Mohammed Soutto 1 , 2 , Zheng Chen 1 , 2 , Ajaz A. Bhat 2 , 3 , Lihong Wang 4 , Shoumin Zhu 2 , Ahmed Gomaa 2 , Andreia Bates 4 , Nadeem S. Bhat 2 , Dunfa Peng 2 , Abbes Belkhiri 4 , M. Blanca Piazuelo 5 , M. Kay Washington 6 , Xi Chen Steven 7 , Richard Peek Jr. 5 , Wael El-Rifai , 1 , 2 , 8
10 July 2019
TFF1, a secreted protein, plays an essential role in keeping the integrity of gastric mucosa and its barrier function. Loss of TFF1 expression in the TFF1-knockout (KO) mouse leads to a pro-inflammatory phenotype with a cascade of gastric lesions that include low-grade dysplasia, high-grade dysplasia, and adenocarcinomas. In this study, we demonstrate nuclear localization of p-STAT Y705, with significant overexpression of several STAT3 target genes in gastric glands from the TFF1 -KO mice. We also show frequent loss of TFF1 with nuclear localization of STAT3 in human gastric cancers. The reconstitution of TFF1 protein in human gastric cancer cells and 3D gastric glands organoids from TFF1-KO mice abrogates IL6-induced nuclear p-STAT3 Y705 expression. Reconstitution of TFF1 inhibits IL6-induced STAT3 transcription activity, suppressing expression of its target genes. TFF1 blocks IL6Rα-GP130 complex formation through interfering with binding of IL6 to its receptor IL6Rα. These findings demonstrate a functional role of TFF1 in suppressing gastric tumorigenesis by impeding the IL6-STAT3 pro-inflammatory signaling axis.
Trefoil factor 1 (TFF1) is a protein secreted by the gastric mucosa that protects against gastric tumourigenesis. Here, the authors show that TFF1 inhibits the oncogenic inflammatory response and IL-6-mediated STAT3 activation by interfering with the binding of IL6 to its receptor IL6Rα.