Ferroptosis-related genes coordinated with PD-L2 shapes matrix stiffness-driven tumor environment and predict hepatocellular carcinoma development

Abstract Background: Ferroptosis have been implicated in tumorigenesis, tumor progression, and immuno-therapy in cirrhotic hepatocellular carcinoma (HCC), indicating its association with extracellular matrix stiffness and immune checkpoint inhibitor. Here, we postulated that increased matrix stiffness reduces ferroptosis and impairs tumor immunity by regulating the expression of ferroptosis- and immune-related genes in HCC, which might be a robust predictor of therapeutic efficacy.Methods: Using publicly available tissue microarray datasets, liver cancer rat model, and clinical specimen, ferroptosis-related differential genes in cirrhotic HCC and its mechanical heterogeneous pattern of expression were screened and identified. Further investigation on the underlying mechanism of matrix stiffness-regulated ferroptosis and the expression of immune mediator were performed.Results: SLC7A11 and STEAP3 were identified as the ferroptosis-related differential genes in cirrhotic HCC, especially induced by HBV and HCV virus. Stiffer matrix increased SLC7A11 and decreased STEAP3 in the invasive front area of HCC and the liver cirrhotic tissue. Contrarily, softer matrix reduced SLC7A11 and induced STEAP3 in the central area of HCC and the normal liver tissue. Immunological correlation of SLC7A11 and STEAP3 in cirrhotic HCC showed that SLC7A11- or STEAP3-mediated immune infiltration of CD4+ T and CD8+ T cells, macrophages, neutrophils, and dendritic cells and HCC prognosis, predicting to regulate immune infiltration. Knockdown of SLC7A11 or overexpression of STEAP3 induced ferroptosis and inhibited the expression of immune mediator of PD-L2 on a stiff matrix.Conclusions: This finding identifies matrix stiffness impairs ferroptosis and anti-tumor immunity by mediating SLC7A11, STEAP3, and PD-L2, and thus targeting it could be a potential diagnosis and treatment strategy for HCC.