RPRD1A drives lenvatinib resistance in hepatocellular carcinoma via the ITGA5-FAK signaling axis.

Hepatocellular carcinoma (HCC) constitutes a formidable global health challenge. Lenvatinib, a multi-targeted tyrosine kinase inhibitor (TKI), has gradually become a cornerstone therapeutic agent for advanced HCC; however, the emergence of drug resistance severely compromises its clinical efficacy and remains a major obstacle to improving patient outcomes. In this study, we identified key genes associated with lenvatinib resistance, among which regulator of nuclear pre-mRNA domain-containing protein 1A (RPRD1A) emerged as a prominent candidate. Functional assays demonstrated that RPRD1A overexpression significantly reduces the sensitivity of HCC to lenvatinib, whereas its knockdown restores drug responsiveness. Mechanistically, RPRD1A competes with RNA polymerase II-associated protein 2 (RPAP2) for binding to RNA polymerase II (RNA Pol II), thereby derepressing integrin subunit alpha 5 (ITGA5) transcription via a c-JUN-dependent pathway. Upregulated ITGA5 subsequently activates focal adhesion kinase (FAK) signaling, which critically drives lenvatinib resistance. Notably, combined treatment with lenvatinib and either the ITGA5 inhibitor volociximab or the FAK inhibitor defactinib effectively reversed lenvatinib resistance in preclinical models. Furthermore, clinical analyses revealed that elevated expression of RPRD1A and ITGA5 correlates with poor response to lenvatinib in HCC patients, reinforcing their potential as predictive biomarkers for therapeutic resistance. Collectively, our results demonstrate that co-targeting the RPRD1A-ITGA5-FAK signaling axis in combination with lenvatinib represents a promising strategy to improve therapeutic efficacy in HCC.