Chondrosarcoma of the urinary bladder and establishment of a human chondrosarcoma cell line (OCUU-6)

Chondrosarcoma is a very rare tumor of the urinary bladder, with only 4 cases reported to date. In this study, we report on a case of a 73-year-old male who presented bladder mass and right hydroureteronephrosis. Radical cystectomy, right nephrectomy and left ureterocutaneoustomy were performed, and histological study disclosed chondrosarcoma of the urinary bladder. As reported in other cases, the tumor was highly aggressive with a short clinical course, and the patient died of carcinomatous pleuritis at one month after surgery. Subsequently, we successfully established a human chondrosarcoma cell line (OCUU-6) from the pleural effusion of the patient.     

Large-scale analysis of the genes involved in fin regeneration and blastema formation in the medaka, Oryzias latipes

Medaka is an attractive model to study epimorphic regeneration. The fins have remarkable regenerative capacity and are replaced about 14 days after amputation. The formation of blastema, a mass of undifferentiated cells, is essential for regeneration; however, the molecular mechanisms are incompletely defined. To identify the genes required for fin regeneration, especially for blastema formation, we constructed cDNA libraries from fin regenerates at 3 days postamputation and 10 days postamputation. A total of 16,866 expression sequence tags (ESTs) were sequenced and subjected to BLASTX analysis. The result revealed that about 60% of them showed strong matches to previously identified proteins, and major signaling molecules related to development, including FGF, BMP, Wnt, Notch/Delta, and Ephrin/Eph signaling pathways were isolated. To identify novel genes that showed specific expression during fin regeneration, cDNA microarray was generated based on 2900 independent ESTs from each library which had no sequence similarity to known proteins. We obtained 6 candidate genes associated with blastema formation by gene expression pattern screening in competitive hybridization analyses and in situ hybridization. Olrfe16d23 and olrfe14k04 were expressed only in early regenerating stages when blastema formation was induced. The expression of olrf5n23, which encodes a novel signal peptide, was detected in wound epidermis throughout regeneration. Olrfe23l22, olrfe20n22, and olrfe24i02 were expressed notably in the blastema region. Our study has thus identified the gene expression profiles and some novel candidate genes to facilitate elucidation of the molecular mechanisms of fin regeneration.     

A CAF-1 dependent pool of HP1 during heterochromatin duplication

To investigate how the complex organization of heterochromatin is reproduced at each replication cycle, we examined the fate of HP1-rich pericentric domains in mouse cells. We find that replication occurs mainly at the surface of these domains where both PCNA and chromatin assembly factor 1 (CAF-1) are located. Pulse-chase experiments combined with high-resolution analysis and 3D modeling show that within 90 min newly replicated DNA become internalized inside the domain. Remarkably, during this time period, a specific subset of HP1 molecules (alpha and gamma) coinciding with CAF-1 and replicative sites is resistant to RNase treatment. Furthermore, these replication-associated HP1 molecules are detected in Suv39 knockout cells, which otherwise lack stable HP1 staining at pericentric heterochromatin. This replicative pool of HP1 molecules disappears completely following p150CAF-1 siRNA treatment. We conclude that during replication, the interaction of HP1 with p150CAF-1 is essential to promote delivery of HP1 molecules to heterochromatic sites, where they are subsequently retained by further interactions with methylated H3-K9 and RNA.     

2-Ureidoquinoline: a useful molecular element for stabilizing single cytosine and thymine bulges

We have demonstrated that aromatic heterocycles having hydrogen-bonding surfaces complementary to those of nucleotide bases are effective molecular elements for the binding to single nucleotide bulges and base mismatches. We here report that a new molecule, 2-ureidoquinoline having an alignment of hydrogen-bonding groups in the order of acceptor-donor-donor stabilizes single cytosine and thymine bulges in duplex DNAs. Furthermore, a dimeric form of 2-ureidoquinoline stabilizes cytosine-cytosine and cytosine-thymine mismatches.     

Edaravone inhibits acute renal injury and cyst formation in cisplatin-treated rat kidney

Background: Although cis-diamminedichloroplatinum (II) (cisplatin) is an effective anticancer agent, its clinical use is highly limited predominantly due to its adverse effects on renal functions. The present work examined the therapeutic potential of edaravone, a free radical scavenger, for inhibiting cisplatin-induced renal injury.

Methods: Edaravone, 3-methyl-1-phenyl-pyrazolin-5-one, was administrated intravenously at a dose of 30 mg/kg of body weight to male Wistar rats (200-220 g). After 30 min, cisplatin was injected intraperitoneally at a dose of 5 mg/kg of body weight. At the indicated times after the treatment, functions and histological changes of the kidney were analyzed. To test the therapeutic potential of edaravone in chemotherapy, its effect on the anticancer action of cisplatin was examined in ascites cancer-bearing rats.

Results: We found that cisplatin rapidly impaired the respiratory function and DNA of mitochondria in renal proximal tubules, thereby inducing apoptosis of tubular epithelial cells within a few days and chronic renal dysfunction associated with multiple cysts one-year after the administration. Administration of edaravone inhibited the cisplatin-induced acute injury of mitochondria and their DNA and renal epithelial cell apoptosis as well as the occurrence of chronic renal dysfunction and multiple cyst formation. The anticancer effect of cisplatin remained unaffected by intravenous administrating of edaravone.

Conclusions: These results indicate that edaravone may have therapeutic potential for inhibiting the acute and chronic injury of the kidney induced by cisplatin.     

Possible novel therapy for diabetes with cell-permeable JNK-inhibitory peptide

The JNK pathway is known to be activated in several tissues in the diabetic state, and is possibly involved in the development of insulin resistance and suppression of insulin biosynthesis. Here we show a potential new therapy for diabetes using cell-permeable JNK-inhibitory peptide. Intraperitoneal administration of the peptide led to its transduction into various tissues in vivo, and this treatment markedly improved insulin resistance and ameliorated glucose tolerance in diabetic mice. These data indicate that the JNK pathway is critically involved in diabetes and that the cell-permeable JNK-inhibitory peptide may have promise as a new therapeutic agent for diabetes.     

Contribution of membrane-associated prostaglandin E2 synthase to bone resorption

This study initially confirmed that, among prostaglandins (PGs) produced in bone, only PGE(2) has the potency to stimulate osteoclastogenesis and bone resorption in the mouse coculture system of osteoblasts and bone marrow cells. For the PGE(2) biosynthesis two isoforms of the terminal and specific enzymes, membrane-associated PGE(2) synthase (mPGES) and cytosolic PGES (cPGES) have recently been identified. In cultured mouse primary osteoblasts, both mPGES and cyclooxygenase-2 were induced by the bone resorptive cytokines interleukin-1, tumor necrosis factor-alpha, and fibroblast growth factor-2. Induction of mPGES was also seen in the mouse long bone and bone marrow in vivo by intraperitoneal injection of lipopolysaccharide. In contrast, cPGES was expressed constitutively both in vitro and in vivo without being affected by these stimuli. An antisense oligonucleotide blocking mPGES expression inhibited not only PGE(2) production, but also osteoclastogenesis and bone resorption stimulated by the cytokines, which was reversed by addition of exogenous PGE(2). We therefore conclude that mPGES, which is induced by and mediates the effects of bone resorptive stimuli, may make a target molecule for the treatment of bone resorptive disorders.     

Coupling between cyclooxygenases and prostaglandin F(2alpha) synthase. Detection of an inducible,glutathione-activated,membrane-bound prostaglandin F(2alpha)-synthetic activity

Distinct functional coupling between cyclooxygenases (COXs) and specific terminal prostanoid synthases leads to phase-specific production of particular prostaglandins (PGs). In this study, we examined the coupling between COX isozymes and PGF synthase (PGFS). Co-transfection of COXs with PGFS-I belonging to the aldo-keto reductase family into HEK293 cells resulted in increased production of PGF(2alpha) only when a high concentration of exogenous arachidonic acid (AA) was supplied. However, this enzyme failed to produce PGF(2alpha) from endogenous AA, even though significant increase in PGF(2alpha) production occurred in cells transfected with COX-2 alone. This poor COX/PGFS-I coupling was likely to arise from their distinct subcellular localization. Measurement of PGF(2alpha)-synthetic enzyme activity in homogenates of several cells revealed another type of PGFS activity that was membrane-bound, glutathione (GSH)-activated, and stimulus-inducible. In vivo, membrane-bound PGFS activity was elevated in the lung of lipopolysaccharide-treated mice. Taken together, our results suggest the presence of a novel, membrane-associated form of PGFS that is stimulus-inducible and is likely to be preferentially coupled with COX-2.     

Akt is an endogenous inhibitor toward tumor necrosis factor-related apoptosis inducing ligand-mediated apoptosis in rheumatoid synovial cells

Akt is known to be activated in the rheumatoid synovial tissues. We examined here functional role of Akt during tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-mediated apoptosis in rheumatoid synovial cells. Rheumatoid synovial cells in vitro were rapidly committed to apoptosis in response to TRAIL in mitochondria-dependent manner whereas Akt and extracellular signal-regulated kinase (ERK) were also phosphorylated. TRAIL-mediated apoptosis in synovial cells was significantly increased through inactivation of Akt by LY294002, however, that process was not so changed by adding ERK inhibitor, PD98059. Platelet-derived growth factor (PDGF) clearly phosphorylated both Akt and ERK in synovial cells, and PDGF pretreatment markedly suppressed TRAIL-mediated synovial cell apoptosis. The use of not PD98059 but LY294002 abrogated PDGF-mediated inhibitory effect toward TRAIL-induced apoptosis in synovial cells. The above protective effect of Akt was confirmed by the use of short interfering RNA (siRNA)-directed inhibition of Akt. Our data suggest that Akt is an endogenous inhibitor during TRAIL-mediated synovial cell apoptotic pathway, which may explain that synovial cells in situ of the rheumatoid synovial tissues are resistant toward apoptotic cell death in spite of death receptor expression.     

Cytology of basaloid squamous carcinoma of the bronchus. A case report

BACKGROUND: The cytologic appearance of basaloid squamous carcinoma (BSC) arising in the lower respiratory tract has not been described very well because of its rarity. This article describes a surgical case of bronchial BSC and provides the first documentation of the sputum and imprint cytologic features of the tumor. CASE: A 74-year-old man presented with hemoptysis. An abnormal intrabronchial mass was revealed by computed tomography and bronchoscopy. Preoperative cytology and biopsy showed that the mass was composed of small, round, atypical cells, but correct diagnosis was difficult. Under a tentative diagnosis of small round cell carcinoma, a right lobectomy was performed. The resected tumor was composed of small cells showing peripheral palisading and partial epidermoid differentiation. There was no glandular differentiation. Focal necrosis was also noted. Immunohistochemical markers for smooth muscle and neuroendocrine cells were negative. The tumor was eventually diagnosed as BSC or basaloid carcinoma (BC) with squamous differentiation. CONCLUSION: It is important to recognize this disease, especially when undetermined small round cell carcinoma is noted in cytologic specimens, in order to properly assess prognosis. Cytologic detection of nuclear palisading of the neoplastic cells, one of the hallmarks of the disease, may be difficult, however, careful examination to reveal neoplastic cells showing squamous differentiation appears helpful for diagnosis.