REMEDY FOR CHEMOTHERAPY RESISTANT CANCER CONTAINING HLA CLASS I-RECOGNIZING ANTIBODY AS THE ACTIVE INGREDIENT AND USE OF THE SAME

摘要

The present invention describes therapeutic agents for chemotherapeutic agent-resistant cancers that include an HLA class I-recognizing antibody as an active ingredient. A further objective of the present invention is to provide methods for treating chemotherapeutic agent-resistant cancers that include the step of administering an HLA class I-recognizing antibody to a subject. It is herein demonstrated that cytotoxic activity due to C3B3 diabody is induced at a lower concentration in chemotherapeutic agent-resistant hematological tumor cell lines having high MDRl and HLA class IA protein expression, than in their parent cell lines. It was also found that when the chemotherapeutic agent-resistant hematological tumor cell line is pretreated with a C3B3 diabody, cell injury associated with sole use of chemotherapeutic agent is enhanced and the amount of pharmaceutical agents taken up into cells are increased. More specifically, it was discovered that the C3B3 diabody exhibits anti-tumor activity on MDRl-expressing tumor cells having high HLA class I expression, and thereby is effective in overcoming drug resistance.