Background: Cuproptosis is a new type of copper-induced cell death that is characterized by the aggregation of lipoylated tricarboxylic acid (TCA) cycle proteins. However, its role in hepatocellular carcinoma (HCC) remains unclear. The goal of this research is to develop a cuproptosis-related signature predicting the prognosis of HCC. Methods: The cuproptosis-related genes were defined using Pearson correlation coefficients. LASSO-Cox regression analysis was used to evaluate the prognostic values of cuproptosis-related genes to construct a cuproptosis-related prognostic model. The immune microenvironment analysis was performed by “ssGSEA” to reveal the associated immune cell infiltration patterns with the cuproptosis-related genes signature. The expression levels of one of the prognostic genes PDXK were then verified in HCC samples by Western Blot and immunohistochemistry. The potential roles of target genes in cuproptosis were further explored during in-vitro experiments. Results: A total of 136 cuproptosis-related genes were discovered using Pearson correlation analysis in HCC. A cuproptosis-related signature that included 5 cuproptosis-related genes (PDXK, HPN, SLC25A28, RNFT1, CLEC3B) was established in the TCGA-LIHC training cohort. TCGA validation cohort and another two external validation cohorts confirmed the robustness of the signature’s predictive value. Moreover, a nomogram using the risk score was created to best predict the survival of HCC patients. The immune microenvironment analysis revealed distinct immune infiltrations patterns between different risk groups based on the signature model. Furthermore, the upregulation of PDXK was confirmed in HCC tumor tissues in 30 clinical HCC specimens. The knockdown of PDXK reduced the proliferation, migration and invasion of HCC cells. Besides, the expression of PDXK was upregulated after the induction of cuproptosis by elesclomol–CuCL₂, which could be suppressed when pretreated with a copper ion chelator. And PDXK deficiency increased the sensitivity of HCC cells to cuproptosis inducer. Conclusion: Our study identified a new cuproptosis-related gene signature that could predict the prognosis of HCC patient. Besides, the upregulated PDXK could promote the proliferation and metastasis of HCC. And PDXK deficiency facilities cuproptosis in HCC. Therefore, these fundings highlighted that PDXK might serve as a potential diagnostic and therapeutic target for HCC.

Finding new targets is necessary for understanding tumorigenesis and developing cancer therapeutics. DExH-box helicase 9 (DHX9) plays a central role in many cellular processes but its expression pattern and prognostic value in most types of cancer remain unclear. In this study, we extracted pan-cancer data from TCGA and GEO databases to explore the prognostic and immunological role of DHX9. The expression levels of DHX9 were then verified in tumor specimens by western blot and immunohistochemistry (IHC). The oncogenic roles of DHX9 in cancers were further verified by in vitro experiments. We first verified that DHX9 is highly expressed in most tumors but significantly decreased in kidney and thyroid cancers, and it is prominently correlated with the prognosis of patients with different tumors. The phosphorylation level of DHX9 was also increased in cancers. Enrichment analysis revealed that DHX9 was involved in Spliceosome, RNA transport and mRNA surveillance pathway. Furthermore, DHX9 expression exhibited strong correlations with immune cell infiltration, immune checkpoint genes, and tumor mutational burden (TMB)/microsatellite instability (MSI). In liver, lung, breast and renal cancer cells, the knockdown or depletion of DHX9 significantly affected the proliferation, metastasis and EMT process of cancer cells. In summary, this pan-cancer investigation provides a comprehensive understanding of the prognostic and immunological role of DHX9 in human cancers, and experiments indicated that DHX9 was a potential target for cancer treatment.

Chemoresistance in patients with glioblastoma multiforme (GBM) is a common reason hindering the success of treatment. Recently, ferroptosis has been reported to be associated with chemoresistance in different types of cancer, while the role of ferroptosis-related genes in GBM have not been fully elucidated. This study aimed to demonstrate the roles and mechanism of ferroptosis-related genes in chemoresistance and metastasis of GBM. First, two candidate genes, squalene epoxidase (SQLE) and FANCD2, were identified to be associated with ferroptosis-related chemoresistance in GBM from three temozolomide (TMZ) therapeutic datasets and one ferroptosis-related gene dataset. Then, comprehensive bio-informatics data from different databases testified that SQLE was significantly downregulated both in GBM tissue and cells and displayed a better prognosis in GBM. Clinical data identified lower expression of SQLE was significantly associated with WHO grade and 1p/19q codeletion. Moreover, through in vitro experiments, SQLE was confirmed to suppress ERK-mediated TMZ chemoresistance and metastasis of GBM cells. The KEGG analysis of SQLE-associated co-expressed genes indicated SQLE was potentially involved in the cell cycle. Furthermore, SQLE was found to have the most significant correlations with tumor-infiltrating lymphocytes and immunomodulators. These findings highlighted that SQLE could be a potential target and a biomarker for therapy and prognosis of patients with GBM.

Background Despite the successful application of immunotherapy, both innate and acquired resistance are typical in melanoma. Ferroptosis induction appears to be a potential strategy to enhance the effectiveness of immunotherapy. However, the relationship between the status of ferroptosis and the effectiveness of immunotherapy, as well as viable strategies to augment ferroptosis, remains unclear. Methods A screening of 200 cardiovascular drugs obtained from the Food and Drug Administration-approved drug library was conducted to identify the potential ferroptosis sensitizer. In vitro and in vivo experiments explored the effects of propafenone on ferroptosis in melanoma. Animal models and transcriptomic analyses evaluated the therapeutic effects and survival benefits of propafenone combined with immune checkpoint blockades (ICBs). The relationship between propafenone targets and the efficacy of ICBs was validated using the Xiangya melanoma data set and publicly available clinical data sets. Results Through large-scale drug screening of cardiovascular drugs, we identified propafenone, an anti-arrhythmia medication, as capable of synergizing with ferroptosis inducers in melanoma. Furthermore, we observed that propafenone, in combination with glutathione peroxidase 4 inhibitor RSL3, collaboratively induces mitochondrial-associated ferroptosis. Mechanistically, propafenone transcriptionally upregulates mitochondrial heme oxygenase 1 through the activation of the Jun N-terminal kinase (JNK)/JUN signaling pathway under RSL3 treatment, leading to overloaded ferrous iron and reactive oxygen species within the mitochondria. In xenograft models, the combination of propafenone and ferroptosis induction led to nearly complete tumor regression and prolonged survival. Consistently, propafenone enhances immunotherapy-induced tumorous ferroptosis and antitumor immunity in tumor-bearing mice. Significantly, patients exhibiting high levels of ferroptosis/JUN/HMOX1 exhibited improved efficacy of immunotherapy and prolonged progression-free survival. Conclusions Taken together, our findings suggest that propafenone holds promise as a candidate drug for enhancing the efficacy of immunotherapy and other ferroptosis-targeted therapies in the treatment of melanoma.

Background: Lung cancer is the most prevalent and deadly tumors around the world. Here we aimed to investigate the effect of wogonoside (also called baicalin) on the invasion and migration of lung cancer A549 cells and angiogenesis in xenograft tumors in nude mice. Methods: A549 cells of lung cancer were treated with different doses of wogonoside. After 24 h, CCK8 was used to detect the survival rate of cells. The non-toxic doses of wogonoside (0, 10, 25, and 50 µM) were selected for subsequent experiments. Transwell and scratch assays were used to detect invasion and migration. The number of microtubule nodules was detected by microtubule formation experiment, and the expressions of VEGF, E-cadherin, N-cadherin, and Vimentin were detected by Western blotting. BALB/c nude mice were subcutaneously injected with lung cancer A549 cells to establish the xenograft model, followed by intraperitoneal injection of 80 mg/kg of wogonoside. After 30 days, tumor volume was measured, and the levels of VEGF and vimentin were detected with immunohistochemistry. The level of CD34 was determined by flow sorting. Results: A549 cell survival decreased in a concentration-dependent manner, with the survival rate significantly reduced when the concentration of wogonoside exceeded 100 µM (P<0.05). A549 cell invasion and the number of microtubule nodules were significantly lower in the wogonoside 20 µM and the wogonoside 50 µM groups (P<0.05) compared with the wogonoside 0 µM group, while the rate of scratch closure and the protein levels of VEGF, N-cadherin, and Vimentin were all significantly reduced (P<0.05), and the expression level of E-cadherin was significantly increased (P<0.05). Compared with the control group, the tumor volumes of wogonoside (80 mg/kg) treated mice were significantly reduced after 30 days (P<0.05), and the levels of VEGF and vimentin positive cells were significantly reduced (P<0.05), as was the level of CD34 (P<0.05). Conclusions: Wogonoside can inhibit the invasion and migration of lung cancer A549 cells and angiogenesis of xenograft tumors in nude mice.

Human Epstein-Barr virus (EBV)-negative Burkitt lymphomas cells usually grow as malignant subcutaneous tumors in athymic mice, but these tumors regress when the Burkitt cells are injected in conjunction with EBV-positive lymphoblastoid cells or when the Burkitt cells are transfected with the EBV latent membrane protein-1 (LMP-1) gene. Tumor regression is mediated, in part, by murine interferon γ (IFN-γ) and the IFN-γ-induced murine chemokine IFN-γ-inducible protein-10 (IP-10). The mechanisms by which EBV-LMP-1 promotes the expression of IFN-γ has remained unclear. Here we show that murine interleukin (IL)-18 was consistently expressed in regressing Burkitt tumors but was either expressed at low levels or absent from progressively growing Burkitt tumors. By immunohistochemical methods, IL-18 protein was visualized in regressing but not in progressively growing Burkitt tumors. In contrast, IL-12 p35 and IL-12 p40 were only rarely expressed in regressing Burkitt tumors. In splenocyte cultures, EBV-infected lymphoblastoid cells and LMP-1-transfected Burkitt cells promoted the expression of IL-18 but not the expression of IL-12 p35 and IL-12 p40. A neutralizing antibody directed at murine IL-18 reduced murine IP-10 expression induced by EBV-immortalized cells in splenocyte cultures. These results provide evidence for IL-18 expression in response to a viral latency protein and suggest that IL-18 may play an important role as an endogenous inducer of IFN-γ expression, thereby contributing to tumor regression.