Proposal to modify the International Union Against Cancer staging system for perihilar cholangiocarcinomas

BACKGROUND

The International Union Against Cancer (UICC) staging system for perihilar cholangiocarcinoma changed in 2009. The aim of this study was to validate and optimize the UICC system for these tumours.

METHODS

This retrospective study was conducted in eight Japanese hospitals between 2001 and 2010. Perihilar cholangiocarcinoma was defined as a cholangiocarcinoma that involves the hilar bile duct, independent of the presence or absence of a liver mass component. The stratification ability of the UICC tumour node metastasis (TNM) system was compared with that of a modified system.

RESULTS

Of 1352 patients, 35.9, 44.8 and 12.6 per cent had Bismuth type IV tumours, nodal metastasis (N1) and distant metastasis (M1) respectively. T4 tumours (43.2 per cent) and stage IVA (T4 Nany M0; 36.3 per cent) disease were most common. Survival was not significantly different between patients with T3 versus T4 tumours (P = 0.284). Survival for patients with stage IVA disease was comparable to that for patients with stage IIIB tumours (T1-3 N1 M0) (P = 0.426). Vascular invasion, pancreatic invasion, positive margin, N1 and M1 status were identified as independent predictors of survival. When Bismuth type IV tumours were removed from the T4 determinants and N1 tumours grouped together, the modified grouping had a higher linear trend χ2 and likelihood ratio χ2 compared with the original system (245.6 versus 170.3 respectively and 255.8 versus 209.3 respectively).

CONCLUSION

The present data suggest that minimal modification with removal of Bismuth type IV tumours from the T4 determinants and bundling of N1 disease may enhance the prognostic ability of the UICC system. However, this requires validation on an independent data set.

Development of polyvinyl alcohol bioartificial pancreas with rat islets and mesenchymal stem cells

To improve the function of the polyvinyl alcohol (PVA) bioartificial pancreas, we focused on bone marrow-derived mesenchymal stem cells (MSCs). We examined whether the function of PVA-encapsulated rat islets could be improved by coencapsulation with syngeneic MSCs. We macroencapsulated 1,500 rat islet equivalents (IEQ) with or without 1 × 10(6) MSCs with the use of 3% PVA solution before implantation intraperitoneally into diabetic BALB/c mice. We evaluated the function of the device in vitro (the residual rate, viability, and insulin-releasing function of the islets) and in vivo assessments (blood glucose and serum C-peptide changes after transplantation and glucose tolerance test). Although cultured islets also were destroyed, the shapes of the islets cocultured with MSCs were preserved but not different from encapsulated islets without MSCs. At 96 hours after culture the residual rates of islet recovery among those cocultured with versus without MSCs were 66% versus 39.5%, respectively, (P = .03). On the other hand, there was no significant difference between encapsulated islets with versus without MSCs. Furthermore, the stimulation index of the islets was improved by coculture with MSCs (2.6 ± 0.6 vs 1.4 ± 0.1; P = .03), but no beneficial effects were observed between islets encapsulated with versus without MSCs. The viability of islets cocultured with MSCs was significantly better than that without MSCs (84.2 ± 2.5 vs 73.3 ± 0.9; P = .037), but MSCs did not improve the viability of encapsulated islets. There were no significant differences in blood glucose or serum C-peptide between islets encapsulated with versus without MSCs. The histologic findings showed many degenerative islets and MSCs soon after transplantation. In conclusion, further studies are necessary to develop a novel PVA bioartificial pancreas that can be used with MSCs.

Splice variants in apoptotic pathway

Elimination of superfluous or mutated somatic cells is provided by various mechanisms including apoptosis, and deregulation of apoptotic signaling pathways contributes to oncogenesis. 40 years have passed since the term "apoptosis" was introduced by Kerr et al. in 1972; among the programmed cell death, a variety of therapeutic strategies especially targeting apoptotic pathways have been investigated. Alternative precursor messenger RNA splicing, by which the process the exons of pre-mRNA are spliced in different arrangements to produce structurally and functionally distinct mRNA and proteins, is another field in progress, and it has been recognized as one of the most important mechanisms that maintains genomic and functional diversity. A variety of apoptotic genes are regulated through alternative pre-mRNA splicing as well, some of which have important functions as pro-apoptotic and anti-apoptotic factors. In this article we summarized splice variants of some of the apoptotic genes including BCL2L1, BIRC5, CFLAR, and MADD, as well as the regulatory mechanisms of alternative splicing of these genes. If the information of the apoptosis and aberrant splicing in each of malignancies is integrated, it will become possible to target proper variants for apoptosis, and the trans-elements themselves can become specific targets of cancer therapy as well. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".

Randomized clinical trial of external stent drainage of the pancreatic duct to reduce postoperative pancreatic fistula after pancreaticojejunostomy

BACKGROUND

Postoperative pancreatic fistula (POPF) remains one of the most common causes of morbidity following pancreaticoduodenectomy (PD). This randomized trial examined whether external stent drainage of the pancreatic duct decreases the rate of POPF after PD and subsequent pancreaticojejunostomy (PJ).

METHODS

Consecutive patients who underwent PD with subsequent construction of a duct-to-mucosa PJ were randomized into a stented and a non-stented group. The primary outcome was the incidence of clinically relevant POPF. Secondary outcomes were morbidity and mortality rates, and hospital stay.

RESULTS

Of 114 PD procedures, 93 were suitable for inclusion in the study after informed consent. The rate of clinically relevant POPF was significantly lower in the stented group than in the non-stented group: three of 47 (6 per cent) versus ten of 46 (22 per cent) (P = 0·040). Among patients with a dilated duct, rates of POPF were similar in both groups. Among patients with a non-dilated duct, clinically relevant POPF was significantly less common in the stented group than in the non-stented group: two of 21 (10 per cent) versus eight of 20 (40 per cent) (P = 0·033). No significant differences in morbidity or mortality were observed. Univariable analysis identified body mass index (BMI), pancreatic cancer,pancreatic texture, pancreatic duct size and duct stenting as risk factors related to clinically relevant POPF. Multivariable analysis taking these five factors into account identified high BMI (risk ratio(RR) 11·45; P = 0·008), non-dilated duct (RR 5·33; P = 0·046) and no stent (RR 10·38; P = 0·004) as significant risk factors.

CONCLUSION

External duct stenting reduced the risk of clinically relevant POPF after PD and subsequent duct-to-mucosa PJ.

A phase II multicenter trial of neoadjuvant chemotherapy FOLFOX6 in combination with bevacizumab for patients with resectable synchronous liver metastases after R0-resections of primary colorectal cancers: The interim analysis

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Background: Therapeutic strategies for colorectal cancer (CRC) patients with synchronous liver metastases are still indeterminate; therefore, we conducted a phase II multicenter trial of neoadjuvant chemotherapy mFOLFOX6 combined with bevacizumab for resectable synchronous liver metastases after R0-resections of primary CRCs. This study was started in June 2008. This is the interim report. Purpose: The aim of this interim analysis is to evaluate the response rate (RR) and adverse events (AEs) of the enrolled patients.

Methods: Eligibility criteria included CRC patients with 10 or less synchronous liver metastases that were preoperatively diagnosed as surgically resectable. 20 of the enrolled patients received 8 courses of mFOLFOX6 with bevacizumab, but bevacizumab was omitted at the initial and the final courses, to avoid the AEs at the operations. The primary endpoint was the RR.

Results: Among the 20 patients, one patient was excluded from the study because the assumed metastasis was diagnosed to be hemangioma later with the MRI imaging. RR was analyzed for the 19 patients, and AEs were analyzed for the 20 patients. Complete response and partial response were achieved in 2 (10.5%) and 11 (57.9%), respectively (RR: 68.4%); 4 (21.1%) were stable disease, and 2 (10.5%) were progressive disease. The RR was higher than the prespecified boundary; therefore, this study was scheduled to be continued. AEs were the following: neutropenia, hypertension, anemia, leucopenia, nausea, appetite loss, stomatitis, bleeding and proteinuria. Grade 3 neutropenia occurred in 4 cases (20.0%), and sensory neuropathy, stomatitis, diarrhea, and cerebral infarctions occurred in each one (5.0%) of the patients. There was no AE of grade 4 or 5. Liver resections were performed in 17 cases, and R0-resection was achieved in all of the operable cases (R0 rate was 85%).

Conclusions: Neoadjuvant chemotherapy mFOLFOX6 combined with bevacizumab appears to be effective and well tolerated. The study is continued as scheduled, to further evaluate the benefit of this regimen.

No significant financial relationships to disclose.

Risk of facial splashes in four major surgical specialties in a multicentre study

This study analyses the results of face-shield blood spatter contamination at six medical facilities to determine exposure risk when facial protection is not used. Blood spatter exposure was evaluated on the basis of overall incidence, location of spatter on face shields, surgical specialty, risk for operating room staff, length of surgery and volume of blood loss. Six hundred face shields were evaluated for blood spatter contamination by visual inspection as well as by staining with leucomalachite green. The face shield was divided into three regions: Orbital (O-region), Paraorbital (P-region) and Mask (M-region). Visual examination detected blood spatter contamination in 50.5% (303/600) of the face shields, whereas leucomalachite green staining detected blood contamination in 66.0% (396/600). Blood contamination was 36.6% (220/600) in the O-region, 37.8% (227/600) in the P-region and 57.0% (342/600) in the M-region. Among operating room staff, the incidence of blood spatter was greatest among lead surgeons at 83.5% (167/200), followed by the first assistant at 68.5% (137/200) and the scrub nurse at 46.0% (92/200). By specialty, cardiovascular surgery was at highest risk with an incidence of 75.3% (113/150) followed by neurosurgery at 69.3% (104/150), gastrointestinal at 60.0% (90/150) and orthopaedic surgery at 60.0% (90/150).

Expression of organic anion transporting polypeptide E (OATP-E) in human placenta

PURPOSE

To examine the expression of multifunctional Na(+)-independent organic anion transporting polypeptide, termed OATP-E, involved in the transport of thyroid hormone in human placenta.

METHODS

Western blot analysis was performed using a specific antibody against OATP-E in human placenta to confirm the expression of OATP-E at the protein level. Immunohistochemistry was also performed using the specific antibody against OATP-E on frozen sections of human placenta.

RESULTS

By Western blot analysis, a single band for OATP-E was observed in human placenta. Immunohistochemistry revealed that OATP-E was predominantly expressed at the apical surface of the syncytiotrophoblasts in placenta.

CONCLUSION

These results reveal that OATP-E is expressed in human placenta, suggesting a functional role for the transplacental transfer of thyroid hormone.

Crystal structure at 1.5-A resolution of Pyrus pyrifolia pistil ribonuclease responsible for gametophytic self-incompatibility

The crystal structure of the Pyrus pyrifolia pistil ribonuclease (S(3)-RNase) responsible for gametophytic self-incompatibility was determined at 1.5-A resolution. It consists of eight helices and seven beta-strands, and its folding topology is typical of RNase T(2) family enzymes. Based on a structural comparison of S(3)-RNase with RNase Rh, a fungal RNase T(2) family enzyme, the active site residues of S(3)-RNase assigned were His(33) and His(88) as catalysts and Glu(84) and Lys(87) as stabilizers of an intermediate in the transition state. Moreover, amino acid residues that constitute substrate binding sites of the two RNases could be superimposed geometrically. A hypervariable (HV) region that has an S-allele-specific sequence comprises a long loop and short alpha-helix. This region is far from the active site cleft, exposed on the molecule's surface, and positively charged. Four positively selected (PS) regions, in which the number of nonsynonymous substitutions exceeds that of synonymous ones, are located on either side of the active site cleft, and accessible to solvent. These structural features suggest that the HV or PS regions may interact with a pollen S-gene product(s) to recognize self and non-self pollen.

Interleukin-10 induction after combined resection of liver and pancreas

BACKGROUND/AIMS

Recently in Japan, combined resection of liver and pancreas is being performed in cases of advanced biliary neoplasms. As we previously reported, in the rat model of combined resection of the liver and pancreas, the potential for liver regeneration after this operation was decreased compared to that after hepatectomy only. Moreover, non-parenchymal cells play an important role in the production of inhibitory factors for liver regeneration. The anti-inflammatory cytokine IL-10, downregulates the release of TNF-alpha, and affects the progressive regeneration of the hepatic parenchyma. To investigate the role of IL-10 and TNF-alpha in hepatic regeneration in the rat, we measured the levels of IL-10 and TNF-alpha in the conditioned medium of non-parenchymal cells stimulated with portal plasma. We also investigated the concentration of IL-10 and TNF-alpha in the portal plasma after combined resection of the liver and pancreas.

METHODOLOGY

Adult male Sprague-Dawley rats were used. Rats were divided into 3 groups: group I underwent 70% partial hepatectomy only (Hx), group II underwent 70% partial pancreatectomy only (Px) and in group III both procedures were used, Hx plus Px (HPx). Portal plasma was harvested at 1, 3, 6, 12 and 24 hours after surgery and was used to stimulate the culture medium of non-parenchymal cells. Cytokine concentrations in the plasma and in the conditioned medium were measured by ELISA. Northern blot analysis for IL-10 mRNA was performed on liver, pancreas, kidney, lung and spleen at 1, 3 and 6 hours after surgery.

RESULTS

The level of IL-10 released by non-parenchymal cells stimulated with HPx portal plasma was 154.1 +/- 20.3 pg/mL and significantly higher than when stimulated with Hx portal plasma, which was 100.1 +/- 6.4 pg/mL (P < 0.05) during the first hour. Also, the level of TNF-alpha released by Kupffer cells stimulated with HPx portal plasma was 86.6 +/- 13.4 pg/mL, significantly less than when stimulated with Hx portal plasma, which was 138.7 +/- 15.1 pg/mL (P < 0.005) during the first hour. Furthermore, the plasma levels of IL-10 in the HPx group remained significantly higher than those of the other groups from 6 hours up to 12 hours. In northern blot analyses, higher IL-10 mRNA expression were detected in the spleen and moderately high levels in the liver at 1 and 3 hours after HPx, in contrast to those after Hx.

CONCLUSIONS

IL-10 expression is induced in the spleen and liver remnant just after HPx. IL-10 released by the spleen and liver might downregulate TNF-alpha production, thereby inhibiting the liver regeneration.

Hemodynamic patterns of phosphatidylcholine hydroperoxide and hyaluronic acid during hepatic ischemia-reperfusion

We investigated the hemodynamic pattern of serum hyaluronic acid (HA) and compared it with that of plasma phosphatidylcholine hydroperoxide (PCOOH) in terms of a convenient parameter of reperfusion injury. Using pig models, we designed two continuous ischemia groups, prepared by blockage of the blood flow at the hepatic hilum for 10 or 30 min. A discontinuous ischemia model was prepared by repeating the 10-min ischemia procedure, followed by 10 min of reperfusion, to a total ischemia period of 30 min. The PCOOH level started to increase just after reperfusion and reached the peak at 90 min, followed by a gradual decline after 6 h. The HA level increased rapidly in the continuous ischemia groups, starting immediately after ischemia onset until immediately before reperfusion, followed by a gradual decrease during up to 6 h of reperfusion. The HA levels in the three groups were almost normalized after 90 min of reperfusion, when the PCOOH level reached the peak. These results indicated that the plasma PCOOH level is a useful parameter for predicting the onset and progress of reperfusion injury in its initial stages.

Resonance Raman and EPR investigations of the D251N oxycytochrome P450cam/putidaredoxin complex

We have performed resonance Raman and electron paramagnetic resonance (EPR) studies on the dioxygen bound state of the D251N mutant of cytochrome P450cam (oxy-P450cam) and its complex with reduced putidaredoxin (Pd). The D251N oxy-P450cam/Pd complex has a perturbed proton delivery mechanism and shows a significantly red-shifted UV-visible spectrum as observed in Benson et al. [Benson, D. E., Suslick, K. S., and Sligar, S. G. (1997) Biochemistry 36, 5104-5107]. The red shift has been interpreted to indicate a major perturbation of the electronic structure of the oxy-heme complex. However, we find no evidence that electron transfer has occurred from Pd to the heme active site of D251N oxy-P450cam. This suggests that both electron and proton transfer are perturbed by the D251N mutation and that these processes may be coupled. Three oxygen isotope sensitive Raman features are identified in the Pd complex, and occur at 1137, 536, and 399 cm(-1). These values are not significantly different from those for WT or D251N oxy-P450cam. However, a careful examination of the oxygen stretching feature near 1137 cm(-1) reveals the presence of three peaks at 1131, 1138, and 1146 cm(-1), which we attribute to the presence of conformational substates in oxy-P450cam. A significant change in the conformational substate population is observed for the D251N oxy-P450cam when the Pd complex is formed. We suggest that the conformational population redistribution of oxy-P450cam, along with the red-shifted electronic spectra, reflects a structural equilibrium of the oxy-heme that is perturbed upon Pd binding. We propose that this structural perturbation is connected to the effector function of Pd and may involve changes in the electron donation properties of the thiolate ligand.

LST-2, a human liver-specific organic anion transporter, determines methotrexate sensitivity in gastrointestinal cancers

BACKGROUND & AIMS

One approach to the development of targeted cancer chemotherapy exploits increased uptake of the agent into neoplastic cells. In this scenario, higher concentrations of the agent in cancer cells are responsible for differential killing, whereas the low concentration in normal human cells decreases side effects. The aim of this study was to isolate an organic anion transporter that is weak in normal cells, but abundantly expressed in cancer cells, to deliver the anticancer drugs to the cells.

METHODS

A human liver complementary DNA (cDNA) library was screened with liver-specific transporter (LST)-1 cDNA as a probe. Northern blot analyses were performed using the isolated cDNA (termed LST-2). An LST-2-specific antibody was raised, and immunohistochemical analyses including immunoelectron microscopy were performed. Xenopus oocyte expression system was used for functional analysis. We also established a permanent cell line that consistently expresses LST-2 to examine the relationship between methotrexate uptake and sensitivity.

RESULTS

The isolated cDNA, LST-2, has 79.7% of overall homology with human LST-1. LST-2 exclusively expressed in the liver under normal conditions and its immunoreactivity was highest at the basolateral membrane of the hepatocytes around the central vein. Although its weak expression in the liver, LST-2 is abundantly expressed in the gastric, colon, and pancreatic cancers. On the other hand, the LST-1 was only detected in a hepatic cell line. LST-2 transports methotrexate in a saturable and dose-dependent manner. Furthermore, introduction of the LST-2 gene into mammalian cells potentiates sensitivity to methotrexate.

CONCLUSIONS

LST-2 is one of the prime candidate molecules for determining methotrexate sensitivity and may be a good target to deliver anticancer drugs to the gastrointestinal cancers.

Identification of thyroid hormone transporters in humans: different molecules are involved in a tissue-specific manner

We have recently identified that rat organic anion transporters, polypeptide2 (oatp2) and oatp3, both of which transport thyroid hormones. However, in humans the molecular organization of the organic anion transporters has diverged, and the responsible molecule for thyroid hormone transport has not been clarified, except for human liver-specific transporter (LST-1) identified by us. In this study we isolated and characterized a novel human organic anion transporter, OATP-E from human brain. The isolated complementary DNA encodes a polypeptide of 722 amino acids with 12 transmembrane domains. A rat counterpart, oatp-E, was also identified. Homology analysis and the phylogenetic tree analysis revealed that OATP-E/oatp-E is a subfamily of the organic anion transporter. Human OATP-E transported 3,3',5-triiodo-L-thyronine (K(m), 0.9 microM), thyronine, and rT(3) in a Na(+)-independent manner. Although the clone was isolated from the brain, OATP-E messenger RNA was abundantly expressed in various peripheral tissues. The rat counterpart, oatp-E, also transported 3,3',5-triiodo-L-thyronine. In addition, in this study we revealed that human OATP, which is exclusively expressed in the brain, transported 3,3',5-triiodo-L-thyronine (K(m), 6.5 microM), T(4) (K(m), 8.0 microM), and rT(3). These data suggest that in humans, several different molecules are involved in transporting thyroid hormone: OATP in the brain, LST-1 in the liver, and OATP-E in peripheral tissues.

Malignant pheochromocytoma with hepatic metastasis diagnosed 10 years after a resection of the primary incidentaloma adrenal lesion: report of a case

A 40-year-old woman developed hepatic tumors 10 years after a resection of pheochromocytoma of the left adrenal gland. Computed tomography showed a round tumor measuring about 35mm in diameter at segment V of the liver (Couinaud's classification), and magnetic resonance imaging showed another tumor measuring about 5mm at segment V-VIII of the liver. The results of the endoscopic examination of her upper gastrointestinal tract and barium enema were normal. Owing to a suspected hepatic metastasis of malignant pheochromocytoma, a right lobectomy of the liver was performed. Postoperatively, [131I]metaiodobenzylguanidine scintigram and computed tomography showed no other residual tumors nor metastasis. The present case suggests that a long-term follow-up only by endocrinological examinations is insufficient to find newly developed metastatic foci, while routine diagnostic imaging at frequent intervals is necessary in cases of pheochromocytoma.

[Possible inhibitory mechanism of liver regeneration through non-parenchymal cells after combined hepatectomy and pancreatectomy]

BACKGROUND

Recently, simultaneous hepatectomy (Hx) and pancreaticoduodenectomy have been performed in the treatment of biliary tract cancer. Postoperative hepatic failure is a common and potentially fatal complication. The aim of this study was to examine the reduced rate of liver regeneration after 70% Hx alone or in combination with 70% pancreatectomy (HPx).

MATERIALS AND METHODS

Male Sprague-Dawley rats underwent Hx or combined Hx and Px. The ratio of liver-body weight, labeling index of hepatocytes in vivo, and DNA synthesis of hepatocytes and/or Kupffer cells in primary culture were analyzed.

RESULTS

The ratio of liver-body weight in HPx rats was found to be significantly lower than that in Hx rats from 12 hours to 72 hours after surgery. There was no difference in blood glucose or ALT levels between the two groups. An inhibitory effect on DNA synthesis was observed in cocultured hepatocytes and Kupffer cells when portal plasma obtained one hour after surgery was added. We further observed that conditioned medium of Kupffer cells stimulated by portal plasma obtained one hour after HPx inhibited DNA synthesis by hepatocytes. This effect was abolished after incubation at 56 degrees C for 30 min.

CONCLUSIONS

These results clearly indicate the existence of a growth inhibitory factor in portal serum after HPx. This heat-labile growth inhibitory factor was released from Kupffer cells stimulated by portal plasma after HPx and appears to act on hepatocytes in a paracrine manner.

Activation of Reg gene, a gene for insulin-producing -cell regeneration: Poly(ADP-ribose) polymerase binds Reg promoter and regulates the transcription by autopoly(ADP-ribosyl)ation

The regeneration of pancreatic islet beta cells is important for the prevention and cure of diabetes mellitus. We have demonstrated that the administration of poly(ADP-ribose) synthetase/polymerase (PARP) inhibitors such as nicotinamide to 90% depancreatized rats induces islet regeneration. From the regenerating islet-derived cDNA library, we have isolated Reg (regenerating gene) and demonstrated that Reg protein induces beta-cell replication via the Reg receptor and ameliorates experimental diabetes. However, the mechanism by which Reg gene is activated in beta cells has been elusive. In this study, we found that the combined addition of IL-6 and dexamethasone induced the expression of Reg gene in beta cells and that PARP inhibitors enhanced the expression. Reporter gene assays revealed that the -81 approximately -70 region (TGCCCCTCCCAT) of the Reg gene promoter is a cis-element for the expression of Reg gene. Gel mobility shift assays showed that the active transcriptional DNA/protein complex was formed by the stimulation with IL-6 and dexamethasone. Surprisingly, PARP bound to the cis-element and was involved in the active transcriptional DNA/protein complex. The DNA/protein complex formation was inhibited depending on the autopoly(ADP-ribosyl)ation of PARP in the complex. Thus, PARP inhibitors enhance the DNA/protein complex formation for Reg gene transcription and stabilize the complex by inhibiting the autopoly(ADP-ribosyl)ation of PARP.