Epithelial Mesenchymal Transition in Cancer Progression: Preventive Phytochemicals

Background: Epithelial-Mesenchymal Transition (EMT) is the conversion of epithelial cells into mesenchymal phenotype generally observed during embryogenesis and wound healing as well as in malignant transformation. Several signaling pathways and transcription factors associated with EMT have been explored. Dietary phytochemicals that are multi-targeted agents which interfere with these pathways, assume preventive potential against pathologic EMT. Objective: The present review aims to provide a detailed description of the nature and characteristics of EMT in physiological and pathophysiological conditions and the scope of phytochemicals in its prevention. Method: Details regarding the initiation, progression as well as prevention of pathologic EMT and metastasis and recent patents on preventive phytochemicals were obtained from PubMed literatures and patent databases. Results: The phenotypic changes during EMT are regulated by transcription factors like Snail, Slug, Twist and Zeb, which are activated through diverse signaling pathways of TGF-beta, NF-kappa B, Wnt and Notch. Scientific documentations till date have identified numerous phytocompounds that are potent enough to interfere with these signaling pathways, which in turn prevent pathological implications of EMT. Present review also discusses 28 recent patents on those phytocompounds. Conclusion: EMT is a significant pharmacological target for developing preventive agents to combat pathological conditions like malignancy. Many of the phytochemicals cited in this review are being enrolled for different phases of clinical trials for their efficacy. In spite of the major limitations regarding bioavailability, sensitivity and tolerance of these compounds, their synthetic analogs, formulations and efficient drug delivery systems are also being attempted which will hopefully generate productive and promising results in near future.