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1.  Fucosylated TGF-β receptors transduces a signal for epithelial–mesenchymal transition in colorectal cancer cells 
British Journal of Cancer  2013;110(1):156-163.
Transforming growth factor-β (TGF-β) is a major inducer of epithelial–mesenchymal transition (EMT) in different cell types. TGF-β-mediated EMT is thought to contribute to tumour cell spread and metastasis. Sialyl Lewis antigens synthesised by fucosyltransferase (FUT) 3 and FUT6 are highly expressed in patients with metastatic colorectal cancer (CRC) and are utilised as tumour markers for cancer detection and evaluation of treatment efficacy. However, the role of FUT3 and FUT6 in augmenting the malignant potential of CRC induced by TGF-β is unclear.
Colorectal cancer cell lines were transfected with siRNAs for FUT3/6 and were examined by cell proliferation, invasion and migration assays. The expression and phosphorylation status of TGF-β downstream molecules were analysed by western blot. Fucosylation of TGF-β receptor (TβR) was examined by lectin blot analysis.
Inhibition of FUT3/6 expression by siRNAs suppressed the fucosylation of type I TβR and phosphorylation of the downstream molecules, thereby inhibiting the invasion and migration of CRC cells by EMT.
Fucosyltransferase 3/6 has an essential role in cancer cell adhesion to endothelial cells by upregulation of sialyl Lewis antigens and also by enhancement of cancer cell migration through TGF-β-mediated EMT.
PMCID: PMC3887298  PMID: 24253505
colorectal cancer; fucosyltransferase; TGF-β; EMT
2.  A novel strategy inducing autophagic cell death in Burkitt's lymphoma cells with anti-CD19-targeted liposomal rapamycin 
Blood Cancer Journal  2014;4(2):e180-.
Relapsed or refractory Burkitt's lymphoma often has a poor prognosis in spite of intensive chemotherapy that induces apoptotic and/or necrotic death of lymphoma cells. Rapamycin (Rap) brings about autophagy, and could be another treatment. Further, anti-CD19-targeted liposomal delivery may enable Rap to kill lymphoma cells specifically. Rap was encapsulated by anionic liposome and conjugated with anti-CD19 antibody (CD19-GL-Rap) or anti-CD2 antibody (CD2-GL-Rap) as a control. A fluorescent probe Cy5.5 was also liposomized in the same way (CD19 or CD2-GL-Cy5.5) to examine the efficacy of anti-CD19-targeted liposomal delivery into CD19-positive Burkitt's lymphoma cell line, SKW6.4. CD19-GL-Cy5.5 was more effectively uptaken into SKW6.4 cells than CD2-GL-Cy5.5 in vitro. When the cells were inoculated subcutaneously into nonobese diabetic/severe combined immunodeficiency mice, intravenously administered CD19-GL-Cy5.5 made the subcutaneous tumor fluorescent, while CD2-GL-Cy5.5 did not. Further, CD19-GL-Rap had a greater cytocidal effect on not only SKW6.4 cells but also Burkitt's lymphoma cells derived from patients than CD2-GL-Rap in vitro. The specific toxicity of CD19-GL-Rap was cancelled by neutralizing anti-CD19 antibody. The survival period of mice treated with intravenous CD19-GL-Rap was significantly longer than that of mice treated with CD2-GL-Rap after intraperitoneal inoculation of SKW6.4 cells. Anti-CD19-targeted liposomal Rap could be a promising lymphoma cell-specific treatment inducing autophagic cell death.
PMCID: PMC3944660  PMID: 24510029
CD19; liposome; rapamycin; Burkitt's lymphoma
3.  Stromal cells expressing hedgehog-interacting protein regulate the proliferation of myeloid neoplasms 
Blood Cancer Journal  2012;2(9):e87-.
Aberrant reactivation of hedgehog (Hh) signaling has been described in a wide variety of human cancers including cancer stem cells. However, involvement of the Hh-signaling system in the bone marrow (BM) microenvironment during the development of myeloid neoplasms is unknown. In this study, we assessed the expression of Hh-related genes in primary human CD34+ cells, CD34+ blastic cells and BM stromal cells. Both Indian Hh (Ihh) and its signal transducer, smoothened (SMO), were expressed in CD34+ acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)-derived cells. However, Ihh expression was relatively low in BM stromal cells. Remarkably, expression of the intrinsic Hh-signaling inhibitor, human Hh-interacting protein (HHIP) in AML/MDS-derived stromal cells was markedly lower than in healthy donor-derived stromal cells. Moreover, HHIP expression levels in BM stromal cells highly correlated with their supporting activity for SMO+ leukemic cells. Knockdown of HHIP gene in stromal cells increased their supporting activity although control cells marginally supported SMO+ leukemic cell proliferation. The demethylating agent, 5-aza-2′-deoxycytidine rescued HHIP expression via demethylation of HHIP gene and reduced the leukemic cell-supporting activity of AML/MDS-derived stromal cells. This indicates that suppression of stromal HHIP could be associated with the proliferation of AML/MDS cells.
PMCID: PMC3461706  PMID: 22961059
acute myeloid leukemia (AML); myelodysplastic syndrome (MDS); human hedgehog-interacting protein (HHIP); stromal cells
4.  Hepatitis C virus core protein promotes proliferation of human hepatoma cells through enhancement of transforming growth factor α expression via activation of nuclear factor‐κB 
Gut  2006;55(12):1801-1808.
Hepatitis C virus (HCV) infection is a major cause of human hepatocellular carcinoma (HCC). The precise mechanism of hepatocarcinogenesis in humans by HCV is currently unclear. It was recently shown, however, that transgenic mice with the HCV core gene often develop HCC, suggesting tumorigenic activity of the HCV core protein. Further, the HCV core protein expressed in HepG2 cells transfected with the core gene was shown to stimulate proliferation of transfectants through activation of nuclear factor‐κB (NF‐κB). The downstream target molecule(s) of NF‐κB activated by the HCV core protein to evoke cell proliferation is not yet identified. Transforming growth factor (TGF) α, which is often overexpressed in various tumour tissues such as HCC, has been shown to stimulate hepatocyte proliferation through activation of the mitogen‐activated protein kinase or extracellular signal‐related protein kinase (MAPK/ERK) cascade.
To explore the possibility that TGFα might be a target molecule for NF‐κB activated by the HCV core, and that TGFα participates in the growth promotion of the core transfectants in an autocrine manner, activating the MAPK/ERK pathway.
A HCV core expression vector was transfected into human hepatoma Huh‐7, HepG2 and Hep3B cells. NF‐κB activity was examined by an electrophoretic mobility shift assay. TGFα transcription was assessed by a luciferase reporter assay. TGFα protein was determined by immunoblot and ELISA. MAPK/ERK activity was examined by an in vitro kinase assay. Cell proliferation was assessed by a water‐soluble tetrazolium salt‐1 assay.
In the HCV core transfectants, NF‐κB bound to the κB site in the TGFα proximal promoter region, resulting in an increase in TGFα transcription. Immunoblot as well as ELISA showed increased TGFα expression in the HCV core transfectants. SN50, a specific inhibitory peptide for NF‐κB, cancelled HCV core‐induced TGFα expression. HCV core protein increased cell proliferation as well as ERK activity of the HCV core transfectants as compared with the mock transfectants. The growth‐promoting activity and activation of ERK by the HCV core protein were negated by treatment with anti‐TGFα antibodies.
These results suggest that the HCV core protein promotes proliferation of human hepatoma cells by activation of the MAPK/ERK pathway through up regulation of TGFα transcription via activation of NF‐κB. Our finding provides a new insight into the mechanism of hepatocarcinogenesis by HCV infection.
PMCID: PMC1856483  PMID: 16581947
5.  Denatured H-ferritin subunit is a major constituent of haemosiderin in the liver of patients with iron overload 
Gut  2002;50(3):413-419.
Background and aims: Iron is stored in hepatocytes in the form of ferritin and haemosiderin. There is a marked increase in iron rich haemosiderin in iron overloaded livers, and ferric iron in amounts exceeding the ferritin and haemosiderin binding capacity may promote free radical generation, causing cellular damage. The aim of this study was to characterise hepatic haemosiderin using four antibodies specific for either native or denatured H/L-ferritin subunits.
Methods: Ferritin and haemosiderin were prepared from the livers of three patients with post-transfusional iron overload. The assembled ferritin molecules were analysed by non-denaturing polyacrylamide gel electrophoresis (PAGE)-immunoblotting. Ferritin subunits in the haemosiderin fraction were assessed by denaturing sodium dodecyl sulphate (SDS)-PAGE-immunoblotting. Distribution of native and denatured ferritin subunits in hepatocytes was examined by immunogold electron microscopy.
Results: Non-denaturing PAGE-immunoblot analyses showed that the assembled liver ferritins were recognised by the antibodies for native ferritins and not by those for the denatured subunits. Both SDS-PAGE-immunoblot and immunogold electron microscopic analyses disclosed that haemosiderin of iron overloaded liver reacted predominantly to the monoclonal antibody for the denatured H-ferritin subunit, to a lesser degree to that for denatured L-ferritin, and very weakly, if any, with antibodies for native H-ferritin or L-ferritin.
Conclusions: These results suggest that in iron overloaded liver, haemosiderin consists predominantly of denatured H-ferritin subunits.
PMCID: PMC1773135  PMID: 11839724
iron overload; haemosiderin; ferritin; immunoelectron microscopy
6.  Hepatic iron deprivation prevents spontaneous development of fulminant hepatitis and liver cancer in Long-Evans Cinnamon rats. 
Journal of Clinical Investigation  1996;98(4):923-929.
Several clinical studies have suggested that excess hepatic iron accumulation is a progressive factor in some liver diseases including chronic viral hepatitis and hemochromatosis. However, it is not known whether iron-induced hepatotoxicity may be directly involved in hepatitis, cirrhosis, and liver cancer. The Long-Evans Cinnamon (LEC) rat, which accumulates excess copper in the liver as in patients with Wilson's disease, is of a mutant strain displaying spontaneous hemolysis, hepatitis, and liver cancer. We found previously that LEC rats harbored an additional abnormality: accumulation of as much iron as copper in the liver. In the present study, we compared the occurrence of hepatitis and liver cancer in LEC rats fed an iron-deficient diet (ID) with those in rats fed a regular diet (RD). The RD group showed rapid increments of hepatic iron concentrations as the result of hemolysis, characteristics of fulminant hepatitis showing apoptosis, and a 53% mortality rate. However, no rats in the ID group died of fulminant hepatitis. Hepatic iron, especially "free" iron concentration and the extent of hepatic fibrosis in the ID group were far less than those of the RD group. At week 65, all rats in the RD group developed liver cancer, whereas none did in the ID group. These results suggest that the accumulation of iron, possibly by virtue of synergistic radical formation with copper, plays an essential role in the development of fulminant hepatitis, hepatic fibrosis, and subsequent hepatocarcinogenesis in LEC rats.
PMCID: PMC507506  PMID: 8770863

Results 1-6 (6)