In vitro model for gastroduodenal reflux-induced nuclear factor-kappaB activation and its role in hypopharyngeal carcinogenesis.

BACKGROUND: The purpose of this study was to investigate whether gastroduodenal reflux can play a role in the pathogenesis of hypopharyngeal cancer; therefore, we assessed its effect on the nuclear factor-kappa B (NF-κB) pathway, as similarly noted in the esophagus.

METHODS: We exposed human cells derived from the hypopharyngeal epithelium to bile acids or deoxycholic acid. We centered our study on the transcriptional activation of NF-κB pathway, previously linked to head and neck squamous cell carcinoma (HNSCC).

RESULTS: We show that acidic-bile salts induce: (1) NF-κB activation with high cytoplasmic Bcl-2 expression; (2) significant increase in expression v-rel avian reticuloendotheliosis viral oncogene homolog A (RELA(p65)), v-rel avian reticuloendotheliosis viral oncogene homolog (c-REL) signal transducer and activator of transcription 3 (STAT3), isoform of transformation related protein p63 (ΔNp63), B-cell lymphoma 2 (Bcl-2), tumor necrosis factor alpha (TNF-α), epidermal growth factor receptor (EGFR), and wingless type MMTV integration site family member 5A (WNT5A) and a decrease in tumor protein p53 (Tp53); and (3) phenotypic changes that are similar to the phenotype of the untreated hypopharyngeal cancer cell line, University of Michigan squamous cell carcinoma (UMSCC)-11B. These changes are not seen when cells were exposed to neutral control or acid alone.

CONCLUSION: Our findings in vitro are consistent with the hypothesis that gastroduodenal reflux plays a role in hypopharyngeal carcinogenesis and its effect is mediated through activation of NF-κB pathway. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1381-E1391, 2016.