Combination therapy with Nifuroxazide and Lenvatinib exerts superior anti-hepatocellular carcinoma effect by enhancing the anti-tumor immune response

Abstract

Background Lenvatinib is a first-line multi-target tyrosine kinase inhibitor for hepatocellular carcinoma (HCC) that exerts anti-angiogenic effects by blocking VEGF signaling. However, its clinical efficacy is often compromised by adaptive resistance. Nifuroxazide, an anti-diarrheal agent, has been identified by our group as a potent inhibitor of PD-L1 expression in HCC. Objective This study aimed to evaluate the therapeutic potential and underlying molecular mechanisms of nifuroxazide combined with lenvatinib against HCC. Methods In vitro, HCC cell proliferation, colony formation, and migration were assessed, and Western blot was used to detect p-STAT3, STAT3, PD-L1, and VEGF levels. In vivo, antitumor efficacy was evaluated in mouse xenograft models. Tumor tissues were analyzed by immunohistochemistry, TUNEL, and H&E staining, while flow cytometry was used to measure CD4+ and CD8+ T-cell proportions in the tumor microenvironment, peripheral blood, and spleen. Results The combination synergistically inhibited HCC cell proliferation and migration, and downregulated PD-L1, p-STAT3, and VEGF expression. It also markedly suppressed tumor growth, induced apoptosis, and enhanced CD4+ and CD8+ T-cell infiltration and distribution. Conclusions Nifuroxazide potentiates lenvatinib-induced antitumor activity by regulating the STAT3/PD-L1 axis and enhancing antitumor immune responses. This combination provides a promising therapeutic strategy for HCC.