8.A.237.  The Tumor-associated Calcium Signal Transducer 2 (TACSTD2) Family 

This protein may function as a growth factor receptor of 237 aas and 1 C-terminal TMS.  The relationship between Trop-2 (TACSTD2), chemotherapeutic drugs, and chemoresistance has been studied (Koltai and Fliegel 2023). Trop-2 is highly conserved mammalian glycoprotein that is normally expressed in tissues such as the lungs, intestines, and kidney during embryonic development. It is overexpressed in many epithelial cancers but is absent in non-epithelial tumors. Trop-2 participates in the promotion of cell proliferation, migration, invasion, metastasis, and probably stemness. It also has some tumor suppressor effects. The pro-tumoral actions have been thoroughly investigated and reported. However, Trop-2's activity in chemoresistance is less well known. Koltai and Fliegel 2023 reviewed its function, and concluded that there is a role for Trop-2 in some specific chemoresistance events. The development of antibody conjugate drugs (ACD) centered on anti-Trop-2 monoclonal antibodies opened the gates for the treatment of some tumors resistant to classic chemotherapies. Advanced urothelial tumors and breast cancer were among the first malignancies for which these ACDs have been employed (Koltai and Fliegel 2023).