In Vivo Short-Term Topical Application of BAY 11-7082 Prevents the Acidic Bile-Induced mRNA and miRNA Oncogenic Phenotypes in Exposed Murine Hypopharyngeal Mucosa.

ABSTRACT: PURPOSE:Bile-containing gastroesophageal reflux may promote cancer at extraesophageal sites. Acidic bile can accelerate NF-?B activation and molecular events, linked to premalignant changes in murine hypopharyngeal mucosa (HM). We hypothesize that short-term in vivo topical application of NF-?B inhibitor BAY 11-7082 can prevent acidic bile-induced early preneoplastic molecular events, suggesting its potential role in disease prevention. EXPERIMENTAL DESIGN:We topically exposed HM (C57Bl/6j wild-type) to a mixture of bile acids at pH 3.0 with and without BAY 11-7082 3 times/day for 7 days. We used immunofluorescence, Western blotting, immunohistochemistry, quantitative polymerase chain reaction, and polymerase chain reaction microarrays to identify NF-?B activation and its associated oncogenic mRNA and miRNA phenotypes, in murine hypopharyngeal cells in vitro and in murine HM in vivo. RESULTS:Short-term exposure of HM to acidic bile is a potent stimulus accelerating the expression of NF-?B signaling (70 out of 84 genes) and oncogenic molecules. Topical application of BAY 11-7082 sufficiently blocks the effect of acidic bile. BAY 11-7082 eliminates NF-?B activation in regenerating basal cells of acidic bile-treated HM and prevents overexpression of molecules central to head and neck cancer, including bcl-2, STAT3, EGFR, TNF-?, and WNT5A. NF-?B inhibitor reverses the upregulated "oncomirs" miR-155 and miR-192 and the downregulated "tumor suppressors" miR-451a and miR-375 phenotypes in HM affected by acidic bile. CONCLUSION:There is novel evidence that acidic bile-induced NF-?B-related oncogenic mRNA and miRNA phenotypes are generated after short-term 7-day mucosal exposure and that topical mucosal application of BAY 11-7082 can prevent the acidic bile-induced molecular alterations associated with unregulated cell growth and proliferation of hypopharyngeal cells.

SUBMITTER: Sasaki CT 

PROVIDER: S-EPMC5909679 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature