Characterization of a novel Le(x)-active ganglioside from chick intestinal tissues recognized by murine monoclonal antibody 188C1.

A monoclonal antibody, 188C1, raised against skin tissue from the back of bullfrogs (Rana catesbeiana) was found to recognize a common antigen in neural and intestinal tissues of chicken (Fujita, S. (1989) in Biological Transduction Mechanisms (Kasai, M., Yoshioka, T., and Suzuki, H., eds) pp. 159-177, Japan Scientific Societies Press, Tokyo Japan). The 188C1 antigen was isolated from chick intestinal tissues and characterized as a novel ganglioside by means of Q-Sepharose and Iatrobeads column chromatography, and chemical, immunochemical, and immunohistochemical analyses. The chemical structure was as follows: Gal beta 1-4 GlcNAc beta 1-3Gal beta 1-3GalNAc beta 1-4Gal beta 1-4Glc beta 1-1'Cer Fuc alpha 1-3 NeuAc alpha 2-3 This represents a novel hybrid structure of type 2 Le(x) epitope and GM1 ganglioside core structure, designated as Le(x)-GM1. Monoclonal antibody 188C1 reacted strongly with Le(x)-GM1 on thin layer chromatography, but its reactivity was greatly reduced when sialic acid was removed from the antigen. This indicated that the internal sialic acid residue might participate in antigenicity of the Le(x) determinant. In addition to 188C1, a more specific antibody reacting with Le(x)-GM1 but not with asialo-Le(x)-GM1 was raised by immunizing a rabbit with Le(x)-GM1. TLC/enzyme immunostaining using this specific antibody showed the presence of Le(x)-GM1 in chick intestinal tissue, but not in chick brain.     

Technetium-99m monoclonal antibody fragment (FAb) scintigraphy in the evaluation of small cell lung cancer: a preliminary report

Small cell lung cancer (SCC) has the most rapid growth rate of the four cell types and metastasizes early. Present imaging modalities for staging include chest x-ray, CT, MRI and bone scans. In this preliminary study, we assessed the clinical role of ^99mTc-monoclonal antibody (MOAB) scintigraphy in five patients with histologically proven SCC. Each patient was infused with 20–30 mCi of ^99mTc labeled Fab fragment of MOAB (NR-LU-10, NeoRx, Seattle, Wash.). Total body simultaneous anterior and posterior images were obtained 14–16 h post injection. SPECT images of the chest were obtained through a 360 ° rotation of the gamma camera and recorded on a 62 × 64 × 16 matrix. Images (1.2cm thick) were generated in transaxial, sagittal and coronal views.Fourteen of fifteen chest lesions detected by CT were confirmed by ^99mTc MOAB scintigraphy. Scintigraphy detected one additional chest lesion not seen by CT. Scintigraphy failed to detect a brain lesion (2 cm), a chest lesion, and two adrenal lesions, all of which were seen by CT. In one patient with multiple (more than 10) lesions in the liver, both scintigraphy and CT detected all lesions. Three spine lesions seen on ^99mTc MDP scan and positive for metastasis on MRI concentrated ^99mTc MOAB, but two rib lesions seen on ^99mTc MDP bone scan did not concentrate ^99mTc MOAB. It is concluded from these preliminary results that the potential usefulness of ^99mTc MOAB scintigraphy as a complementary imaging modality in the staging of small cell lung cancer should be investigated further.     

Design,synthesis and evaluation of [3H]PF-7191, a highly specific nociceptin opioid peptide (NOP) receptor radiotracer for in vivo receptor occupancy (RO) studies

Herein we report the identification of (+)-N-(2-((1H-pyrazol-1-yl)methyl)-3-((1R,3r,5S)-6′-fluoro-8-azaspiro[bicyclo[3.2.1]octane-3,1′-isochroman]-8-yl)propyl)-N-[³H]-methylacetamide {[³H]PF-7191 [(+)-11]} as a promising radiotracer for the nociceptin opioid peptide (NOP) receptor. (+)-11 demonstrated high NOP binding affinity (K_i = 0.1 nM), excellent selectivity over other opioid receptors (>1000×) and good brain permeability in rats (C_b,u/C_p,u = 0.29). Subsequent characterization of [³H](+)-11 showed a high level of specific binding and a brain bio-distribution pattern consistent with known NOP receptor expression. Furthermore, the in vivo brain binding of [³H](+)-11 in rats was inhibited by a selective NOP receptor antagonist in a dose–responsive manner. This overall favorable profile indicated that [³H](+)-11 is a robust radiotracer for pre-clinical in vivo receptor occupancy (RO) measurements and a possible substrate for carbon-11 labeling for positron emission tomography (PET) imaging in higher species.     

Anti-breast cancer action of carbonic anhydrase IX inhibitor 4-[4-(4-Benzo[1,3]dioxol-5-ylmethyl-piperazin-1-yl)-benzylidene-hydrazinocarbonyl]-benzenesulfonamide (BSM-0004): in vitro and in vivo studies

Anti-breast cancer action of novel human carbonic anhydrase IX (hCA IX) inhibitor BSM-0004 has been investigated using in vitro and in vivo models of breast cancer. BSM-0004 was found to be a potent and selective hCA IX inhibitor with a Ki value of 96 nM. In vitro anticancer effect of BSM-0004 was analysed against MCF 7 and MDA-MA-231 cells, BSM-0004 exerted an effective cytotoxic effect under normoxic and hypoxic conditions, inducing apoptosis in MCF 7 cells. Additionally, this compound significantly regulates the expression of crucial biomarkers associated with apoptosis. The investigation was extended to confirm the efficacy of this hCA IX inhibitor against in vivo model of breast cancer. The results specified that the treatment of BSM-0004 displayed an effective in vivo anticancer effect, reducing tumour growth in a xenograft cancer model. Hence, our investigation delivers an effective anti-breast cancer agent that engenders the anticancer effect by inhibiting hCA IX.     

Nmr and computer-aided studies of the three interchanging stereoisomers of the cyclic hexapeptide cyclo[-Pro1-Gly2-Glu3(OBzl)-Pro4-Phe5-Leu6-]: Unexpected observation of a cis isomer of a secondary amide peptide bond in the presence of two trans proline peptide bonds

The cyclic hexapeptide cyclo[-Pro¹-Gly²-Glu³(OBzl)-Pro⁴-Phe⁵-Leu⁶-] ( 1 ; OBzl: benzyl ester) was modeled and synthesized to be used as a chiral site for the separation of enantiomers. Total correlation spectroscopy and nuclear Ovehauser effect spectroscopy spectra of the peptide in CDCl₃ showed the presence of three stereoisomers. The two dominant stereoisomers 1a and 1b exchanged chemically with each other, while the minor stereoisomer 1c exchanged exclusively with the stereoisomer 1b . Stereoisomer 1a had two cis proline peptide bonds while stereoisomer 1b had all-trans peptide bonds. The stereoisomer 1c had, for nonstrained peptides, an unusual cis phenylalanine peptide bond while both proline peptide bonds were trans. © 1993 John Wiley & Sons, Inc.