Positron emission tomography imaging of a novel Anxa1-targeted peptide 18 F-Al-NODA-Bn-p-SCN-GGGRDN-IF7 in A431 cancer mouse models.

Annexin 1 (Anxa1) is a highly specific surface marker of tumor vasculature in the lung and prostate solid tumors. The IF7 peptide was modified with a hydrophilic linker, GGGRDN, and coupled with a new bifunctional chelating agent NODA-Bn-p-SCN. The resulting peptides (NODA-Bn-p-SCN-GGGRDN-IF7) were successfully labeled with Al18 F. The targeting characteristics of the radiolabeled peptides were evaluated in the Anxa1 positive A431 tumor model. Micro-positron emission tomography (micro-PET) imaging revealed that the A431 tumors were clearly visualized (5.74 ± 1.13%ID/g, 3.92 ± 0.78%ID/g and 1.30 ± 0.43%ID/g at 0.5, 1, and 2 h post-injection, respectively). Anxa1 binding specificity was also demonstrated by reduced tumor uptake after co-injection with excessive unlabeled GGGRDN-IF7 peptide at 30, 60, and 120 min post-injection. 18 F-Al-NODA-Bn-p-SCN-GGGRDN-IF7 might be a potential PET imaging agent for detecting Anxa1 levels in cancers due to the favorable characteristics such as convenient synthesis, specific Anxa1 targeting, and good tumor uptakes.

Epigynumgenane-type pregnane glycosides from Epigynum cochinchinensis and their immunosuppressive activity.

Five undescribed C21 pregnane glycosides, epigycosides D-H, together with four known analogues, two lignans, and a flavonoid have been isolated from the stems of Epigynum cochinchinensis. The structures of pregnane glycosides were elucidated using spectroscopic techniques and acid hydrolysis. The in vitro immunological activities were assessed against Con A-stimulated proliferation of mice splenocytes. The C21 pregnane glycosides showed immunosuppressive activity in a concentration-dependent manner. Moreover, epigycoside E exhibited a potent immunosuppressive effect, and the IC50 value on Con A-stimulated mice splenocytes was 22.1 ±â€¯6.4 µM. Epigycoside E also caused G0/G1 arrest, and inhibited TNF-α and IL-2 production.

Structural characterization and immunosuppressive activity of a new pregnane glycoside from Epigynum cochinchinensis.

Phytochemical investigation on the ethyl acetate fraction of the leaves of Epigynum cochinchinensis led to the isolation of a new C21 pregnane glycoside, epigycoside B (1), together with three known analogues. Their structures were elucidated on the basis of extensive spectroscopic techniques, including UV, MS, and NMR experiments, as well as the chemical methods. Compound 1 displayed in vitro immunosuppressive activity against concanavalin A (Con A)/Lipopolysaccharides (LPS)-stimulated proliferation of mice splenocyte. The activity was significant as compared with control group at 50 µM concentration.

Synthesis and biological assessment of folate-accepted developer (99m)Tc-DTPA-folate-polymer.

A novel cancer-targetable folate-poly(2-hydroxyethyl methacrylate) (PFDH) copolymer containing DTPA segment was prepared by conventional chemical synthesis and labeled with (99m)Tc subsequently. The (99m)Tc-labled PFDH could be produced easily with high radiochemical yield of 91% and radiochemical purity of 95%. The LogP octanol-water value for the (99m)Tc-labled PFDH was -2.19 and the radiotracer was stable in phosphate-buffered saline and human serum for 2h (>95% in PBS or ∼90% in human serum). To investigate (99m)Tc-labled PFDH tumor targeting, the in vitro and in vivo stability, cell uptake, in vivo biodistribution, and SPECT imaging were evaluated, respectively. These preliminary results strongly suggest that the novel folate conjugated dendrimer maybe developed to be potential for delivery of therapeutic radionuclides.

Preliminary studies of (99m)Tc-memantine derivatives for NMDA receptor imaging.

INTRODUCTION: Novel technetium-labeled ligands, (99m)Tc-NCAM and (99m)Tc-NHAM were developed from the N-methyl-d-aspartate (NMDA) receptor agonist memantine as a lead compound by coupling with N(2)S(2). This study evaluated the binding affinity and specificity of the ligands for the NMDA receptor. METHODS: Ligand biodistribution and uptake specificity in the brain were investigated in mice. Binding affinity and specificity were determined by radioligand receptor binding assay. Three antagonists were used for competitive binding analysis. In addition, uptake of the complexes into SH-SY5Y nerve cells was evaluated. RESULTS: The radiochemical purity of (99m)Tc-labeled ligands was more than 95%. Analysis of brain regional uptake showed higher concentration in the frontal lobe and specific uptake in the hippocampus. (99m)Tc-NCAM reached a higher target to nontarget ratio than (99m)Tc-NHAM. The results indicated that (99m)Tc-NCAM bound to a single site on the NMDA receptor with a K(d) of 701.21 nmol/l and a B(max) of 62.47 nmol/mg. Specific inhibitors of the NMDA receptor, ketamine and dizocilpine, but not the dopamine D(2) and 5HT(1A) receptor partial agonist aripiprazole, inhibited specific binding of (99m)Tc-NCAM to the NMDA receptor. Cell physiology experiments showed that NCAM can increase the viability of SH-SY5Y cells after glutamate-induced injury. CONCLUSIONS: The new radioligand (99m)Tc-NCAM has good affinity for and specific binding to the NMDA receptor, and easily crosses the blood-brain barrier; suggesting that it might be a potentially useful tracer for NMDA receptor expression.

Generation of a liver targeting fusion interferon and its bioactivity analysis in vitro.

The objective of this study was to generate a liver targeting fusion interferon, galactosyl-human serum albumin-interferon alpha2b (G-HSA-IFN) and to evaluate its bioactivity in vitro on HepG2.2.15 cells which express hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). The cell proliferation was determined by Sulpho Rhodamine B (SRB) staining method and flow cytometry (FCM) assay. Hochest33342 and Propidium Iodide (PI) double staining and Western blot analysis of Bcl-2/Bax were also performed to evaluate cell lethality and apoptosis. The concentrations of HBsAg and HBeAg secreted in culture supernatant were detected using Enzyme-Linked Immunosorbent Assay (ELISA). The results demonstrated that G-HSA-IFN could inhibit the proliferation of HepG2.2.15 cells and the cell cycle was arrested at G0/G1 phase. Western blotting results showed that the expression of Bcl-2 was inhibited in a dose-dependent manner while the expression of Bax was enhanced. The expression of HBsAg was inhibited by G-HSA-IFN in a dose-dependent manner, while no significant inhibiting effect on the expression of HBeAg was observed. Conclusively, G-HSA-IFN could not only significantly inhibit the HBsAg expression and the proliferation of HepG2.2.15 cells, but also induce the apoptosis of the target cells, rendering it a promising drug candidate for hepatitis B.

[Influence of betulinic acid on proliferation, migration, cell cycle and apoptosis of pancreatic cancer cells].

OBJECTIVE: To investigate the effect of betulinic acid (BA) on the proliferation, migration, apoptosis and cell cycle of pancreatic cancer cells (BxPC-3) in vitro and elucidate the underlying. METHOD: The effect of BA on the proliferation of BxPC-3 was measured by using sulforhodamine B (SRB) assay. Migratory ability of BxPC3 cells were detected by wound healing assay, and the morphological change was observed with light microscope. The influence of BA on cell cycle of BxPC-3 cells was tested by flow cytometry (FCM). Apoptosis was analyzed by using Hochest33342-PI double staining. Western blot technologies were applied to detect the expression of Bcl-2 and Bax. RESULT: BA exhibited significant cell proliferation and migration inhibition, as well as its potency of inducing apoptosis in BxPC-3 cells in vitro in a dose-dependent manner. The IC50 value for 72 h was 16.54 mg x L(-1). Cell migration was significantly inhibited at 5 mg x L(-1) of BA. Cells treated with BA showed increased cell population in G0 phase, with decreased G2/M phase population. The expression of Bax and Bcl-2 was up and down-regulated respectively in BA-treated BxPC-3 cells in a dose-dependent manner. CONCLUSION: BA exerted potent effect on growth inhibition, G0 cell cycle arrest and induction of apoptosis in BxPC-3 cells in vitro, possibly associated with the down-regulation of Bcl-2 and up-regulation of Bax expression. The potent antitumor capacity of BA suggested that it could be a promising new anticancer agent in human pancreatic cancer treatment.

3-(2-Fluoro-phen-oxy)propanoic acid.

In the title compound, C(9)H(9)FO(3), the dihedral angle between the carboxyl group and the benzene ring is 79.4 (3)°. In the crystal, mol-ecules form centrosymmetric dimers through pairs of classical O-H⋯O hydrogen bonds. These are further linked by weaker C-H⋯O inter-actions, forming a three-dimensional network.

tert-Butyl 6-amino-3,4-dihydro-2H-1,4-benzoxazine-4-carboxyl-ate.

The title mol-ecule, C(13)H(18)N(2)O(3), contains a benzene ring fused to an oxazine ring and one tert-but-oxy-carbonyl group bound to the N atom of the oxazine ring. A weak intra-molecular C-H⋯O inter-action occurs. In the crystal, inter-molecular N-H⋯O and C-H⋯O hydrogen bonds stack the mol-ecules down the b axis. Weak C-H⋯N contacts connect the stacks, generating a three-dimensional network.

Preparation and biological evaluation of a glycosylated fusion interferon directed to hepatic receptors.

The antiviral activity and biodistribution of a glycosylated fusion interferon directed to hepatic receptors were evaluated to determine whether its pharmaceutical concentration in the liver could be improved. The novel glycosylated fusion interferon, galactosyl-human serum albumin-interferon-alpha2b (G-HSA-IFN) was obtained from a long-term recombinant fusion protein (HSA-IFN) by covalent coupling with a bifunctional reagent, 2-imino-2-ethyloxymethy1-1-thiogalactose. There are about 24 thiogalactose residues in each G-HSA-IFN molecular on average. The antiviral activities of IFNalpha2b, HSA-IFN, and G-HSA-IFN were compared in a cytopathic effect inhibition assay with the WISH/VSV system in vitro, and the modification had little effect on its antiviral activity. Both G-HSA-IFN and HSA-IFN were labeled with 125I and the radiochemical purity of 125I-G-HSA-IFN was greater than 96%. 125I-G-HSA-IFN bound to the asialoglycoprotein receptor (ASGP-R) on hepatic cells much more specifically than 125I-HSA-IFN, with specific binding rates of 89.53% and 6.66%, respectively (p < 0.01). Biodistribution research in mice showed that 125I-G-HSA-IFN could concentrate effectively in the liver (>45%/g) and suggested that it also could be a good imaging agent of hepatic receptors.

[In vitro inhibitory effect of 23-HBA on angiogenesis].

AIM: To study the inhibitory effect of 23-HBA on angiogenesis in vitro. METHODS: The effect of 23-hydroxy butulinic acid (23-HBA) on the in vitro proliferation of human microcapillary endothelial cells(HMECs) was examined by sulfonylrhodamine B (SRB) assay. The effect of 23-HBA on endothelial cell migration, and tubule formation on Matrigel was also observed. The CD31 expression in HMECs was dectected by immunohistochemical staining. RESULTS: The proliferation of HMECs was inhibited significantly by 23-HBA with IC(50) being 40.44 mg/L. 23-HBA inhibited endothelial cell migration and tubule formation in a dose-dependent manner. The expression of CD31 in HMECs was reduced after treatment with 10 mg/L 23-HBA. CONCLUSION: 23-HBA can inhibit angiogenesis in vitro, which would become a promising antiangiogenic drug.