Background In this study, we comprehensively analyzed genes related to ferroptosis and iron metabolism to construct diagnostic and prognostic models and explore the relationship with the immune microenvironment in HCC. Methods Integrated analysis, cox regression and the least absolute shrinkage and selection operator (LASSO) method of 104 ferroptosis- and iron metabolism-related genes and HCC-related RNA sequencing were performed to identify HCC-related ferroptosis and iron metabolism genes. Results Four genes (ABCB6, FLVCR1, SLC48A1 and SLC7A11) were identified to construct prognostic and diagnostic models. Poorer overall survival (OS) was exhibited in the high-risk group than that in the low-risk group in both the training cohort (P < 0.001, HR = 0.27) and test cohort (P < 0.001, HR = 0.27). The diagnostic models successfully distinguished HCC from normal samples and proliferative nodule samples. Compared with low-risk groups, high-risk groups had higher TMB; higher fractions of macrophages, follicular helper T cells, memory B cells, and neutrophils; and exhibited higher expression of CD83, B7H3, OX40 and CD134L. As an inducer of ferroptosis, erastin inhibited HCC cell proliferation and progression, and it was showed to affect Th17 cell differentiation and IL-17 signaling pathway through bioinformatics analysis, indicating it a potential agent of cancer immunotherapy. Conclusions The prognostic and diagnostic models based on the four genes indicated superior diagnostic and predictive performance, indicating new possibilities for individualized treatment of HCC patients. Graphical abstract

Here, taking layered polymeric carbon nitride (CN) as an example, the dominant role of in-plane charge transport is demonstrated both theoretically and experimentally. The in-plane “sewing” and interlayer “cutting” effects of three alkaline potassium salts on the CN polymerization process are enhanced with the increase of alkalinity. The in-plane crystallinity-dependent charge transfer and separation and photocatalytic activity are elucidated through the samples of three alkaline potassium salt series. Our findings provide guidance for improving the photoelectric conversion efficiency by optimizing in-plane charge transfer rather than interlayer charge transfer, targeting layered photoelectric conversion materials.

Tumor‐associated macrophages (TAMs) play an essential role in tumor progression, metastasis, and antitumor immunity. Ferroptosis has attracted extensive attention for its lethal effect on tumor cells, but the role of ferroptosis in TAMs and its impact on tumor progression have not been clearly defined. Using transgenic mouse models, this study determines that xCT‐specific knockout in macrophages is sufficient to limit tumorigenicity and metastasis in the mouse HCC models, achieved by reducing TAM recruitment and infiltration, inhibiting M2‐type polarization, and activating and enhancing ferroptosis activity within TAMs. The SOCS3‐STAT6‐PPAR‐γ signaling may be a crucial pathway in macrophage phenotypic shifting, and activation of intracellular ferroptosis is associated with GPX4/RRM2 signaling regulation. Furthermore, that xCT‐mediated macrophage ferroptosis significantly increases PD‐L1 expression in macrophages and improves the antitumor efficacy of anti‐PD‐L1 therapy is unveiled. The constructed Man@pSiNPs‐erastin specifically targets macrophage ferroptosis and protumoral polarization and combining this treatment with anti‐PD‐L1 exerts substantial antitumor efficacy. xCT expression in tumor tissues, especially in CD68+ macrophages, can serve as a reliable factor to predict the prognosis of HCC patients. These findings provide further insight into targeting ferroptosis activation in TAMs and regulating TAM infiltration and functional expression to achieve precise tumor prevention and improve therapeutic efficacy.