Choline ameliorates tris (2-chloroisopropyl) phosphate-induced hepatocellular carcinoma metastasis by inhibiting ROS/Nrf2/Keap1-mediated autophagy

Abstract

Tris (2-chloroisopropyl) phosphate (TCPP) is an emerging environmental pollutant associated with liver diseases. However, its effects on hepatocellular carcinoma (HCC) remain unknown. Choline, a necessary dietary nutrient, has previously demonstrated inhibitory effects on HCC. Therefore, elucidating the underlying mechanism of TCPP exposure on HCC development and investigating whether choline could mitigate these effects may improve the prognosis of HCC patients. In this study, we examined the tumor-promoting effects of TCPP on HCC and explored the protective effects of choline. Our findings revealed that choline treatment attenuated the tumor-promoting effects of TCPP exposure on HCC cells’ epithelial-mesenchymal transition (EMT) and lung metastasis. Further investigation showed that TCPP exposure induced ROS production via NOX4 upregulation, while choline inhibited ROS generation, thereby mitigating the effects of TCPP on EMT and metastasis in HCC cells. Mechanistic analysis demonstrated that excessive ROS inhibited levels of Keap1, leading to upregulation and nuclear translocation of Nrf2, which promoted autophagy flux and accelerated EMT and metastasis of HCC cells. However, choline treatment significantly impaired TCPP-induced autophagy by attenuating the ROS/Nrf2/Keap1 pathway. Overall, our data illustrate the adverse effects of TCPP on the malignant progression of HCC and suggest that choline may serve as a potential nutrient to counteract the tumor-promoting effects of TCPP on HCC.