TNP-470, an angiogenesis inhibitor, suppresses the progression of peritoneal fibrosis in mouse experimental model

BACKGROUND: In patients on long-term peritoneal dialysis (PD), angiogenesis and vasculopathy are observed in the peritoneum, and the degree of vascularization correlates with the area of fibrotic tissue, suggesting the involvement of angiogenesis in the progression of peritoneal fibrosis. The aim of the present study was to evaluate the effect of TNP-470, an anti-angiogenic compound, on the development of peritoneal fibrosis induced by chlorhexidine gluconate (CG). METHODS: Peritoneal fibrosis was induced by injection of CG into peritoneal cavity of Institute for Cancer Research (ICR) mice. TNP-470 was injected subcutaneously with CG. Mice were sacrificed, and peritoneal tissues were dissected out at days eight and 16 after CG and TNP-470 injection. The expression patterns of CD31 (as a marker of endothelial cells), vascular endothelial cell growth factor (VEGF), alpha-smooth muscle actin (as a marker of myofibroblasts), heat shock protein 47 (HSP47), type III collagen, F4/80 (as a marker of mice macrophages), proliferating cell nuclear antigen (PCNA), and cyclin-dependent kinase 2 (Cdk2) were examined by immunohistochemistry. RESULTS: CG-injected mice showed thickening of the submesothelial zone and increased number of vessels, myofibroblasts, and infiltrating macrophages. The expression levels of VEGF, type III collagen, and HSP47 were increased, and a large number of PCNA-positive cells and Cdk2-expressing cells were observed in the thickened submesothelial area. Treatment with TNP-470 suppressed the submesothelial zone thickening and reduced collagen III expression as well as angiogenesis. TNP-470 also decreased the number of VEGF-expressing cells, myofibroblasts, macrophages, PCNA-positive cells, and Cdk2-expressing cells. CONCLUSION: Our results indicate the involvement of angiogenesis in the progression of peritoneal fibrosis, and suggest that TNP-470 may be potentially useful for the prevention of peritoneal fibrosis through inhibition of angiogenesis and suppression of myofibroblast proliferation.     

Aberrant nuclear/cytoplasmic localization and gene mutation of beta-catenin in classic pulmonary blastoma: beta-catenin immunostaining is useful for distinguishing between classic pulmonary blastoma and a blastomatoid variant of carcinosarcoma

It is now known that gene mutation of beta-catenin with subsequent nuclear/cytoplasmic (N/C) overaccumulation of the protein plays an important role in tumorigenesis of various organs. We recently demonstrated that low-grade adenocarcinoma of the fetal lung type (L-FLAC)/well-differentiated fetal adenocarcinoma (WDFA), the epithelial prototype of classic pulmonary blastoma (CPB), shows N/C localization of beta-catenin with genetic mutation. This prompted us to further investigate the state of beta-catenin abnormality in CPB and related neoplasms. We studied 9 lung tumors previously diagnosed as biphasic pulmonary blastoma (PB). Histologically, 4 cases (median age 34 years) were CPB with l-FLAC/WDFA as the epithelial component, whereas 5 cases (median age 65 years) were a variant of carcinosarcoma with high-grade FLAC/clear cell adenocarcinoma with fetal lung features as the epithelial component, which we term the blastomatoid variant of carcinosarcoma (BCS). Immunohistochemically, all 4 CPBs showed aberrant N/C localization of beta-catenin both in the epithelial and mesenchymal components, with especially high staining intensity in the budding glands and morules. In contrast, all 5 BCSs showed preserved or diminished membranous expression and no significant N/C expression of beta-catenin in the epithelial component, and absent or focal N/C expression of beta-catenin in the mesenchymal component. Mutational analysis of exon 3 of the beta-catenin gene revealed that 3 CPBs harbored missense mutations (S29F, S37F, and S37F), whereas none of the 5 BCSs had this mutation. This study suggests that beta-catenin gene mutations may play a role in the tumorigenesis of CPB. Although CPB and BCS have often been grouped together as biphasic PB, they are different entities based on immunohistochemical and molecular analysis of beta-catenin. Immunostaining for beta-catenin is useful for the discrimination.     

Active chemotherapy with gemcitabine, carboplatin and docetaxel for three patients with MVAC-resistant liver metastasis of urothelial carcinoma

We report three cases with methotrexate-vinblastin-adriamycin-cisplatin (MVAC) resistant multiple liver metastases of urothelial carcinoma that responded to combination chemotherapy consisting of gemcitabine plus carboplatin (GC) with additional docetaxel (GCD) as salvage chemotherapy. Case 1: A 55-year-old man underwent left nephroureterectomy for ureteral cancer (TCC, G3, pT3pN1M0). Three courses of GC followed by three courses of GCD were given via intra-hepatic arterial infusion for multiple liver metastases, which appeared after adjuvant high-dose MVAC therapy. Complete response was obtained and maintained for 11 months. Case 2: A 46-year-old man underwent radical cystectomy for locally advanced bladder cancer (TCC G3 + adenocarcinoma. pT3pN0M0). Two courses of GC followed by 2 courses of GCD systemic therapies were performed for multiple liver metastases, which appeared after adjuvant high-dose MVAC therapy. Partial response was obtained and maintained for six months. Case 3: A 66-year-old man received three courses of MVAC for multiple metastases of the bladder cancer (TCC, G3, > pT2), which resulted in disease progression. Eight courses of GC followed by six courses of GCD were administrated via intra-hepatic arterial infusion. Partial response was obtained and maintained for 12 months. Although the response duration was still short, GC and GCD may be promising salvage chemotherapeutic regimens for the patients with MVAC-resistant liver metastases of urothelial carcinoma.     

Involvement of OCTN1 (SLC22A4) in pH-dependent transport of organic cations

OCTN1 (SLC22A4) transports cationic compounds such as tetraethylammonium in a pH-sensitive and sodium-independent manner in cultured cells, and is expressed in wide variety of tissues, including kidney, muscle, placenta, heart, and others. This study focused on the clarification of its subcellular distribution in kidney and on its driving force to throw light on the pharmacological and physiological roles of OCTN1. Uptake of [14C]tetraethylammonium by membrane vesicles prepared from HEK293 cells stably transfected with human OCTN1 cDNA was osmolarity-sensitive, and the Km of tetraethylammonium was 1.28 mM at intravesicular and extravesicular pH values of 6.0 and 7.4, respectively. Tetraethylammonium uptake was pH-dependent, and overshoot uptake was observed in the presence of an outwardly directed proton gradient. A protonophore and membrane potential affected the overshoot uptake. Furthermore, preloading tetraethylammonium in the vesicles significantly increased the rate of uptake of [14C]tetraethylammonium. In mouse kidney, OCTN1 was expressed predominantly at the apical membrane of cortical proximal tubular epithelial cells. It was concluded that OCTN1 is involved in renal excretion of organic cations across the apical membrane in a pH-dependent, membrane potential-sensitive manner and is affected significantly by the organic cations on the trans side, showing counter transport activity.     

Remarkable improvement of myocardial metaiodobenzylguanidine uptake after surgery in a patient with pheochromocytoma-a case report

A patient with pheochromocytoma showed remarkable improvement of myocardial metaiodobenzylguanidine (MIBG) uptake within a short time after surgical resection of the tumor. Myocardial MIBG findings in this case may contribute to an interpretation of the kinetics of MIBG in the human heart.     

Aftereffects of mechanical vibration and muscle contraction on limb position-sense

Mechanical vibration (MV) of a muscle causes position-sense errors during and after application. Isometric muscle contraction at a shorter (hold-short conditioning) or longer (hold-long conditioning) length causes limb position-sense errors after the muscle returns to its intermediate length by means of intrafusal muscle thixotropy. However, it is unclear whether MV enhances these thixotropic position-sense errors. We studied the after-effects of MV on position-sense errors induced by hold-short and hold-long conditioning in the biceps of 12 healthy men. After hold-short conditioning, subjects perceived that the conditioned forearm was placed in a more extended position than occurred in reality; after hold-long conditioning, a more flexed position was perceived. Use of MV with hold-short or hold-long conditioning enhanced both errors, which were most obvious at 100 HZ. These results suggest that MV and muscle conditioning work together efficiently to develop intrafusal muscle thixotropy. MV combined with hold-long conditioning may alleviate thixotropically increased muscle stiffness, such as in spastic hypertonia.     

Characterization of Klebsiella pneumoniae and Escherichia coli strains that produce CTX-M-2-type broad spectrum beta-lactamase isolated from a child with leukemia

An 8-year-old girl with acute leukemia had bacteremia caused by Klebsiella pneumoniae producing CTX-M-2-type broad spectrum beta-lactamase. K. pneumoniae and Escherichia coli strains producing the same enzyme and harboring identical conjugative plasmids were recovered from stoor culture. Patients with frequent episodes of neutropenia and prophylactic administration of beta-lactams are at risk of harboring colonizing strains that produce broad spectrum beta-lactamases.     

Differential role of tissue factor pathway inhibitors 1 and 2 in melanoma vasculogenic mimicry

Vasculogenic mimicry (VM), the formation of matrix-rich vascular-like networks in three-dimensional culture corresponding with the expression of vascular cell-associated genes, and the lining of matrix-rich networks in situ, has been observed in highly aggressive and malignant melanoma. However, little is known about the molecular underpinnings of this phenomenon. On the basis of gene profiling, protein detection, and immunohistochemistry, aggressive relative to poorly aggressive melanoma showed up-regulation of tissue factor (TF), TF pathway inhibitor 1 (TFPI-1) and 2 (TFPI-2), critical genes that initiate and regulate the coagulation pathways. The procoagulant function of TF on highly aggressive melanoma is shown to be regulated by TFPI-1 but not by TFPI-2. Thus, aggressive melanoma exhibits endothelial cell-like anticoagulant mechanisms that may contribute to the fluid-conducting potential of melanoma cell-lined networks, as studied by correlative in vivo Doppler flow measurements. Antibody inhibition experiments reveal that TFPI-2 is required for VM in vitro, but plasmin is an unlikely target protease of TFPI-2. Blockade of TFPI-2 suppressed matrix metalloproteinase-2 activation, and, therefore, TFPI-2 appears to regulate an essential pathway of VM. TFPI-2 is synthesized by endothelial and tumor cells, which deposit TFPI-2 into extracellular matrices. Culturing poorly aggressive melanoma cells on three-dimensional matrix containing recombinant TFPI-2 produces some of the phenotypic changes associated with aggressive, vasculogenic melanoma cells. Thus, TFPI-2 contributes to VM plasticity, whereas TFPI-1 has anticoagulant functions of relevance for perfusion of VM channels formed by TF-expressing melanoma cells.