Identification and Therapeutic Targeting of METTL8-Mediated Lenvatinib Resistance in Hepatocellular Carcinoma Using Rabdosiin

In hepatocellular carcinoma (HCC), lenvatinib is a key first-line treatment that significantly improves survival in some patients with advanced stage. However, lenvatinib resistance presents a major clinical challenge. This study aims to identify key molecular factors driving lenvatinib resistance in HCC and propose intervention strategies to overcome this resistance, thereby enhancing therapeutic efficacy. A genome-wide CRISPR-Cas9 activation screen identified METTL8 as a crucial gene associated with lenvatinib resistance. Validation through in vitro and in vivo assays confirmed METTL8's role in mediating lenvatinib resistance. Higher METTL8 expression was observed in lenvatinib-resistant HCC cells compared to parental cells. Immunohistochemical staining of tissue sections from HCC patients revealed a negative correlation between high METTL8 expression and lenvatinib sensitivity. To inhibit the function of METTL8 that mediate lenvatinib resistance, we conducted a screening using a natural compound library, virtual drug screening identified Rabdosiin as a potential METTL8 inhibitor, subsequent experiments demonstrated that Rabdosiin could effectively overcome METTL8-mediated lenvatinib resistance. In conclusion, this research highlights METTL8 as a novel target for mitigating lenvatinib resistance, proposing that targeting METTL8 could restore lenvatinib sensitivity in HCC, and underscores its value as a biomarker for lenvatinib application in clinical settings.