Integrative analysis of the molecular mechanisms, immunological features and immunotherapy response of ferroptosis regulators across 33 cancer types.

Ferroptosis is a recently described mode of cell death caused by the accumulation of intracellular iron and lipid reactive oxygen species (ROS), which play critical roles in tumorigenesis and cancer progression. However, the underlying molecular mechanisms and promising biomarkers of ferroptosis among cancers remain to be elucidated. In this study, 30 ferroptosis regulators in ferroptosis-related signaling pathways were identified and analyzed in 33 cancer types. We found transcriptomic aberrations and evaluated the prognostic value of ferroptosis regulators across 33 cancer types. Then, we predicted and validated potential transcription factors (including E2F7, KLF5 and FOXM1) and therapeutic drugs (such as cyclophosphamide, vinblastine, and gefitinib) that target ferroptosis regulators in cancer. Moreover, we explored the molecular mechanisms of ferroptosis and found that signaling pathways such as the IL-1 and IL-2 pathways are closely associated with ferroptosis. Additionally, we found that ferroptosis regulators have a close relationship with immunity-related parameters, including the immune score, immune cell infiltration level, and immune checkpoint protein level. Finally, we determined a ferroptosis score using GSVA method. We found that the ferroptosis score effectively predicted ferroptotic cell death in tumor samples. And ferroptosis score is served as an independent prognostic indicator for the incidence and recurrence of cancers. More importantly, patients with high ferroptosis scores received greater benefit from immunotherapy. We aslo created an online webserver based on the nomogram prognostic model to predict the survival in immunotherapy cohort. The reason for this outcome is partially the result of patients with a high ferroptosis rate also having high immune scores, HLA-related gene expression and immune checkpoint protein expression, such as PDL2 and TIM3. Moreover, patients with high ferroptosis scores exhibited CD8 T cell and TIL infiltration and immune-related signaling pathway enrichment. In summary, we systematically summarize the molecular characteristics, clinical relevance and immune features of ferroptosis across cancers and show that the ferroptosis score can be used as a prognostic factor and for the evaluation of immunotherapy effects.

Construction of a novel radiomics nomogram for the prediction of aggressive intrasegmental recurrence of HCC after radiofrequency ablation.

OBJECTIVES: To construct a precise prediction model of preoperative magnetic resonance imaging (MRI)-based nomogram for aggressive intrasegmental recurrence (AIR) of hepatocellular carcinoma (HCC) patients treated with radiofrequency ablation (RFA). METHODS: Among 891 patients with HCC treated by RFA, 22 patients with AIR and 36 patients without AIR (non-AIR) were finally enrolled in our study, and each patient was followed up for more than 6 months to determine the occurrence of AIR. The laboratory indicators and MRI features were compared and assessed. Preoperative contrast-enhanced T1-weighted images (CE-T1WI) were used for radiomics analysis. The selected clinical indicators and texture features were finally screened out to generate the novel prediction nomogram. RESULTS: Tumor shape, ADC Value, DWI signal intensity and ΔSI were selected as the independent factors of AIR by univariate and multivariate logistic regression analysis. Meanwhile, two radiomics features were selected from 396 candidate features by LASSO (P < 0.05), which were further used to calculate the Rad-score. The selected clinical factors were further integrated with the Rad-score to construct the predictive model, and the AUCs were 0.941 (95% CI: 0.876-1.000) and 0.818 (95% CI: 0.576-1.000) in the training (15 AIR and 25 non-AIR) and validation cohorts (7 AIR and 11 non-AIR), respectively. The AIR predictive model was further converted into a novel radiomics nomogram, and decision curve analysis showed good agreement. CONCLUSIONS: The predictive nomogram integrated with clinical factors and CE-T1WI -based radiomics signature could accurately predict the occurrence of AIR after RFA, which could greatly help individualized evaluation before treatment.

The ferroptosis and iron-metabolism signature robustly predicts clinical diagnosis, prognosis and immune microenvironment for hepatocellular carcinoma.

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. Video Abstract.

Non-invasive evaluation for benign and malignant subcentimeter pulmonary ground-glass nodules (≤1 cm) based on CT texture analysis.

OBJECTIVES: To investigate potential diagnostic model for predicting benign or malignant status of subcentimeter pulmonary ground-glass nodules (SPGGNs) (≤1 cm) based on CT texture analysis. METHODS: A total of 89 SPGGNs from 89 patients were included; 51 patients were diagnosed with adenocarcinoma, and 38 were diagnosed with inflamed or infected benign SPGGNs. Analysis Kit software was used to manually delineate the volume of interest of lesions and extract a total of 396 quantitative texture parameters. The statistical analysis was performed using R software. The SPGGNs were randomly divided into a training set (n = 59) and a validation set (n = 30). All pre-normalized (Z-score) feature values were subjected to dimension reduction using the LASSO algorithm,and the most useful features in the training set were selected. The selected imaging features were then combined into a Rad-score, which was further assessed by ROC curve analysis in the training and validation sets. RESULTS: Four characteristic parameters (ClusterShade_AllDirection_offset4_SD, ShortRunEmphasis_angle45_offset1, Maximum3DDiameter, SurfaceVolumeRatio) were further selected by LASSO (p < 0.05). As a cluster of imaging biomarkers, the above four parameters were used to form the Rad-score. The AUC for differentiating between benign and malignant SPGGNs in the training set was 0.792 (95% CI: 0.671, 0.913), and the sensitivity and specificity were 86.10 and 65.20%, respectively. The AUC in the validation set was 72.9% (95% CI: 0.545, 0.913), and the sensitivity and specificity were 86.70 and 60%, respectively. CONCLUSION: The present diagnostic model based on the cluster of imaging biomarkers can preferably distinguish benign and malignant SPGGNs (≤1 cm). ADVANCES IN KNOWLEDGE: Texture analysis based on CT images provide a new and credible technique for accurate identification of subcentimeter pulmonary ground-glass nodules.

Cembranoids from a Chinese Collection of the Soft Coral Lobophytum crassum.

Ten new cembrane-based diterpenes, locrassumins A-G (1-7), (-)-laevigatol B (8), (-)-isosarcophine (9), and (-)-7R,8S-dihydroxydeepoxysarcophytoxide (10), were isolated from a South China Sea collection of the soft coral Lobophytum crassum, together with eight known analogues (11-18). The structures of the new compounds were determined by extensive spectroscopic analysis and by comparison with previously reported data. Locrassumin C (3) possesses an unprecedented tetradecahydrobenzo[3,4]cyclobuta[1,2][8]annulene ring system. Compounds 1, 7, 12, 13, and 17 exhibited moderate inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) production with IC50 values of 8-24 µM.

Structurally Diverse Metabolites from the Soft Coral Sinularia verruca Collected in the South China Sea.

Nineteen metabolites with diverse structures, including the rare pyrroloindoline alkaloid verrupyrroloindoline (1), the unprecedented highly fused benzosesquiterpenoid verrubenzospirolactone (2), the new asteriscane-type sesquiterpenoid 10-deoxocapillosanane D (3), and the two new cyclopentenone derivatives (4S*,5S*)-4-hydroxy-5-(hydroxymethyl)-2,3-dimethyl-4-pentylcyclopent-2-en-1-one (4) and (S)-4-hydroxy-5-methylene-2,3-dimethyl-4-pentylcyclopent-2-en-1-one (5), were isolated from a South China Sea collection of the soft coral Sinularia verruca. Eleven previously described marine metabolites (7-15, 18, and 19) were also obtained as well as three new EtOH-adduct artifacts (6, 16, and 17). The structures of the new compounds were elucidated by extensive spectroscopic analysis and by comparison with previously reported data. Compounds 4, 5, and 16 showed protection against the cytopathic effects of HIV-1 infection with EC50 values of 5.8-34 µM, and 4, 6, and 16 exhibited inhibition against LPS-induced NO production with IC50 values of 24-28 µM.

Further New Xenicanes from a Chinese Collection of the Brown Alga Dictyota plectens.

Four new xenicanes, namely 4α-hydroxyisodictyohemiacetal (1), 4α-hydroxyisodictyoacetal (2), 13,18-diacetoxy-4-hydroxyisodictyo-19-al (3), and 4α-hydroxypachylactone (8), were isolated from a Chinese collection of the brown alga Dictyota plectens, along with four known analogues (4-7). The structures of the new diterpenes were determined by extensive spectroscopic data analysis. All compounds were evaluated for their antiviral activities against human immunodeficiency virus type 1 (HIV-1) and the highly pathogenic avian influenza A (H5N1) virus, and inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in mouse peritoneal macrophages (PEMΦ).

Diterpenes from a Chinese collection of the brown alga Dictyota plectens.

Twenty-seven diterpenes of six chemical classes, including seven new diterpenes (1, 2, 6, 10, 11, 16, and 19), have been isolated from a collection of the brown alga Dictyota plectens from the South China Sea. The structures of the new diterpenes were elucidated by extensive spectroscopic analysis and by comparison with reported data. In the in vitro assays, 9, 12, 14, 16, and 22 showed inhibitory activity against HIV-1 replication with IC50 values of 16.1-30.5 µM, compounds 5, 13, 24, and 26 exhibited anti-H5N1 activity with inhibition rates of 50%-62% at 30.0 µM, and 12 and 24 also showed potent inhibition against LPS-induced NO production with inhibition rates of 90% and 86%, respectively, at 10.0 µM.

Four New 7,8-epoxycembranoids from a Chinese soft coral Lobophytum sp.

Four new 7,8-epoxycembranoids, namely (2S*,7S*,8S*,12R*,1Z,3E,10E)-7,8:2,16-diepoxycembra-1(15),3,10-trien-12-ol (1), (2S*,7S*,8S*,11R*,1Z,3E)-7,8:2,16-diepoxycembra-1(15),3,12(20)-trien-11-ol (2), (4S*,7S*,8S*,1Z,2E,11E)-16-acetoxy-7,8-epoxycembra-1(15),2,11-trien-4-ol (3), and (7S*,8S*,15S*,1E,3E,11E)-7,8-epoxycembra-1,3,11-trien-15,16-diol (4) were isolated from a Chinese soft coral Lobophytum sp., together with eleven known analogues 5-15. The structures of the new compounds were determined by extensive spectroscopic data analysis. All compounds were tested for the inhibitory effect on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in mouse peritoneal macrophages (PEMΦ).