PRDM16 from hepatic stellate cells-derived extracellular vesicles promotes hepatocellular carcinoma progression

Hepatocellular carcinoma (HCC) represents a lethal cancer, and most HCC cases occur in the fibrotic or cirrhotic livers. Hepatic stellate cells (HSCs), the main effector cells of liver fibrosis, could secret biological contents to maintain liver inflammation. Herein, we aimed to identify the key transcription factor secreted by extracellular vesicles (EVs) derived from HSCs and explored its oncogenic mechanism. The activated HSC cell line LX-2 was co-cultured with HCC cells with or without the EVs release inhibitor GW4869. The effects of co-culture with HSC on HCC cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition were analyzed. Co-culture with activated LX-2 enhanced HCC cell growth and motility, while GW4869 inhibited the pro-carcinogenic effect of HSC, suggesting that HSC promoted HCC progression through the secretion of EVs. HSC-derived EVs carried the key oncogenic transcription factor PRDM16, and uptake of EVs-derived PRDM16 by HCC cells activated the NOTCH1-mediated Notch signaling pathway. Knocking down PRDM16 in EVs or blocking Notch signaling in HCC cells significantly inhibited the tumor-promoting effects of HSC-derived EVs. Our study demonstrates that HSC-derived EVs activate the NOTCH1-mediated Notch signaling pathway in HCC cells by carrying PRDM16, leading to HCC progression.