Received for publication September 28, 2007.
Revised February 1, 2008.
Accepted for publication February 1, 2008.

TNF- REGULATES INFLAMMATORY AND MESENCHYMAL RESPONSES VIA MEK, p38, NF-B IN HUMAN ENDOMETRIOTIC EPITHELIAL CELLS

Abstract

Tumor Necrosis Factor-alpha (TNF-) is central to the endometriotic disease process. TNF- receptor signaling regulates epithelial cell secretion of inflammation and invasion mediators. Since epithelial cells are a disease-inducing component of the endometriotic lesion, we explored the response of 12Z immortalized human epithelial endometriotic cells to TNF-. This report reveals the impact of disruption of established TNF- induced signaling cascades on the expression of biomarkers of inflammation and EMT (Epithelial-Mesenchymal Transition) from endometriotic epithelial cells. Importantly, we show the molecular potential of sTNF-R1 (TBP) and a panel of small molecule kinase inhibitors to block endometriotic gene expression, directly. TNF- receptor is demonstrated to signal through IKK2>IB>NF, Erk>MEK, p38, and PI3K>Akt1/2. TNF- induces the expression of transcripts for inflammatory mediators IL-6, IL-8, RANTES, TNF-, GMCSF, MCP-1 and also invasion mediators MMP-7, MMP-9, and ICAM-1. Indeed, TBP inhibits the TNF- induced expression of all the above endometriotic genes in 12Z endometriotic epithelial cells. The secretion of IL-6, IL-8, GMCSF, and MCP-1 by TNF- nis blocked by TBP. Interestingly, MEK, p38, and IKK inhibitors block TNF- induced IL-8, IL-6 and GM-CSF secretion and 12z invasion while the PI3K inhibitors does not. The only inhibitor to block MCP-1 expression is the p38 inhibitor. Lastly, TBP, MEK inhibitor, or p38 inhibitor also block cell surface expression of N-cadherin, a marker of mesenchymal cells. Taken together these results demonstrate, that interruption of TNF- induced signaling pathways in human endometriotic epithelial cells results in decreased expression and secretion of biomarkers for inflammation, EMT, and disease progression.

Key words: Interleukins, Tumor necrosis factor, MAP Kinase, Jun Kinase, P38 MAP Kinase, NFkappaB, Signaling network analyses