Objective: The overexpression of somatostatin receptor 2 (sst2) in neuroendocrine tumors is the molecular basis for diagnostic and therapeutic application of the stable somatostatin analog octreotide. Recent evidence has shown that the immunocytochemical evaluation of sst2A status is of value for predicting response to octreotide therapy and disease prognosis. However, due to the lack of monoclonal and limited availability of specific polyclonal anti-sst2A antibodies, only very few patients can currently benefit from in vitro sst2 evaluation.
Methods: In the present study, we extensively characterized the novel rabbit monoclonal anti-sst2A antibody (clone UMB-1) using tissues from sst2-deficient mice and their wild-type littermates. UMB-1 was then subjected to a comparative study of immunohistochemistry on a series of histological specimens from formalin-fixed, paraffin-embedded human tumors and adjacent normal tissues.
Results: Immunoprecipitation experiments unequivocally demonstrated that UMB-1 selectively detected its cognate sst2A and did not cross-react with other proteins present in crude tissue homogenates. The UMB-1 monoclonal antibody, when compared with currently available polyclonal antisera, yielded several times more effective immunohistochemical staining of fixed-embedded tissues with a predominance of plasma membrane staining and very low cytoplasmic signal even without heat-based antigen retrieval. In addition, dual immunofluorescence revealed for the first time that the sst2A is present on not only gastrin-containing but also ghrelin-containing cells in human gastric mucosa.
Conclusion: Thus, the rabbit monoclonal antibody UMB-1 may prove of great value in the assessment of sst2A status in human neuroendocrine tumors during routine histopathological examination.
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http://dx.doi.org/10.1210/jc.2008-1063 | DOI Listing |
Biochem Biophys Res Commun
January 2025
Section of Host Defences, Institute of Natural Medicine, University of Toyama, Sugitani 2630, Toyama-shi, Toyama, 930-0194, Japan. Electronic address:
Asialo-GM1 (ASGM1) has been identified as a cell surface marker of murine NK cells. Although polyclonal anti-asialo-GM1 antibodies (anti-ASGM1 pAb) have been widely used for studying natural killer (NK) cell functions in vivo, the technical challenges have existed in their specificity for NK cell depletion. Furthermore, the exact expression of ASGM1 on the NK cell lineage and other immune cells has not been characterized due to the lack of appropriate reagents.
View Article and Find Full Text PDFBlood Adv
December 2024
Universidade Federal de São Paulo, Brazil.
Immunosuppressive therapy (IST) using horse antithymocyte globulin (h-ATG) combined with cyclosporine (CsA) and eltrombopag is the standard care for aplastic anemia (AA) in patients without a suitable matched donor. However, in many countries, h-ATG use has been discontinued, leaving rabbit ATG (r-ATG), which has a lower response rates and poorer survival, as the only alternative. In previous studies, alemtuzumab (ALZ), a humanized monoclonal antibody targeting CD52, combined with CsA resulted in an adequate ORR in AA patients.
View Article and Find Full Text PDFMethods
December 2024
Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy; Consorzio Interuniversitario Biotecnologie (CIB), Unit of Brescia, Brescia, Italy. Electronic address:
ELISA and RT-PCR represent the standard tools for the sensitive identification of viruses in biological samples, but they lack the capacity to finely characterize the binding of viruses or viral antigens to monoclonal antibodies (MAbs). Biosensing technologies are gaining increasing importance as powerful MAb characterization tools in the field of virology. Surface plasmon resonance (SPR) is an optical biosensing technology already used for the in depth characterization of MAbs of diagnostic and therapeutic value.
View Article and Find Full Text PDFSovrem Tekhnologii Med
December 2024
MD, DSc, Professor of the Russian Academy of Sciences, Head of the Laboratory of Functional Morphology of Central and Peripheral Nervous System; Head of the Department of General and Special Morphology; The Institute of Experimental Medicine, 12 Akademika Pavlova St., Saint Petersburg, 197376, Russia.
Unlabelled: The importance of identifying pathological changes in the liver both in fundamental researches and in diagnostic practice dictates the necessity to have a convenient method of assessing functional condition of resident macrophages and connective tissue fibers. is to assess the technology of combined histo-immunohistochemical detection of collagen fibers of connective tissue and resident liver macrophages using aniline blue histological stain and available antibodies to the microglial marker, the Iba-1 protein.
Materials And Methods: Liver samples from adult rats (n=6) have been used in the study.
Mol Cell
December 2024
Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA. Electronic address:
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