Hepatic arterial infusion of autologous CD34+ cells for hepatitis C virus-related decompensated cirrhosis: A multicenter, open-label, exploratory randomized controlled trial.

Introduction: In this multicenter clinical study, we aimed to investigate the efficacy and safety of the transhepatic arterial administration of granulocyte-colony stimulating factor (G-CSF)-mobilized autologous peripheral blood (PB)-CD34+ cells compared with standard therapy in patients with decompensated cirrhosis type C. Methods: Patients were randomly assigned (2:1) to the CD34+ cell transplant (CD34+ cell) or standard-of-care (SOC) group and followed up for 52 weeks. The primary endpoints were the non-progression rate of Child-Pugh (CP) scores at 24 weeks post-enrollment and the safety of the protocol treatment. Results: Fourteen patients (CD34+ cell group: 10; SOC group: 4) were enrolled. CP scores at 24 weeks had a non-progression rate of 90% in the CD34+ cell group and 100% in the SOC group, with no significant difference between groups. Importantly, 4 out of 10 patients in the CD34+ cell group exhibited an improvement from decompensated to compensated cirrhosis, whereas all patients in the SOC group remained in decompensated cirrhosis. With regard to secondary endpoints, a trend toward increased serum albumin levels in the CD34+ cell group was noted. Serious adverse events (SAEs) occurred in three patients in the CD34+ cell group and in one patient in the SOC group. No causal relationship was observed between all SAEs and G-CSF, leukapheresis, or cell transplantation in the CD34+ cell group. No patients died and no hepatocellular carcinoma occurred within the study period. Conclusions: PB-CD34+ cell infusion therapy may have the potential to circumvent the decompensated stage of cirrhosis, thus avoiding the need for liver transplantation.

Ex-vivo expanded CD34+ cell transplantation alleviates fibrotic liver injury via innate immune modulation in metabolic dysfunction-associated steatohepatitis mice.

BACKGROUND: In drug-induced liver injury, vascular endothelial progenitor cells, specifically the CD34+ cell fractions, have been found to decrease liver fibrosis and promote regeneration. However, it is unclear whether CD34+ cell transplantation has anti-fibrogenic effects on MASH, which has previously been treated effectively with anti-angiogenic therapy. We investigated the efficacy of ex vivo-expanded CD34+ cells in treating MASH livers. MATERIALS AND METHODS: Diet-induced MASH mice were fed a choline-deficient, L-amino acid-defined, high-fat diet for 12 or 20 weeks, and were designated as a mild and a severe fibrosis model, respectively. Mouse bone marrow CD34+ cells were expanded for 7 days, transplanted into each mouse once or twice 2 weeks later, and sacrificed at 4 weeks after the first transplantation. RESULTS: Expanded CD34+ cell transplantation ameliorated liver fibrosis, regardless of fibrosis degree, as indicated by the decrease in α-smooth muscle actin-positive cells, hydroxyproline concentration, and fibrogenic gene expression of Col1a1 and Timp1. Furthermore, engrafted CD34+ cells reduced alanine transaminase levels, the number of TUNEL+ hepatocytes, and 8-OHdG concentration. RNA-sequencing data showed that "defense response to virus" was the most down-regulated category in the Gene Ontology analysis and subsequent analysis revealed the suppression of RIG-I-like receptors/Irf7/Stat1/Cxcl10 axis in expanded CD34+ cell-transplanted livers. Finally, the downregulation of CXCL10 expression inhibits the mobilization of inflammatory immune cells, macrophages, T cells, and natural killer cells to the MASH liver. CONCLUSIONS: These findings suggest that transplanted expanded CD34+ cells alleviate fibrotic liver injury in MASH mouse models through possible modulation of the innate immune response, which is abnormally activated by hepatocyte lipotoxicity.

A tumor endothelial cell-specific microRNA replacement therapy for hepatocellular carcinoma.

Current approved anti-angiogenic drugs (AAD) for hepatocellular carcinoma (HCC) inhibit tumor angiogenesis, but affect the hepatic vasculature resulting in adverse effects. Tumor endothelial cells (TECs) differ from normal endothelial cells. In this study, we aimed to detect TEC-specific miRNAs and develop an anti-angiogenic treatment specific for TECs. We established HCC orthotopic mouse models. TEC-specific miRNAs were detected using a microRNA array. Finally, we evaluated the therapeutic effects of the TEC-specific miRNA agonist cocktail. In total, 260 TEC-specific genes were detected. Among the top ten downregulated TEC-specific miRNAs, miR-139-3p and 214-3p were important for the TEC phenotype. The TEC-specific microRNA agonist cocktail showed significant anti-tumor effects by inhibiting tumor angiogenesis without affecting hepatic vasculatures in HCC orthotopic mouse models. Moreover, it significantly downregulated tip-cell sprouting-related genes. We identified two downregulated TEC-specific miRNAs; microRNA replacement therapy, which targets the downregulated TEC-specific miRNAs, is an effective and promising treatment for HCC.

Fibroblast growth factor inhibition by molecular-targeted agents mitigates immunosuppressive tissue microenvironment in hepatocellular carcinoma.

BACKGROUND & AIMS: Combination immunotherapy refers to the use of immune checkpoint inhibitors (ICI) and molecular-targeted agents (MTA), which have recently been approved for the treatment of advanced hepatocellular carcinoma (HCC). Owing to its relatively low antitumor effect (up to 30%), sequential therapy following ICIs treatment is required in patients with HCC. This study aimed to determine the impact of MTAs on the tumor immune microenvironment (TIME). METHODS: We established immune syngeneic orthotopic HCC mouse models using Hep-55.1C and Hep-53.4, and treated them with MTAs (lenvatinib, sorafenib, regorafenib, cabozantinib, and DC101 as anti-vascular endothelial growth factor receptor-2 antibodies, and AZD4547 as a fibroblast growth factor receptor (FGFR)-1/2/3/4 inhibitor) for 2 weeks. Subsequently, alterations in the TIME caused by MTAs were evaluated using immunohistochemistry (antibodies for CD3, CD8, Foxp3, Granzyme B, Arginase-1, NK1.1, F4/80, CD11c, PD-1, and PD-L1). We conducted RNA-seq analysis using lenvatinib- and AZD4547-treated tumors. To confirm the clinical relevance of these findings, we analyzed the transcriptome data of human HCC cells (MHCC-97H) treated with various concentrations of lenvatinib for 24 h using RNA-seq data from the Gene Expression Omnibus database. RESULTS: The number of Foxp3- and F4/80-positive cells in the TIME was decreased in many MTAs. Cabozantinib increased the numbers in NK1.1-, Granzyme B, and CD11c-positive cells. Lenvatinib and AZD4547 increased the number of CD8, Granzyme B, and PD-L1-positive cells. Gene ontology enrichment analysis revealed that lipid metabolism-related genes were downregulated by lenvatinib and AZD4547. In total, 161 genes downregulated by FGFR inhibition in rodent models overlapped with those downregulated by lenvatinib in human HCC cells. CONCLUSIONS: In this study, we showed that cabozantinib activated the innate immune system, and lenvatinib and AZD4547, which commonly inhibit FGFR signaling, altered TIME to a hot immune state by downregulating lipid metabolism-related genes. These findings support the therapeutic use of combination immunotherapies.

Anti-PD-L1 antibodies promote cellular proliferation by activating the PD-L1-AXL signal relay in liver cancer cells.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are emerging treatments for advanced hepatocellular carcinoma (HCC); however, evidence has shown they may induce hyperprogressive disease via unexplained mechanisms. METHODS: In this study, we investigated the possible stimulative effect of ICIs on programmed cell death-ligand 1 (PD-L1)-harboring liver cancer cells under immunocompetent cell-free conditions. RESULTS: The sarcomatous HAK-5 cell line displayed the highest expression of PD-L1 among 11 human liver cancer cell lines used in this study. HLF showed moderate expression, while HepG2, Hep3B, and HuH-7 did not show any. Moreover, sarcomatous HCC tissues expressed high levels of PD-L1. We observed approximately 20% increase in cell proliferation in HAK-5 cells treated with anti-PD-L1 antibodies, such as durvalumab and atezolizumab, for 48 h compared with that of those treated with the control IgG and the anti-PD-1 antibody pembrolizumab. No response to durvalumab or atezolizumab was shown in PD-L1-nonexpressing cells. Loss-of-function and gain-of-function experiments for PD-L1 in HAK-5 and HepG2 cells resulted in a significant decrease and increase in cell proliferation, respectively. Phosphorylated receptor tyrosine kinase array and immunoprecipitation revealed direct interactions between PD-L1 and AXL in tumor cells. This was stabilized by extrinsic anti-PD-L1 antibodies in a glycosylated PD-L1-dependent manner. Activation of AXL, triggering signal relay to the Akt and Erk pathways, boosted tumor cell proliferation both in vitro and in xenografted tumors in NOD/SCID mice. CONCLUSION: Collectively, this suggests that anti-PD-L1 antibodies stimulate cell proliferation via stabilization of the PD-L1-AXL complex in specific types of liver cancer, including in HCC with mesenchymal components. SIGNIFICANCE: Therapeutic anti-PD-L1 antibodies promote cell proliferation by stabilizing the PD-L1-AXL complex in PD-L1-abundant neoplasms, including in HCC with mesenchymal components. Such a mechanism may contribute to the development of hyperprogressive disease.

Tumor-derived insulin-like growth factor-binding protein-1 contributes to resistance of hepatocellular carcinoma to tyrosine kinase inhibitors.

BACKGROUND: Antiangiogenic tyrosine kinase inhibitors (TKIs) provide one of the few therapeutic options for effective treatment of hepatocellular carcinoma (HCC). However, patients with HCC often develop resistance toward antiangiogenic TKIs, and the underlying mechanisms are not understood. The aim of this study was to determine the mechanisms underlying antiangiogenic TKI resistance in HCC. METHODS: We used an unbiased proteomic approach to define proteins that were responsible for the resistance to antiangiogenic TKIs in HCC patients. We evaluated the prognosis, therapeutic response, and serum insulin-like growth factor-binding protein-1 (IGFBP-1) levels of 31 lenvatinib-treated HCC patients. Based on the array of results, a retrospective clinical study and preclinical experiments using mouse and human hepatoma cells were conducted. Additionally, in vivo genetic and pharmacological gain- and loss-of-function experiments were performed. RESULTS: In the patient cohort, IGFBP-1 was identified as the signaling molecule with the highest expression that was inversely associated with overall survival. Mechanistically, antiangiogenic TKI treatment markedly elevated tumor IGFBP-1 levels via the hypoxia-hypoxia inducible factor signaling. IGFBP-1 stimulated angiogenesis through activation of the integrin α5ß1-focal adhesion kinase pathway. Consequently, loss of IGFBP-1 and integrin α5ß1 by genetic and pharmacological approaches re-sensitized HCC to lenvatinib treatment. CONCLUSIONS: Together, our data shed light on mechanisms underlying acquired resistance of HCC to antiangiogenic TKIs. Antiangiogenic TKIs induced an increase of tumor IGFBP-1, which promoted angiogenesis through activating the IGFBP-1-integrin α5ß1 pathway. These data bolster the application of a new therapeutic concept by combining antiangiogenic TKIs with IGFBP-1 inhibitors.

Hyperlipidemia as a risk factor for Trousseau syndrome-related cerebral infarction in patients with advanced gastrointestinal cancer.

Trousseau syndrome-related cerebral infarction rarely occurs during chemotherapy in patients with gastrointestinal (GI) cancer, and its clinical features remain unclear. The present study aimed to examine the clinical features of Trousseau syndrome-related cerebral infarction developed during chemotherapy for GI cancer. The present retrospective cohort study consecutively enrolled 878 patients with unresectable GI cancer who received chemotherapy at the Multidisciplinary Treatment Cancer Center, Kurume University Hospital (Kurume, Japan) between April 2014 and March 2020. Patients with colorectal cancer (n=308) were the most common, followed by those with pancreatic (n=242), gastric (n=222) and biliary tract (n=59) cancer, neuroendocrine tumors (n=34) and duodenal cancer (n=11). Among the 878 patients, Trousseau syndrome-related cerebral infarction occurred in 8 (0.9%) patients with a median age of 70.5 years (range, 58-75 years), and 50% of the patients were male (4/8). In total, 3 patients had gastric cancer, 3 had pancreatic cancer and 2 had biliary tract cancer. A greater percentage of patients with Trousseau syndrome-related cerebral infarction had hyperlipidemia (38.0%) than those without (8.2%; P=0.005). Hyperlipidemia was a risk factor for occurrence of Trousseau syndrome-related cerebral infarction with an odds ratio of 7.009 (95% confidence interval, 1.785-27.513). Trousseau syndrome-related cerebral infarction developed during GI chemotherapy was rare and hyperlipidemia may predict its onset.

Efficacy and tolerability of Sorafenib plus metronomic chemotherapy S-1 for advanced hepatocellular carcinoma in preclinical and clinical assessments.

OBJECTIVE: Although sorafenib, a molecular targeted agent, has survival benefits for advanced hepatocellular carcinoma (HCC) patients, its disease control rate remains limited. To explore the potential for augmenting its antitumor effect, we assessed the preclinical and clinical efficacy and tolerability of S-1 metronomic chemotherapy (MC) plus sorafenib. METHODS: Antitumor effects and toxicity of this combination were tested with HAK-1B xenograft and spontaneous HCC mouse models, and a prospective pilot study was performed to compare therapeutic effects and safety between sorafenib plus MC S-1 for 12 advanced HCC cases and the historical control of 363 sorafenib-treated advanced HCC patients at our hospital from July 2011 to June 2015. RESULTS: In mice, the combination chemotherapy enhanced anti-angiogenic effects, resulting in a stronger tumor hypoxic environment and increased tumor cell apoptosis. Clinically, the objective response rate of the combination chemotherapy was higher than that of sorafenib mono therapy (16.7%; 2/12 vs 5.2%; 19/363, p < 0.05); however, there were no significant differences in overall survival and time to progression. Adverse events including alopecia, thrombocytopenia, and pancreatic enzymes elevation in the combination chemotherapy were higher than those of sorafenib. No patient treated with the combination chemotherapy discontinued treatment due to severe adverse events. CONCLUSIONS: Sorafenib plus MC S-1 seems to be effective and tolerable for patients with advanced HCC and could be considered a treatment option for these patients.

Promotion of liver regeneration and anti­fibrotic effects of the TGF­ß receptor kinase inhibitor galunisertib in CCl4­treated mice.

The cytokine transforming growth factor­ß (TGF­ß) serves a key role in hepatic fibrosis and has cytostatic effects on hepatocytes. The present study investigated the anti­fibrogenic and regenerative effects of the TGF­ß receptor type I kinase inhibitor galunisertib (LY2157299) in mice with carbon tetrachloride (CCl4)­induced liver cirrhosis and in vitro. Mice were intraperitoneally treated with CCl4 for 8 weeks. At week 5, the mice were divided randomly into four treatment groups: Vehicle­treated; and treated with low­; middle­; and high­dose galunisertib, which was administered from weeks 5­8. The mice were sacrificed after 8 weeks of CCl4 treatment. Liver fibrosis, as evaluated by histology and determination of hydroxyproline content, progressed during week 4­8 of CCl4 treatment in the vehicle­treated mice. Galunisertib treatment dose­dependently prevented liver fibrosis, as demonstrated by the direct inhibition of α­smooth muscle actin­positive activated hepatic stellate cells (HSCs) after 8 weeks of CCl4 treatment. The levels of active matrix metalloproteinase (MMP)­9 in galunisertib­treated livers were significantly increased compared with the vehicle­treated livers. In the high­dose group, the number of PCNA­positive hepatocytes and endothelial cells markedly increased compared with the vehicle group. Reverse transcription­quantitative PCR analysis verified that interleukin­6 and epiregulin expression levels were significantly increased in livers from the group treated with high­dose galunisertib compared with the vehicle­treated group. Galunisertib inhibited the proliferation of activated HSCs and collagen synthesis in addition to restoring MMP activity. Moreover, galunisertib promoted liver remodeling by proliferating hepatocytes and vascular endothelial cells, while significantly increasing liver weight. These results are consistent with the cytostatic action of TGF­ß that negatively regulates liver regeneration, and demonstrated that galunisertib inhibited TGF­ß signaling, halted liver fibrosis progression and promoted hepatic regeneration. The results of the present study suggest that galunisertib may be an effective treatment for liver cirrhosis.

Weekends-Off Lenvatinib for Unresectable Hepatocellular Carcinoma Improves Therapeutic Response and Tolerability toward Adverse Events.

Background: Although lenvatinib has become the standard therapy for hepatocellular carcinoma (HCC), the high incidence rate of adverse events (AEs) is an issue. This study aimed to clarify the AEs of lenvatinib and the therapeutic impact of five days-on/two days-off administration (i.e., weekends-off strategy) for lenvatinib. Methods: We retrospectively assessed the therapeutic effects and AEs of 135 patients treated with lenvatinib, and the improvement of tolerability and therapeutic efficacy of 30 patients treated with the weekends-off strategy. We also evaluated lenvatinib-induced vascular changes in tumors and healthy organs using a mouse hepatoma model. Results: The incidence rates of any grade and grade ≥ 3 AEs were 82.1% and 49.6%. Fatigue was the most important AE since it resulted in dose reduction and discontinuation. Of the 30 patients who received weekends-off lenvatinib, 66.7% tolerated the AEs. Although 80.8% of the patients showed progression after dose reduction, the therapeutic response improved in 61.5% of the patients by weekends-off lenvatinib. Notably, weekends-off administration significantly prolonged the administration period and survival (p < 0.001 and p < 0.05). The mouse hepatoma model showed that weekends-off administration contributed to recovery of vascularity in the organs. Conclusion: Weekends-off administration of lenvatinib was useful to recover the therapeutic response and tolerability toward AEs.

Glycosylation of ascites-derived exosomal CD133: a potential prognostic biomarker in patients with advanced pancreatic cancer.

Cancer cells surviving in ascites exhibit cancer stem cell (CSC)-like features. This study analyzed the expression of the CSC marker CD133 in the ascites-derived exosomes obtained from patients with unresectable pancreatic cancer. In addition, inverse correlation of CD133 expression with prognosis was examined. Of the 133 consecutive patients, 19 patients were enrolled in the study. Exosomes derived from the malignant ascites demonstrated higher density and wider variation in size than those from non-malignant ascites. Western blot revealed enhanced expression of CD133 in exosomes obtained from patients with pancreatic cancer compared to those obtained from patients with gastric cancer or liver cirrhosis. A xenograft mouse model with malignant ascites was established by intraperitoneal inoculation of human pancreatic cancer cells in nude mice. Results obtained from the human study were reproduced in the mouse model. Statistically significant equilateral correlation was identified between the band intensity of CD133 in western blot and overall survival of patients. Lectin microarray analyses revealed glycosylation of CD133 by sialic acids as the major glycosylation among diverse others responsible for the glycosylation of exosomal CD133. These findings suggest that highly glycosylated CD133 in ascites-derived exosomes as a potential biomarker for better prognosis of patients with advanced pancreatic cancer.

High expression of CD44v9 and xCT in chemoresistant hepatocellular carcinoma: Potential targets by sulfasalazine.

CD44v9 is expressed in cancer stem cells (CSC) and stabilizes the glutamate-cystine transporter xCT on the cytoplasmic membrane, thereby decreasing intracellular levels of reactive oxygen species (ROS). This mechanism confers ROS resistance to CSC and CD44v9-expressing cancer cells. The aims of the present study were to assess: (i) expression status of CD44v9 and xCT in hepatocellular carcinoma (HCC) tissues, including those derived from patients treated with hepatic arterial infusion chemoembolization (HAIC) therapy with cisplatin (CDDP); and (ii) whether combination of CDDP with sulfasalazine (SASP), an inhibitor of xCT, was more effective on tumor cells than CDDP alone by inducing ROS-mediated apoptosis. Twenty non-pretreated HCC tissues and 7 HCC tissues administered HAIC therapy with CDDP before surgical resection were subjected to immunohistochemistry analysis of CD44v9 and xCT expression. Human HCC cell lines HAK-1A and HAK-1B were used in this study; the latter was also used for xenograft experiments in nude mice to assess in vivo efficacy of combination treatment. CD44v9 positivity was significantly higher in HAIC-treated tissues (5/7) than in non-pretreated tissues (2/30), suggesting the involvement of CD44v9 in the resistance to HAIC. xCT was significantly expressed in poorly differentiated HCC tissues. Combination treatment effectively killed the CD44v9-harboring HAK-1B cells through ROS-mediated apoptosis and significantly decreased xenografted tumor growth. In conclusion, the xCT inhibitor SASP augmented ROS-mediated apoptosis in CDDP-treated HCC cells, in which the CD44v9-xCT system functioned. As CD44v9 is typically expressed in HAIC-resistant HCC cells, combination treatment with SASP with CDDP may overcome such drug resistance.

STAT3 deficiency prevents hepatocarcinogenesis and promotes biliary proliferation in thioacetamide-induced liver injury.

AIM: To elucidate the role of STAT3 in hepatocarcinogenesis and biliary ductular proliferation following chronic liver injury. METHODS: We investigated thioacetamide (TAA)-induced liver injury, compensatory hepatocyte proliferation, and hepatocellular carcinoma (HCC) development in hepatic STAT3-deficient mice. In addition, we evaluated TAA-induced biliary ductular proliferation and analyzed the activation of sex determining region Y-box9 (SOX9) and Yes-associated protein (YAP), which regulate the transdifferentiation of hepatocytes to cholangiocytes. RESULTS: Both compensatory hepatocyte proliferation and HCC formation were significantly decreased in hepatic STAT3-deficient mice as compared with control mice. STAT3 deficiency resulted in augmentation of hepatic necrosis and fibrosis. On the other hand, biliary ductular proliferation increased in hepatic STAT3-deficient livers as compared with control livers. SOX9 and YAP were upregulated in hepatic STAT3-deficient hepatocytes. CONCLUSION: STAT3 may regulate hepatocyte proliferation as well as transdifferentiation into cholangiocytes and serve as a therapeutic target for HCC inhibition and biliary regeneration.

Pancreatic Neuroendocrine Tumors and EMT Behavior Are Driven by the CSC Marker DCLK1.

Doublecortin-like kinase 1 (DCLK1), a marker for intestinal and pancreatic cancer stem cells, is highly expressed in neuroblastomas. This study was conducted to assess DCLK1 expression levels in pancreatic neuroendocrine tumor (PNET) tissues and to explore the roles of this molecule in clinical tissue from multiple PNET patients, cells (BON1, QGP1, and CM) and tumor xenografts. Immunohistochemically, all PNET tissues highly and diffusely expressed DCLK1 as a full-length isoform, identical to that detected in primary liver NETs. A DCLK1-overexpressing PNET cell line (QGP1-DCLK1) exhibited epithelial-mesenchymal transition (EMT)-related gene signatures, and robust upregulation of Slug (SNAI2), N-Cadherin (CDH2), and Vimentin (VIM) was validated by real-time PCR and immunoblotting. QGP1-DCLK1 cells had increased cell migration in a wound-healing assay and formed significantly larger xenograft tumors in nude mice. The factors involved in the formation of the fast-growing tumors included p-FAK (on Tyr925), p-ERK1/2, p-AKT, Paxillin, and Cyclin D1, which upon knockdown or pharmacologic inhibition of DCLK1 abolished the expression of these molecules. In conclusion, robust and ubiquitous expression of DCLK1 was first demonstrated here in human PNET tissue specimens and cells. DCLK1 characterized the PNET cell behavior, inducing p-FAK/SLUG-mediated EMT. These findings suggest the possibility of developing novel therapeutic strategies against PNETs by targeting DCLK1.Implications: Evidence here reveals that human PNETs diffusely and robustly express the cancer stem cell marker DCLK1, which drives SLUG-mediated EMT, and suggests that NETs share biological features for druggable targets with other tumors, including neuroblastoma that also highly expresses DCLK1. Mol Cancer Res; 15(6); 744-52. ©2017 AACR.

Ex vivo expansion of circulating CD34(+) cells enhances the regenerative effect on rat liver cirrhosis.

Ex vivo expansion of autologous cells is indispensable for cell transplantation therapy of patients with liver cirrhosis. The aim of this study was to investigate the efficacy of human ex vivo-expanded CD34(+) cells for treatment of cirrhotic rat liver. Recipient rats were intraperitoneally injected with CCl4 twice weekly for 3 weeks before administration of CD34(+) cells. CCl4 was then re-administered twice weekly for 3 more weeks, and the rats were sacrificed. Saline, nonexpanded or expanded CD34(+) cells were injected via the spleen. After 7 days, CD34(+) cells were effectively expanded in a serum-free culture medium. Expanded CD34(+) cells were also increasingly positive for cell surface markers of VE-cadherin, VEGF receptor-2, and Tie-2. The expression of proangiogenic growth factors and adhesion molecules in expanded CD34(+) cells increased compared with nonexpanded CD34(+) cells. Expanded CD34(+) cell transplantation reduced liver fibrosis, with a decrease of αSMA(+) cells. Assessments of hepatocyte and sinusoidal endothelial cell proliferative activity indicated the superior potency of expanded CD34(+) cells over non-expanded CD34(+) cells. The inhibition of integrin αvß3 and αvß5 disturbed the engraftment of transplanted CD34(+) cells and aggravated liver fibrosis. These findings suggest that expanded CD34(+) cells enhanced the preventive efficacy of cell transplantation in a cirrhotic model.

Inhibition of hypoxia-inducible factor via upregulation of von Hippel-Lindau protein induces "angiogenic switch off" in a hepatoma mouse model.

"Angiogenic switch off" is one of the ideal therapeutic concepts in the treatment of cancer. However, the specific molecules which can induce "angiogenic switch off" in tumor have not been identified yet. In this study, we focused on von Hippel-Lindau protein (pVHL) in hepatocellular carcinoma (HCC) and investigated the effects of sulfoquinovosyl-acylpropanediol (SQAP), a novel synthetic sulfoglycolipid, for HCC. We examined mutation ratio of VHL gene in HCC using 30 HCC samples and we treated the HCC-implanted mice with SQAP. Thirty clinical samples showed no VHL genetic mutation in HCC. SQAP significantly inhibited tumor growth by inhibiting angiogenesis in a hepatoma mouse model. SQAP induced tumor "angiogenic switch off" by decreasing hypoxia-inducible factor (HIF)-1, 2α protein via pVHL upregulation. pVHL upregulation decreased HIFα protein levels through different multiple mechanisms: (i) increasing pVHL-dependent HIFα protein degradation; (ii) decreasing HIFα synthesis with decrease of NF-κB expression; and (iii) decrease of tumor hypoxia by vascular normalization. We confirmed these antitumor effects of SQAP by the loss-of-function experiments. We found that SQAP directly bound to and inhibited transglutaminase 2. This study provides evidence that upregulation of tumor pVHL is a promising target, which can induce "angiogenic switch off" in HCC.