OI-3 

OI-3 is a monoclonal antibody targeting CD146 (MCAM). OI-3 specifically binds to CD146 on the surface of human mesothelioma cells and undergoes endocytosis; both chimeric (chOI-3) and murine (mOI-3) variants possess this activity. When conjugated with ²¹²Pb to form ²¹²Pb-TCMC-OI-3, OI-3 acts as a cytotoxic agent that delivers α-emitting radionuclides to induce targeted cytotoxicity. OI-3 can be used in research related to malignant peritoneal mesothelioma^[1].

Human

Compared with mouse-derived OI-3 (mOI-3), chimeric OI-3 (chOI-3) exhibits higher apparent affinity for CD146 on the surface of human pleural mesothelioma cells MSTO-211H and NCI-H226; the K_DAPP values of chOI-3 are 3.3 nM and 5.9 nM, respectively, while those of mOI-3 are 9.2 nM and 11.4 nM^[1].
mOI-3 and chOI-3 (0.25 μg; 1-24 h) are efficiently internalized into MSTO-211H human mesothelioma cells, reaching the internalization peak at 6-24 h; in contrast, chOI-3 shows extremely weak internalization into NCI-H226 human mesothelioma cells within 24 h^[1].
chOI-3 (0.25 μg/mL; 16 h) internalizes into the human pleural mesothelioma cell line MSTO-211H within 16 h, and its internalization rate in real-time live-cell imaging assays is significantly higher than that of the human IgG1 isotype control^[1].
²¹²Pb-TCMC-chOI-3 (5-10 kBq/mL; 2-24 h) is internalized into MSTO-211H human pleural mesothelioma cells. At 24 h, the number of internalized ²¹²Pb and ²¹²Bi atoms per cell is significantly higher than that at 2 h, reaching 13.7-fold and 8.5-fold of that of the isotype control, respectively^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

²¹²Pb-TCMC-mOI-3 (348 kBq; i.p.; single bolus) significantly prolongs median survival to 55 days in mice with intraperitoneal malignant mesothelioma xenografts, with no significant body weight changes^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

4162  [NCBI]

P43121

MUC18/MCAM/CD146

ELISA, FACS, Functional assay

Unconjugated

The product can be reconstituted/diluted with sterile PBS or saline.

Please refer to the lot-specific COA for specific buffer information.

Please store the product under the recommended conditions in the Certificate of Analysis.

• [1]. Lindland K, et al. Antigen targeting and anti-tumor activity of a novel anti-CD146 ²¹²Pb internalizing alpha-radioimmunoconjugate against malignant peritoneal mesothelioma. Sci Rep. 2024;14(1):25941. Published 2024 Oct 29.