Notch1 regulates the JNK signaling pathway and increases apoptosis in hepatocellular carcinoma

Notch1-induced pathways are involved in cell growth, apoptosis, motility, and invasion in many cancers. In the present study, the expression of Notch1 and NICD1 was detected in hepatocellular carcinoma (HCC) tissues using in-vitro assays. And then, we explored cell biology and signaling pathways using Notch1 siRNA or plasmids. Here, the expression of Notch1 and NICD1 was significantly decreased in HCC tissues. In-vitro, Notch1 plasmids inhibited cell proliferation, migration and invasion, but enhanced apoptosis of HepG2 and Hep3B cells. Conversely, si-Notch1 enhanced cell proliferation, migration and invasion, but inhibited apoptosis of HepG2 and Hep3B cells. Mechanically, Notch1 decreased the expression of cyclin D1, MMP-9 and Bcl-2, but increased the expression of p-JNK, Bax and cleaved caspase 3 in HepG2 and Hep3B cells. Besides, si-JNK or JNK inhibitor SP600125 affected the activation of Notch1 signaling pathway, and prevents cell apoptosis. In conclusion, Notch1 regulates the JNK signaling pathway and increases apoptosis in HCC. Because patients with HCC have a poor prognosis, Notch1 pathway may provide a novel treatment strategy.