Optical fiber microwire current sensor

We demonstrate a compact optical fiber microwire current sensor based on the Faraday effect with gigahertz frequency of current sensing capabilities.

Antitumor effect of novel small chemical inhibitors of Snail-p53 binding in K-Ras-mutated cancer cells

p53 is frequently mutated by genetic alternation or suppressed by various kinds of cellular signaling pathways in human cancers. Recently, we have revealed that p53 is suppressed and eliminated from cells by direct binding with oncogenic K-Ras-induced Snail. On the basis of the fact, we generated specific inhibitors against p53-Snail binding (GN25 and GN29). These chemicals can induce p53 expression and functions in K-Ras-mutated cells. However, it does not show cytotoxic effect on normal cells or K-Ras-wild-type cells. Moreover, GN25 can selectively activate wild-type p53 in p53(WT/MT) cancer cells. But single allelic mt p53 containing cell line, Panc-1, does not respond to our chemical. In vivo xenograft test also supports the antitumor effect of GN25 in K-Ras-mutated cell lines. These results suggest that our compounds are strong candidate for anticancer drug against K-Ras-initiated human cancers including pancreatic and lung cancers.

Role of CK1 in GSK3beta-mediated phosphorylation and degradation of snail

The epithelial to mesenchymal transition (EMT) that occurs during embryonic development has begun to attract attention as a potential mechanism for tumor cell metastasis. Snail is a well-known Zn-finger transcription factor that promotes EMT by repressing E-cadherin expression. It is known that Snail is phosphorylated by GSK3beta and degraded by beta-TrCP-mediated ubiquitination. Here we described another protein kinase, CK1, whose phosphorylation of Snail is required for the subsequent GSK3beta phosphorylation. Specific inhibition or depletion of CK1varepsilon inhibits the phosphorylation and degradation of Snail and promotes cell migration, suggesting a central role of CK1varepsilon in the EMT process. Furthermore, our study uncovered distinct roles and steps of Snail phosphorylation by CK1varepsilon and GSK3beta. Taken together, we identified CK1varepsilon as a new component of the Snail-mediated EMT process, providing insight into the mechanism of human cancer metastasis.

Pharmacokinetics of oltipraz in diabetic rats with liver cirrhosis

BACKGROUND AND PURPOSE

The incidence of diabetes mellitus is increased in patients with liver cirrhosis. Oltipraz is currently in trials to treat patients with liver fibrosis and cirrhosis induced by chronic hepatitis types B and C and is primarily metabolized via hepatic cytochrome P450 isozymes CYP1A1/2, 2B1/2, 2C11, 2D1 and 3A1/2 in rats. We have studied the influence of diabetes mellitus on pharmacokinetics of oltipraz and on expression of hepatic, CYP1A, 2B1/2, 2C11, 2D and 3A in rats with experimental liver cirrhosis.

EXPERIMENTAL APPROACH

Oltipraz was given intravenously (10 mg x kg(-1)) or orally (30 mg x kg(-1)) to rats with liver cirrhosis induced by N-dimethylnitrosamine (LC rats) or with diabetes, induced by streptozotocin (DM rats) or to rats with both liver cirrhosis and diabetes (LCD rats) and to control rats, and pharmacokinetic variables measured. Protein expression of hepatic CYP1A, 2B1/2, 2C11, 2D and 3A was measured using Western blot analysis.

KEY RESULTS

After i.v. or p.o. administration of oltipraz to LC and DM rats, the AUC was significantly greater and smaller, respectively, than that in control rats. In LCD rats, the AUC was that of LC and DM rats (partially restored towards control rats). Compared with control rats, the protein expression of hepatic CYP1A increased, that of CYP2C11 and 3A decreased, but that of CYP2B1/2 and 2D was not altered in LCD rats.

CONCLUSIONS AND IMPLICATIONS

In rats with diabetes and liver cirrhosis, the AUC of oltipraz was partially restored towards that of control rats.

The usefulness of interphase fluorescence in situ hybridization at diagnosis of myeloma in addition to metaphase cytogenetics

e19558

Background: Multiple myeloma is characterized by the accumulation of malignant plasma cells within the bone marrow and regarded as incurable, but remissions may be induced with steroids, chemotherapy, thalidomide and stem cell transplants. The clinical heterogeneity of myeloma is dictated by the cytogenetic aberrations present in the clonal plasma cells. Fluorescence in situ hybridization (FISH) overcomes the limitations of standard cytogenetics and allows for the detection of numerical and structural chromosomal abnormalities in both metaphase spreads and interphase nuclei. Methods: We evaluated the chromosome abnormalities in 34 MM patients using conventional cytogenetics and interphase FISH with 6 probes such as IGH/CCND1, IGH/FGFR3, IGH/MAF, DS13S319/LAMP1, IGH/BAP, and p53/CEP17. Results: Cytogenetic abnormalities were found in 24 (70.6%) of the 28 MM patients. 10 (35.7%) patients had abnormal metaphases by conventional cytogenetics. Interphase FISH results were abnormal in 21 (61.8%) patients and 11 (52.3%) patients had abnormal interphase FISH but normal metaphases. The evidence of the loss of D13S319 with or without loss of LAMP1 was found in 6 (21.4%) patients, and loss of p53±CEP17 for 2 patients, IGH-BAP for 9 (26.5%) patients, IGH/FGFR3 for 2 patients, and IGH/CCND1 for 7 (20.6%) patients, respectively. However, there were none positive for IGH/MAF. Chromosome 13 abnormalities and IGH rearrangement is correlated with poor clinical outcome. Conclusions: Interphase FISH can provide useful information to evaluate the presence of prognostic chromosome abnormalities in addition to metaphase cytogenetics. And it should be used in the routine evaluation of multiple myeloma.

No significant financial relationships to disclose.

The hedgehog pathway regulates remodelling responses to biliary obstruction in rats

BACKGROUND

Chronic biliary obstruction provokes fibrosis and accumulation of immature ductular cells. This fibroductular reaction resolves following biliary decompression, suggesting that it may also be involved in the repair of biliary damage. The hedgehog (Hh) pathway becomes activated in liver after bile duct ligation (BDL), and might modulate hepatic remodelling because Hh ligands are potent morphogens.

OBJECTIVE

To study the induction of the Hh pathway during progression and resolution of biliary fibrosis, and to clarify whether Hh signalling regulates accumulation of bile duct progenitor cells.

DESIGN AND MAIN OUTCOME MEASURES

Livers from rats with BDL were examined by quantitative real-time polymerase chain reaction analysis and immunohistochemistry to identify factors that might stimulate Hh signalling. BDL rats were subjected to Roux-en-Y hepaticojejunostomy (R-Y) to relieve biliary obstruction in order to determine whether these factors and Hh signalling declined as ductular populations and concomitant fibrosis regressed. Cultures of immature ductular cells were treated with putative Hh inducers and Hh ligands to confirm their functional relevance.

RESULTS

BDL increased expression of platelet-derived growth factor-BB (PDGF-BB) and sonic hedgehog (Shh), downregulated hedgehog-interacting protein (Hip), activated Hh signalling, and expanded populations of Hh-responsive ductular cells that expressed pancyotkeratin, a liver progenitor cell marker. After R-Y, Hip remained suppressed, expression of PDGF-BB and Shh gradually declined, and populations of hedgehog-responsive ductular cells regressed. In cultured ductular cells, PDGF-BB treatment induced Shh expression, and incubation with Shh inhibited apoptotic activity.

CONCLUSIONS

These results identify a mechanism for activation of the Hh pathway during cholestasis and suggest that Hh signalling regulates ductular cell accumulation after biliary injury.