Up-regulated ITGB4 promotes hepatocellular carcinoma metastasis by activating hypoxia-mediated glycolysis and cancer-associated fibroblasts

Abstract

The pre-metastatic niche constructed by cancer-associated fibroblasts (CAFs) plays a key role in the hypoxic tumor microenvironment (TME), promoting hepatocellular carcinoma (HCC) metastasis. Integrin, which is involved in cell-to-cell or cell-to-matrix interactions and TME regulation, affects tumor metastasis. However, the complex interactions between integrin-mediated HCC cells and CAFs remain unclear. Co-culture experiments were used to assess the behaviors of HCC cells and CAFs, demonstrating HCC metastatic traits and CAFs activation in vitro. Transcriptome sequencing analysis and molecular detection identified key genes, with overexpression and knockdown experiments further confirming their roles in HCC progression. Xenograft models validated these findings in vivo. We showed that HCC cells induced the conversion of normal hepatic stellate cells (HSCs) into CAFs and recruit additional CAFs, driven by lactate produced by HCC. Integrin beta 4 (ITGB4) was identified as a key gene in the process. Inhibiting ITGB4 reduced lactate secretion, reversed CAFs activation and recruitment, and decreased HCC metastasis, while overexpressing ITGB4 significantly enhanced these malignant phenotypes. ITGB4 influences glycolysis and HCC metastasis through the AKT/HK2 signaling pathway, and CAFs activation and recruitment through the TGF-β/Smads signaling pathway. Compared to tumors derived from control cells, ITGB4-knockdown tumors showed fewer and smaller intrahepatic metastatic nodules, reduced lactate production and CAFs formation, along with inhibition of AKT/HK2 and TGF-β/Smads signaling pathways. Our findings highlighted the impact of hypoxia on HCC progression, revealing the roles of ITGB4-mediated glycolysis and lactate-induced CAFs in the pre-metastatic niche on HCC metastasis.

Keywords: CAFs; Glycolysis; HCC; ITGB4; Metastasis; Pre-metastatic niche.