2014 Jan 28. [Epub ahead of print]

Slug Signaling Axis in Human Bronchial Cells.

Joannes A1, Grelet S, Duca L, Gilles C, Kileztky C, Dalstein V, Birembaut P, Polette M, Nawrocki-Raby B.

Author information

1SFR CAP-Sante (FED 4231), University of Reims Champagne-Ardenne.

Abstract

In many cancers, including lung carcinomas, Fragile histidine triad (Fhit) is frequently decreased or lost. Fhit status has recently been shown to be associated with elevated in vitro and in vivo invasiveness in lung cancer. Tumor cell invasion is facilitated by epithelialmesenchymal transition (EMT), a process by which tumor cells lose their epithelial features to acquire a mesenchymal cell-like phenotype. In this study, the mechanism underlying Fhitregulated EMT was deciphered. Using Slug knockdown, pharmacological inhibitors PD98059, PP1, and gefitinib as well as an anti-EGFR antibody, it was demonstrated that Fhit silencing in bronchial cells induced overexpression of two primary EMT-associated targets, MMP-9 and vimentin, to regulate cell invasion dependent on an EGFR/Src/ERK/Slug signaling pathway. Moreover, ectopic expression of Fhit in Fhit-deficient lungcancer cells down-regulated this pathway. Finally, an inverse correlation was observed between Fhit and phospho-EGFR levels in a cohort of human squamous-cell lung carcinoma specimens. These results demonstrate a Fhit-dependent mechanism in the control of EMT-regulated EGFR signaling. Implications: This study adds new insight into the regulatory mechanism of EMT, a process known to increase resistance to conventional and targeted therapies in lung cancer.

TimAllenMDJD

Thursday, March 13, 2014