Abstract 2008: Effect of histone deacetylase inhibitor in combination with 5-fluorouracil on pancreas cancer and cholangiocarcinoma cell line

Background: Histone deacetylase (HDAC) is well known to be associated with epigenetic regulation and carcinogenesis, and its inhibitors (HDACIs) induce the differentiation or apoptosis of cancer cells. Valproic acid (VPA) is one of the HDACIs, and it is clinically available as an oral antiepilepsy drug. We have reported that VPA augmented the anti-tumor effects of gemcitabine (GEM) in pancreas cancer cell lines and a cholangiocarcinoma cell line (2010 ASCO-GI), and we plan the clinical trial of combination therapy, S-1, that is a novel oral fluoropyrimidine derivative consisting of 5-fluorouracil (5-FU) prodrug tegafur, and VPA. We examined the augment effects of VPA with a combination of 5-FU in vitro.

Methods: A human pancreas cancer cell line (SUIT-2) and a cholangiocarcinoma cell line (HuCCT1) were used. The anticancer effects of VPA combined with 5-FU in SUIT-2 and HuCCT1. The cell viability was evaluated by MTT assay.

Results: Pancreas cancer cell line (SUIT-2): In 5-FU alone group, no effect of 5-FU was observed in dose of 1.0μM, and 17% and 30% of proliferation-inhibitory effects were observed in dose of 2.5 and 5.0μM, respectively. VPA (0.5mM) weakly suppressed cell viability by 13%. In combination of 5-FU and VPA, 19% of inhibitory effect was observed in dose of 5-FU 1.0μM/VPA 0.5mM, respectively.

Cholangiocarcinoma cell line: 5-FU (1.0μM) did not suppress the cell viability, 5-FU (2.5μM) suppressed by 23%. VPA (0.5mM) did not suppress the cell viability, while VPA (1.0mM) weakly decreased it by 11%. 5-FU (1.0μM) and VPA (0.5mM) reduced by 30%, which significantly augmented the anticancer effect of 5-FU alone or VPA alone (P<0.01).

Conclusion: VPA augmented the anti-tumor effect of 5-FU in both a pancreas cancer cell line and a cholangiocarcinoma cell line. Therefore, 5-FU plus VPA is suggested to be a promising therapeutic option for both pancreas cancer and cholangiocarcinoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2008. doi:10.1158/1538-7445.AM2011-2008

Abstract 79: Role of histone deacetylase expression in intrahepatic cholangiocarcinoma

Introduction: Histone deacetylase (HDAC) plays an important role in chromatin remodeling, gene expression and in regulating cell cycle progression and differentiation. Furthermore, HDAC inhibitors have recently been found to repress the function of hypoxia inducible factors (HIF) through inducing hyperacetylation of histones. However, few studies have been conducted regarding the role of HDAC in IHCC. The aim of this study was to elucidate the role of HDAC in IHCC.

Methods: Thirty-five patients with IHCC who underwent hepatic resection were evaluated. The expressions of HDAC1 and HIF-1α were determined immunohistochemically, and the patients were divided into two groups: HDAC1 positive group (n=21); and HDAC1 negative group (n=14). Clinicopathological variables including HIF-1α expression were compared between the two groups.

Results: The HDAC1 expression correlated significantly with higher stage carcinoma, lymph node metastasis, and vascular invasion. The prognosis in the HDAC1 positive group was poorer than in the HDAC1 negative group (5-year survival: 77.9% vs. 7.9%, p=0.001). In the multivariate analysis, HDAC1 positive expression was identified as the only independent prognostic factor for disease free survival (Hazard Ratio: 7.194, p=0.0018). Furthermore, there was a significant correlation between HDAC1 expression and HIF-1α expression (p=0.007), and co-expressions of these markers in same cancer cells were proven by immunofluorescent stainings in the serial section

Conclusions: The findings suggested that a positive expression of HDAC1 is a new prognostic indicator of IHCC, and that HDAC1 might be a possible promising molecular target of IHCC, through the regulation of HIF-1α.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 79. doi:10.1158/1538-7445.AM2011-79

Impact of FOLFOXIRI plus bevacizumab on resectability and survival in patients with initially unresectable liver metastases from colorectal cancer

621

Background: Prognosis in patients with unresectable liver metastases from colorectal cancer is known to be very poor. However, thanks to progress of chemotherapy including molecular-target agents, “conversion” (from unresectable to resectable) has been sometimes seen. The aim of this preliminary study is to clarify the impact of FOLFOXIRI plus bevacizumab (Bev) on conversion and prognosis in patients with initially unresectable liver metastases from colorectal cancer.

Methods: Seven patients with initially unresectable liver metastases from colorectal cancer, who received FOLFOXIRI (LOHP 85mg/m2 D1, CPT-11 150mg/m2 D1, LV 200mg/m2 D1, and 5FU 2,400mg/m2 infusion over 46 hours, D1) plus Bev 5mg/kg bolus every 2 weeks, were included in this study. Resectability, disease-free survival (DFS), and overall survival (OS) after hepatic resection were investigated in detail. In addition, completeness and adverse effects were examined in this regimen.

Results: All 7 patients tolerated the regimen well, and no adverse effect of grade 3-4 was observed. Five out of 7 patients (71%) became resectable (conversion), except for 2 with multiple lung metastases and bone metastasis prior to chemotherapy. Our historical conversion rates were, 0% (0/7) in 5FU/LV regimen from 1994 to 2003, 25% (7/27) other regimens such as FOLFIRI and FOLFOX except for FOLFOXIRI plus Bev from 2004. In 5 patients who became resectable, CR was not observed, however, all had PR after 6 cycles of chemotherapy (RR 100%). All 5 patients could undergo curative (R0) hepatic resection, furthermore, all had pathological major response (grade 2). Follow-up period ranged from 8 to 18 months, with a median period of 14 months, and 2 patients relapsed (lung recurrence and peritoneal dissemination), and one died of lung metastases (1.5-year OS and DFS are 80 % and 60%).

Conclusions: Our preliminary data suggested the feasibility of this new therapeutic combination in patients with initially unresectable liver metastases from colorectal cancer, and a high conversion rate and better prognosis.

[Table: see text]

The impact of bevacizumab on liver regeneration following hepatectomy in rats

228

Background: In our clinical data, we had the interesting findings that the pathologic sinusoidal obstruction syndrome and serum hyaluronic acid after neoadjuvant oxaliplatin-associated chemotherapy for liver metastatic colorectal cancer with bevacitumab (Bev) was ameliorated compared to those without Bev. The purpose of this study was to investigate the influence of bevacizumab administration on regenerating liver in rat 70% and 90% hepatectomy (Hx) model as a surrogate model of human massive hepatectomy for liver metastatic colorectal cancer.

Methods: Male Wister rats weighing 180-230g were divided into the following four groups: 70%Hx, 70%Hx + Bev, 90%Hx and 90%Hx+Bev group. The rats were pretreated with intraperitoneal administration of bevacizumab (5mg/kg) 7 days before hepatectomy. The remnant liver and blood samples were taken one day after hepatectomy, and the following parameters were evaluated: blood analysis (AST, ALT, LDH, T- Bil, and hyaluronic acid), liver weight to body weight (Lw/Bw) ratio, and postoperative survival rate for three days.

Results: In the 70%Hx model, there was no significant difference between the 70%Hx group and 70%Hx + Bev group in blood analysis one day after hepatectomy; AST (1928 vs. 923 IU/L), ALT (1282 vs. 670 IU/L), T-Bil (0.17 vs. 0.19 mg/dl), LDH (3822 vs. 2967 U/L) and hyaluronic acid (995.7 vs. 1026.6 ng/ml) and in Lw/Bw ratio (1.78 vs. 1.84). In 90%Hx model, AST and ALT of blood analysis in 90%Hx+Bev group significantly decreased compared to those in 90%Hx group; AST (3428 vs. 4995 IU/L, P<0.05), ALT (1471 vs. 2287 IU/L, P<0.05), T-Bil (1.94 vs. 2.57 mg/dl), LDH (3229 vs. 5351 U/L) and hyaluronic acid (3865.7 vs. 7862.2 ng/ml). The Lw/Bw ratio in 90%Hx+Bev group significantly increased compared to that in 90%Hx group (0.80 vs. 0.67, P<0.05). The postoperative survival rate in 90%Hx+Bev group showed tendency to improve compared to that in 90%Hx group (75% vs. 50%, P=0.19).

Conclusions: The administration of bevacizumab seven days before hepatectomy did not significantly affect the liver functions and liver regeneration rate. These findings suggest that hepatectomy might be safe and feasible after the use of bevacizumab.

No significant financial relationships to disclose.

Effect of a histone deacetylase inhibitor on antitumor effect of gemcitabine to focus the gene network of ingenuity pathways analysis

230

Background: Histone deacetylase (HDAC) is strongly associated with epigenetic regulation and carcinogenesis, and its inhibitors induce the differentiation or apoptosis of cancer cells. Valproic acid (VPA) is one of the clinically available HDAC inhibitors. We previously showed that VPA augmented antitumor effect of GEM in choalngiocarcinoma cell line (2010 GI Symposium); this time, we performed microarray analysis and Ingenuity Pathways Analysis (IPA) to identify the systematic mechanism of the augmentative effect of VPA.

Methods: Human cholangiocarcinoma cell line (HuCCT1) was used. The anticancer effects of VPA or gemcitabine (GEM), and the effects of VPA combined with GEM were studied by MTT assay. We divided the following four groups: control group, VPA group, GEM group, VPA plus GEM combination group. The gene expressions of p21, HDAC, VEGF, and HIF-1 were evaluated by RT-PCR. And, the microarray analysis was performed, the genes were picked up using Gene Spring GX10, and then IPA was performed.

Results: In GEM alone group, no effect of GEM was observed in dose of 5 mm, and 16% of proliferation-inhibitory effects were observed in dose of 10 nm. In VPA alone group, no effect of VPA was observed in dose of 0.5 mm, and 12%, 35%, and 67% of proliferation-inhibitory effects were observed in dose of 1.0, 5.0, and 10mm, respectively. GEM (5 nm) and VPA (0.5 mm) reduced by 23%, which significantly augmented the anticancer effect of GEM alone or VPA alone (p<0.01). Furthermore, GEM combined with VPA upregulated the p21 expression compared with single agent (p<0.05). And, in regard to microarray analysis, we analyzed in 28,869 genes. The 24 genes were picked up with the comparison between VPA group and VPA plus GEM combination group using Gene Spring GX10, and the gene network of the cellular development containing the gene relevant to the differentiation of cancer cell, HLA-DR, was formed with IPA.

Conclusions: VPA augmented the effects of anticancer agents in a cholangiocarcinoma cell line. Such effects may be owing to the gene network of the cellular development. HDAC inhibitor may have the effect of the differentiation of cancer cell.

No significant financial relationships to disclose.

Role of histone deacetylase expression on regulating cancer stem cells in intrahepatic cholangiocarcinoma

219

Background: Histone deacetylase (HDAC) modulates gene expressions by chromatin remodeling during malignant transformation, and showed malignant behavior in intrahepatic cholangiocarcinoma (IHCC) (ASCO GI 2008). HDAC inhibitors have recently been found to repress the function of hypoxia inducible factors (HIF) through inducing hyperacetylation of histones. We also reported that the correlation between the expression of CD133, which was one of the cancer stem cell marker, and HIF-1α in IHCC (J Gastroenterol. 2010), and hypothesized that the cancer stem cell could be regulated by histone acetylation through the HIF-1α pathway. The aim of this study was to elucidate the potential mechanism of HDAC for the regulation of malignant behavior including the cancer stem cell in IHCC.

Methods: Thirty-five patients with IHCC who underwent hepatic resection were evaluated. The expressions of HDAC1 (sc-6298 Santa Cruz Biotechnology, USA), HIF-1α (NB100-105 Novus Biologicals, USA) and CD133 (Ab27699 Abcam Inc, UK) were determined immunohistochemically, and the patients were divided into two groups: HDAC1 positive group (n=21); and negative group (n=14). Clinicopathological variables including HIF-1α and CD133 expressions were analyzed according to these expressions.

Results: The HDAC1 expression correlated significantly with higher stage, lymph node metastasis, and vascular invasion. The prognosis in the HDAC1 positive group was poorer than in the HDAC1 negative group (5-year survival: 77.9% vs. 7.9%, p=0.001). In the multivariate analysis, HDAC1 positive expression was identified as the only independent prognostic factor for disease free survival (Hazard Ratio: 7.194, p=0.0018). There was a significant correlation between HDAC1 expression and HIF-1α expression (p=0.007), and also between HIF-1α expression and CD133 expression (p=0.10). Furthermore, co-expressions of these markers in same cancer cells were proven by immunofluorescent staining in the serial section.

Conclusions: The findings suggested that histone acetylation regulated cancer stem cell through the HIF-1α pathway; therefore, HDAC1 might be a possible promising molecular target in IHCC.

No significant financial relationships to disclose.

Role of dihydropyrimidine dehydrogenase and thymidylate synthase expression in immunohistochemistry of intrahepatic cholangiocarcinoma

AIMS

  Dihydropyrimidine dehydrogenase (DPD) and thymidylate synthase (TS) are key enzymes in the metabolism of 5-fluorouracil and have been implicated as possible prognostic markers for cancer patients. However, the clinical roles of DPD and TS in intrahepatic cholangiocarcinoma (IHCC) have not been investigated. The aim of this study was to clarify the clinicopathological role of DPD and TS expressions in IHCC.

METHODS

  Twenty-nine patients who had undergone hepatic resection for IHCC were enrolled in this study. Expressions of DPD and TS in the resected IHCC specimens were examined using anti-DPD or anti-TS antibody. The patients were divided into positive and negative groups according to DPD/TS expressions: DPD-positive group (n = 18) and DPD-negative group (n = 11)/TS-positive group (n = 14) and TS-negative group (n = 15). Clinicopathological factors were compared between the two groups.

RESULTS

  The overall survival rate was significantly lower in the DPD-negative group than in the DPD-positive group (1-year 36.4% vs. 77.4%, 3-year 18.2% vs. 43.0%; P < 0.05). The disease-free survival rate in the DPD-negative group tended to be lower than that in the DPD-positive group. The overall survival rate or disease-free survival rate did not appear to be associated with the TS-expression status. The Ki-67 labeling index in the DPD-negative group was significantly higher than that in the DPD-positive group (16.9 ± 3.2% vs.13.2 ± 3.3%; P < 0.05).

CONCLUSIONS

  The negative DPD expression was significantly associated with the enhanced tumor cell proliferation and poorer prognosis in patients with IHCC. DPD expression is a potential prognostic indicator for IHCC.

Human adipose-derived stem cells: potential clinical applications in surgery

Regenerative medicine is emerging as a rapidly evolving field of research and therapeutics. Stem cells hold great promise for future translational research and clinical applications in many fields. Much research has focused on mesenchymal stem cells isolated from bone marrow in vitro and in vivo; however, bone marrow procurement causes considerable discomfort to the patient and yields a relatively small number of harvested cells. By contrast, adipose tissue represents an abundant and easily accessible source of adult stem cells, termed adipose-derived stem cells (ADSCs), with the ability to equally differentiate along multiple lineage pathways. These stem cells have angiogenic properties, possibly because of their secretion of cytokines. They may also play a role in healing acute and chronic tissue damage. Subsequently, they have a wide range of potential clinical implications. This article reviews the potential preclinical and clinical applications of mesenchymal stem cells, especially ADSCs, in surgery.

Impact of a new refrigerator for the preservation of whole blood

BACKGROUND

A new refrigerating system has been recently developed, which can cool the inside of a material to the required temperature by frequently sensing the temperature of both the inside and the surface of the materials. The purpose of this study was to evaluate the usefulness of this new system in whole blood preservation.

MATERIALS AND METHODS

Study 1 (human blood): Whole blood samples from healthy volunteers were anticoagulated with CPDA. The samples were divided into two groups. Group A, whole blood preserved in ordinary refrigerator and Group B, whole blood preserved in new refrigerator (4°C, 15 wk). After preservation, ammonia, lactate, pH. and ATP levels were analyzed. Study 2 (rat experiment): Whole blood samples from male Wistar rats, stored in ordinary refrigerator (Group C) or new refrigerator (Group D). Whole blood was transfused after 8-wk storage and survival was compared.

RESULTS

Study 1: The ammonia concentrations in Group B were significantly lower than those in Group A at 7 and 9 wk after preservation (P < 0.05). The lactate levels in Group B were significantly lower than those in Group A at 9 wk after preservation (P < 005). The pH levels in Group B were higher than those in Group A at 5 to 13 wk after preservation (P < 0.05). The ATP levels in Group B were higher than those in Group A at 5 to 13 wk after preservation. Study 2: In rat studies using blood transfusion in acute hemorrhagic shock model, survival rate in Group C was significantly higher than those in Group D (P < 0.05).

CONCLUSIONS

Our new refrigerator is useful in preserving whole blood with good condition during preservation.

Impact of splenectomy in patients with liver cirrhosis: Results from 18 patients in a single center experience

AIM

  With the recent advances in medical or surgical treatments in chronic hepatic disorders, the indications for splenectomy in hepatic disorders have greatly expanded. We performed splenectomy for cirrhotic patients and investigated the effects of splenectomy on hepatic functional reserve and nutrition metabolism.

METHODS

  Eighteen patients (Child-Pugh B/C: 12/6; Child-Pugh A: excluded) who underwent splenectomy at our institute between 2005 and 2008 were enrolled. Twelve patients (67%) had hepatocellular carcinoma (HCC), eight of whom met the Milan criteria.

RESULTS

  Overall survival rate was 83.3% at 1 year and 62.7% at 2 years. The survival rate of six patients with liver cirrhosis classified a Child-Pugh C was 80.0% at 1 year and 60.0% at 2 years. Three patients underwent hepatic resection and nine patients received ablation therapy against hepatocelluar carcinoma. Portal pressure decreased after splenectomy in most patients (mean decrease, 4.7 mmHg). Four weeks after the operation, the markers of hepatic functional reserve, indocyanine green retention rate at 15 min (ICGR15) and Technetium-99m-galactosyl human serum albumin value ((99m)Tc-GSA), improved from 38.5% to 35.1% and from 0.773 to 0.788 (LHL15), respectively. The non-protein respiratory quotient (npRQ) did not change in short period after the operation. Other outcomes, including liver function test in cirrhotic patients with long-term (1 year) follow-up after splenectomy (n = 7), did not improve significantly. Post-operative complications included portal thrombus (n = 2), ascites (n = 2) were observed in six patients (33%).

CONCLUSION

  Splenectomy improved hepatic functional reserve and nutritional metabolism in some cases. However, the long-term outcomes should still be evaluated.

CD133 expression is a potential prognostic indicator in intrahepatic cholangiocarcinoma

BACKGROUND AND AIM

CD133 is one of the most important cancer-initiating (stem) cell markers and was confirmed to be expressed in solid cancers such as colon cancer. However, no one has investigated the role of CD133 in intrahepatic cholangiocarcinoma (IHCC). The aim of this study was to clarify the clinical role of CD133 expression in IHCC.

PATIENTS AND METHODS

Twenty-nine patients with IHCC who underwent hepatic resection at our institution were enrolled in this study. Expression of CD133 was examined using anti-CD133 antibody. Staining was observed in the cytoplasm of cancer cells and CD133-positive cells distributed in the whole tumor. The patients were divided into two groups: the CD133-positive group (n = 14) and CD133-negative group (n = 15), in which no staining of CD133 was observed. Clinicopathological factors including hypoxia-inducible factor-1alpha expression were compared between the two groups. The prognostic factors were investigated by multivariate analysis using Cox's proportional hazard model.

RESULTS

The 5-year survival rate in the CD133-positive group (8.0%) was worse than that in the CD133-negative group (57.0%). In the CD133-positive group, the incidence of intrahepatic metastasis and positive expression of hypoxia-inducible factor-1alpha tended to be higher than that in the CD133 negative group. The multivariate analysis revealed CD133 expression was an independent prognostic indicator in IHCC.

CONCLUSIONS

CD133 expression tended to be related to higher incidences of intrahepatic metastasis and positive expression of hypoxia-inducible factor-1alpha; furthermore, it was independently related to worse prognosis. Therefore, the CD133 expression is a potential prognostic indicator in IHCC.

Ductal injection of JNK inhibitors before pancreas preservation prevents islet apoptosis and improves islet graft function

Human islet isolation to obtain high-quality islets is still challenging. This study investigates how c-Jun NH2- terminal kinase (JNK ) is activated during human and porcine islet isolation. We also investigated whether ductal injection of preservation solution with JNK inhibitors improves islet isolation results by preventing apoptosis of islet cells. A low molecular weight inhibitor (SP600125) and a cell-permeable peptide inhibitor, the latter introduced by protein transduction technology, were used in porcine and human studies, respectively. JNK activity progressively increased during the isolation procedure. The addition of 10 microM JNK inhibitors into the ductal preservation solution prevented JNK activation during the isolation procedure and prevented islet apoptosis immediately after isolation. We incubated islets (2000 islet equivalents) for 24-48 hr and then transplanted them below the kidney capsule of streptozotocin-induced diabetic mice. The blood glucose levels reached normoglycemia in more than 80% of the JNK inhibitor-positive group, whereas less than 20% of the JNK inhibitor-negative group achieved normoglycemia. These findings suggest that the JNK pathway is the major mediator of islet deterioration during/immediately after isolation and that JNK inhibition before islet isolation could improve outcomes after pancreatic islet transplantation.

Characterization of human pancreatic progenitor cells

β-Cell replacement therapy via islet transplantation is an effective treatment for diabetes mellitus, but its widespread use is severely limited by the shortage of donor organs. Because pancreatic stem/progenitor cells are abundantly available in the pancreas of these patients and in donor organs, the cells could become a useful target for β-cell replacement therapy. We previously established a mouse pancreatic stem cell line without genetic manipulation. In this study, we used the techniques to identify and isolate human pancreatic stem/progenitor cells. The cells from a duct-rich population were cultured in 23 kinds of culture media, based on media for mouse pancreatic stem cells or for human embryonic stem cells. The cells in serum-free media formed "cobblestone" morphologies, similar to a mouse pancreatic stem cell line. On the other hand, the cells in serum-containing medium and the medium for human embryonic stem cells formed "fibroblast-like" morphologies. The cells divided actively until day 30, and the population doubling level (PDL) was 6-10. However, the cells stopped dividing after 30 days in any culture conditions. During the cultures, the nucleus/cytoplasm (N/C) ratio decreased, suggesting that the cells entered senescence. Exendin-4 treatment and transduction of PDX-1 and NeuroD proteins by protein transduction technology into the cells induced insulin and pancreas-related gene expression. Although the duplications of these cells were limited, this approach could provide a potential new source of insulin-producing cells for transplantation.

Assessment of islet quality following international shipping of more than 10,000 km

Islet transplantation is an attractive therapy for type 1 diabetes, although some issues remain. One of them is the severe donor shortage in some countries. In this study, we investigated the possibility of international islet shipping beyond 10,000 km to supply islets to countries with donor shortages. Human islets were isolated from six cadaver donors and cultured until shipment. Islets were packed in either gas-permeable bags or in non-gas-permeable bags and shipped from Baylor Research Institute (Dallas, TX, USA) to Fukuoka University (Fukuoka, Japan). Pre- and postshipment islet number, purity, viability, and stimulation index (by glucose stimulation test) were assessed. Shipped 1,500 IE islets were transplanted into streptozotocin-induced diabetic nude mice for in vivo assay. The distance of our shipment was 11,148.4 km, and the mean duration of the shipments was 48.2 ± 8.2 h. The islet number recovery rate (postshipment/preshipment) was significantly higher in gas-permeable bags (56.4 ± 10.1% vs. 20.5 ± 20.6%, p < 0.01). Islet purity was significantly reduced during shipment in non-gas-permeable bags (from 47.7 ± 18.6% to 40.2 ± 28.2 in gas-permeable bags vs. from 50.4 ± 6.4% to 25.9 ± 15.6% in non-gas-permeable bags, p < 0.05). Islet viability and stimulation index did not change significantly between pre- and postshipping, in either gas-permeable bags or in non-gas-permeable bags. One of three diabetic nude mice (33.3%) converted to normoglycemia. It is feasible to ship human islet cells internationally in gas-permeable bags. This strategy would promote basic and preclinical research for countries with donor shortages, even though the research centers are remote (over 10,000 km from the islet isolation center).

Molecular signatures of noncancerous liver tissue can predict the risk for late recurrence of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an aggressive malignancy mainly due to tumor metastases or recurrence even after undergoing potentially curative treatment. There are two types of HCC recurrence. The early and late tumor recurrences appear in distinct biological contexts, and their clinical courses are quite different. Therefore, it is important to precisely and distinctly discriminate the risk of each type of HCC recurrence. Many researchers have used DNA microarray technology to reclassify HCC with respect to its malignant potential. Some of these studies successfully identified specific gene-expression signatures derived from the cancerous tissues of HCC for predicting the early recurrence due to intrahepatic metastasis. However, there are no well-defined predictors for late recurrence. Recently, a few studies have focused on the nontumorous portion of liver tissues to predict late recurrence, possibly due to de novo hepatocarcinogenesis based on the idea of "field cancerization." This study reviewed the possible value of a gene-expression analysis of noncancerous liver tissue to clarify the risk for multicentric late recurrence of HCC. These findings may have important implications for chemopreventive strategies and tailored surveillance programs. Furthermore, this approach may also be applicable to other multifocal tumors, such as head and neck carcinoma.

Low-temperature preservation of isolated islets is superior to conventional islet culture before islet transplantation

BACKGROUND

Although culturing islets before transplantation provides flexibility for evaluation of isolated islets and pretreatment of patients, it is well-known that isolated islets deteriorate rapidly in culture. In this study, we evaluated optimal temperature for culture/preservation of isolated human islets before transplantation.

METHODS

Isolated islets were cultured or preserved for 48 hr in the following culture/preservation conditions: preservation at 4 degrees C in University of Wisconsin solution and culture at 22 degrees C or 37 degrees C in culture medium.

RESULTS

Islet morphology after 4 degrees C preservation was similar to that of fresh islets, whereas islet diameter after 37 degrees C or 22 degrees C culture was smaller than that of fresh islets. Islet yield significantly decreased at higher temperatures (24% loss in 37 degrees C culture and 19% loss in 22 degrees C culture, but <5% loss in 4 degrees C preservation). Cultured/preserved islets were transplanted into diabetic nude mice. The attainability of posttransplantation normoglycemia was significantly higher in the 4 degrees C preservation group than in 22 degrees C and 37 degrees C culture groups.

CONCLUSION

Preservation of isolated islets at 4 degrees C improves the outcome of islet transplantation more efficiently than preservation at 22 degrees C or 37 degrees C. Based on these data, we have performed short-time cold storage of isolated islets instead of culturing for current clinical islet transplantation.

Comparison of modified Celsior solution and M-kyoto solution for pancreas preservation in human islet isolation

Since the successful demonstration of the Edmonton protocol, islet transplantation has advanced significantly on several fronts, including improved pancreas preservation systems. In this study, we evaluated two different types of organ preservation solutions for human islet isolation. Modified Celsior (Celsior solution with hydroxyethyl starch and nafamostat mesilate; HNC) solution and modified Kyoto (MK) solution were compared for pancreas preservation prior to islet isolation. Islet yield after purification was significantly higher in the MK group than in the HNC group (MK = 6186 ± 985 IE/g; HNC = 3091 ± 344 IE/g). The HNC group had a longer phase I period (digestion time), a higher volume of undigested tissue, and a higher percentage of embedded islets, suggesting that the solution may inhibit collagenase. However, there was no significant difference in ATP content in the pancreata or in the attainability of posttransplant normoglycemia in diabetic nude mice between the two groups, suggesting that the quality of islets was similar among the two groups. In conclusion, MK solution is better for pancreas preservation before islet isolation than HNC solution due to the higher percentage of islets that can be isolated from the donor pancreas. MK solution should be the solution of choice among the commercially available solutions for pancreatic islet isolation leading to transplantation.

Seven consecutive successful clinical islet isolations with pancreatic ductal injection

Inconsistent islet isolation is one of the issues of clinical islet transplantation. In the current study, we applied ductal injection to improve the consistency of islet isolation. Seven islet isolations were performed with the ductal injection of ET-Kyoto solution (DI group) and eight islet isolations were performed without the ductal injection (standard group) using brain-dead donor pancreata. Isolated islets were evaluated based on the Edmonton protocol for transplantation. The DI group had significantly higher islet yields (588,566 +/- 64,319 vs. 354,836 +/- 89,649 IE, p < 0.01) and viability (97.3 +/- 1.2% vs. 92.6 +/- 1.2%, p < 0.02) compared with the standard group. All seven isolated islet preparations in the DI group (100%), versus only three out of eight isolated islet preparations (38%) in the standard group met transplantation criteria. The islets from the DI group were transplanted into three type 1 diabetic patients and all three patients became insulin independent. Ductal injection significantly improved quantity and quality of isolated islets and resulted in high success rate of clinical islet transplantation. This simple modification will reduce the risk of failure of clinical islet isolation.