Ferroptosis Markers Predict the Survival, Immune Infiltration, and Ibrutinib Resistance of Diffuse Large B cell Lymphoma.

Diffuse large B cell lymphoma (DLBCL) is the most common hematological malignancy in adults. Ferroptosis is an iron-dependent programmed cell death caused by lipid peroxidation. However, the potential functions of ferroptosis in the DLBCL prognosis, immune infiltration, and drug resistance remain unknown. Data of DLBCL patients were downloaded from public GEO databases and TCGA cohort. R software was used for analysis. Ferroptosis-related risk score model was constructed using LASSO Cox regression analysis. The prognosis of the model and its association with immune cells infiltration and ibrutinib-resistance were studied by single-sample gene set enrichment analysis (ssGSEA) and correlation analysis. Ferroptosis-related risk score model was constructed with 11 ferroptosis-related genes. DLBCL patients can be divided into high- or low-risk groups with this model. High-risk patients had significant shorter survival (p < 0.001). The area under curve at 3-year was 0.779. Functional enrichment analysis was mainly associated with the immune response. High score patients were positively correlated with immunosuppressive cell infiltration, including macrophages and regulatory T cells, and immunoevasion checkpoints, such as CTLA4, PD-L1, LAG-3, and TIM-3. We also found that tumors with high risk would resist to ibrutinib treatment and uncovered that acetaminophen, as a ferroptosis inducer, inhibited the defined high-risk gene expression in the ibrutinib-resistant DLBCL cell lines. Ferroptosis-related risk score model can predict the overall survival (OS) of DLBCL patients and ibrutinib resistance of ABC-DLBCL cells, which was associated with immunosuppression status within the tumor microenvironment.

Comprehensive analysis of SLC43A2 on the tumor immune microenvironment and prognosis of liver hepatocellular carcinoma.

Background: Tumor cells outcompete T cells for methionine via overexpressing SLC43A2, causing T cells exhaustion. We explored the influence of SLC43A2 on tumor immune microenvironment (TIME), immune-related genes (IRGs) and the prognosis of liver hepatocellular carcinoma (LIHC) patients. Methods: The TCGA-LIHC dataset (n = 374) and the ICGC-LIRI-JP-LIHC (n = 231) datasets were used as training and validation cohort, respectively. IRGs were obtained from ImmPort. Statistical analyses were performed using R (V 4.0.5). Online databases such as GEPIA, GSCALite, the Kaplan-Meier plotter, KEGG, TIMER2, and CMap were used for differential expression, immune infiltration, functional enrichment, survival, and drug-induced gene perturbation analysis. Results: SLC43A2 expression was higher in LIHC, correlated with worse survival, but could not predict prognosis of LIHC separately (AUC = 0.467). SLC43A2 positively correlated with immune exhaustion markers (all p < 0.001) and with increased infiltration of Tregs, macrophages and myeloid-derived suppressor cells (MDSC) (all p < 0.05). SLC43A2 may regulate 120 IRGs. A prognostic risk score model was developed using the TCGA-LIHC cohort and validated by the ICGC-LIRI-JP cohort. Arachidonic acid, SB-202190 and guanethidine were identified as possible immunomodulators pharmacologically targeting SLC43A2 in LIHC. Conclusion: SLC43A2 may create suppressive tumor microenvironment and regulate related IRGs, thus affecting the prognosis of LIHC. Arachidonic acid, SB-202190, and guanethidine may be worthy of further study as immunomodulators on SLC43A2.

Inhibition of acylglycerol kinase sensitizes DLBCL to venetoclax via upregulation of FOXO1-mediated BCL-2 expression.

Background: Despite of the paradigm change on the treatments of acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL) by venetoclax, it has been less successful in the treatment of diffuse large B-cell lymphoma (DLBCL). Here, we explored whether acylglycerol kinase regulates the sensitivity of DLBCLs to venetoclax and its mechanism in both cell lines and preclinical animal models. Methods: The expression of AGK and sensitivity to venetoclax of seven DLBCL cell lines were determined. Upon knockdown and overexpression of AGK by lentivirus in DLBCL cells, the venetoclax-induced apoptosis and PTEN-FOXO1-BCL-2 signaling axis were evaluated in vitro. The efficacy of venetoclax and PTEN-FOXO1-BCL-2 signaling axis were evaluated in immunodeficient NCG mice that were implanted with control or shAGK stably transduced SU-DHL4 cells. The expressions of AGK, BCL-2 and FOXO1 were evaluated in tumor tissues of DLBCL patients. Results: AGK expression was inversely correlated with sensitivity of DLBCL to venetoclax. Inhibition of AGK rendered the DLBCL cells more sensitive to venetoclax. Mechanistically, AGK phosphorylated and inactivated PTEN, which led to AKT activation and reduced FOXO1 nuclear translocation. Inhibition of AGK also led to enhanced efficacy of venetoclax for suppression of DLBCL tumor growth in vivo, which was dependent on FOXO1. In human DLBCL tumor tissues, the expression of AGK inversely correlated with BCL-2 expression, as well as the amounts of nuclear FOXO1. Conclusions: Our data demonstrated that AGK regulates venetoclax response in DLBCL via PTEN-FOXO1-BCL-2 signaling axis. Targeting AGK may enhance the efficacy of venetoclax for the treatment of DLBCL patients.