The inhibitory effect and mechanism of quetiapine on tumor progression in hepatocellular carcinoma in vivo

Hepatocellular carcinoma (HCC) is the primary tumor of the liver and the fourth leading cause of cancer‐related death. Recently, several studies indicated the anti‐tumor potential of antipsychotic medicine. Quetiapine, an atypical antipsychotic, is used to treat schizophrenia, bipolar disorder, and major depressive disorder since 1997. However, whether quetiapine may show potential to suppress HCC progression and its underlying mechanism is persisting unclear. Quetiapine has been shown to induce apoptosis and inhibit invasion ability in HCC in vitro. Here, we established two different HCC (Hep3B, SK‐Hep1) bearing animals to identify the treatment efficacy of quetiapine. Tumor growth, signaling transduction, and normal tissue pathology after quetiapine treatment were validated by caliper, bioluminescence image, immunohistochemistry (IHC), and hematoxylin and eosin staining, respectively. Quetiapine suppressed HCC progression in a dose‐dependent manner. Extracellular signal‐regulated kinases (ERKs) and Nuclear factor‐κB (NF‐κB) mediated downstream proteins, such as myeloid leukemia cell differentiation protein (MCL‐1), cellular FLICE‐inhibitory protein (C‐FLIP), X‐linked inhibitor of apoptosis protein (XIAP), Cyclin‐D1, matrix metallopeptidase 9 (MMP‐9), vascular endothelial growth factor‐A (VEGF‐A) and indoleamine 2,3‐dioxygenase (IDO) which involved in proliferation, survival, angiogenesis, invasion and anti‐tumor immunity were all decreased by quetiapine. In addition, extrinsic/intrinsic caspase‐dependent and caspase‐independent pathways, including cleaved caspase‐3, −8, and − 9 were increased by quetiapine. In sum, the tumor inhibition that results from quetiapine may associate with ERK and NF‐κB inactivation.