Abstract 1552: Cigarette smoke induces TNF-α secretion from macrophages through a pathway consisting of PPARγ, MUC1, ERK and JNK.

Abstract

Abstract The glycoprotein Mucin 1 (MUC1 in human and Muc1 in animals) is expressed in the lung and has been shown to be associated with lung carcinogenesis. Recently we have found that cigarette smoke (CS) significantly increased MUC1 expression in mouse lung macrophages and that MUC1 is required for CS-induced tumor necrosis factor-alpha (TNF-α) secretion from macrophages. Because CS potently elicits chronic pulmonary inflammation that is important for the development of lung cancer, we investigated the cell signaling pathways for CS-induced MUC1 expression and MUC1-mediated TNF-α secretion in macrophages using an in vitro model. The results showed that: CS extract (CSE) strongly induced MUC1 expression at both the mRNA and protein levels; Suppression of PPARγ effectively blocked CSE-induced MUC1 expression in THP1 cells, suggesting CSE induces MUC1 expression through PPARγ-mediated transcription; The induction of TNF-α expression was effectively blocked when ERK and JNK were blocked, suggesting these pathways are involved in CSE-induced TNF-α expression in macrophages; Knockdown of MUC1 significantly suppressed CSE-induced ERK and JNK activation; and Suppression of PPARγ that effectively blocked CSE-induced MUC1 expression also inhibited CSE-induced TNF-α secretion from macrophages. Thus, our results suggest a possible involvement of a signaling pathway consisting of PPARγ, MUC1 and ERK/JNK for CSE-induced TNF-α secretion from macrophages that may contribute to inflammation-associated lung cancer development. Note: This work is supported by the NIH/NIEHS grant 1R01ES017328. Citation Format: Xiuling Xu, Mabel T. Padilla, Alexandria Wells, Kwang Chul Kim, yong Lin. Cigarette smoke induces TNF-α secretion from macrophages through a pathway consisting of PPARγ, MUC1, ERK and JNK. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1552. doi:10.1158/1538-7445.AM2013-1552