Synthesis and antitumor activity of arginine–glucosamine conjugate

Using d-glucosamine hydrochloride (GlcNH₂·HCl) as starting material, a new amino acid sugar conjugate, arginine–glucosamine (Arg–GlcNH₂), was synthesized and characterized by infrared spectroscopy, ¹³C NMR and element analysis. Its cytotoxicity in vitro was evaluated by MTT assay. The inhibition ratio against human hepatoma cell SMMC-7721 was higher than that of GlcNH₂·HCl. This effect was accompanied by a marked increase in the proportion of S cells as analyzed by flow cytometry. In addition, SMMC-7721 cells treated with Arg–GlcNH₂ resulted in the induction of apoptosis as assayed qualitatively by agarose gel electrophoresis. The manner of Arg–GlcNH₂ cytocidal activity was concluded to be apoptosis.     

ent-Abietane diterpenoids from Isodon rubescens var. rubescens

ent-Abietane diterpenoids, hebeiabinins A-F (1-5), together with seven known diterpenoids were isolated from leaves of Isodon rubescens var. rubescens. The structures of 1-5 were established on the basis of spectroscopic analyses, including application of 2D NMR spectroscopic techniques. The diterpenoids isolated were evaluated for the cytotoxicity against A549, HT-29, and K562 tumor cells. Compound 5 was the most active with IC(50) value of 0.91 microM against A549 cells.     

Smad7 antagonizes transforming growth factor beta signaling in the nucleus by interfering with functional Smad-DNA complex formation

Smad7 plays an essential role in the negative-feedback regulation of transforming growth factor beta (TGF-beta) signaling by inhibiting TGF-beta signaling at the receptor level. It can interfere with binding to type I receptors and thus activation of receptor-regulated Smads or recruit the E3 ubiquitin ligase Smurf to receptors and thus target them for degradation. Here, we report that Smad7 is predominantly localized in the nucleus of Hep3B cells. The targeted expression of Smad7 in the nucleus conferred superior inhibitory activity on TGF-beta signaling, as determined by reporter assay in mammalian cells and by its effect on zebrafish embryogenesis. Furthermore, Smad7 repressed Smad3/4-, Smad2/4-, and Smad1/4-enhanced reporter gene expression, indicating that Smad7 can function independently of type I receptors. An oligonucleotide precipitation assay revealed that Smad7 can specifically bind to the Smad-responsive element via its MH2 domain, and DNA-binding activity was further confirmed in vivo with the promoter of PAI-1, a TGF-beta target gene, by chromatin immunoprecipitation. Finally, we provide evidence that Smad7 disrupts the formation of the TGF-beta-induced functional Smad-DNA complex. Our findings suggest that Smad7 inhibits TGF-beta signaling in the nucleus by a novel mechanism.     

Synthesis and anti-inflammatory activity of N-phthalimidomethyl 2,3-dideoxy- and 2,3-unsaturated glycosides

3,4,6-Tri-O-acetyl-D-galactal, 3,4,6-tri-O-acetyl-D-glucal and 3,6,2',3',4'6'-hexa-O-acetyl-D-lactal were reacted with N-hydroxymethylphthalimide and boron trifluoride etherate to produce the corresponding phthalimidomethyl unsaturated glycosides via Ferrier rearrangement. When the galactal derivative was used, a non-Ferrier rearrangement product was also isolated as a minor product under classical Ferrier conditions. Phthalimidomethyl deoxy glycosides were readily prepared by hydrogenation of the unsaturated glycosides. Following deacetylation, the anti-inflammatory activities of these compounds were tested on mice and three were found to possess potent activity compared to hydrocortisone sodium succinate (HSS).     

Retrospective Analysis of 234 Nasopharyngeal Carcinoma Patients with Distant Metastasis at Initial Diagnosis: Therapeutic Approaches and Prognostic Factors

Purpose

The purpose of this retrospective study was to identify the independent prognostic factors and optimize the treatment for nasopharyngeal carcinoma (NPC) patients with distant metastasis at initial diagnosis.

Methods

A total of 234 patients referred between January 2001 and December 2010 were retrospectively analyzed. Among the 234 patients, 94 patients received chemotherapy alone (CT), and 140 patients received chemoradiotherapy (CRT). Clinical features, laboratory parameters and treatment modality were examined with univariate and multivariate analyses.

Results

The median overall survival (OS) time was 22 months (range, 2-125 months), and the 1-year, 2-year, 3-year overall survival rates were 82.2%, 51.3% and 34.1%. The overall response and disease control rates of metastatic lesions after chemotherapy were 56.0% and 89.8%. The factors associated with poor response were karnofsky performance score (KPS) <80, liver metastasis, lactate dehydrogenase (LDH)>245 IU/L, and number of chemotherapy cycles <4. The 3-year OS of patients receiving CRT was higher than those receiving CT alone (48.2% vs. 12.4%, p<0.001). Subgroup analysis showed that significantly improved survival was also achieved by radiotherapy of the primary tumor in patients who achieved complete remission (CR)/partial remission (PR) or stable disease (SD) of metastatic lesions after chemotherapy. Significant independent prognostic factors of OS were KPS, liver metastasis, levels of LDH, and multiple metastases. Treatment modality, response to chemotherapy and chemotherapy cycles were also associated with OS.

Conclusion

A combination of radiotherapy and chemotherapy seems to have survival benefits for selected patients with distant metastases at initial diagnosis. Clinical and laboratory characteristics can help to guide treatment selection. Prospective randomized studies are needed to confirm the result.     

In vitro development of reconstructed porcine oocytes after somatic cell nuclear transfer

This study was designed to examine the developmental ability of porcine embryos after somatic cell nuclear transfer. Porcine fibroblasts were isolated from fetuses at Day 40 of gestation. In vitro-matured porcine oocytes were enucleated and electrically fused with somatic cells. The reconstructed eggs were activated using electrical stimulus and cultured in vitro for 6 days. Nuclear-transferred (NT) embryos activated at a field strength of 120 V/mm (11.6 +/- 1.6%) showed a higher developmental rate as compared to the 150-V/mm group (6.5 +/- 2.3%) (P: < 0.05), but the mean cell numbers of blastocysts were similar between the two groups. Rates of blastocyst development from NT embryos electrically pulsed at different times (2, 4, and 6 h) after electrofusion were 11.6 +/- 2.9, 6.6 +/- 2.3, and 8.1 +/- 3.3%, respectively. The mean cell numbers of blastocysts developed from NT embryos were gradually decreased (30.4 +/- 10.4 > 24.6 +/- 10.1 > 16.5 +/- 7.4 per blastocyst) as exposure time (2, 4, and 6 h) of nuclei to oocyte cytoplast before activation was prolonged. There was a significant difference in the cell number between the 2- and 6-h groups (P: < 0. 05). Nuclear-transferred embryos (9.4 +/- 0.9%) had a lower developmental rate than in vitro fertilization (IVF)-derived (21.4 +/- 1.9%) or parthenogenetic embryos (22.4 +/- 7.2%) (P: < 0.01). The mean cell number (28.9 +/- 11.4) of NT-derived blastocysts was smaller than that (38.6 +/- 10.4) of IVF-derived blastocysts (P: < 0. 05) and was similar to that (29.9 +/- 12.1) of parthenogenetic embryos. Our results suggest that porcine NT eggs using somatic cells after electrical activation have developmental potential to the blastocyst stage, although with smaller cell numbers compared to IVF embryos.     

Synthesis and evaluation of benzoxazole derivatives as 5-lipoxygenase inhibitors

5-Lipoxygenase (5-LOX) is important enzyme in the biosynthesis of leukotrienes, and is a potential target in the treatment of asthma and allergy. We designed and synthesized a series of benzoxazoles and benzothiazoles as 5-LOX inhibitors. Fourteen compounds prepared showed the inhibition of LTC4 formation with IC₅₀ value of 0.12–23.88 μM. Also two compounds 2d and 2g showed improved airway hypersensitiveness.     

Purification of a bioactive recombinant human Reg IV expressed in Escherichia coli

Regenerating gene (Reg) IV is a newly discovered member of the regenerating gene family belonging to the calcium (C-type) dependent lectin superfamily. Reg IV is highly expressed in the gastrointestinal tract and markedly up-regulated in colon adenocarcinoma, pancreatic cancer, gastric adenocarcinoma, and inflammatory bowel disease. However, the physiological and pathological functions of Reg IV are largely unknown, partly due to the limited access of the bioactive protein. We report here the first expression and purification of Reg IV proteins using a prokaryotic system. Human Reg IV was expressed in Escherichia coli as an insoluble protein which was identified in the fraction of inclusion body after ultrasonication of the bacteria. After the protein aggregate was solubilized by guanidine–HCl, it was refolded by sucrose and arginine-assisted procedures and purified using cation-exchange chromatography. The protein identity and purity of the final preparation were confirmed by analysis of the protein mass and immune specificity in SDS–PAGE, Western blotting, and HPLC assay. The biological activity of the protein was determined by the HCT116 and HT29 cell proliferation assays. The highly purified bioactive human Reg IV should aid in further characterization of its physiological and pathological functions.