Reversal of microRNA-blocked tumor suppressors by biphenyl- dicarboxylate impedes endotoxin-induced hepatic hyperplasia

Hepatocellular carcinoma (HCC) is one of the most common malignant tumor and the leading cause of cancer-related death worldwide. Biphenyldicarboxylate (BPDC), an intermediate of schisandrin C from Schisandra chinensis, has been used as a hepatoprotective agent that compromises hepatic injuries in China for decades. Whether BPDC is also implicated in the prevention of HCC remains understood. Here, we report that the bacterial endotoxin lipopolysaccharide (LPS) promotes hepatic inflammation and hyperplasia, during which the common tumor markers, alpha fetoprotein (AFP) and carcinoembryonic antigen (CEA), were unregulated, whereas the tumor suppressors, PTEN, FOXO1 and MEN1, were downregulated through increasing the microRNAs, miR-21, miR-122 and miR-24. In contrast, BPDC dampened hepatic inflammation and hyperplasia accompanied by the upregulation of PTEN, FOXO1 and MEN1 through decreasing miR-21, miR-122 and miR-24. However, BPDC failed to downregulate the tumor marker AEG-1 via increasing miR-195. Taken together, BPDC exerts anti-tumor effects by upregulating tumor suppressors upon decreases of miRNAs rather than downregulating tumor markers by increases of miRNAs.