Artesunate Inhibits the Growth of Insulinoma Cells via SLC7A11/ GPX4-mediated Ferroptosis.

BACKGROUND: Artesunate (ART) has been recognized to induce ferroptosis in various tumor phenotypes, including neuroendocrine tumors. We aimed to investigate the effects of ART on insulinoma and the underlying mechanisms by focusing on the process of ferroptosis. METHODS: The CCK8 and colony formation assays were conducted to assess the effectiveness of ART. Lipid peroxidation, glutathione, and intracellular iron content were determined to validate the process of ferroptosis, while ferrostatin-1 (Fer-1) was employed as the inhibitor of ferroptosis. Subcutaneous tumor models were established and treated with ART. The ferroptosis-associated proteins were determined by western blot and immunohistochemistry assays. Pathological structures of the liver were examined by hematoxylin-eosin staining. RESULTS: ART suppressed the growth of insulinoma both in vitro and in vivo. Insulinoma cells treated by ART revealed signs of ferroptosis, including increased lipid peroxidation, diminished glutathione levels, and ascending intracellular iron. Notably, ART-treated insulinoma cells exhibited a decline in the expressions of catalytic component solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4). These alterations were negated by Fer-1. Moreover, no hepatotoxicity was observed upon the therapeutic dose of ART. CONCLUSION: Artesunate might regulate ferroptosis of insulinoma cells through the SLC7A11/GPX4 pathway.

Identification of ZBTB4 as an immunological biomarker that can inhibit the proliferation and invasion of pancreatic cancer.

BACKGROUND: Zinc finger and BTB domain-containing protein 4 (ZBTB4) belongs to the zinc finger protein family, which has a role in regulating epigenetic inheritance and is associated with cell differentiation and proliferation. Previous studies have identified aberrant ZBTB4 expression in cancer and its ability to modulate disease progression, but studies on the immune microenvironment, immunotherapy and its role in cancer are still lacking. METHODS: Human pan-cancer and normal tissue transcriptome data were obtained from The Cancer Genome Atlas. The pan-cancer genomic alteration landscape of ZBTB4 was investigated with the online tool. The Kaplan-Meier method was used to evaluate the prognostic significance of ZBTB4 in pancreatic cancer. In parallel, ZBTB4 interacting molecules and potential functions were analyzed by co-expression and the correlation between ZBTB4 and immune cell infiltration, immune modulatory cells and efficacy of immune checkpoint therapy was explored. Next, we retrieved the Gene Expression Omnibus database expression datasets of ZBTB4 and investigated ZBTB4 expression and clinical significance in pancreatic cancer by immunohistochemical staining experiments. Finally, cell experiments were performed to investigate changes in pancreatic cancer cell proliferation, migration and invasion following overexpression and knockdown of ZBTB4. FINDINGS: ZBTB4 showed loss of expression in the majority of tumors and possessed the ability to predict cancer prognosis. ZBTB4 was closely related to the tumor immune microenvironment, immune cell infiltration and immunotherapy efficacy. ZBTB4 had good diagnostic performance for pancreatic cancer in the clinic, and ZBTB4 protein expression was lost in pancreatic cancer tumor tissues. Cell experiments revealed that overexpression of ZBTB4 inhibited the proliferation, migration and invasion of pancreatic cancer cells, while silencing ZBTB4 showed the opposite effect. CONCLUSIONS: According to our results, ZBTB4 is present in pancreatic cancer with aberrant expression and is associated with an altered immune microenvironment. We show that ZBTB4 is a promising marker for cancer immunotherapy and cancer prognosis and has the potential to influence pancreatic cancer progression.

The Long Noncoding RNA Gm9866/Nuclear Factor-κB Axis Promotes Macrophage Polarization.

Macrophages are a type of immune cells with high levels of plasticity and heterogeneity. They can polarize into M1 or M2 functional phenotypes. These two phenotypes exhibit a dynamic balance during polarization-related diseases and play opposing roles. Long noncoding RNAs (lncRNAs) play an important role in biological processes such as cell proliferation, death, and differentiation; however, how long noncoding RNAs affect the cellular functionality of macrophages remains to be studied. Long noncoding RNA Gm9866 was found to be closely related to macrophage polarization through bioinformatics analysis. In this study, by conducting real-time polymerase chain reaction analysis, it was observed that long noncoding RNA Gm9866 expression significantly increased after treatment with interleukin-4 but significantly decreased after treatment with lipopolysaccharide. Fluorescence in situ hybridization revealed that long noncoding RNA Gm9866 was expressed mainly in the nucleus. Real-time polymerase chain reaction analysis showed that overexpression of long noncoding RNA Gm9866 in RAW264.7 cells further promoted the expression of M2 markers MRC1 (macrophage mannose receptor 1) and MRC2 (macrophage mannose receptor 2). Western blotting analysis demonstrated inhibition of nuclear factor-κB (NF-κB) expression. EdU (5-ethynyl-2'-deoxyuridine) and TUNEL (TdT-mediated dUTP nick-end labeling) staining assays revealed that overexpression of long noncoding RNA Gm9866 promoted cell proliferation and inhibited apoptosis. These findings thus indicated that long noncoding RNA Gm9866 promoted macrophage polarization and inhibited the nuclear factor-κB signaling pathway. Thus, long noncoding RNA Gm9866 may serve as a potential diagnostic and therapeutic target for polarization-related diseases such as infectious diseases, inflammatory diseases, liver fibrosis, and tumors.

5-Iodotubercidin Inhibits the Growth of Insulinoma Cells by Inducing Apoptosis.

INTRODUCTION: 5-Iodotubercidin, a type of purine derivative, has attracted increasing attention in tumor chemotherapy because of its potential as an antitumor agent in recent years. In this study, we confirmed the effects on apoptosis in insulinoma cell lines induced by 5-iodotubercidin and tried to illuminate the underlying mechanisms. METHODS: We used 5-iodotubercidin in the treatment of insulinoma cells and the cell proliferation was examined using CCK-8 assay, colony-forming assays, and insulinoma animal models. Cell apoptosis was examined using TUNEL assays and Western blotting. Cellular DNA damage was shown by comet assay and immunofluorescence. The expression of apoptosis-regulating proteins and DNA damage biomarker was investigated by Western blotting. Subcutaneous inoculation of the insulinoma cells into nude mice was to measure blood glucose, insulin levels, and tumor growth. ATM siRNA and p53 siRNA were used as loss-of-function targets to evaluate 5-iodotubercidin treatment. RESULTS: 5-Iodotubercidin inhibited the proliferation of insulinoma cells and induced DNA damage and cell apoptosis. Moreover, 5-iodotubercidin induced ATM and p53 activated. In vivo, 5-iodotubercidin inhibited the growth of Ins-1 and Min-6 cells xenografts in nude mice. CONCLUSION: 5-Iodotubercidin induces DNA damage leading to insulinoma cells apoptosis by activating ATM/p53 pathway. Therefore, this is a potential strategy for treating insulinoma.

Differential Plasma Proteins Identified via iTRAQ-Based Analysis Serve as Diagnostic Markers of Pancreatic Ductal Adenocarcinoma.

Objective: We aimed to identify differentially expressed proteins in the plasma of patients with pancreatic cancer and control subjects, which could serve as potential tumor biomarkers. Methods: Differentially expressed proteins were determined via isostatic labeling and absolute quantification (iTRAQ). Potential protein biomarkers were identified via enzyme-linked immunosorbent assay (ELISA) in 40 patients and 40 control subjects, and those eventually selected were further validated in 40 pancreatic cancer and normal pancreatic tissues. Results: In total, 30 proteins displayed significant differences in expression among which 21 were downregulated and 9 were upregulated compared with the control group. ELISA revealed downregulation of peroxiredoxin-2 (PRDX2) and upregulation of alpha-1-antitrypsin (AAT), Ras-related protein Rab-2B (RAB2B), insulin-like growth factor-binding protein 2 (IGFBP2), Rho-related GTP-binding protein RhoC (RHOC), and prelamin-A/C (LMNA) proteins in 40 other samples of pancreatic cancer. Notably, only AAT, RAB2B, and IGFBP2 levels were consistent with expression patterns obtained with iTRAQ. Moreover, all three proteins displayed a marked increase in pancreatic cancer tissues. Data from ROC curve analysis indicated that the diagnostic ability of AAT, RAB2B, and IGFBP2 combined with carbohydrate antigen 19-9 (CA19-9) for pancreatic cancer was significantly greater than that of the single indexes (area under the curve (AUC): 90% vs. 75% (CA19-9), 76% (AAT), 71% (RAB2B), and 71% (IGFBP2), all P < 0.01). Conclusion: AAT, RAB2B, and IGFBP2 could serve as effective biomarkers to facilitate the early diagnosis of pancreatic cancer.

microRNA-30a inhibits the liver cell proliferation and promotes cell apoptosis through the JAK/STAT signaling pathway by targeting SOCS-1 in rats with sepsis.

Sepsis is a systemic inflammatory response that may be induced by trauma, infection, surgery, and burns. With the aim of discovering novel treatment targets for sepsis, this current study was conducted to investigate the effect and potential mechanism by which microRNA-30a (miR-30a) controls sepsis-induced liver cell proliferation and apoptosis. Rat models of sepsis were established by applying the cecal ligation and puncture (CLP) method to simulate sepsis models. The binding site between miR-30a and suppressor of cytokine signaling protein 1 (SOCS-1) was determined by dual luciferase reporter gene assay. The gain-of-and-loss-of-function experiments were applied to analyze the effects of miR-30a and SOCS-1 on liver cell proliferation and apoptosis of the established sepsis rat models. The expression of miR-30a, SOCS-1, Janus kinase 2 (JAK2), signal transducer and activator of transcription 3 (STAT3), Bcl-2 associated X protein (Bax), B cell lymphoma-2 (Bcl-2), toll-like receptor 4 (TLR4), and high-mobility group box 1 (HMGB1), and the extent of JAK2 and STAT3 phosphorylation were all determined. Sepsis led to an elevation of miR-30a and also a decline of SOCS-1 in the liver cells. SOCS-1 was negatively regulated by miR-30a. Upregulated miR-30a and downregulated SOCS-1 increased the expression of JAK2, STAT3, Bax, TLR4, and HMGB1 as well as the extent of JAK2 and STAT3 phosphorylation whereas impeding the expression of SOCS-1 and Bcl-2. More important, either miR-30a elevation or SOCS-1 silencing suppressed liver cell proliferation and also promoted apoptosis. On the contrary, the inhibition of miR-30a exhibited the opposite effects. Altogether, we come to the conclusion that miR-30a inhibited the liver cell proliferation and promoted cell apoptosis by targeting and negatively regulating SOCS-1 via the JAK/STAT signaling pathway in rats with sepsis.