Inhibition of nuclear receptor coactivator 5 overcomes acquired lenvatinib resistance driven by protein kinase B-mammalian target of rapamycin signaling in hepatocellular carcinoma.

Lenvatinib, a multiple-receptor tyrosine kinase inhibitor, has gained recent approval for its use as a first-line treatment of hepatocellular carcinoma (HCC). While lenvatinib demonstrates notable therapeutic efficacy, the drug resistance undermines its sustained tumor control potential. The restricted clinical utility of lenvatinib underscores the imperative necessity to elucidate the mechanisms underpinning drug resistance. We established lenvatinib-resistant cell lines and investigated the changes in their biological characteristics. Next-generation sequencing was performed to identify genes associated with lenvatinib resistance. Western blots were utilized to confirm the involvement of these genes. Using lentiviral technology, we generated cell lines with lowered nuclear receptor coactivator 5 (NCOA5), a pivotal drug resistance-related gene, to explore the underlying resistance mechanism. Moreover, we developed a subcutaneous HCC xenograft tumor model to explore strategies for reversing drug resistance. Our study showed that HCC cells acquire resistance to lenvatinib through the activation of NCOA5, thereby stimulating the NCOA5-Protein Kinase B-mammalian target of rapamycin (AKT-mTOR) axis. Furthermore, the clinical evaluation of HCC specimens established a correlation between the activation of the NCOA5 pathway and the response to lenvatinib treatment. Everolimus, an mTOR inhibitor, in combination with lenvatinib and everolimus, exerted significant synergistic effects against HCC in vivo and in vitro. HCC cells develop resistance to lenvatinib by activating the NCOA5-AKT-mTOR pathway. The combination therapy of lenvatinib with everolimus is a promising strategy to overcome acquired resistance, thereby enhancing the clinical efficacy of lenvatinib.