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Hypoxia is a serious issue that affects the marine environment, with a growing number of hypoxic “dead zones” occurring each year. Reports have indicated that hypoxia is detrimental to the reproductive function and sexual development of fish via the disruption of endocrine signaling in organs involved in the hypothalamus–pituitary–gonad axis, including the brain. While we previously reported that hypoxia induces transcriptome-wide alterations in the brain of marine medaka (Oryzias melastigma), whether these effects were reflected at the protein level remains unclear. Therefore, the present study used high-throughput proteomic sequencing along with bioinformatics analysis to assess the short-term and multi-generational effects of hypoxia on the brain proteome of O. melastigma. We identified 36,567 peptides and 7,599 proteins (1% false discovery rate in brain samples), with functions involved in cellular and metabolic processes such as signaling and reproductive processes as well as energy production and conversion. Furthermore, we determined that hypoxia resulted in the significant differential expressions of 33 upregulated and 69 downregulated proteins in the short-term exposure group and 24 upregulated and 52 downregulated proteins in the multi-generational exposure group. Pathway enrichment analysis of the deregulated proteins indicated that hypoxia could impair brain function by altering arachidonic acid metabolism, tight junctions, and adrenergic signaling under short-term hypoxic exposure and by altering p53 and PI3K–Akt signaling under multi-generational hypoxic exposure, which may lead to the onset of neurodegenerative disorders including Alzheimer’s disease and amyotrophic lateral sclerosis. Ingenuity pathway analysis of the deregulated proteins showed that hypoxia affected common signaling pathways in the brain (e.g., integrin, paxillin, and epithelial adherens junction signaling) under both short-term and multi-generational exposures. Hypoxia also deregulated pathways specific to short-term exposure (including integrin-linked kinase, calcium, and integrin signaling) and multi-generational exposure (including sphingosine-1-phosphate signaling, endocannabinoid neuronal synapse pathway, and endoplasmic reticulum stress pathway). Overall, our results provide additional insights into the mechanisms of hypoxia disrupting neuronal function at the protein level in marine medaka.

Abstract Background B7-H4 is among the B7 family members which may serve as a new targetable immune checkpoint molecule. It was reported that high level of serum B7-H4 level may be correlated with lymphoma. Nevertheless, the role of B7-H4 in Epstein-Barr Virus-Positive diffuse large B cell lymphoma (EBV+DLBCL) has not been addressed although it has been suggested that B7-H4 could promote tumor growth and metastatic progression in certain cancers. Methods Between January 2005 and November 2017 at the department of Hematology, Shanghai Jiao Tong University School of Medicine affiliated Shanghai General Hospital 260 DLBCL samples were analyzed for EBV-encoded small RNA (EBV-EBER) by in situ hybridization. The expression level of B7-H4 in DLBCL tumor tissue was evaluated by immunohistochemistry. Furthermore, the role of B7-H4 in DLBCL was further investigated in DLBCL cell line. Results EBV+DLBCL patients suffered from markedly lower overall survival (OS) and progression-free survival (PFS) rates in our study. We showed that B7-H4 was significantly overexpressed in 16 EBV+-subgroup cases out of 260 DLBCL patients. We further found that EBV infection in lymphoblast cells led to enhanced expression of B7-H4 followed by increased cell viability and reduced apoptosis. In contrast, inhibition of B7-H4 simultaneously impaired cell viability and induced apoptosis. Mechanistically, inhibiting B7-H4 resulted in decreased phosphorylation Erk 1/2 and Akt. Conclusion Our study reveals a critical role of B7-H4 in EBV+DLBCL development by regulating cell survival and apoptosis through the Erk and Akt signalling pathways. Targetting B7-H4 may be promising in the therapy of EBV+DLBCL.

Tumor cell in the peritoneum are often exposed to shear forces generated by ascitic flow during metastasis. Here, the authors show that metastatic cancer stem cells tether more and roll slower than the non-metastatic counterparts, and that sialyl-Lewisx -P-selectin axis mediates peritoneal metastasis.

Abstract Background T-cell acute lymphoblastic leukemia (T-ALL) is a lymphoid malignancy caused by the oncogenic transformation of immature T-cell progenitors with poor outcomes. WP1130 has shown potent activity against a variety of cancer but whether WP1130 has anti-T-ALL activity is not clear. USP24, one target of WP1130, is one of the largest deubiquitinases and its detailed mechanism is poorly understood. The aim of this study was to explore whether WP1130 could suppress T-ALL and the role of USP24 in T-ALL. Methods Molecular docking and cellular thermal shift assay were performed to determine whether and how WP1130 directly interact with USP24. Mitochondrial transmembrane potential assay was measured via Rhodamine 123 staining. USP24 was reactivated using the deactivated CRISPR-associated protein 9 (dCas9)-synergistic activation mediator (SAM) system. The in vivo results were examined by tumor xenografts in NOD-SCID mice. All statistical analyses were performed with the SPSS software package. Results WP1130 treatment decreased the viability and induces apoptosis of T-ALL cells both in vitro and in vivo. Furthermore, we demonstrated that knockdown of USP24 but not USP9X could significantly induce growth inhibition and apoptosis of T-ALL cells. Oncomine database showed that USP24 expression was upregulated in T-ALL samples and Kaplan–Meier results indicated that the USP24 was negatively but USP9X was positively associated with survival in T-ALL patients. Additionally, we proposed that WP1130 directly interacts with the activity site pocket of USP24 in T-ALL cells, which leads to the decrease of its substrates Mcl-1. Mechanistically, WP1130 induces apoptosis by accelerating the collapse of mitochondrial transmembrane potential via USP24-Mcl-1 axis. Conclusions Altogether, using WP1130 as a chemical probe, we demonstrate that USP24 but not USP9X is a novel target in T-ALL cells. Moreover, we uncovered that WP1130 induces apoptosis by accelerating the collapse of mitochondrial transmembrane potential via USP24-Mcl-1 axis. These results provide that USP24-Mcl-1 axis may represent a novel strategy in the treatment of T-ALL and WP1130 is a promising lead compound for developing anti-T-ALL drugs.

Different strategies were taken to make virotherapy more effective at killing cancer cells. Among them, oncolytic virus which arms the therapeutic gene to enhance antitumor activity is a prevalent approach. In this study, a newly developed oncolytic vaccinia virus (OVV) that expresses Beclin-1 (OVV-BECN1) was tested for its in vitro and in vivo oncolytic activity in blood cancer. Results showed that the OVV exhibited higher infectivity for leukemia cells. OVV-BECN1 induced significant apoptosis-independent cell death either in wild-type leukemia and multiple myeloma (MM) cell lines or caspase-3 shRNA leukemia cell lines, and had a superior antitumor activity compared to the parent OVV. Autophagic cell death induced by OVV-BECN1 was demonstrated in vitro and in vivo experiments. Finally, upregulation of SIRT-1, a member of class III histone deacetylases, by OVV-BECN1 resulted in the deacetylation of LC3 and its distribution from the nucleus toward the cytoplasm, which might contribute to induction of autophagy. Overall, our data showed a favorable therapeutic effect of the oncolytic vaccinia virus on blood cancers through oncolytic and autophagic mechanisms, and may therefore constitute a promising and effective therapeutic strategy for treating human leukemia and MM. However, further studies are warranted for its reliable clinical translation.

Abstract Aberrant promoter methylation is a common mechanism for tumor suppressor inactivation in cancer. We develop a set of tools to identify genome-wide DNA methylation in distal regions with causal effect on tumorigenesis called MICMIC. Many predictions are directly validated by dCas9-based epigenetic editing to support the accuracy and efficiency of our tool. Oncogenic and lineage-specific transcription factors are shown to aberrantly shape the methylation landscape by modifying tumor-subtype core regulatory circuitry. Notably, the gene regulatory networks orchestrated by enhancer methylation across different cancer types are seen to converge on a common architecture. MICMIC is available on https://github.com/ZhangJlab/MICMIC.

Abstract Background Macrophages in the tumor microenvironment play a critical role in tumorigenesis and anti-cancer drug resistance. Burkitt’s lymphoma (BL) is a B-cell non-Hodgkin’s lymphoma with dense macrophage infiltration. However, the role for macrophages in BL remains largely unknown. Methods B7-H1, a transmembrane glycoprotein in the B7 family, suppresses T cell activation and proliferation and induces the apoptosis of activated T cells. The expression of B7-H1 in BL clinical tissues was determined by streptavidin-peroxidase immunohistochemistry. The mutual regulation between macrophages and BL Raji cells was investigated in a co-culture system. The cell proliferation and cell cycle distribution of Raji cells were determined using BrdU staining coupled with flow cytometry. CD163, CD204 and B7-H1 expression was assessed by flow cytometry and Western blot. Cell invasion was analyzed by Transwell assay. The expression of cytokines was detected by quantitative RT-PCR. Immunofluorescence and allogeneic T-cell proliferation assays were used to compare the expression of B7-H1, p-STAT6, or p-STAT3 and CD3+ T cell proliferation treated with or without amphotericin B. Results B7-H1 was highly expressed in tumor infiltration macrophages in most clinical BL tissues. In vitro, Raji cells synthesized IL-4, IL-6, IL-10 and IL-13 to induce CD163, CD204 and B7-H1 expression in co-cultured macrophages, which in turn promoted Raji cell proliferation and invasion. Interestingly, antifungal agent amphotericin B not only inhibited STAT6 phosphorylation to suppress the M2 polarization of macrophages, but also promoted CD3+ T cell proliferation by regulating B7-H1 protein expression in macrophages. Conclusion Amphotericin B might represent a novel immunotherapeutic approach to treat patients with BL.

Abstract Background Multidrug resistance-associated protein 1 (MRP1) overexpression plays a major role in chemoresistance in glioblastoma multiforme (GBM) contributing to its notorious deadly nature. Although MRP1-siRNA transfection to GBM in vitro has been shown to sensitise the cells to drug, MRP1 silencing in vivo and the phenotypic influence on the tumour and normal tissues upon MRP1 down-regulation have not been established. Here, porous silicon nanoparticles (pSiNPs) that enable high-capacity loading and delivery of siRNA are applied in vitro and in vivo. Result We established pSiNPs with polyethyleneimine (PEI) capping that enables high-capacity loading of siRNA (92 µg of siRNA/mg PEI-pSiNPs), and optimised release profile (70% released between 24 and 48 h). These pSiNPs are biocompatible, and demonstrate cellular uptake and effective knockdown of MRP1 expression in GBM by 30%. Also, siRNA delivery was found to significantly reduce GBM proliferation as an associated effect. This effect is likely mediated by the attenuation of MRP1 transmembrane transport, followed by cell cycle arrest. MRP1 silencing in GBM tumour using MRP1-siRNA loaded pSiNPs was demonstrated in mice (82% reduction at the protein level 48 h post-injection), and it also produced antiproliferative effect in GBM by reducing the population of proliferative cells. These results indicate that in vitro observations are translatable in vivo. No histopathological signs of acute damage were observed in other MRP1-expressing organs despite collateral downregulations. Conclusions This study proposes the potential of efficient MRP1-siRNA delivery by using PEI-capped pSiNPs in achieving a dual therapeutic role of directly attenuating the growth of GBM while sensitising residual tumour cells to the effects of chemotherapy post-resection.