Development and characterization of TrMab-6, a novel anti-TROP2 monoclonal antibody for antigen detection in breast cancer

Trophoblast cell-surface antigen 2 (TROP2) is a type I transmembrane glycoprotein that is overexpressed in a number of cancer types, including triple-negative breast cancer. The current study aimed to develop a highly sensitive and specific monoclonal antibody (mAb) targeting TROP2, which could be used to evaluate TROP2 expression using flow cytometry, western blot analysis and immunohistochemistry by employing the Cell-Based Immunization and Screening (CBIS) method. The established anti-TROP2 mAb, TrMab-6 (mouse IgG2b, κ), detected TROP2 on PA-tagged TROP2-overexpressing Chinese hamster ovary-K1 (CHO/TROP2-PA) and breast cancer cell lines, including MCF7 and BT-474 using flow cytometry. Western blot analysis indicated a 40 kDa band in lysates prepared from CHO/TROP2-PA, MCF7 and BT-474 cells. Furthermore, TROP2 in 57/61 (93.4%) of the breast cancer specimens was strongly detected using immunohistochemical analysis with TrMab-6. In conclusion, the current study demonstrated that TrMab-6 may be a valuable tool for the detection of TROP2 in a wide variety of breast cancer types.