Cytokine-inducible SH2-containing protein (CIS; encoded by the gene CISH) is a key negative regulator of interleukin-15 (IL-15) signaling in natural killer (NK) cells. Here, we develop human ...CISH-knockout (CISH−/−) NK cells using an induced pluripotent stem cell-derived NK cell (iPSC-NK cell) platform. CISH−/− iPSC-NK cells demonstrate increased IL-15-mediated JAK-STAT signaling activity. Consequently, CISH−/− iPSC-NK cells exhibit improved expansion and increased cytotoxic activity against multiple tumor cell lines when maintained at low cytokine concentrations. CISH−/− iPSC-NK cells display significantly increased in vivo persistence and inhibition of tumor progression in a leukemia xenograft model. Mechanistically, CISH−/− iPSC-NK cells display improved metabolic fitness characterized by increased basal glycolysis, glycolytic capacity, maximal mitochondrial respiration, ATP-linked respiration, and spare respiration capacity mediated by mammalian target of rapamycin (mTOR) signaling that directly contributes to enhanced NK cell function. Together, these studies demonstrate that CIS plays a key role to regulate human NK cell metabolic activity and thereby modulate anti-tumor activity.
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•Deletion of CISH in human NK cells leads to improved anti-tumor activity•CISH−/− NK cells demonstrate more efficient glycolytic and OxPhos activity•The improved metabolic profile is mediated by mTOR signaling•CISH−/− NK cells more effectively treat AML in vivo with longer NK cell persistence
CISH normally inhibits IL-15 signaling in natural killer (NK) cells. Here, Zhu and colleagues delete CISH expression in NK cells derived from human induced pluripotent stem cells (iPSCs). CISH−/− iPSC-derived NK cells demonstrate improved killing of tumor cells that is directly attributable to a more efficient metabolic profile.
Context: Combination therapies provide a potential solution to address the tumor heterogeneity and drug resistance issues by taking advantage of distinct mechanisms of action of the multiple ...therapeutics.
Objective: To design arginine-glycineaspartic acid (RGD) modified lipid-coated nanoparticles (NPs) for the co-delivery of the hydrophobic drugs against hepatocellular carcinoma (HCC).
Materials and methods: RGD modified lipid-coated PLGA NPs were developed for the targeted delivery of both sorafenib (SRF) and quercetin (QT) (RGD-SRF-QT NPs). Chemical-physical characteristics and release profiles were evaluated. In vitro cell viability assays were carried out on HCC cells. In vivo antitumor efficacies were evaluated in HCC animal model.
Results and discussion: The combination of SRF and QT formulations was more effective than the single drug formulations in both NPs and solution groups. RGD-SRF-QT NPs achieved the most significant tumor growth inhibition effect in vitro and in vivo.
Conclusion: The resulting NPs could provide a promising platform for co-delivery of multiple anticancer drugs for achievement of combinational therapy and could offer potential for enhancing the therapeutic efficacy on HCC.
The importance of intratumoral heterogeneity has been highlighted by the identification and characterization of cancer stem cells (CSCs). Based on the differential responsiveness to a Sox2 reporter, ...SRR2, we had found a novel dichotomy in esophageal squamous cell carcinoma (ESCC) cells, with reporter-responsive (RR) cells showing more CSC-like features than reporter-unresponsive (RU) cells. Specifically, RR cells exhibited significantly higher tumorsphere formation capacity, proportions of CD44(High) cells, chemoresistance to cisplatin, and tumorigenic potential in vivo. H2 O2 , a potent inducer of oxidative stress and reactive oxygen species, was found to induce a conversion from RU to RR cells; importantly, converted RR cells acquired CSC-like features. The PI3K/AKT/c-MYC signalling axis is important in this context, since pharmacologic blockade of PI3K-AKT or siRNA knockdown of c-MYC effectively inhibited the RR phenotype and its associated CSC-like features, as well as the H2 O2 -induced RU/RR conversion. In a cohort of 188 ESCC patient samples, we found a significant correlation between strong c-MYC expression and a short overall survival (p = .009). In conclusion, we have described a novel intratumoral heterogeneity in ESCC. The identification of the PI3K/AKT/c-MYC axis as a driver of CSC-like features carries therapeutic implications. Stem Cells 2016;34:2040-2051.
The phenomenon that malignant cells can acquire stemness under specific stimuli, encompassed under the concept of cancer cell plasticity, has been well-described in epithelial malignancies. To our ...knowledge, cancer cell plasticity has not yet been described in hematopoietic cancers. To illustrate and study cancer cell plasticity in hematopoietic cancers, we employed an in-vitro experimental model of ALK-positive anaplastic large-cell lymphoma (ALK+ALCL) that is based on the phenotypic and functional dichotomy of these cells, with cells responsive to a Sox2 reporter (i.e. RR cells) being significantly more stem-like than those unresponsive to the reporter (i.e. RU cells).
H
O
was employed to trigger oxidative stress. GFP expression and luciferase activity, readouts of the Sox2 reporter activity, were quantified by using flow cytometry and luciferase activity assay, respectively. Doxorubicin-resistance and clonogenicity were assessed by using the MTS, methylcellulose colony formation and limiting dilution assays. Western blotting and quantitative PCR were used to assess the expression of various members of the Wnt/β-catenin pathway. Pull-down studies using a Sox2 binding consensus sequence were used to assess Sox2-DNA binding. Quercetin and 10074-G5 were used to inhibit β-catenin and MYC, respectively. siRNA was used to downregulate Sox2.
Under H
O
-induced oxidative stress, a substantial fraction of RU cells was found to convert to RR cells, as evidenced by their acquisition of GFP expression and luciferase activity. Compared to the native RU cells, converted RR cells had significantly higher levels of doxorubicin-resistance, clonogenicity and sphere formation. Converted RR cells were characterized by an upregulation of the Wnt/β-catenin/MYC/Sox2 signaling axis, previously found to be the key regulator of the RU/RR dichotomy in ALK+ALCL. Furthermore, Sox2 was found to bind to DNA efficiently in converted RR cells but not RU cells, and this finding correlated with significant elevations of several Sox2 downstream targets such as WNT2B and BCL9. Lastly, inhibition of β-catenin, MYC or Sox2 in RU cells significantly abrogated the H
O
-induced RU/RR conversion.
We have demonstrated that cancer cell plasticity exists in ALK+ALCL, a type of hematopoietic cancer. In this cancer type, the Wnt/β-catenin/MYC/Sox2 axis is an important regulator of cancer cell plasticity.
Installing an energy saving device such as a pre-swirl duct (PSD) is a major investment for a ship owner and prior to an order a reliable prediction of the energy savings is required. Currently there ...is no standard for how such a prediction is to be carried out, possible alternatives are both model-scale tests in towing tanks with associated scaling procedures, as well as methods based on computational fluid dynamics (CFD). This paper summarizes a CFD benchmark study comparing industrial state-of-the-art ship-scale CFD predictions of the power reduction through installation of a PSD, where the objective was to both obtain an indication on the reliability in this kind of prediction and to gain insight into how the computational procedure affects the results. It is a blind study, the KVLCC2, which the PSD is mounted on, has never been built and hence there is no ship-scale data available. The 10 participants conducted in total 22 different predictions of the power reduction with respect to a baseline case without PSD. The predicted power reductions are both positive and negative, on average 0.4%, with a standard deviation of 1.6%-units, when not considering two predictions based on model-scale CFD and two outliers associated with large uncertainties in the results. Among the variations present in computational procedure, two were found to significantly influence the predictions. First, a geometrically resolved propeller model applying sliding mesh interfaces is in average predicting a higher power reduction with the PSD compared to simplified propeller models. The second factor with notable influence on the power reduction prediction is the wake field prediction, which, besides numerical configuration, is affected by how hull roughness is considered.
Malignant glioma is a common primary tumor of the central nervous system. Brevican, an abundant extracellular matrix component in the adult brain, plays a critical role in the process of glioma. The ...mechanisms for the highly invasive behavior of gliomas are still poorly understood. The aim of this study was to examine whether brevican is a predictor of glioma and its roles in glioma cell motility.
In this study, immunohistochemistry staining for brevican expression was performed in malignant gliomas and benign controls. We also explored the effects of brevican on cell adhesion and migration in brevican-overexpressed cells. Knockdown of brevican expression was achieved by stable transfection of U251 cells transduced with a construct encoding a short hairpin DNA directed against the brevican gene, which correspondingly, down-regulated the proliferation, invasion and spread of brevican-expressing cells. Moreover, the role of brevican in the growth and progression of glioma was demonstrated by in vivo studies.
Our results provide evidence for the molecular and cellular mechanisms that may underlie the motility-promoting role of brevican in the progression of glioma. The role of brevican as a target for immunotherapy might be taken into consideration in future studies.
This study suggests that expression of brevican is associated with glioma cell adhesion, motility and tumor growth, and also is related to glioma cell differentiation, therefore it may be a marker for malignance degree of glioma.
STAT3 is an oncoprotein which has been shown to contribute to drug resistance in multiple myeloma (MM). Nonetheless, the clinical utility of STAT3 inhibitors in treating MM has been limited, partly ...related to some of their pharmacologic properties. To overcome these challenges, our group had previously packaged STAT3 inhibitors using a novel formulation of nanoparticles (NP) and found encouraging results. In this study, we aimed to further improve the pharmacologic properties of these NP by decorating them with monoclonal anti-CD38 antibodies. NP loaded with S3I-1757 (a STAT3 inhibitor), labeled as S3I-NP, were generated. S3I-NP decorated with anti-CD38 (labeled as CD38-S3I-NP) were found to have a similar nanoparticular size, drug encapsulation, and loading as S3I-NP. The release of S3I-1757 at 24 h was also similar between the two formulations. Using Cy5.5 labeling of the NP, we found that the decoration of anti-CD38 on these NP significantly increased the cellular uptake by two MM cell lines (
< 0.001). Accordingly, CD38-S3I-NP showed a significantly lower inhibitory concentration at 50% (IC50) compared to S3I-NP in two IL6-stimulated MM cell lines (
< 0.001). In a xenograft mouse model, CD38-S3I-NP significantly reduced the tumor size by 4-fold compared to S3I-NP on day 12 after drug administration (
= 0.006). The efficacy of CD38-S3I-NP in suppressing STAT3 phosphorylation in the xenografts was confirmed by using immunocytochemistry and Western blot analysis. In conclusion, our study suggests that the decoration of anti-CD38 on NP loaded with STAT3 inhibitors can further improve their therapeutic effects against MM.
The tumorigenicity of most cases of ALK-positive anaplastic large-cell lymphoma (ALK+ ALCL) is driven by the oncogenic fusion protein NPM-ALK in a STAT3-dependent manner. Because it has been shown ...that STAT3 can be inhibited by STAT1 in some experimental models, we hypothesized that the STAT1 signaling pathway is defective in ALK+ ALCL, thereby leaving the STAT3 signaling unchecked. Compared with normal T cells, ALK+ ALCL tumors consistently expressed a low level of STAT1. Inhibition of the ubiquitin-proteasome pathway appreciably increased STAT1 expression in ALK+ ALCL cells. Furthermore, we found evidence that NPM-ALK binds to and phosphorylates STAT1, thereby promoting its proteasomal degradation in a STAT3-dependent manner. If restored, STAT1 is functionally intact in ALK+ ALCL cells, because it effectively upregulated interferon-γ, induced apoptosis/cell-cycle arrest, potentiated the inhibitory effects of doxorubicin, and suppressed tumor growth in vivo. STAT1 interfered with the STAT3 signaling by decreasing STAT3 transcriptional activity/DNA binding and its homodimerization. The importance of the STAT1/STAT3 functional interaction was further highlighted by the observation that short interfering RNA knockdown of STAT1 significantly decreased apoptosis induced by STAT3 inhibition. Thus, STAT1 is a tumor suppressor in ALK+ ALCL. Phosphorylation and downregulation of STAT1 by NPM-ALK represent other mechanisms by which this oncogenic tyrosine kinase promotes tumorigenesis.
•Oncogenic tyrosine kinase NPM-ALK binds to and phosphorylates STAT1, thereby promoting its proteasome-/STAT3-dependent degradation.•STAT1 tumor suppressor effects in ALK+ ALCL include creating a STAT1/interferon-γ loop and interfering with STAT3 transcriptional activities.
We have previously described the existence of two phenotypically distinct cell subsets in ALK-positive anaplastic large cell lymphoma (ALK + ALCL) based on their differential responsiveness to a Sox2 ...reporter (SRR2), with reporter-responsive (RR) cells being more tumorigenic and chemoresistant than reporter-unresponsive (RU) cells. However, the regulator(s) of RU/RR dichotomy are not identified. In this study, we aim to delineate the key regulator(s) of RU/RR dichotomy.
JASPER motif match analysis was used to identify the putative factors binding to SRR2 sequence. SRR2 probe pull-down assay and quantitate real-time PCR were performed to analyze the regulation of Sox2 transcriptional activity by MYC. Methylcellulose colony formation assay, chemoresistance to doxorubicin and mouse xenograft study were performed to investigate the biological functions of MYC. PCR array and western blotting were executed to study related signaling pathways that regulate MYC expression. Immunofluorescence and immunohistochemistry assay were initiated to evaluate the expression of MYC and its correlation with its regulator by chi-square test analysis in human primary tumor cells.
We identified MYC as a potential regulator of RU/RR dichotomy. In support of its role, MYC was highly expressed in RR cells compared to RU cells, and inhibition of MYC substantially decreased the Sox2/SRR2 binding, Sox2 transcriptional activity, chemoresistance, and methylcellulose colony formation. In contrast, enforced expression of MYC in RU cells conferred the RR phenotype. The Wnt/β-catenin pathway, a positive regulator of MYC, was highly active in RR but not RU cells. While inhibition of this pathway in RR cells substantially decreased MYC expression and SRR2 reporter activity, experimental activation of this pathway led to the opposite effects in RU cells. Collectively, our results support a model in which a positive feedback loop involving Wnt/β-catenin/MYC and Sox2 contributes to the RR phenotype. In a mouse xenograft model, RU cells stably transfected with MYC showed upregulation of the Wnt/β-catenin/MYC/Sox2 axis and increased tumorigenecity. Correlating with these findings, there was a significant correlation between the expression of active β-catenin and MYC in ALK + ALCL primary tumor cells.
A positive feedback loop involving the Wnt/β-catenin/MYC/Sox2 axis defines a highly tumorigenic cell subset in ALK + ALCL.
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