Kai Fruth

ACTIVATION OF MITOGEN-ACTIVATED PROTEIN KINASE EXTRACELLULAR SIGNAL-RELATED KINASE IN HEAD AND NECK SQUAMOUS CELL CARCINOMAS AFTER IRRADIATION AS PART OF A RESCUE MECHANISM

Irradiation plays a pivotal role in head and neck squamous cell carcinoma (HNSCC) treatment. However, especially recurrent tumors frequently show increased radioresistance. We analyzed irradiation‐stimulated mitogen‐activated protein kinase (MAPK) signaling pathways to define cellular rescue mechanisms.

Demethylation treatment restores hic1 expression and impairs aggressiveness of head and neck squamous cell carcinoma

Promoter hypermethylation of tumor suppressor genes is a common feature of primary cancer cells. However, at date the somatic epigenetic events that occur in head and neck squamous cell carcinoma (HNSCC) tumorigenesis are not yet been well defined. In the present study we analysed the methylation status of the gene hypermethylated in cancer-1 (hic1), a gene located on chromosome 17p13.3, a region frequently lost in HNSCC. We analysed 22 HNSCC samples and three cell lines using methylation specific PCR (MSP). We found hic1 methylated in 21 out of 22 samples and in all three cell lines. Treatment of the cell lines with the demethylating agent 5-Azacytidin (5-Aza) resulted in the demethylation of the hic1 promoter and reactivation of hic1 expression as determined by MSP, qPCR and Western blot. Functional analyses revealed decreased proliferative activity and colony forming ability of treated cells. In summary, we found in HNSCC hic1 regulated by promoter methylation. 5-Aza application resulted in the reexpression of hic1 and was followed by decreased aggressiveness of the cancer cells. Our data indicate that hic1 might be a player in HNSCC development and suggest further evaluation of 5-Aza for HNSCC treatment.

Increased radioresistance via G12S K-Ras by compensatory upregulation of MAPK and PI3K pathways in epithelial cancer.

Irradiation‐induced signaling via the 2 pathways, Raf‐MEK‐ERK and PI3K‐Akt, is known to be closely associated with a limited response to radiotherapy. In the present study we analyzed the relevance of constitutively active K‐Ras for postradiogenic pathway stimulation and the option of coordinated inhibition to overcome these rescue mechanisms.

Pharmacological genome demethylation increases radiosensitivity of head and neck squamous carcinoma cells

Aberrant inactivation of tumor suppressor genes by promoter hypermethylation has been recognized as a crucial step of tumor development and is related to aggressiveness and therapy resistance. To identify potential novel treatment strategies, we evaluated pharmacological genome demethylation for the increase of irradiation treatment effectiveness in head and neck squamous cell carcinoma (HNSCC) in this in vitro study. HNSCC cells were cultured with 2 different concentrations of 5-azacytidine (5-Aza) for 72 h, followed by a single fraction irradiation with 4 or 50 Gy, respectively. To show successful genome demethylation, the methylation status of the tumor suppressor gene hic1 (hypermethylated in cancer) promoter was analyzed by methylation specific PCR (MSP) as well as hic1 transcription by quantitative RT-PCR. Survival, apoptosis, viability, and migration of the tumor cells were analyzed as functional parameters of combined treatment response. After 5-Aza treatment the hic1 promoter was demethylated and gene transcription restored demonstrating genome demethylation. 5-Aza treated cells tended to be less viable and showed decreased survival indicated by lower colony numbers. Apoptosis and migration were not affected. The combined application of irradiation and 5-Aza significantly reduced survival compared to the single treatments. Accordingly, apoptosis was strongly increased after combined 4 Gy/5-Aza treatment. Viability was not additionally affected by combined treatment. Migration was affected weakly by combined high dosage irradiation/5‑Aza treatment. Our data show that the combined application of 5-Aza and irradiation is effective in vitro. A demethylating concept prior to irradiation should be further evaluated for its potential to reduce irradiation resistance.

Low SPINK5 Expression in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a multifactorial disease that probably arises as a result of genetic diversity and environmental factors. SPINK5 is a serine protease inhibitor, which is supposed to be an important regulator of epithelial barrier maintenance. The role of SPINK5 polymorphisms and expression in CRS, especially in individuals with aspirin intolerance, is unclear.

Radiofrequency tissue volume reduction for treatment of auricle keloids

Keloids are often refractive to treatment, and recurrences occur quite frequently. Radiofrequency tissue volume reduction (RFTVR) is a surgical technology that induces extensive fibrosis at the target tissues.

Evaluation of the efficacy of the ‘nasal airflow-inducing manoeuvre’ for smell rehabilitation in laryngectomees by means of the Sniffin′ Sticks test

Clin. Otolaryngol. 2011, 36, 17–23

Correlation of Skin Test Results and Specific Immunoglobulin E Blood Levels with Nasal Provocation Testing for House-Dust Mite Allergies:

Background Allergen-specific immunotherapy for house-dust mite (HDM) allergies is associated with lower success rates when compared with similar treatments for other inhalant allergens, such as grass or birch. One reason might be the greater difficulty in diagnosing patients with assumed HDM allergies because symptoms occur perennially and may differ from those of a conventional allergic rhinitis. Objective The aim of the study was to compare the different methods of diagnosis in patients with assumed HDM allergy. Methods We performed a retrospective analysis of nasal provocation tests (NPT) from patients (n = 161) evaluated for Dermatophagoides pteronyssinus (n = 127) and Dermatophagoides farinae (n = 104) allergies, and compared the results with other allergen testing methods (skin-prick test [SPT], intracutaneous test, and allergen specific immunoglobulin E levels [sIgE] to detect sensitization). Receiver operating characteristic curves were used for the analyses and the areas under the curve were calculated. Results For D. pteronyssinus and D. farinae, 86 and 70 complete data files, respectively, were available. For both tested HDMs, the results of the receiver operating characteristic curves showed a significant correlation for SPT and sIgE, with the results of the NPT (area under the curve, 0.742 to 0.763) but not for the intracutaneous test. In patients with a positive SPT (≤3 mm), an allergy was confirmed by the NPT in 69% of cases for D. pteronyssinus and 71% for D. farinae. A positive sIgE result (ImmunoCAP class of ≤2) was verified by the NPT in 69% of cases (D. pteronyssinus) and 70% (D. farinae). Conclusion The predictability value for a positive NPT result is best for SPT and sIgE. Nevertheless, even if the results of both test systems are combined, the positive predictive value that was achieved was only 0.77 for D. pteronyssinus and 0.69 for D. farinae. Therefore, in patients eligible for immunotherapy for HDM, an NPT should be performed before the start of the therapy to verify a clinically relevant allergy.

Fascin upregulation in primary head and neck squamous cell carcinoma is associated with lymphatic metastasis

Fascin is an actin-bundling protein that is associated with cellular motility and cancer-cell invasion. The present study aimed to examine the expression of fascin in head and neck squamous cell carcinoma (HNSCC) and its potential use as a biomarker. In a prospective study with a median follow-up time of 48.8 months, tumor tissues, adjacent healthy tissues and cervical lymph node metastases were collected from 25 patients and analyzed by immunohistochemistry. The specimens were scored according to the intensity of fascin staining and the percentage of tumor cells stained using a semi-quantitative scoring approach; the data were analyzed and correlated with clinical follow-up observations. All of the investigators were blinded to the origin of the specimens. The expression levels of fascin were significantly increased in the tumor tissues (P=0.03) and lymph node metastases (P=0.03) compared with that of the normal tissues. The high expression level of fascin in the tumor tissues was correlated with the N-status, however, not with overall survival. Therefore, fascin may be a suitable marker for the prediction of regional lymphatic metastasis in HNSCC.

Angiogenesis-related prognosis in patients with oral squamous cell carcinoma-role of the VEGF +936 C/T polymorphism.

BACKGROUND The aim of the study was the immunohistological assessment of VEGF-single nucleotide polymorphism (SNP)-related angiogenic activity in oral squamous cell carcinoma (OSCC) in correlation with prognosis. METHODS Fifty OSCC samples were immunostained with CD31-antibodies. Mean microvessel density (MVD) and staining intensity were determined and associated with clinicopathological/prognostic features as well as with the VEGF +936C/T SNP. RESULTS A significant higher MVD could be seen for T3 and T4 compared with T1 and T2, N > 0 vs. N0 as well as G3-G4 vs. G1-G2 OSCCs (all: P < 0.05). A higher MVD was also associated with increased and earlier rates of local relapses, more metastases, and a significant decreased overall as well as disease-free survival (all: P < 0.05). When comparing T1 and T2 samples with +936-T-allele with T 1&2 samples without this allele, staining intensity was significantly increased (P = 0.002). CONCLUSIONS Angiogenesis influences local as well as distant growth of OSCCs with a significant correlation between prognostic parameters. The correlation between VEGF +936-T-allele and increased CD31 immunostain needs further confirmation.