Gene expression profiles of p53 depleted human mammary epithelial cells with their Ras-infected epithelial and mesenchymal derivatives

The epithelial-mesenchymal transition (EMT) is an embryonic transdiffrentiation program which consists of the conversion of polarized epithelial cells into a motile mesenchymal phenotype. EMT is aberrantly reactivated during tumor progression, promoting metastatic dissemination. Herein, we demonstrate that EMT permissive conditions also favor tumor initiation by minimizing the number of events required for neoplastic transformation. We further demonstrated that even partial commitment of human mammary epithelial cells into an EMT program is sufficient to confer malignant properties, suggesting that the reactivation of embryonic EMT inducers participate to the primary tumor growth long before the initiation of the invasion-metastasis cascade.

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