The use of embryonic stem cells for cell-replacement therapy in diseases like diabetes mellitus requires methods to control the development of multipotent cells. We report that treatment of mouse embryonic stem cells with inhibitors of phosphoinositide 3-kinase, an essential intracellular signaling regulator, produced cells that resembled pancreatic β cells in several ways. These cells aggregated in structures similar, but not identical, to pancreatic islets of Langerhans, produced insulin at levels far greater than previously reported, and displayed glucose-dependent insulin release in vitro . Transplantation of these cell aggregates increased circulating insulin levels, reduced weight loss, improved glycemic control, and completely rescued survival in mice with diabetes mellitus. Graft removal resulted in rapid relapse and death. Graft analysis revealed that transplanted insulin-producing cells remained differentiated, enlarged, and did not form detectable tumors. These results provide evidence that embryonic stem cells can serve as the source of insulin-producing replacement tissue in an experimental model of diabetes mellitus. Strategies for producing cells that can replace islet functions described here can be adapted for similar uses with human cells.

BACKGROUND: The objective of this study was to evaluate the clinical outcome of proton and carbon ion therapy for hepatocellular carcinoma (HCC).METHODS: In total, 343 consecutive patients with 386 tumors, including 242 patients (with 278 tumors) who received proton therapy and 101 patients (with 108 tumors) who received carbon ion therapy, were treated on 8 different protocols of proton therapy (52.8‐84.0 gray equivalents [GyE] in 4‐38 fractions) and on 4 different protocols of carbon ion therapy (52.8‐76.0 GyE in 4‐20 fractions).RESULTS: The 5‐year local control and overall survival rates for all patients were 90.8% and 38.2%, respectively. Regarding proton and carbon ion therapy, the 5‐year local control rates were 90.2% and 93%, respectively, and the 5‐year overall survival rates were 38% and 36.3%, respectively. These rates did not differ significantly between the 2 therapies. Univariate analysis identified tumor size as an independent risk factor for local recurrence in proton therapy, carbon ion therapy, and in all patients. Multivariate analysis identified tumor size as the only independent risk factor for local recurrence in proton therapy and in all patients. Child‐Pugh classification was the only independent risk factor for overall survival in proton therapy, in carbon ion therapy, and in all patients according to both univariate and multivariate analyses. No patients died of treatment‐related toxicities.CONCLUSIONS: Proton and carbon ion therapies for HCC were comparable in terms of local control and overall survival rates. These therapies may represent innovative alternatives to conventional local therapies for HCC. Cancer 2011;. © 2011 American Cancer Society.

Background: Resection of the non-fibrotic pancreas is prone to postoperative pancreatic fistula because of well preserved exocrine secretions and easily crushed soft parenchyma. The purpose of this study was to evaluate ultrasonic dissection for division of the non-fibrotic pancreas in distal pancreatectomy. Methods: All pancreata included in this study were soft on direct palpation and their main ducts had no dilatation, at least proximally from the transection line. Fifty-eight patients with gastric cancer or pancreatic disease were randomly assigned to the two groups. In the ultrasonic dissection (UD) group (n = 27), all pancreatic ducts were identified and ligated securely. The stump was left open without parenchymal suturing. In the conventional (CV) group (n = 31), the pancreas was cut with a knife and the stump was oversewn in mattress fashion. The main pancreatic duct was ligated in all patients in both groups. Pancreatic fistula was defined as a pancreatic fluid discharge for more than 7 days after operation diagnosed according to amylase concentration in the drainage fluid. Results: In the UD group, approximately 20–30 tubes including a mean(s.d.) 5·2(0·8) (range 4–6) pancreatic ducts were skeletonized and ligated per patient. There were nine pancreatic fistulas (16 per cent); one in the UD group and eight in the CV group (P= 0·020). Conclusion: In distal pancreatectomy for the non-fibrotic pancreas, ultrasonic dissection without suture closure of the stump reduced the incidence of pancreatic fistula compared with conventional division and suture, in this randomized trial.

Background: Intratumoral hypoxia is known to lead to increased aggressiveness and distant metastasis. However, the interplay underlying these actions is still unknown. Objective: We explored whether cancer cells might acquire a stem-like phenotype under hypoxia, consequently leading to an aggressive phenotype, including invasiveness and metastasis. Methods: Under normoxia (20% O2) or hypoxia (1% O2), the expression of CD133 (cancer stem cell marker), CXC chemokine receptor 4 (CXCR4) and hypoxia-inducible factor-1α (HIF-1α) was examined by RT-PCR and immunostaining using human pancreatic cancer cell lines. We also examined if hypoxia facilitates the invasiveness of CD133+ cancer cells. Furthermore, we transfected dominant active HIF-1α (HIF-1αΔODD) by the retroviral gene transfer and examined the effects both in vitro and in vivo. Results: Compared with normoxia, hypoxia elevated the expression of CD133, CXCR4 and HIF-1α. Moreover, hypoxia facilitated the invasiveness of CD133+ pancreatic cancer cells. The behavior of HIF-1αΔODD-transfected cells under normoxia was compatible with that of the parent cells under hypoxia. Furthermore, a xenograft model of HIF-1αΔODD cells showed aggressiveness, including metastasis and highly tumorigenic ability. Conclusion: Hypoxia induces tumor aggressiveness associated with the expansion of CD133+ pancreatic cancer cells in a predominantly HIF-1α-dependent manner.

Nodal signaling induces the formation of the endoderm and mesoderm during gastrulation. Nodal expression persists until the definitive endoderm progenitor has completely formed, and disappears thereafter. A tightly regulated Nodal expression system is essential for the differentiation of embryonic stem (ES) cells into distinct tissue lineages. On this basis, we established an ES cell differentiation system with the tetracycline-regulated expression of Nodal. The upregulated Nodal signaling pathway and its downstream transcriptional targets induced the specification of ES cells into definitive endoderm and mesoderm derivatives, and the subsequent downregulation of Nodal signaling promoted further maturation of the gut tube both in vitro and in vivo. Sustained expression of the Nodal gene inhibited the maturation of the definitive endoderm owing to persistent Oct3 and/or Oct4 expression and teratoma formation. Furthermore, quantitative single cell analysis by flow cytometry using CXCR4, VEGFR2 and PDGFR-α indicated that this protocol for definitive endoderm and mesoderm differentiation is superior to any other available protocol. Our findings also indicated that the Nodal or Nodal-related molecules secreted from Nodal-expressing ES cells could cause genetically unmanipulated ES cells to induce the expression of the Nodal signaling pathway and its downstream targets, which consequently leads to the differentiation of the ES cells into definitive endoderm and mesoderm. Our differentiation system, using tightly regulated Nodal expression, enabled us to investigate the mechanism of ES cell differentiation into definitive endoderm or mesoderm derivatives. Our findings also demonstrate that Nodal-expressing ES cells might be a source of highly active proteins that could be used for developing endoderm or mesoderm tissues in regenerative medicine.