Vaccinia-related kinase 2 blunts sorafenib's efficacy against hepatocellular carcinoma by disturbing the apoptosis-autophagy balance.

Abstract

Hepatocellular carcinoma (HCC) is a lethal malignancy with limited treatment options. Sorafenib is the only Food and Drug Administration (FDA)-approved first-line targeted drug for the treatment of advanced HCC. However, its effect on patient survival is limited. Recently, studies have demonstrated that the imbalance between apoptosis and autophagy plays a critical role in chemoresistance, and it is hypothesised that restoring the balance between these processes is a potential treatment strategy for improving chemoresistance in cancer. However, there is currently no evidence supporting this hypothesis. We aimed to investigate if vaccinia-related kinase 2 (VRK2), a serine/threonine protein kinase, confers sorafenib resistance in HCC cells. Here, we found that VRK2 was enriched in sorafenib-resistant HCC cells and patient-derived xenografts. Both in vivo and in vitro evidences showed that VRK2 blunts the efficacy of sorafenib against hepatocellular carcinoma by disturbing the balance between apoptosis and autophagy. Mechanistically, VRK2 promotes the phosphorylation of Bcl-2 by activating JNK1/MAPK8, thereby enhancing the dissociation of Bcl-2 from Beclin-1 and promoting the formation of the Beclin-1-Atg14-Vps34 complex, which facilitates autophagy. Furthermore, VRK2-induced phosphorylation of Bcl-2 promotes the interaction of Bcl-2 with BAX, thereby inhibiting apoptosis. In conclusion, targeting VRK2 for modulation of the balance between autophagy and apoptosis may be a novel strategy for overcoming sorafenib resistance in HCC.

• Authors: Sisi Chen, Yunyan Du, Bin Xu, Qing Li, Le Yang, Zi Jiang, Zhaoxia Zeng, Leifeng Chen
• Journal: Oncogene (Oncogene) Vol. 40 Issue 19 Pg. 3378-3393 (05 2021) ISSN: 1476-5594 [Electronic] England
• PMID: 33875785 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• BAX protein, human
• BCL2 protein, human
• BECN1 protein, human
• Beclin-1
• Protein Kinase Inhibitors
• Proto-Oncogene Proteins c-bcl-2
• bcl-2-Associated X Protein
• Sorafenib
• Protein Serine-Threonine Kinases
• VRK2 protein, human

Topics

• Animals
• Apoptosis (drug effects, physiology)
• Autophagy (drug effects)
• Beclin-1 (metabolism)
• Carcinoma, Hepatocellular (drug therapy, genetics, metabolism, pathology)
• Cell Line, Tumor
• Cell Proliferation (drug effects)
• Disease Progression
• Drug Resistance, Neoplasm
• Humans
• Liver Neoplasms (drug therapy, genetics, metabolism, pathology)
• Male
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Phosphorylation
• Protein Kinase Inhibitors (pharmacology)
• Protein Serine-Threonine Kinases (genetics, metabolism)
• Proto-Oncogene Proteins c-bcl-2 (genetics, metabolism)
• Sorafenib (pharmacology)
• Survival Rate
• Xenograft Model Antitumor Assays
• bcl-2-Associated X Protein (metabolism)