The Impact of Pepsin on Human Nasal Epithelial Cells In Vitro: A Potential Mechanism for Extraesophageal Reflux Induced Chronic Rhinosinusitis.

OBJECTIVES: To describe potential mechanisms by which pepsin induces inflammation in refractive chronic rhinosinusitis (CRS). Our hypothesis was that pepsin induces mitochondrial damage and cytokine expression in human nasal epithelial cells (HNEpC) in vitro. METHODS: Western blot was used to detect pepsin in sinus lavages from patients with CRS and controls. The HNEpC cells were treated with pepsin (pH 7; 0.1 mg/mL) for 1 or 16 hours and routine electron microscopy (EM) and MTT assay were performed. Cytokine ELISA was performed on media collected from HNEpC cells 16 hours following a 1-hour pepsin treatment. RESULTS: Pepsin was detected in sinus lavages from 4 out of 6 CRS patients and 0 out of 3 controls. The EM showed mitochondrial damage in pepsin-treated HNEpC cells but not in control cells. The MTT assay demonstrated reduced mitochondrial activity in pepsin-treated HNEpC cells compared to controls (P < .001). Pepsin increased IL-1A (P = .003) and IL-6 (P = .04) expression in HNEpC cells. CONCLUSIONS: Pepsin in sinus lavages from patients with CRS is consistent with previous studies. This study reveals the damaging effect of pepsin on mitochondria in nasal epithelial cells in vitro. Cytokines previously associated with CRS were elevated following pepsin treatment of HNEpC cells in vitro. These results demonstrate mechanisms by which pepsin may potentiate CRS.

Dysphagia due to adenoid cystic carcinoma of the base of the tongue.

OBJECTIVES: Although oropharyngeal neoplasia can often lead to dysphagia, salivary gland tumors rarely grow within the tongue base. We present the case of a 75-year-old man with adenoid cystic carcinoma of the base of the tongue causing profound dysphagia and weight loss, and provide a current literature review and update on the management of these rare tumors. METHODS: We present a case report and a literature review. RESULTS: Physical examination performed at the initial visit revealed a firm right base-of-tongue mass with no palpable lymphadenopathy. Flexible fiberoptic laryngoscopy confirmed a large submucosal mass at the right base of the tongue that obscured the right vallecula. Histopathologic analysis of the operative biopsy specimens revealed the classic features of adenoid cystic carcinoma. Treatment included radical pharyngotomy with wide local excision and primary closure, followed by postoperative radiation treatment. CONCLUSIONS: We demonstrate the clinical examination findings and histopathologic characteristics of this disease, and review the literature for clinical treatment recommendations for this rare cause of dysphagia.

Pepsin promotes proliferation of laryngeal and pharyngeal epithelial cells.

OBJECTIVE/HYPOTHESIS: Laryngopharyngeal reflux (LPR) is thought to be a significant risk factor for laryngeal squamous cell carcinoma (SCC), but causality has never been proven. It is accepted that chronic reflux into the esophagus can induce metaplastic changes in esophageal mucosa with subsequent increased risk of esophageal adenocarcinoma, but no similar associations have been established for LPR and laryngopharyngeal SCC. The objective of this study was to test the hypothesis that reflux of pepsin into the laryngopharynx can promote carcinogenesis. STUDY DESIGN: Translational research study. METHODS: Normal human laryngeal primary epithelial cell cultures and hypopharyngeal FaDu SCC cells were exposed to human pepsin and analyzed by Human Cancer PathwayFinder and miRNA Superarrays, flow cytometry, and Western blot to determine the effect of pepsin on carcinogenesis. Laryngeal biopsy specimens taken from cancer patients and normal control subjects were analyzed for the presence of pepsin by Western blot. RESULTS: Microarray analysis demonstrated that pepsin significantly altered the expression of 27 genes implicated in carcinogenesis and also affected the expression of 22 microRNAs known to be altered in human head and neck cancers. Pepsin increased proliferation in both FaDu SCC cells and cultured normal laryngeal epithelial primary cells by increasing S phase distribution on flow cytometry analysis in a time- and dose-dependent manner. Furthermore, pepsin was detected in 60% (3/5) human laryngeal cancer biopsies, absent in all (0/5) normal control specimens. CONCLUSIONS: These data support a role for refluxed pepsin in the promotion of epithelial proliferation and carcinogenesis of the larynx and pharynx.