Mesenchymal to Epithelial Transition Induced by Reprogramming Factors Attenuates the Malignancy of Cancer Cells

Epithelial to mesenchymal transition (EMT) is a biological process of metastatic cancer. However, an effective anticancer therapy that directly targets the EMT program has not yet been discovered. Recent studies have indicated that mesenchymal to epithelial transition (MET), the reverse phenomenon of EMT, is observed in fibroblasts during the generation of induced pluripotent stem cells. In the present study, we investigated the effects of reprogramming factors (RFs) on squamous cell carcinoma (SCC) cells. RFs-introduced cancer cells (RICs) demonstrated the enhanced epithelial characteristics in morphology with altered expression of mRNA and microRNAs. The motility and invasive activities of RICs in vitro were significantly reduced. Furthermore, xenografts of RICs exhibited no lymph node metastasis, whereas metastasis was detected in parental SCC-inoculated mice. Thus, we concluded that RICs regained epithelial properties through MET and showed reduced cancer malignancy in vitro and in vivo. Therefore, the understanding of the MET process in cancer cells by introduction of RFs may lead to the designing of a novel anticancer strategy.