About InVivoMAb anti-mouse/human HER2 (domain III) (CD340) The H2Mab-19 monoclonal antibody reacts with domain III of mouse and human receptor tyrosine-protein kinase erbB-2 (ERBB2), also known as human epidermal growth factor receptor 2 (HER2), CD340, or NEU. HER2 is a 185 kDa transmembrane receptor tyrosine kinase that is part of the EGFR family. The HER2 receptor contains a cytoplasmic tyrosine kinase domain, multiple cytoplasmic tyrosine residues that function as phosphorylation sites, a hydrophobic single-pass transmembrane domain, and an extensive extracellular domain (ECD) subdivided into four functional domains (I, II, III, and IV). Domains I and III facilitate ligand binding, domain II reinforces protein-protein interactions during dimerization, and domain IV stabilizes interactions between HER2 and its dimerization partner. HER2 lacks identified ligands; nonetheless, its homodimerization (HER2/HER2) and heterodimerization (EGFR/HER2, HER2/HER3, and HER2/HER4) facilitate HER2 activation, subsequently modulating downstream signaling pathways, including PI3K/Akt/mTOR and NF-kB. HER2 is essential for cell proliferation, survival, and differentiation, and in cancers, dysregulated HER2 signaling or its overexpression often correlates with aggressive tumor growth. In addition to breast cancer, HER2 is overexpressed in gastric, gastroesophageal, colorectal, lung, endometrial, and ovarian cancers. The H2Mab-19 antibody has been shown to have anti-tumor activity in HER2+ xenograft models. InVivoMAb anti-mouse/human HER2 (domain III) (CD340) Specifications IsotypeMouse IgG2b, κ Recommended Isotype Control(s)InVivoMAb mouse IgG2b isotype control, unknown specificity Recommended Dilution BufferInVivoPure pH 7.0 Dilution Buffer ImmunogenRecombinant human HER2 extracellular domain Reported Applicationsin vivo antitumor activity in HER2+ xenograft model in vitro induction of ADCC in HER2+ cells in vitro induction of CDC in HER2+ cells Immunohistochemistry (frozen) Flow cytometry 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-mouse/human HER2 (domain III) (CD340) (CLONE: H2Mab-19)Kaneko MK, Suzuki H, Kato Y (2024). "Establishment of a Novel Cancer-Specific Anti-HER2 Monoclonal Antibody H2Mab-250/H2CasMab-2 for Breast Cancers" Monoclon Antib Immunodiagn Immunother 43(2):35-43. PubMedOverexpression of human epidermal growth factor receptor 2 (HER2) in breast and gastric cancers is an important target for monoclonal antibody (mAb) therapy. All therapeutic mAbs, including anti-HER2 mAbs, exhibit adverse effects probably due to the recognition of antigens expressed in normal cells. Therefore, tumor-selective or specific mAbs can be beneficial in reducing the adverse effects. In this study, we established a novel cancer-specific anti-HER2 monoclonal antibody, named H2Mab-250/H2CasMab-2 (IgG1, kappa). H2Mab-250 reacted with HER2-positive breast cancer BT-474 and SK-BR-3 cells. Importantly, H2Mab-250 did not react with nontransformed normal epithelial cells (HaCaT and MCF 10A) and immortalized normal epithelial cells in flow cytometry. In contrast, most anti-HER2 mAbs, such as H2Mab-119 and trastuzumab reacted with both cancer and normal epithelial cells. Immunohistochemical analysis demonstrated that H2Mab-250 possesses much higher reactivity to the HER2-positive breast cancer tissues compared with H2Mab-119, and did not react with normal tissues, including heart, breast, stomach, lung, colon, kidney, and esophagus. The epitope mapping demonstrated that the Trp614 of HER2 domain IV mainly contributes to the recognition by H2Mab-250. H2Mab-250 could contribute to the development of chimeric antigen receptor-T or antibody-drug conjugates without adverse effects for breast cancer therapy.Kato Y, Ohishi T, Takei J, Nakamura T, Kawada M, Kaneko MK (2020). "An Antihuman Epidermal Growth Factor Receptor 2 Monoclonal Antibody (H2Mab-19) Exerts Antitumor Activity in Glioblastoma Xenograft Models" Monoclon Antib Immunodiagn Immunother 39(4):135-139. PubMedOverexpression of human epidermal growth factor receptor 2 (HER2) has been reported in glioblastoma as well as breast, gastric, lung, colorectal, and pancreatic cancers. Its expression is associated with poor clinical outcomes. Anti-HER2 antibodies have provided significant survival benefits to patients with HER2-overexpressing breast and gastric cancers. We recently developed an anti-HER2 monoclonal antibody (mAb), H2Mab-19 (IgG2b, kappa), by immunizing mice with the extracellular domain of HER2, which is expressed in LN229 glioblastoma cells. In this study, we investigated the antitumor activity of H2Mab-19 in an LN229 glioblastoma xenograft model. H2Mab-19 showed high binding affinity (KD: 1.1 × 10-8 M) against LN229 cells. Furthermore, H2Mab-19 significantly reduced tumor development in an LN229 xenograft. These results suggest that treatment with H2Mab-19 may be a useful therapy for patients with HER2-expressing glioblastomas.Kato Y, Ohishi T, Takei J, Nakamura T, Sano M, Asano T, Sayama Y, Hosono H, Kawada M, Kaneko MK (2020). "An Anti-Human Epidermal Growth Factor Receptor 2 Monoclonal Antibody H2Mab-19 Exerts Antitumor Activity in Mouse Colon Cancer Xenografts" Monoclon Antib Immunodiagn Immunother 39(4):123-128. PubMedTrastuzumab is a humanized antibody against human epidermal growth factor receptor 2 (HER2) that offers significant survival benefits to patients with HER2-overexpressing breast or gastric cancer. HER2 is also known to be overexpressed in colon cancers. In this study, a novel anti-HER2 monoclonal antibody (mAb), H2Mab-19 (IgG2b, κ) was characterized for its anticancer activity in colon cancers. H2Mab-19 showed both antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity activities against Caco-2, a colon cancer cell line. Furthermore, H2Mab-19 significantly reduced tumor development in a Caco-2 xenograft model. These results suggest that treatment with H2Mab-19 may be a useful therapy for patients with HER2-expressing colon cancers.Kato Y, Ohishi T, Sano M, Asano T, Sayama Y, Takei J, Kawada M, Kaneko MK (2020). "H2Mab-19 Anti-Human Epidermal Growth Factor Receptor 2 Monoclonal Antibody Therapy Exerts Antitumor Activity in Pancreatic Cancer Xenograft Models" Monoclon Antib Immunodiagn Immunother 39(3):61-65. PubMedOverexpression of human epidermal growth factor receptor 2 (HER2) has been reported in breast cancer, gastric, lung, colorectal, oral, and pancreatic cancers. HER2 expression is associated with poor clinical outcomes. An anti-HER2 humanized antibody, trastuzumab, has improved survival rates in patients with HER2-overexpressing breast and gastric cancers. Previously, we established a novel anti-HER2 monoclonal antibody (mAb), H2Mab-19 (IgG2b, kappa). It has also been characterized for breast, oral, and colon cancers. In this study, we investigated the antitumor activities of H2Mab-19 in pancreatic cancer xenograft models. We selected MIA PaCa-2, a pancreatic cancer cell line which expresses HER2. H2Mab-19 showed high binding affinity (KD: 1.2 × 10-8 M) against MIA PaCa-2 cells. Furthermore, H2Mab-19 significantly reduced tumor development in a MIA PaCa-2 xenograft model. These results suggest that treatment with H2Mab-19 may be a useful therapy for patients with HER2-expressing pancreatic cancers.Takei J, Kaneko MK, Ohishi T, Kawada M, Harada H, Kato Y (2020). "H2Mab-19, an anti-human epidermal growth factor receptor 2 monoclonal antibody exerts antitumor activity in mouse oral cancer xenografts" Exp Ther Med 20(2):846-853. PubMedHuman epidermal growth factor receptor 2 (HER2) is reported to be overexpressed in breast cancers and is associated with poor clinical outcome. Trastuzumab is a humanized anti-HER2 antibody that offers significant survival benefits to patients with HER2-overexpressing breast cancer. In this study, a novel anti-HER2 monoclonal antibody (mAb), H2Mab-19 (IgG2b, kappa) was developed. Antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antitumor activity of H2Mab-19 were investigated using both breast cancer and oral cancer cell lines. H2Mab-19 demonstrated cytotoxicity in BT-474 (a human breast cancer cell line) and HSC-2 or SAS (human oral cancer cell lines). H2Mab-19 also possessed both ADCC and CDC activity against BT-474, HSC-2, and SAS cell lines. In comparison to control mouse IgG, H2Mab-19 significantly reduced tumor development in BT-474, HSC-2, and SAS xenografts. Collectively, these results suggest that treatment with H2Mab-19 may be a useful therapy for patients with HER2-expressing breast and oral cancers.