PKM2 Confers Purine Metabolic Advantage and Enhances Lenvatinib Resistance in Hepatocellular Carcinoma

Abstract Acquired resistance largely impedes the clinical efficacy of lenvatinib in hepatocellular carcinoma (HCC). Despite the identification of several underlying drivers, the comprehensive mechanism underlying lenvatinib resistance remains largely unknown. In the present study, we establish a lenvatinib-resistant model (Len-R) in HCC patients-derived organoids to simulate the emergence of resistant tumors. We demonstrate that upregulation of PKM2 is a hallmark of Len-R and PKM2 directly contributes to lenvatinib resistance. We also identify that purine metabolic flux enriched in Len-R confers the resistance property to tumor cells in a PKM2-dependent manner. For the molecular mechanism, PKM2 interacts directly with SMAD4 and enhances its occupancy on the SMAD4 binding element (SBE) at DHFR promoter region. Consequently, upregulated DHFR enhances purine nucleotide pool to resist the effectiveness of lenvatinib on purine metabolism pathway. Clinically, upregulation of PKM2 together with DHFR is associated with lenvatinib resistance and worse outcome in HCC patients. In summary, our data suggest that PKM2-SMAD4-DHFR axis drives lenvatinib resistance in HCC by provoking de novo purine biosynthesis.