A case of pancreatic well-differentiated neuroendocrine carcinoma surviving 8 years and 5 months with treatments for multiple liver tumors diagnosed as carcinoid tumor

The case was a 58-year-old woman who visited our hospital for a thorough examination after multiple liver tumors were found in her at a nearby hospital. By liver tumor biopsy, we diagnosed them as carcinoid. Bone scintigraphy showed an abnormal accumulation in the external left scapula and in both of her hip joints, but the primary lesion was unclear. She died 8 years and 5 months after disease onset from deterioration of liver lesions, inspite of our treatments, such as gemcitabine administration of systemic chemotherapy, transcatheter arterial chemoembolization for liver lesions, and radiation therapy for bone lesions. Pathological anatomy suggested a pancreatic, well-differentiated neuroendocrine carcinoma.     

Corrective effect on Fabry mice of yeast recombinant human α-galactosidase with N-linked sugar chains suitable for lysosomal delivery

We have previously reported the production of a recombinant -galactosidase with engineered N-linked sugar chains facilitating uptake and transport to lysosomes in a Saccharomyces cerevisiae mutant. In this study, we improved the purification procedure, allowing us to obtain a large amount of highly purified enzyme protein with mannose-6-phosphate residues at the non-reducing ends of sugar chains. The products were incorporated into cultured fibroblasts derived from a patient with Fabry disease via mannose-6-phosphate receptors. The ceramide trihexoside (CTH) accumulated in lysosomes was cleaved dose-dependently, and the disappearance of deposited CTH was maintained for at least 7 days after administration. We next examined the effect of the recombinant -galactosidase on Fabry mice. Repeated intravascular administration of the enzyme led to successful degradation of CTH accumulated in the liver, kidneys, heart, and spleen. However, cleavage of the accumulated CTH in the dorsal root ganglia was insufficient. As the culture of yeast cells is easy and economical, and does not require fetal calf serum, the recombinant -galactosidase produced in yeast cells is highly promising as an enzyme source for enzyme replacement therapy in Fabry disease.     

Centrally injected angiotensin II trans-synaptically activates angiotensin II-sensitive neurons in the anterior hypothalamic area of rats

Previously, we have demonstrated that pressure-ejected application of angiotensin II onto some neurons in the anterior hypothalamic area (AHA) of rats increases their firing rate. In contrast, pressure application of the angiotensin AT1 receptor antagonist losartan onto AHA neurons blocked the basal firing of the neurons. To investigate possible participation of these AHA neurons in the brain angiotensin system, we examined whether intracerebroventricular injection of angiotensin II results in an activation of angiotensin II-sensitive neurons in the AHA of rats. Intracerebroventricular injection of angiotensin II increased the firing rate of AHA angiotensin II-sensitive neurons. The angiotensin II-induced increase of unit firing in AHA neurons was abolished by pressure application of losartan onto the same neurons. In addition, the angiotensin II-induced increase of firing in AHA neurons was abolished by pressure application of N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W7), a calmodulin inhibitor, onto the same neurons. Pressure application of W7 onto AHA neurons affected neither the basal firing rate nor the increase in unit firing induced by pressure application of angiotensin II onto the same neurons. Intracerebroventricular injection of the cholinergic agonist carbachol did not affect the firing rate of angiotensin II-sensitive neurons in the AHA. These findings suggest that intracerebroventricular injection of angiotensin II activates AHA angiotensin II-sensitive neurons via angiotensinergic inputs to the neurons.     

Potentiation of catechin gallate-mediated sensitization of Staphylococcus aureus to oxacillin by nongalloylated catechins

(-)-Epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg) reduce oxacillin resistance in mecA-containing strains of Staphylococcus aureus. Their binding to staphylococcal cells is enhanced by the nongalloyl analogues (-)-epicatechin (EC) and (-)-epigallocatechin (EGC). EC and EGC significantly increased the capacity of ECg and EGCg to reduce levels of staphylococcal oxacillin resistance.     

Agmatine suppresses mesangial cell proliferation by modulating polyamine metabolism

Polyamines play an essential role in the growth and differentiation of mammalian cells. The depletion of intracellular polyamines results in the suppression of growth. Proliferation of glomerular mesangial cells (MC) is the most common pathologic change in many forms of glomerulonephritis. Agmatine is a metabolite of arginine via arginine decarboxylase (ADC), highly expressed in the kidney, and unique in its capacity to suppress intracellular polyamine levels required for proliferation. As agmatine enters mammalian cells via the polyamine transport system, its antiproliferative effects may preferentially target cells with increased proliferative kinetics. In the present study, we evaluated the antiproliferative effects of agmatine on human MC in vitro. MC proliferation was stimulated with 20% fetal bovine serum (FBS) or platelet-derived growth factor (PDGF-BB, 20 ng/ml). Cell proliferation was measured using the (4.3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) (MTT) proliferation assay. Intracellular polyamine levels were assayed by high performance liquid chromatography, and cell death was assessed by cellular DNA fragmentation enzyme-linked immunosorbent assay. The MTT proliferation assay showed that agmatine significantly suppressed proliferation of human MC treated with 20% FBS or 5% FBS + PDGF as compared to human MC treated with 5% FBS. Polyamine levels were markedly lower in cells treated with agmatine, and proliferation was rescued by administration of putrescine. The fragmented DNA was hardly detected in agmatine-treated human MC. In summary, human MC stimulated to increase their proliferative kinetics are significantly more sensitive to the antiproliferative effects of agmatine than normally cultured cells. Suppressed proliferation of the agmatine-treated human MC is not due to increased cell death. These results suggest that agmatine is a promising drug candidate for the treatment of human mesangial proliferative glomerulonephritis.     

Preparation and characterization of laminin-derived peptide AG73-coated liposomes as a selective gene delivery tool

Targeted gene delivery to cancer cells is considered as a promising strategy for cancer therapy. Since, several targeting ligands have been studied for cancer gene therapy, such as transferrin, folate, anisamide, RGD-peptide, and antibodies. We have focused on AG73 peptide, which is derived from the globular domain of the laminin α1 chain. AG73 peptide is known as a ligand for syndecans, one of the major heparin sulfate-containing transmembrane proteoglycans. Syndecan-2 is highly expressed in various cancer cells and plays a role in angiogenesis. In this study, we prepared AG73-labeled polyethyleneglycol-modified liposomes (AG73-PEG liposomes) for gene delivery tool to syndecan-2 overexpressing cancer cells, and assessed the characterization of AG73-PEG liposomes. We confirmed the conjugation of AG73 peptide to PEG liposomes by reverse-phase high-performance liquid chromatography analysis. Electron microscopy analysis showed that monodiseperse AG73-labeled lipsomes were prepared. We also assessed the gene transfection efficiency of AG73-PEG liposomes in syndecan-2 overexpressing cancer cells or syndecan-2 less expressing cancer cells. As a result, AG73-mediated liposomal gene transfection efficiency was increased by 100-fold in syndecan-2 overexpressing cancer cells compared to syndecan-2 less expressing cancer cells. These results suggested that AG73-PEG liposomes were successfully prepared from a point of view of the modification of AG73 peptide to PEG-liposomes and the particle size of liposomes, which presented nano size. Furthermore, our results suggest that AG73-PEG liposomes can be a useful targeted gene delivery vehicle for syndecan-2 overexpressing cancer cells.