Publications by authors named "Yuquan Xiong"

Infiltration of tumor by T cells is a prerequisite for successful immunotherapy of solid tumors. In this study, we investigate the influence of tumor-targeted radiation on chimeric antigen receptor (CAR) T-cell therapy tumor infiltration, accumulation, and efficacy in clinically relevant models of pleural mesothelioma and non-small cell lung cancers. We use a nonablative dose of tumor-targeted radiation prior to systemic administration of mesothelin-targeted CAR T cells to assess infiltration, proliferation, antitumor efficacy, and functional persistence of CAR T cells at primary and distant sites of tumor.

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The limited efficacy of chimeric antigen receptor (CAR) T cell therapy for solid tumors necessitates engineering strategies that promote functional persistence in an immunosuppressive environment. Herein, we use c-Kit signaling, a physiological pathway associated with stemness in hematopoietic progenitor cells (T cells lose expression of c-Kit during differentiation). CAR T cells with intracellular expression, but no cell-surface receptor expression, of the c-Kit D816V mutation (KITv) have upregulated STAT phosphorylation, antigen activation-dependent proliferation and CD28- and interleukin-2-independent and interferon-γ-mediated co-stimulation, augmenting the cytotoxicity of first-generation CAR T cells.

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Introduction: In solid tumor immunotherapy, less than 20% of patients respond to anti-programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) agents. The role of transforming growth factor β (TGFβ) in diverse immunity is well-established; however, systemic blockade of TGFβ is associated with toxicity. Accumulating evidence suggests the role of crosstalk between TGFβ and PD-1/PD-L1 pathways.

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Mesothelioma is an aggressive cancer of the serous membranes with poor prognosis despite combination therapy consisting of surgery, radiotherapy, and platinum-based chemotherapy. Targeted therapies, including immunotherapies, have reported limited success, suggesting the need for additional therapeutic targets. This study investigates a potential new therapeutic target, gC1qR/HABP1/p32 (gC1qR), which is overexpressed in all morphologic subtypes of mesothelioma.

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Objective: Aggregation and modification of LDLs (low-density lipoproteins) promote their retention and accumulation in the arteries. This is a critical initiating factor during atherosclerosis. Macrophage catabolism of agLDL (aggregated LDL) occurs using a specialized extracellular, hydrolytic compartment, the lysosomal synapse.

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Macrophages use an extracellular, hydrolytic compartment formed by local actin polymerization to digest aggregated LDL (agLDL). Catabolism of agLDL promotes foam cell formation and creates an environment rich in LDL catabolites, including cholesterol and ceramide. Increased ceramide levels are present in lesional LDL, but the effect of ceramide on macrophage proatherogenic processes remains unknown.

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Endothelial dysfunction, a hallmark of vascular disease, is restored by plasma high-density lipoprotein (HDL). However, a generalized increase in HDL abundance is not beneficial, suggesting that specific HDL species mediate protective effects. Apolipoprotein M-containing HDL (ApoMHDL), which carries the bioactive lipid sphingosine 1-phosphate (S1P), promotes endothelial function by activating G protein-coupled S1P receptors.

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Rationale: Sphingosine-1-phosphate (S1P) signaling is essential for vascular development and postnatal vascular homeostasis. The relative importance of S1P sources sustaining these processes remains unclear.

Objective: To address the level of redundancy in bioactive S1P provision to the developing and mature vasculature.

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TRAF2 is a component of TNF superfamily signalling complexes and plays an essential role in the regulation and homeostasis of immune cells. TRAF2 deficient mice die around birth, therefore its role in adult tissues is not well-explored. Furthermore, the role of the TRAF2 RING is controversial.

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Transport of oxygen by red blood cells (rbc) is critical for life and embryogenesis. Here, we determined that provision of the lipid mediator sphingosine 1-phosphate (S1P) to the systemic circulation is an essential function of rbc in embryogenesis. Mice with rbc-specific deletion of sphingosine kinases 1 and 2 (Sphk1 and Sphk2) showed embryonic lethality between E11.

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Sphingosine 1-phosphate (S1P), a lipid mediator produced by sphingolipid metabolism, promotes endothelial cell spreading, vascular maturation/stabilization, and barrier function. S1P is present at high concentrations in the circulatory system, whereas in tissues its levels are low. This so-called vascular S1P gradient is essential for S1P to regulate much physiological and pathophysiological progress such as the modulation of vascular permeability.

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Sphingosine kinases (Sphks), which catalyze the formation of sphingosine 1-phosphate (S1P) from sphingosine, have been implicated as essential intracellular messengers in inflammatory responses. Specifically, intracellular Sphk1-derived S1P was reported to be required for NFκB induction during inflammatory cytokine action. To examine the role of intracellular S1P in the inflammatory response of innate immune cells, we derived murine macrophages that lack both Sphk1 and Sphk2 (MΦ Sphk dKO).

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HuR, also known as Elavl1, is an RNA-binding protein that regulates embryonic development, progenitor cell survival, and cell stress responses. The role of HuR in angiogenesis is not known. Using a myeloid-specific HuR knock-out mouse model (Elavl1Mø KO), we show that HuR expression in bone marrow-derived macrophages (BMDMs) is needed to maintain the expression of genes enriched in AU-rich elements and U-rich elements in the 3'-UTR.

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Background & Aims: Antiangiogenic agents can sometimes promote tumor invasiveness and metastasis, but little is known about the effects of the antiangiogenic drug sorafenib on progression of hepatocellular carcinoma (HCC).

Methods: Sorafenib was administered orally (30 mg · kg(-1) · day(-1)) to mice with orthotopic tumors grown from HCC-LM3, SMMC7721, or HepG2 cells. We analyzed survival times of mice, along with tumor growth, metastasis within liver and to lung, and induction of the epithelial-mesenchymal transition.

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Background: Antiangiogenesis is a promising therapy for advanced hepatocellular carcinoma (HCC), but the effects are difficult to be evaluated. Pazopanib (GW786034B) is a pan-vascular endothelial growth factor receptor inhibitor, the antitumor effects or antiangiogenic effects haven't been investigated in HCC.

Methods: In vitro direct effects of pazopanib on human HCC cell lines and endothelial cells were evaluated.

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Objective: Sphingomyelin deposition and metabolism occurs in the atherosclerotic plaque, leading to the formation of sphingosine-1-phosphate (S1P), which activates G protein-coupled receptors to regulate vascular and immune cells. The role of S1P receptors in atherosclerosis has not been examined.

Methods And Results: We tested the hypothesis that S1P receptor-2 (S1PR2) regulates atherosclerosis.

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Purpose: To investigate the role of macrophages in tumor progression under sorafenib treatment and to explore whether combination of drugs that deplete macrophages improved the antitumor effect of sorafenib.

Experimental Design: Tumor growth, lung metastasis, and tumor angiogenesis were observed in HCCLM3-R and SMMC7721, two human hepatocellular carcinoma xenograft nude mouse models, when treated with sorafenib (30 mg/kg daily, n = 6 per group) or a vehicle as control. Macrophage infiltration was measured in the peripheral blood and in sorafenib-treated tumor by immunohistochemistry and flow cytometry with F4/80 antibody and CD11b antibody.

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Purpose: In recent years, anti-angiogenesis drugs have shown promising clinical effects against many tumors, particularly in combination with chemotherapy. Although the combination has become a standard of care for many tumors, the mechanisms of the chemosensitizing activity of anti-angiogenic drugs are not fully understood. Here, we sought to determine if anti-angiogenesis drug bevacizumab could enhance the chemosensitivity of HCC by inhibition of survivin.

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Purpose: To elucidate the effect of IFN-α treatment on tumor growth and metastasis of hepatocellular carcinoma (HCC).

Methods: IFN-α administration was conducted in nude mice using an orthotopic implantation model of human HCC, and the key molecular markers in the IFN-α treatment was detected by immunohistochemistry staining and PCR array.

Results: Up to 12 weeks of IFN-α treatment significantly suppressed tumor growth of HCC, but relatively increased the number of circulating tumor cells, which might be due to the enhanced tumor hypoxia as well as up-regulation of metastasis-related genes, such as HIF-1α, c-met, u-PA, PDGF-A, and IL-8.

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Purpose: Increasing evidence indicates that tumor-derived endothelial cells (TEC) possess a distinct and unique phenotype compared with endothelial cells (NEC) from adjacent normal tissue and may be able to acquire resistance to drugs. The aim of this study was to investigate the angiogenesis activity and response to drug treatment of TECs and NECs derived from human hepatocellular carcinoma (HCC).

Experimental Design: TECs or NECs were isolated from HCC or adjacent normal liver tissue using anti-CD105 antibody coupled to magnetic beads.

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Purpose: To examine expression profile and prognostic significance of vascular endothelial growth factor (VEGF) and its receptors in hepatocellular carcinoma (HCC) and peritumoral tissue.

Methods: Expression of VEGF-A, VEGF-C, and VEGF receptor 1(VEGFR-1), VEGFR-2, and VEGFR-3 in tumor and peritumoral liver tissue was studied by immunohistochemistry in a tissue microarray from 107 patients with HCC. Unsupervised hierarchical cluster analyses were conducted to identify relevant clusters.

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Purpose: To investigate prognostic values of the intratumoral and peritumoral expression of macrophage colony-stimulating factors (M-CSF) in hepatocellular carcinoma (HCC) patients after curative resection.

Patients And Methods: Expression of M-CSF and density of macrophages (M Phi) were assessed by immunohistochemistry in tissue microarrays containing paired tumor and peritumoral liver tissue from 105 patients who had undergone hepatectomy for histologically proven HCC. Prognostic value of these and other clinicopathologic factors was evaluated.

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Special designed group I intron ribozymes can specifically splice objective RNA, repair the mutant gene in RNA level. The specificity of ribozyme is determined by nucleotides specific internal guide sequence (IGS) introduced to the enzyme. In this study, fragment sequence containing Tetrahymena thermophilia intron I of 26S rRNA gene was cloned and cis-splicing activity of this ribozyme was confirmed by in vitro transcription.

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