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A 69-year-old Japanese female was diagnosed with primary intestinal follicular lymphoma. Esophagogastroduodenoscopy with high-definition imaging revealed not only the typical feature of whitish polyps of up to 2 mm in diameter in the duodenal second and third portions, but also more detailed morphology, such as enlarged whitish villi and tiny whitish depositions. These findings appeared to reflect the pathological structures; infiltration of lymphoma cells into the villi were probably seen as enlargement of the villi, and the formation of lymphoid follicles were shown as opaque white spots or tiny white depositions. Thus, the above features might contribute to the distinct diagnosis of intestinal follicular lymphoma. This case indicates that routine esophagogastroduodenoscopy can visualize microsurface structures, which can be pathognomonic and help to diagnose intestinal follicular lymphoma, even without magnifying endoscopy.

Precursor B lymphoblastic lymphoma is a high-grade neoplasm arising from precursor lymphocytes of B-cell lineage. Extranodal sites such as the skin and bone are often involved, but gastrointestinal lesions of this disease are rarely encountered. Due to the infrequency, macroscopic forms of the gastrointestinal lesions have not been fully described. In this report, we present a case of precursor B lymphoblastic lymphoma involving the stomach, pancreas, bone, and bone marrow. Esophagogastroduodenoscopy showed multiple flat elevated lesions with irregular mucosa in the stomach.

A 73-year-old Japanese man with synchronous follicular lymphoma and adenocarcinoma of the stomach underwent curative surgical resection. The follicular lymphoma lesion was preoperatively diagnosed as extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) according to biopsy samples. However, postoperative pathological evaluations revealed components of CD10-positive and CD10-negative lymphoma cells within the lymphoma lesion. This case highlights the potential difficulty of diagnosing gastric follicular lymphoma. In such cases, conducting repeat pathological examinations of biopsy samples or resected specimens is required to obtain a correct diagnosis of follicular lymphoma.

Background: Bioartificial liver systems, designed to support patients with liver failure, are composed of bioreactors and functional hepatocytes. Immunological rejection of the embedded hepatocytes by the host immune system is a serious concern that crucially degrades the performance of the device. Induced pluripotent stem (iPS) cells are considered a desirable source for bioartificial liver systems, because patient-derived iPS cells are free from immunological rejection. The purpose of this paper was to test the feasibility of a bioartificial liver system with iPS cell-derived hepatocyte-like cells., Methods: Mouse iPS cells were differentiated into hepatocyte-like cells by a multi-step differentiation protocol via embryoid bodies and definitive endoderm. Differentiation of iPS cells was evaluated by morphology, PCR assay, and functional assays. iPS cell-derived hepatocyte-like cells were cultured in a bioreactor module with a pore size of 0.2 μm for 7 days. The amount of albumin secreted into the circulating medium was analyzed by ELISA. Additionally, after a 7-day culture in a bioreactor module, cells were observed by a scanning electron microscope., Results: At the final stage of the differentiation program, iPS cells changed their morphology to a polygonal shape with two nucleoli and enriched cytoplasmic granules. Transmission electron microscope analysis revealed their polygonal shape, glycogen deposition in the cytoplasm, microvilli on their surfaces, and a duct-like arrangement. PCR analysis showed increased expression of albumin mRNA over the course of the differentiation program. Albumin and urea production was also observed. iPS-Heps culture in bioreactor modules showed the accumulation of albumin in the medium for up to 7 days. Scanning electron microscopy revealed the attachment of cell clusters to the hollow fibers of the module. These results indicated that iPS cells were differentiated into hepatocyte-like cells after culture for 7 days in a bioreactor module with a pore size of 0.2 μm., Conclusion: We consider the combination of a bioreactor module with a 0.2-μm pore membrane and embedded hepatocytes differentiated from iPS cells to be a promising option for bioartificial liver systems. This paper provides the basic concept and preliminary data for an iPS cell-oriented bioartificial liver system.PACS code: 87. Biological and medical physics, 87.85.-d Biomedical engineering, 87.85.Lf Tissue engineering, 87.85.Tu Modeling biomedical systems.

Loss or decreased expression of runt-related transcription factor 3 (RUNX3), a tumor suppressor gene involved in gastric and other cancers, has been frequently observed in hepatocellular carcinoma (HCC). The objective of this study was to identify the regulatory mechanism of the epithelial-mesenchymal transition (EMT) by RUNX3 in HCC. Human HCC cell lines, Hep3B, Huh7, HLF and SK-Hep1, were divided into low- and high-EMT lines, based on their expression of TWIST1 and SNAI2, and were used in this in vitro study. Ectopic RUNX3 expression had an anti-EMT effect in low-EMT HCC cell lines characterized by increased E-cadherin expression and decreased N-cadherin and vimentin expression. RUNX3 expression has previously been reported to reduce jagged-1 (JAG1) expression; therefore, JAG1 ligand peptide was used to reinduce EMT in RUNX3-expressing low-EMT HCC cells. Immunohistochemical analyses were performed for RUNX3, E-cadherin, N-cadherin and TWIST1 in 33 human HCC tissues, also divided into low- and high-EMT HCC, based on TWIST1 expression. E-cadherin expression was correlated positively and N-cadherin expression was correlated negatively with RUNX3 expression in low-EMT HCC tissues. Correlations between EMT markers and RUNX3 mRNA expression were analyzed using Oncomine datasets. Similarly, mRNA expression of E-cadherin was also significantly correlated with that of RUNX3 in low-EMT HCC, while mRNA expression of JAG1 was negatively correlated with that of RUNX3. These results suggest a novel mechanism by which loss or decreased expression of RUNX3 induces EMT via induction of JAG1 expression in low-EMT HCC., (Copyright © 2012 UICC.)

Aim: To investigate the capacity for 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) to evaluate patients with gastrointestinal lesions of follicular lymphoma., Methods: This retrospective case series consisted of 41 patients with follicular lymphoma and gastrointestinal involvement who underwent 18F-FDG-PET and endoscopic evaluations at ten different institutions between November 1996 and October 2011. Data for endoscopic, radiological, and biological examinations performed were retrospectively reviewed from clinical records. A semi-quantitative analysis of 18F-FDG uptake was performed for each involved area by calculating the maximum standardized uptake value (SUVmax). Based on the positivity of 18F-FDG uptake in the gastrointestinal lesions analyzed, patients were subdivided into two groups. To identify potential predictive factors for 18F-FDG positivity, these two groups were compared with respect to gender, age at diagnosis of lymphoma, histopathological grade, pattern of follicular dendritic cells, mitotic rate, clinical stage, soluble interleukin-2 receptor levels detected by 18F-FDG-PET, lactate dehydrogenase (LDH) levels, hemoglobin levels, bone marrow involvement, detectability of gastrointestinal lesions by computed tomography (CT) scanning, and follicular lymphoma international prognostic index (FLIPI) risk., Results: Involvement of follicular lymphoma in the stomach, duodenum, jejunum, ileum, cecum, colon, and rectum was identified in 1, 34, 6, 3, 2, 3, and 6 patients, respectively. No patient had esophageal involvement. In total, 19/41 (46.3%) patients exhibited true-positive 18F-FDG uptake in the lesions present in their gastrointestinal tract. In contrast, false-negative 18F-FDG uptake was detected in 24 patients (58.5%), while false-positive 18F-FDG uptake was detected in 5 patients (12.2%). In the former case, 2/19 patients had both 18F-FDG-positive lesions and 18F-FDG-negative lesions in the gastrointestinal tract. In patients with 18F-FDG avidity, the SUVmax value of the involved gastrointestinal tract ranged from 2.6 to 17.4 (median: 4.7). For the 18F-FDG-negative (n = 22) and -positive (n = 19) groups, there were no differences in the male to female ratios (10/12 vs 4/15, P = 0.186), patient age (63.6 ± 2.4 years vs 60.1 ± 2.6 years, P = 0.323), presence of histopathological grade 1 vs 2 (20/2 and 17/2, P = 1.000), follicular dendritic cell pattern (duodenal/nodal: 13/5 vs 10/3, P = 1.000), mitotic rate (low/partly high, 14/1 vs 10/3, P = 0.311), clinical stage according to the Ann Arbor system (stages IE and IIE/other, 15/7 vs 15/4, P = 0.499), clinical stage according to the Lugano system (stages I and II-1/other, 14/8 vs 14/5, P = 0.489), soluble interleukin-2 receptor levels (495 ± 78 vs 402 ± 83, P = 0.884), LDH levels (188 ± 7 vs 183 ± 8, P = 0.749), hemoglobin levels (13.5 ± 0.3 vs 12.8 ± 0.4, P = 0.197), bone marrow involvement (positive/negative, 1/8 vs 1/10, P = 1.000), detectability by CT scanning (positive/negative, 1/16 vs 4/13, P = 0.335), and FLIPI risk (low risk/other, 16/6 vs 13/6, P = 0.763), respectively in each case., Conclusion: These findings indicate that it is not feasible to predict 18F-FDG-avidity. Therefore, 18F-FDG-PET scans represent a complementary modality for the detection of gastrointestinal involvements in follicular lymphoma patients, and surveillance of the entire gastrointestinal tract by endoscopic examinations is required.

Background and Aim: Hepatocellular carcinoma (HCC) is a hypervascular tumor, and angiogenesis plays an important role in its development. Previously, we demonstrated that des-γ-carboxyl prothrombin (DCP) promotes both cell proliferation and migration of human umbilical vein endothelial cells (HUVECs) by inducing the autophosphorylation of kinase insert domain receptor (KDR). In the present study, DCP-associated tumor angiogenesis was assessed by comparing hypovascular and common hypervascular HCC., Methods: The solitary HCCs of 827 patients were classified into two groups according to the tumor density at the arterial phase of a dynamic computed tomography scan; the initial clinical data of patients with the hyper- and hypovascular types were compared. The HCC tissues from 95 tumors were analyzed by immunohistochemical staining for DCP and phosphorylated KDR, and intratumoral microvessel density (MVD) was analyzed to evaluate microvessel angiogenesis., Results: The serum DCP levels (320 ± 3532 mAU/mL) and tumor size (18.4 ± 9.0 mm) of patients with hypervascular HCC were significantly greater than those with hypovascular HCC (38.7 ± 80 mAU/mL and 14.6 ± 5.2 mm, P < 0.001). Immunohistochemical analysis revealed that the expressions of DCP and phospho-KDR were significantly greater in hypervascular HCC (71.4% and 31.0%, respectively) than in hypovascular HCC (7.6% and 5.7%, respectively). Intratumoral MVD was significantly correlated with DCP (r = 0.48, P < 0.0001)., Conclusions: des-γ-carboxyl prothrombin production is associated with tumor angiogenesis in HCC., (© 2012 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.)

Aims: Increased β-oxidation of branched-chain fatty acids provides an additional metabolic advantage for cancer cells thereby enhancing tumour development and progression. Alpha-methylacyl coenzyme A racemase (AMACR) is an enzyme essential for the catabolism of branched-chain fatty acids that allows their subsequent β-oxidation and thus plays an important role in generating biological energy. However, the expression of AMACR has never been systemically investigated in gallbladder carcinoma. This study evaluated the expression status, associations with clinicopathological variables and prognostic implications of AMACR in a well-defined cohort of gallbladder carcinoma and confirmed their expression status in gallbladder carcinoma cells., Methods: AMACR immunostaining was assessable in 89 cases on tissue microarrays of gallbladder carcinoma, and it was correlated with clinicopathological factors and patient survival. In three gallbladder carcinoma cell lines and one non-tumorigenic cholangiocyte, AMACR mRNA expression was measured by real-time reverse transcription PCR and the endogenous expression of AMACR protein was analysed by western blotting., Results: AMACR overexpression was significantly associated with an advanced primary tumour status (p=0.027) and American Joint Committee on Cancer stage (p=0.027), an increased histological grade (p=0.002) and vascular invasion (p=0.017). Importantly, AMACR overexpression independently predicted worse disease-specific survival (p=0.0452, RR 1.887). Expression levels of AMACR mRNA and total protein in various cells were comparable. The abundance of AMACR expression increased in tumour cells and was even higher in the metastatic cell line., Conclusions: In primary gallbladder carcinoma, AMACR overexpression was correlated with important prognosticators and independently portended worse outcomes, highlighting the potential prognostic and therapeutic utility of AMACR in gallbladder carcinoma.

Background/aims: Von Hippel-Lindau disease is an autosomal dominant genetic disorder characterized by neoplasms developing in multiple organs. Although the pancreas is one of the most frequently involved organs, the frequency of pancreatic cysts, cystadenomas, neuroendocrine tumors and diabetes has not been sufficiently evaluated due to the low prevalence of this disease. In this paper, we review and retrospectively analyze 11 patients with von Hippel-Lindau disease., Methodology: Eleven patients (6 males, 5 females) who underwent CT or MRI scans at Okayama University Hospital between 2002 and 2009 were enrolled in this study. Their pancreatic CT scans, MRI scans, biochemical test results and clinical histories were retrospectively reviewed., Results: All patients had one or more pancreatic involvements. Nine of the 11 patients had multiple pancreatic cysts, 2 had dilatation of the main pancreatic duct, 3 had a non-functioning pancreatic endocrine tumor (one patient required pancreatoduodenectomy due to the endocrine carcinoma) and 3 had diabetes mellitus. Pancreatic cystadenomas were not detected in this case series., Conclusions: The prevalence of pancreatic involvement was 100% in this study. Regular screening and scheduled follow-up for pancreatic lesions and diabetes should be performed on individuals predisposed to von Hippel-Lindau disease.

A 52-year-old Japanese woman was diagnosed with primary follicular lymphoma of the duodenum that was curatively resected by pancreatoduodenectomy. She remained in complete remission until 11 years after the surgery, when multiple enlarged intra-abdominal lymph nodes were demonstrated by computed tomography scans and positron emission tomography scans. Two years later, jejunal lesions were detected by endoscopy, and biopsy samples confirmed a recurrence of follicular lymphoma. This case indicates that primary gastrointestinal follicular lymphoma has a potential of relapse after an extended period of time, and thus patients must be followed up for over 10 years after complete remission.

Runt-related transcription factor 3 (RUNX3) is a candidate tumor suppressor gene that is downregulated in various cancers. In the present study, we analyzed the regulatory function of RUNX3 on Jagged-1 (JAG1) expression and cancer stem cell (CSC) signaling in hepatocellular carcinoma (HCC). Eleven HCC cell lines and 30 human HCC tissues were used. RUNX3 and JAG1 expression levels were analyzed by immunoblotting and immunohistochemistry. Ectopic RUNX3 expression was induced by introducing RUNX3 cDNA into the RUNX3-negative HCC cell line Hep3B and Huh7 cells. Furthermore endogenous RUNX3 expression was knocked down by RUNX3 siRNA in SK-Hep-1 cells. In order to analyze JAG1 transcriptional regulation, we conducted reporter assays, chromatin immunoprecipitation (ChIP) assays and electrophoretic mobility shift assays (EMSAs). Tumorigenicity was analyzed using a SCID mouse liver injection model. An inverse correlation was observed between RUNX3 expression and JAG1 expression in most HCC cell lines and tissues. Restoring RUNX3 expression decreased the expression of JAG1 in Hep3B and Huh7 cells, whereas JAG1 expression was upregulated in RUNX3 siRNA-treated SK-Hep-1 cells. Reporter assays, ChIP assays and EMSAs revealed that RUNX3 directly bound to the transcriptional regulatory region of JAG1 and suppressed JAG1 transcription. Moreover, RUNX3 restoration downregulated CSCs by suppressing JAG1-mediated Notch signaling. The tumorigenic capacity of RUNX3-expressing Hep3B cells was lower compared to that of control Hep3B cells. RUNX3 expression suppressed JAG1 expression and resulted in downregulation of tumorigenesis by suppression of JAG1-mediated CSCs.

Hemorrhage from a non-Meckelian jejunoileal diverticulum is rare, and it is generally difficult to diagnose the source of the bleeding. Here, we report the case of a 59-year-old male with hemorrhage from an ileal diverticulum. Contrast computed tomography scans demonstrated the ileal diverticulum and extravasation of the contrast medium around it. The diagnosis was then made by computed tomography scans, and endoscopic mechanical hemostasis was performed under colonoscopy with three metal clips. The management of hemorrhage from jejunoileal diverticula is discussed.

Induced pluripotent stem (iPS) cells, first established in 2006, have the same characteristics of self-renew-ability and pluripotency as embryonic stem (ES) cells. iPS cells are inducible from patient-specific somatic cells; therefore, they hold significant advantages for overcoming immunological rejection as well as the ethical issues associated with the derivation of ES cells from embryos. Generation of patient-derived hepatocytes by iPS technology and their use in cell transplantation therapy for patients with liver disease is quite attractive. Here, we discuss recent advances and challenges in hepatocyte differentiation from iPS cells and their utility in cell therapy.

Background: Runt-related transcription factor 3 (RUNX3) is known as a tumor suppressor gene for gastric cancer and other cancers, this gene may be involved in the development of hepatocellular carcinoma (HCC)., Methods: RUNX3 expression was analyzed by immunoblot and immunohistochemistry in HCC cells and tissues, respectively. Hep3B cells, lacking endogenous RUNX3, were introduced with RUNX3 constructs. Cell proliferation was measured using the MTT assay and apoptosis was evaluated using DAPI staining. Apoptosis signaling was assessed by immunoblot analysis., Results: RUNX3 protein expression was frequently inactivated in the HCC cell lines (91%) and tissues (90%). RUNX3 expression inhibited 90±8% of cell growth at 72 h in serum starved Hep3B cells. Forty-eight hour serum starvation-induced apoptosis and the percentage of apoptotic cells reached 31±4% and 4±1% in RUNX3-expressing Hep3B and control cells, respectively. Apoptotic activity was increased by Bim expression and caspase-3 and caspase-9 activation., Conclusion: RUNX3 expression enhanced serum starvation-induced apoptosis in HCC cell lines. RUNX3 is deleted or weakly expressed in HCC, which leads to tumorigenesis by escaping apoptosis.

Aim: To evaluate the endoscopic manifestations and prognoses of gastrointestinal (GI) mantle cell lymphoma (MCL)., Methods: A database search at the Department of Pathology of Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences revealed 57 MCL patients with GI involvement. Clinical records were available for 35 of the 57 patients from 21 institutions, and those 35 patients were enrolled in this study. We summarized the gross types of endoscopic features, event-free survival (EFS), and overall survival (OS) of those patients., Results: Of the 35 patients, GI involvement in the esophagus, stomach, and duodenum was found in 2 (5.7%), 26 (74.3%), and 12 (34.3%) patients, respectively. Twenty-one of the 35 patients underwent colonoscopy; among them, GI involvement in the ileum, cecum, colon, and rectum was found in 10 (47.6%), 3 (14.3%), 12 (57.1%), and 10 (47.6%), respectively. Various lesions, such as superficial, protruded, fold thickening, or ulcerative, were found in the stomach, whereas multiple lymphomatous polyposis (MLP) was dominant from the duodenum to the rectum. Twelve patients were treated with a hyper-CVAD/MA regimen, and they had better OS (3-year rate, 88.3% vs 46.4%, P < 0.01) and better EFS (3-year rate, 66.7% vs 33.8%, P < 0.05) than the remaining 23 patients who were not treated with this regimen., Conclusion: MLP was a representative form of intestinal involvement, whereas a variety of lesions were found in the stomach. The hyper-CVAD/MA regimen may improve survival in these patients.

Patients with malignant pancreatobiliary neoplasm sometimes manifest duodenal obstruction and biliary stricture synchronously or metachronously. In this paper, we reviewed our experience with and technique for combined endoscopic duodenal stent placement and endoscopic ultrasonography (EUS)-guided biliary drainage. Between May 2007 and September 2009, this combined technique was performed on seven patients with distal biliary strictures and duodenal obstructions. The clinical success rate of the procedure, complications, patency periods of duodenal stents and patency periods of biliary stents were retrospectively evaluated. Clinical success was achieved in all seven cases for both procedures. Complications related to EUS-biliary drainage, namely localized peritonitis due to bile leakage, occurred in two cases. Both patients recovered without additional interventions. Occlusion of a duodenal stent was observed in one patient, but additional intervention could not be performed due to sepsis. Occlusion of both a duodenal stent and a biliary stent was also observed in one patient, and this was resolved with the insertion of an additional duodenal stent and a biliary stent exchange. In conclusion, combined duodenal stent placement and EUS-guided biliary drainage is a therapeutic option in case of failed endoscopic retrograde cannulation of malignant strictures with a malignant duodenal obstruction.

Background & Aims: Transplantation of isolated hepatocytes holds great promise as an alternative to whole organ liver transplantation. For treatment of liver failure, access to the portal circulation has significant risks and intrahepatic hepatocyte engraftment is poor. In advanced cirrhosis, transplantation into an extrahepatic site is necessary and intrasplenic engraftment is short-lived. Strategies that allow repeated extrahepatic infusion of hepatocytes could improve the efficacy and safety of hepatocyte transplantation for the treatment of liver failure., Methods: A non-immunogenic self-assembling peptide nanofiber (SAPNF) was developed as a three-dimensional scaffold and combined with growth factors derived from a conditionally immortalized human hepatocyte cell line to engineer a hepatic tissue graft that would allow hepatocyte engraftment outside the liver., Results: The hepatic tissue constructs maintained hepatocyte-specific gene expression and functionality in vitro. When transplanted into skeletal muscle as an extrahepatic site for engraftment, the engineered hepatic grafts provided life-saving support in models of acute, fulminant, and chronic liver failure that recapitulates these clinical diseases., Conclusions: SAPNF-engineered hepatic constructs engrafted and functioned as hepatic tissues within the muscle to provide life-sustaining liver support. These engineered tissue constructs contained no animal products that would limit their development as a therapeutic approach.

Liver diseases still have a high mortality even though liver transplantation has become a standard treatment. Currently, hepatocyte transplantation has been proposed as another promising strategy. One limitation is the availability of human livers as a source of hepatocytes. Because of an unlimited supply, the use of porcine hepatocytes might address this problem. Regardless of the source, once isolated hepatocytes lose specific functionality due to the loss of the natural microenvironment. For this reason, we tested the ability of a self-assembling peptide nanofiber (SAPNF) to provide a provisional three-dimensional (3D) support to interact with cells to control their function in vivo. Isolated porcine hepatocytes were embedded in SAPNF, or collagen type I and transplanted by direct injection into the splenic pulp of SCID mice suffering from acute liver failure (ALF) by 90% hepatectomy. SAPNF porcine hepatocyte transplantation produced engraftment that was far superior to that obtained using collagen and prolonged the survival of mice with ALF, in contrast with controls. An ultrastructural evaluation using transmission electron microscopy indicated extensive cell-cell communication and preservation of hepatocyte architecture. The transplanted SAPNF hepatocytes showed higher expression of albumin and PAS and lower apoptotic events assessed by TUNEL staining. Hepatocytes culture in a truly 3D network allows in vivo maintaining of differentiated functions, and once transplanted between widely divergent species can function to correct acute liver failure in mice and prolong their survival.

Induced pluripotent stem (iPS) cells are pluripotent and are able to unlimitedly proliferate in vitro. This technical breakthrough in creating iPS cells from somatic cells has noteworthy implications for overcoming the immunological rejection and the ethical issues associated with the derivation of embryonic stem cells from embryos. In the current work, we present an efficient hepatic differentiation of mouse iPS cells in vitro. iPS cells were cultured free floating to induce the formation of embryoid bodies (EB) for 5 days. EB were transferred to a gelatin-coated plate and treated with 100 ng/ml activin A and 100 ng/ml basic fibroblast growth factor (bFGF) for 3 days to induce definitive endoderm. Cells were further cultured for 8 days with 100 ng/ml hepatocyte growth factor (HGF) to generate hepatocytes. Characterization was performed by RT-PCR assay. Functional analysis for albumin secretion and ammonia removal was also carried out. iPS cell-derived hepatocyte-like cells (iPS-Heps) were obtained at the end of the differentiation program. Expression levels of a gestational hepatocyte gene and lineage-specific hepatic genes intensified in iPS-Heps. The production of albumin increased in a time-dependent manner. iPS-Heps were capable of metabolizing ammonia. We present here instant hepatic differentiation of mouse iPS cells using combined 3-day treatments of activin A and bFGF with subsequent 8-day HGF. Our study will be an important step to generate hepatocytes from human iPS cells as a new source for liver-targeted cell therapies.

Maintenance of freshly isolated porcine liver cells in vitro is limited for a short period of time. Therefore, establishment of easy handling cell lines is extremely important for in vitro study for liver cells and their possible utilization for cell differentiation and growth of stem cells. Porcine liver cells were transduced with a retroviral vector SSR#69 expressing SV40T, one of SSR#69-immortalized porcine liver cell lines, JSNK-1, was established and characterized. Morphology of JSNK-1 cells was spindle shaped. When the cells became confluent, JSNK-1 cells revealed hills-and-valleys pattern. In the presence of vitamin A, JSNK-1 cells showed big droplets inside the cytoplasm, which were positive with PAS staining. JSNK-1 cells showed the gene expression of collagen type 1α1, collagen type 1α2, FLT-1, β-actin, and SV40T. Immunostaining study revealed that JSNK-1 cells produced collagen, vimentin, and α-smooth muscle actin. JSNK-1 cells possessed the characteristics of the liver stellate cells. JSNK-1 cells produced hepatocyte growth factor (HGF) in a time-dependent manner. When cocultured with iPS cells towards the hepatic differentiation, JSNK-1 cells facilitated their hepatic differentiation in terms of albumin production. In conclusion, JSNK-1 cells would be valuable in the study of liver stellate cell pathophysiology and contribute to the optimization of hepatic differentiation of iPS cells.

Worldwide, colorectal cancer is the third most common type of cancer affecting both sexes. It has been proposed that a small subset of cancer cells (cancer stem cells) within each tumor is able to initiate tumor growth. In 2007, two research groups simultaneously identified a colon cancer stem cell population in human tumors by the use of CD133 expression. In the present study, we used a human colon cancer cell line, SW620, to analyze the cancer stem cell-like characteristics of CD133(+) cells in vitro and in vivo. In vitro, CD133(+) SW620 cells had a higher proliferative capacity, were more irradiation- and chemotherapy-resistant, and had a higher expression of β-catenin compared with CD133(-) cells. Injections of either CD133(+) or CD133(-) cells into the skin or rectal mucosa of NOD/SCID mice led to tumors; however, injection of CD133(+) cells resulted in the formation of larger tumors. Tumors derived from injections of CD133(-) cells did not contain any CD133(+) cells, whereas tumors derived from injections of CD133(+) cells did contain CD133(+) cells, suggesting self-renewing capability. However, the proportion of CD133(+) cells in the newly formed tumors in vivo was lower than the proportion of CD133(+) cells in vitro. In conclusion, the human colon cancer cell line, SW620, contains both CD133(+) and CD133(-) phenotypes, and the CD133(+) phenotype has characteristics consistent with those of cancer stem cells.

Definitive endoderm (DE) derived from stem cells holds potential to differentiate into hepatocytes. Stem cell therapy using those cells has potential for a treatment of liver disease. To date, various ways of inducing hepatocytes from embryonic stem (ES) cells have been reported by researchers. However, it has not been proved enough that induced pluripotent stem (iPS) cells behave in the same manner as ES cells in endoderm differentiation. The purpose of this study was to establish an efficient method to induce DE from iPS cells, through comparatively analyzing the efficacy of endoderm formation from mouse ES cells. Furthermore, the efficiency of a serum-free medium in the differentiation into DE was investigated. Mouse ES cells and iPS cells were floated in culture medium for 2 or 5 days and embryoid bodies (EB) were formed. Subsequently, DE was induced with 100 ng/ml activin A and 100 ng/ml basic fibroblast growth factor (bFGF). RT-PCR and real-time PCR analyses were carried out at each step to determine the gene expression of EB markers. The difference in cellular proliferation between serum-containing and serum-free media was examined by an MTS assay in EB and DE induction. iPS cells showed the paralleled mRNA expression to ES cells in each step of differentiation into EB, but the levels of expression of Sox17 and Foxa2 were relatively higher in ES cell-derived DE, whereas Cxcr4 expression was higher in iPS cell-derived DE. The utilization of serum-free medium for iPS cells showed significantly favorable cellular proliferation during EB formation and subsequent DE induction. Forming EB for 5 days and subsequently DE induction with activin A and bFGF with serum-free medium was an appropriate protocol in iPS cells. This may represent an important step for generating hepatocytes from iPS cells for the development of cell therapy.

We report 2 cases of small cell carcinoma (SmCC) of the stomach with distant metastasis that were treated with the same chemotherapeutic regimens as used to treat small cell lung cancer. Although the mean survival of patients with SmCC of the stomach is reported to be only 7 months, our patients survived for 15 and 14 months, respectively. In our experience, these chemotherapeutic regimens might provide a survival benefit for patients with SmCC of the stomach, although they demonstrated no remarkable antitumor effects.

Cholangiolocellular carcinoma (CLC) is a rare malignant primary liver tumor, categorized as a subtype of cholangiocellular carcinoma. CLC is considered to originate from hepatic progenitor cells, and sometimes accompanies a component of cholangiocellular carcinoma and/or hepatocellular carcinoma (HCC). We report herein a case of a 53-year-old Japanese male with CLC occurring asynchronously after a resection of HCC. At the age of 50, the patient underwent a first hepatectomy due to HCC, followed by intrahepatic recurrence. At 53, a new type of hepatic tumor was detected. Dynamic computed tomography revealed a multinodular enhanced tumor in the hepatic arterial phase, and an iso-density tumor in the portal venous and delayed phases. Living donor liver transplantation was performed for the treatment of this liver tumor because of his poor liver function. Histological findings confirmed the diagnosis of CLC. Nineteen months after the liver transplantation, bone metastasis of CLC was detected. Although the preoperative diagnosis of CLC is difficult in general, CLC should be considered as a differential diagnosis when a tumor with atypical image findings for HCC is observed after the resection of HCC. Once the diagnosis of CLC is made, postoperative surveillance of the patient must be performed, including the bone.

Nine cases of mantle cell lymphoma with gastrointestinal involvement were retrospectively reviewed, and their clinical features, including the involved organs, macroscopic forms, treatment methods, and prognoses were evaluated. The involved organs in the gastrointestinal tract were the stomach in 5 cases, the duodenum in 4, the ileum in 5, the cecum in 1, the colon in 4, and the rectum in 2. The macroscopic form of the gastric involvement varied, and included the protruding type in 3 cases, the ulcerated type in one, and the superficial type in one. On the other hand, the macroscopic form of the intestinal involvement from the duodenum to the rectum was mostly of the multiple lymphomatous polyposis type, which was observed in 6 cases. A hyper CVAD/MA regimen and high-dose chemotherapy with autologous peripheral blood stem cell transplantation was performed in 5 cases. All of these 5 cases continue to show a complete response.

Intracranial hemangiopericytoma is an uncommon soft tissue sarcoma. We report a case of a 54-year-old Japanese female with hepatic metastasis from primary intracranial hemangiopericytoma. At age 44 years the patient underwent primary resection of the intracranial tumor, followed by no adjuvant therapy. At age 53 years she underwent resection of bone metastases in her left upper arm and tenth right rib. The following year, three hepatic tumors with high vascularity were detected by ultrasonography, computed tomography scans, and magnetic resonance imaging. An ultrasound-guided liver biopsy specimen confirmed the diagnosis of hepatic metastases from the primary intracranial hemangiopericytoma. A combination therapy of transcatheter arterial chemoembolization and radiofrequency ablation was performed against the hepatic metastasis. After 5 years, there has been no local recurrence in the liver.

A 66-year-old woman presented with jaundice, elevated liver enzymes, peripheral eosinophilia and increased levels of immunoglobulin (Ig) G4. The image findings of the biliary tree revealed multifocal strictures mimicking primary sclerosing cholangitis. A biopsy specimen of the liver demonstrated an infiltration of inflammatory cells consisting of several eosinophils and IgG4-positive plasma cells. The liver enzymes and eosinophil count were normalized immediately after the administration of an oral steroid. Finally, the patient was diagnosed with eosinophilic cholangitis based on the clinical manifestations, although she had features of both eosinophilic cholangitis and IgG4-related cholangitis. This case indicates that the two entities may show similar manifestations and thus they should be discriminated carefully.

A 30-year-old woman was referred to us because of hypoglycemic attack. The tumor on the pancreatic body of 22 mm size was revealed by close inspection, and was diagnosed as insulinoma. Surgical resection was performed, but curative resection was impossible because the component of adenocarcinoma infiltrating into surrounding tissue coexisted with insulinoma. Postoperatively, we make a diagnosis of combined tumor of the pancreas, i.e. mixed duct-islet cell carcinoma. In this paper, we discuss this rare disorder and summarize 33 cases reported in the Japanese literature.

A 74-year-old man with compensated hepatitis C virus-related liver cirrhosis was admitted for the treatment of small hepatocellular carcinoma (HCC) by radiofrequency ablation therapy (RFA). As a routine pretreatment examination, gastrointestinal endoscopy was performed, and large nodular varices were observed in the gastric fornix, with telangiectasia on top of the varices. As soon as the RFA was completed, prophylactic balloon-occluded retrograde transvenous obliteration (B-RTO) was performed. Seven days after the B-RTO, the patient complicated of upper abdominal pain. Gastrointestinal endoscopy was performed, and a deep ulcer, located at the top of the tumor-shaped gastric varices, was found. The ulcer showed rapid healing after 1-week administration of a proton pump inhibitor (PPI). A severe ulcer after a B-RTO procedure, is extremely rare, because sclerosing agents rarely flow into the gastric mucosa. The ulcer in this patient was deep and large, and it may have been due to direct mucosal damage caused by the sclerosing agent, because mucosal telangiectasia on top of the varices was observed before the B-RTO. It is likely that, in this patient, the mucosal vessels communicated with the submucosal large varices, and ethanolamine oleate (EOI) flowed into the gastric mucosa via this communication. Based on our experience, we recommend periodic follow-up endoscopy.

A 35-year-old man presented with the complaint of epigastric discomfort. Gastrointestinal endoscopy and endoscopic ultrasonography revealed a cystic lesion 20 mm in size at the ampulla of Vater. Endoscopic retrograde cholangiopancreatography (ERCP) revealed that the cystic lesion communicated with both the common bile duct and pancreatic duct via the common channel. Choledochocele was ruled out by close examination of the ERCP findings. The cystic lesion was surgically resected. Since histological findings revealed that the mucosa inside the lesion was duodenum-like and contained a layer of smooth muscle, the lesion was diagnosed as a congenital duplication cyst of the duodenum.