FOXL1, a Novel Candidate Tumor Suppressor, Inhibits Tumor Aggressiveness and Predicts Outcome in Human Pancreatic Cancer
Menée in vitro, in vivo et sur des échantillons tumoraux prélevés sur des patients atteints d'un adénocarcinome canalaire du pancréas, cette étude met en évidence des mécanismes par lesquels le facteur de transcription FOXL1 joue un rôle de suppresseur de tumeurs et suggère que la sous-expression de FOXL1 est associée à un pronostic défavorable
The Forkhead Box L1 (FOXL1) transcription factor regulates epithelial proliferation and development of gastrointestinal tract, and has been implicated in gastrointestinal tumorigenesis in mouse models. However, the role of FOXL1 in pancreatic cancer development and progression remains to be elucidated. Here, we report that a higher expression of FOXL1 is significantly associated with better clinical outcome in human pancreatic ductal adenocarcinoma (PDAC). A lower FOXL1 expression is correlated with metastasis and advanced pathological stage of pancreatic cancer. Mechanistic analyses demonstrated that over-expression of FOXL1 induces apoptosis and inhibits proliferation and invasion in pancreatic cancer cells, whereas silencing of FOXL1 by siRNA inhibits apoptosis and enhances tumor cell growth and invasion. Furthermore, FOXL1 overexpression significantly suppressed the growth of tumor xenografts in nude mice. FOXL1 promoted apoptosis partly through the induction of TNF-related apoptosis-inducing ligand (TRAIL) in pancreatic cancer cells. In addition, FOXL1 suppressed the transcription of zinc finger E-box-binding homeobox 1 (ZEB1), an activator of epithelial mesenchymal transition (EMT), and the negative regulation of ZEB1 contributed to the inhibitory effect of FOXL1 on tumor cell invasion. Taken together, our findings suggest that FOXL1 expression is a candidate predictor of clinical outcome in patients with resected PDAC and it plays an inhibitory role in pancreatic tumor progression.
Cancer Research , résumé, 2013