however, it does not influence survival when stratified for HPV. In conclusion, the data emphasize the urge for further data on HPV-infection in HNSCC to, e.g. clarify to what extent survival benefits of p16INK4A-positive patients are truly attributed to HPV-infections.

The antileukoprotease secretory leukocyte protease inhibitor (SLPI) and its role in the prevention of HPV-infections in head and neck squamous cell carcinoma.

Recently, we demonstrated a significant inverse correlation between HPV-infection and SLPI-expression suggesting that SLPI protects against HPV-infection of HNSCC. Here we analyzed in a single lab setting 307 formalin-fixed paraffin-embedded HNSCC cases (tonsillar n = 135; non-tonsillar: n = 172) from eight health care centers. Samples were analyzed for SLPI gene- and protein-expression. Annexin A2, its heterotetramer A2t, putatively facilitating HPV- and SLPI-cell entry, was measured to study the correlation between SLPI and annexin A2. Data were correlated with tobacco consumption and HPV-status. Overall, HPV-DNA prevalence was 23.5% (72/307); attributed to: 43.7% (59/135) tonsillar and 7.6% (13/172) non-tonsillar cases. Smoking resulted in 6.44-fold increased and HPV-infection in 3.46-fold decreased SLPI-gene expression in all HNSCC with similar significant results obtained in tonsillar and non-tonsillar SCC separately. Correlating annexin A2- and SLPI-gene expression showed a significant surplus of annexin A2 in HPV-positive tumors (4.21× more annexin A2) and 6.72× more annexin A2 than SLPI in nonsmokers in all HNSCCs and similar significant results for both tumor entities separately. The surplus of annexin A2 in non-smokers and HPV-positive patients supports our hypothesis that decreased SLPI levels facilitate HPV-infection i.e., increased SLPI-expression may protect against HPV-infection of tonsillar and non-tonsillar SCC.

Knowledge of diagnostic and risk factors in oral cancer: results from a large-scale survey among non-dental healthcare providers in Northern Germany.

INTRODUCTION: A survey was conducted to assess the level of knowledge on oral cancer among different medical fields, in particular about diagnostic items and risk factors. MATERIAL AND METHODS: A self-administered questionnaire was mailed to physicians from various fields, such as otorhinolaryngology, general practice, internal medicine, and dermatology. RESULTS: 388 of the 2,952 questionnaires were returned (13.1%), subdivided into otorhinolaryngology (n = 33), internal medicine (n = 135), dermatology (n = 28), and general practice (n = 192). The average knowledge of risk factors was similar in the specialisations, ranging from 68% for internal medicine to 76% for otorhinolaryngology and 77% for dermatology. The three main risk factors: tobacco (93%-100%), alcohol (79%-100%), and prior oral cancer lesions (91%-100%) were the most commonly known. Regarding the diagnostic items, the average percentage of correct answers ranged from 69% for internal and general medicine to 77% for dermatologists. Continuous courses of education and the year of graduation were the only two variables that significantly related to a better level of knowledge of risk factors and diagnostic items. CONCLUSIONS: The average knowledge among the different medical fields was satisfying. These results demonstrated a robust base for all healthcare providers to continue working together to improve the early detection of oral cancer.

Head and neck cancer cells and xenografts are very sensitive to palytoxin: decrease of c-jun n-terminale kinase-3 expression enhances palytoxin toxicity.

OBJECTIVES: Palytoxin (PTX), a marine toxin isolated from the Cnidaria (zooanthid) Palythoa caribaeorum is one of the most potent non-protein substances known. It is a very complex molecule that presents both lipophilic and hydrophilic areas. The effect of PTX was investigated in a series of experiments conducted in head and neck squamous cell carcinoma (HNSCC) cell lines and xenografts. MATERIALS AND METHODS: Cell viability, and gene expression of the sodium/potassium-transporting ATPase subumit alpha1 (ATP1AL1) and GAPDH were analyzed in HNSCC cells and normal epithelial cells after treatment with PTX using cytotoxicity-, clonogenic-, and enzyme inhibitor assays as well as RT-PCR and Northern Blotting. For xenograft experiments severe combined immunodeficient (SCID) mice were used to analyze tumor regression. The data were statistically analyzed using One-Way Annova (SPSS vs20). RESULTS: Significant toxic effects were observed in tumor cells treated with PTX (LD50 of 1.5 to 3.5 ng/ml) in contrast to normal cells. In tumor cells PTX affected both the release of LDH and the expression of the sodium/potassium-transporting ATPase subunit alpha1 gene suggesting loss of cellular integrity, primarily of the plasma membrane. Furthermore, strong repression of the c-Jun N-terminal kinase 3 (JNK3) mRNA expression was found in carcinoma cells which correlated with enhanced toxicity of PTX suggesting an essential role of the mitogen activated protein kinase (MAPK)/JNK signalling cascades pathway in the mechanisms of HNSCC cell resistance to PTX. In mice inoculated with carcinoma cells, injections of PTX into the xenografted tumors resulted within 24 days in extensive tumor destruction in 75% of the treated animals (LD50 of 68 ng/kg to 83 ng/kg) while no tumor regression occurred in control animals. CONCLUSIONS: These results clearly provide evidence that PTX possesses preferential toxicity for head and neck carcinoma cells and therefore it is worth further studying its impact which may extend our knowledge of the biology of head and neck cancer.