About InVivoMAb anti-human CD133 The CMab-43 monoclonal antibody reacts with human CD133, also known as AC133 or prominin 1 (PROM1). CD133 is expressed in early progenitor and hematopoietic stem cells. CD133 was originally discovered in a subset of CD34+ hematopoietic stem and progenitor cells (HSPCs) derived from human fetal hepatic and bone marrow tissues, and subsequent studies established its expression in neuroepithelium and immature epithelia as well. CD133 is expressed in hematological malignancies as well as a range of solid tumors, including pancreatic, hepatocellular, prostate, colon, kidney, skin, ovarian, and brain cancers. CD133 is suggested to play a role in cell differentiation, proliferation, and apoptosis. CD133 binds cholesterol and plays a role in the organization of the apical plasma membrane in epithelial cells. It is involved in the regulation of MAPK and Akt signaling pathways. Antibodies against CD133 antigen are commonly used for identifying hematopoietic stem and progenitor cells (HSPCs) and cancer stem cells (CSCs) derived from cancers. In human colon cancer (Caco-2) xenograft mouse models, in vivo treatment with the CMab-43 antibody has been shown to exert antitumor activity. InVivoMAb anti-human CD133 Specifications IsotypeMouse IgG2a, κ Recommended Isotype Control(s)InVivoMAb mouse IgG2a isotype control, unknown specificity Recommended Dilution BufferInVivoPure pH 7.0 Dilution Buffer ImmunogenHuman CD133 overexpressing LN229 cells Reported Applicationsin vivo targeting of CD133 Flow cytometry Immunohistochemistry (paraffin) Western blot For details on in vivo applications please contact technicalservice@bioxcell.com FormulationPBS, pH 7.0 Contains no stabilizers or preservatives Endotoxin<2EU/mg (<0.002EU/μg) Determined by LAL gel clotting assay Purity>95% Determined by SDS-PAGE Sterility0.2 μm filtered ProductionPurified from cell culture supernatant in an animal-free facility PurificationProtein A Molecular Weight150 kDa StorageThe antibody solution should be stored at the stock concentration at 4°C. Do not freeze. Application ReferencesInVivoMAb anti-human CD133 (CLONE: CMab-43)Kato Y, Ohishi T, Yamada S, Itai S, Furusawa Y, Sano M, Nakamura T, Kawada M, Kaneko MK (2019). "Anti-CD133 Monoclonal Antibody CMab-43 Exerts Antitumor Activity in a Mouse Xenograft Model of Colon Cancer" Monoclon Antib Immunodiagn Immunother 38(2):75-78. PubMedCancer stem cells contribute to tumorigenesis, metastasis, recurrence, and chemoresistance. CD133/prominin-1-a pentaspan membrane glycoprotein-has been used as a stem cell biomarker for the isolation of stem-like cells from a variety of normal and pathological tissues. In our previous studies, we developed several anti-CD133 monoclonal antibodies using Cell-Based Immunization and Screening (CBIS) methods, followed by characterization of their efficacy by flow cytometry, western blotting, and immunohistochemical analyses. One of the 100 clones, CMab-43 (IgG2a, kappa), demonstrated a sensitive and specific reaction against colon cancer cells. This study aimed to investigate the antitumor activity of CMab-43. Caco-2 cells (human colon cancer cell line) were subcutaneously implanted into the flanks of nude mice. CMab-43 and control mouse IgG were injected three times into the peritoneal cavity of mice. Tumor formation was observed in the control and CMab-43-treated mice of Caco-2 xenograft models. CMab-43 significantly reduced tumor development of Caco-2 xenograft in comparison with the control mouse IgG on days 12, 14, and 17. Our results cumulatively suggest that CMab-43 is useful for antibody therapy against CD133-expressing colon cancers.Itai S, Fujii Y, Nakamura T, Chang YW, Yanaka M, Saidoh N, Handa S, Suzuki H, Harada H, Yamada S, Kaneko MK, Kato Y (2017). "Establishment of CMab-43, a Sensitive and Specific Anti-CD133 Monoclonal Antibody, for Immunohistochemistry" Monoclon Antib Immunodiagn Immunother 36(5):231-235. PubMedCD133, also known as prominin-1, was first described as a cell surface marker on early progenitor and hematopoietic stem cells. It is a five-domain transmembrane protein composed of an N-terminal extracellular tail, two small cytoplasmic loops, two large extracellular loops containing seven potential glycosylation sites, and a short C-terminal intracellular tail. CD133 has been used as a marker to identify cancer stem cells derived from primary solid tumors and as a prognostic marker of gliomas. Herein, we developed novel anti-CD133 monoclonal antibodies (mAbs) and characterized their efficacy in flow cytometry, Western blot, and immunohistochemical analyses. We expressed the full length of CD133 in LN229 glioblastoma cells, immunized mice with LN229/CD133 cells, and performed the first screening using flow cytometry. After limiting dilution, we established 100 anti-CD133 mAbs, reacting with LN229/CD133 cells but not with LN229 cells. Subsequently, we performed the second and third screening with Western blot and immunohistochemical analyses, respectively. Among 100 mAbs, 11 strongly reacted with CD133 in Western blot analysis. One of 11 clones, CMab-43 (IgG2a, kappa), showed a sensitive and specific reaction against colon cancer cells, warranting the use of CMab-43 in detecting CD133 in pathological analyses of CD133-expressing cancers.
