Snail-dependent epithelial splicing regulatory protein 1 (ESRP1) silencing drives malignant transformation of human pulmonary epithelial cells [mRNA]

The significance of epithelial-to-mesenchymal transition (EMT)-inducing transcription factors in the onset of non-small cell lung cancer has not been resolved. Here, we report increased Snail expression in pulmonary premalignant lesions relative to histologically normal-appearing pulmonary epithelium. Utilizing immortalized human pulmonary epithelial cells and isogenic derivatives, we document Snail-dependent anchorage-independent growth of the epithelial cells in vitro, as well as transformation, primary tumor growth, and metastatic behavior in vivo. Epithelial splicing regulatory protein 1 (ESRP1) tumor suppressor silencing was a requirement for Snail-driven transformation in vivo, and we identified ESRP1 loss in Snail-expressing pulmonary premalignant lesions in situ. Snail drives these and other carcinogenic signaling programs in an ALDH+CD44+CD24- pulmonary stem cell subset in which ESRP1 and stemness-repressing micro-RNAs are inhibited.

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