Baik-Hwan Cho

Over-expression of the ribosomal protein L36a gene is associated with cellular proliferation in hepatocellular carcinoma.

Using messenger RNA (mRNA) differential display, we identified a single complementary DNA (cDNA) fragment (HG23T1) that was over‐expressed in a hepatocellular carcinoma (HCC) specimen. We cloned the full‐length HG23T1 gene by the rapid amplification of cDNA end (RACE) polymerase chain reaction (PCR) method. It perfectly matched the gene encoding human ribosomal protein L36a (RPL36A also referred to as RPL44). RPL36A mRNA was preferentially over‐expressed in 34 of 40 HCC cases (85%, P < .001) and in all of 8 HCC cell lines. Ectopically over‐expressed L36a ribosomal protein localized in the nucleoli of cells, and this localization seemed to be controlled by the N‐terminal or the internal tetrapeptide consensus with its adjacent N‐terminal domain. Over‐expression of L36a led to enhanced colony formation and cell proliferation, which may have resulted from rapid cell cycling, and an antisense cDNA effectively reversed these alterations. In conclusion, RPL36A plays a role in tumor cell proliferation and may be a potential target for anticancer therapy of HCC. (HEPATOLOGY 2004;39:129–138.)

Choledochal Cyst and Associated Malignant Tumors in Adults: A Multicenter Survey in South Korea

OBJECTIVE To determine the clinical features and clinical outcomes of Korean adults treated surgically for choledochal cyst. DESIGN Retrospective nationwide multicenter study. SETTING Fifteen university hospitals (tertiary care referral centers) located in all 7 Korean provinces. PATIENTS A total of 808 patients aged 18 years or older who underwent surgery for choledochal cyst from January 1, 1990, through December 31, 2007. MAIN OUTCOME MEASURES Demographic information, surgical data, associated biliary malignant tumors, and factors predicting malignant tumors. RESULTS Type I was most common (499 [68.2%]) followed by type IVa (208 [28.4%]). Of 654 patients, anomalous pancreaticobiliary ductal union was identified in 467 patients (71.4%), 291 with the choledochal type (62.3%), 96 with the pancreatic type (20.6%), and 80 with the complex type (17.1%). Biliary tract malignant tumor was associated in 80 patients (9.9%); 40 had bile duct cancer (50.0%), 35 had gallbladder cancer (43.8%), 3 had periampullary cancer, and 2 had synchronous gallbladder and bile duct cancer. Twenty-two patients (26.3%) had a recurrence, with a median follow-up duration of 51.8 months. Factors predicting malignant tumor by univariate analysis were age more than 40 years, the absence of a gallstone, elevated carcinoembryonic antigen or cancer antigen 19-9 serum level, and the presence of anomalous pancreaticobiliary ductal union, and by multivariate analysis, an elevated cancer antigen 19-9 level. CONCLUSIONS Associated biliary malignant tumor should always be considered in patients with choledochal cyst, especially in aged patients or patients with anomalous pancreaticobiliary ductal union or an elevated tumor marker level. Lifelong follow-up is needed even after complete cyst excision because of the risk of the development of a metachronous biliary malignant tumor.

Identification of molecular markers for the oncogenic differentiation of hepatocellular carcinoma

The aim of this study was to identify molecular markers associated with oncogenic differentiation in hepatocellular carcinoma (HCC). Using an unsupervised clustering method with a cDNA microarray, HCC (T) gene expression profiles and corresponding non-tumor tissues (NT) from 40 patients were analyzed. Of total 217 genes, 72 were expressed preferentially in HCC tissues. Among 186 differentially regulated genes, there were molecular chaperone and tumor suppressor gene clusters in the Edmondson grades I and II (GI/II) subclass compared with the liver cirrhosis (LC) subclass. The Edmondson grades III and IV (GIII/IV) subclass with a poor survival (P = 0.0133) contained 122 differentially regulated genes with a cluster containing various metastasis- and invasion-related genes compared with the GI/II subclass. Immunohistochemical analysis revealed that ANXA2, one of the 72 genes preferentially expressed in HCC, was over-expressed in the sinusoidal endothelium and in malignant hepatocytes in HCC. The genes identified in the HCC subclasses will be useful molecular markers for the genesis and progression of HCC. In addition, ANXA2 might be a novel marker for tumor angiogenesis in HCC.

Identification of Cystatin B as a Potential Serum Marker in Hepatocellular Carcinoma

Purpose: The poor survival rate of hepatocellular carcinoma (HCC) is in part due to the inability to diagnose patients at an early stage. Therefore, the aim of this study was to search for candidate serum marker for HCC and to test their ability to distinguish a HCC from benign liver disease. Experimental Design: Genome-wide analysis by a microarray in 40 HCC patients was done between HCC and paired nontumor liver tissues. Expression of cystatin B (CSTB) was examined by mRNA expression analysis and immunohistochemistry. The serum CSTB levels were measured using a sandwich ELISA method in four groups, including normal healthy subjects (group 1, n = 52) and patients with noncirrhotic chronic hepatitis (group 2, n = 53), cirrhosis (group 3, n = 43), and HCC (group 4, n = 62). Results: Microarray and statistical analyses identified 248 genes that were expressed differently between HCC and nontumor liver tissues. One of them, CSTB, was expressed preferentially in the HCCs compared with the nontumor tissues, 36 of 45 specimens (80%) by Northern blot and semiquantitative reverse transcription-PCR analyses. The serum CSTB level was much higher in HCC patients than in those with nonmalignant chronic liver disease (groups 2 and 3; P < 0.0001). The receiver operating characteristic curve indicated 5.34 ng/mL to be the optimal value for CSTB, and the sensitivity and specificity for this CSTB value were 85.5% (95% confidence interval, 74.2-93.1%) and 53.1% (95% confidence interval, 42.7-63.4%), respectively, in distinguishing between patients with HCC and those with nonmalignant chronic liver disease. Conclusion: CSTB is specifically overexpressed in most HCCs and is also elevated in the serum of a large proportion of HCC patients. CSTB or the combination of CSTB and α-fetoprotein may be a useful marker for diagnosing patients with HCC with a high sensitivity.

Genome-wide expression patterns associated with oncogenesis and sarcomatous transdifferentation of cholangiocarcinoma

BackgroundThe molecular mechanisms of CC (cholangiocarcinoma) oncogenesis and progression are poorly understood. This study aimed to determine the genome-wide expression of genes related to CC oncogenesis and sarcomatous transdifferentiation.MethodsGenes that were differentially expressed between CC cell lines or tissues and cultured normal biliary epithelial (NBE) cells were identified using DNA microarray technology. Expressions were validated in human CC tissues and cells.ResultsUsing unsupervised hierarchical clustering analysis of the cell line and tissue samples, we identified a set of 342 commonly regulated (>2-fold change) genes. Of these, 53, including tumor-related genes, were upregulated, and 289, including tumor suppressor genes, were downregulated (<0.5 fold change). Expression of SPP1, EFNB2, E2F2, IRX3, PTTG1, PPARγ, KRT17, UCHL1, IGFBP7 and SPARC proteins was immunohistochemically verified in human and hamster CC tissues. Additional unsupervised hierarchical clustering analysis of sarcomatoid CC cells compared to three adenocarcinomatous CC cell lines revealed 292 differentially upregulated genes (>4-fold change), and 267 differentially downregulated genes (<0.25 fold change). The expression of 12 proteins was validated in the CC cell lines by immunoblot analysis and immunohistochemical staining. Of the proteins analyzed, we found upregulation of the expression of the epithelial-mesenchymal transition (EMT)-related proteins VIM and TWIST1, and restoration of the methylation-silenced proteins LDHB, BNIP3, UCHL1, and NPTX2 during sarcomatoid transdifferentiation of CC.ConclusionThe deregulation of oncogenes, tumor suppressor genes, and methylation-related genes may be useful in identifying molecular targets for CC diagnosis and prognosis.

Glutamine Protects Mice from Lethal Endotoxic Shock via a Rapid Induction of MAPK Phosphatase-1

The nonessential amino acid l-glutamine (Gln) is the most abundant amino acid in plasma. Clinical trials have demonstrated that Gln therapy is safe and improves clinical outcomes in critically ill patients. We have previously shown that Gln protect animals from endotoxic shock through the inhibition of cytosolic phospholipase A2 activity. In this study, we investigated how Gln regulates MAPK activation, as the molecular mechanism underlying Gln-induced cytosolic phospholipase A2 inactivation. Gln rapidly (within 10 min) inactivated p38 and JNK, but not ERK, by dephosphorylating them only when these MAPKs were phosphorylated in response to LPS in vivo as well as in vitro. Western blot analysis revealed that Gln administration resulted in rapid (∼5 min) phosphorylation and protein induction of MAP kinase phosphatase-1 (MKP-1). MKP-1 siRNA abrogated the Gln-mediated 1) inactivation of p38 and JNK, 2) induction of MKP-1, and 3) protection against endotoxic shock. The ERK inhibitor U0126 blocked Gln-induced MKP-1 phosphorylation and protein induction, as well as Gln’s protective activity against endotoxic shock. These data suggest that Gln exerts a beneficial effect on endotoxic shock by inactivating p38 and JNK via a rapid induction of MKP-1 protein in an ERK-dependent way.

Glutamine inhibits lipopolysaccharide-induced cytoplasmic phospholipase A2 activation and protects against endotoxin shock in mouse

ABSTRACT Glutamine (Gln) supplementation is known to play a beneficial role in a number of settings of critical illness as well as laboratory models of endotoxin shock. We have investigated a molecular mechanism of the protective role of Gln in lipopolysaccharide (LPS)-induced shock using a mouse model. To examine the effectiveness of Gln, Gln was administered before or after LPS injection. Treatment of Gln before, but not after, LPS injection resulted in inhibition of nuclear factor &kgr;B activation and tumor necrosis factor &agr; synthesis. In contrast, protection of animal from LPS-mediated death by Gln was observed when the Gln treatment was performed after LPS injection, suggesting that nuclear factor &kgr;B/tumor necrosis factor &agr; signaling does not play an important role in this process. LPS injection induced phosphorylation of cytoplasmic phospholipase A2 (cPLA2), which was blocked by Gln treatment after LPS injection. Similarly, the LPS-stimulated cPLA2 activity was also inhibited by Gln treatment after LPS injection. Moreover, a cPLA2 inhibitor not only inhibited LPS-induced activation of cPLA2, but also significantly prevented LPS-mediated death. These observations indicate that Gln has a capability to inhibit cPLA2 phosphorylation and activation and suggest that Gln might be of a great therapeutic value for controlling inflammatory diseases in which cPLA2 plays an important role in the pathogenesis of the diseases.ABBREVIATIONS-Gln, glutamine; cPLA2, cytoplasmic phospholipase A2; MAPK, mitogen-activated protein kinase; NF-&kgr;B, nuclear factor &kgr;B; TFMK, arachidonyltrifluoromethyl ketone; p65 AS, antisense against p65 components of NF-&kgr;B; p65 NS, p65 nonsense against p65 components of NF-&kgr;B; TNF-&agr;, tumor necrosis factor &agr;; LPS, lipopolysaccharide; PMSF, phenylmethylsulfonyl fluoride

Glutamine preferentially inhibits T-helper type 2 cell-mediated airway inflammation and late airway hyperresponsiveness through the inhibition of cytosolic phospholipase A2 activity in a murine asthma model

Background The non‐essential amino acid, l‐glutamine (Gln), is abundant in the human body. Gln exhibits beneficial effects on endotoxic shock through the inhibition of cytosolic phospholipase A2 (cPLA2) activity. cPLA2 has been reported to be implicated in the pathogenesis of asthma, but the effects of Gln on asthma have not yet been defined.

Clinical Outcomes of Multicenter Domino Kidney Paired Donation

Domino kidney paired donation (KPD) is a method by which an altruistic living nondirected donor (LND) is allocated to a pool of incompatible donor–recipient pairs (DRP) and a series of KPDs is initiated. To evaluate the feasibility and clinical outcomes of multicenter domino KPD, we retrospectively analyzed a cohort of DRPs who underwent domino KPD between February 2001 and July 2007 at one of 16 transplant centers. One hundred seventy‐nine kidney transplants were performed, with 70 domino chains initiated by altruistic LND. There were 45 two‐pair chains, 15 three‐pair chains, 7 four‐pair chains, 2 five‐pair chains and 1 six‐pair chain. A majority of donors were spouses (47.5%) or altruistic LNDs (39.1%). DRPs with a blood type O recipient or an AB donor comprised 45.9% of transplanted DRPs. HLA mismatch improved in transplanted donors compared to intended donors in pairs enrolled to improve HLA mismatch (3.4 ± 0.7 vs. 4.8 ± 1.0, p < 0.001). One‐year and 5‐year graft survival rates were 98.3% and 87.7%, respectively, with a median follow‐up of 46 months. One‐year and 5‐year patient survival rates were 97.2% and 90.8%, respectively. In conclusion, multicenter domino KPD could multiply the benefits of donation from LNDs, with patients and graft survival rates comparable to those seen with conventional KPD.

Glutamine suppresses DNFB-induced contact dermatitis by deactivating p38 mitogen-activated protein kinase via induction of MAPK phosphatase-1.

L-glutamine (Gln) is a nonessential amino acid that is the most abundant amino acid in plasma. Gln has been reported to have an anti-inflammatory activity that involves deactivation of mitogen-activated protein kinases (MAPKs) in a MAPK phosphatase (MKP)-1-dependent manner. This study investigated the role of Gln in the inhibition of DNFB-induced allergic contact dermatitis (CD) in the ears of mice, and specifically the involvement of Gln in p38 MAPK inhibition. Topical application of Gln or the p38 inhibitor, SB202190, suppressed DNFB-induced CD. Gln application inhibited DNFB-induced p38 phosphorylation. Western blot analysis revealed that Gln application resulted in early phosphorylation and protein induction of MKP-1. MKP-1 small interfering RNA (siRNA), but not control siRNA, abrogated Gln-mediated early phosphorylation, protein induction of MKP-1, deactivation of p38, and Gln-mediated suppression of CD. The extracellular signal-regulated kinase (ERK) inhibitor, U0126, blocked Gln-induced MKP-1 phosphorylation and protein induction, as well as Gln suppression of CD. These results suggest that Gln suppresses DNFB-induced CD via deactivation of p38 MAPK through the early induction of MKP-1, the negative regulator of p38, in an ERK-dependent manner.