[Overcoming of multidrug resistance by anti-P-glycoprotein monoclonal antibody]

P-glycoprotein is one of the key molecules in multidrug resistance. Monoclonal antibodies against P-glycoprotein could be useful tools for killing MDR tumor cells. To overcome multidrug resistance, many anti-P-glycoprotein monoclonal antibodies have been made such as MRK16 and MRK17. Conjugated moAb, such as bispecific antibody, immunotoxin and radioisotope conjugates have also been constructed to enhance the anti-tumor activity of moAb. Cytokine-gene transduction for accumulation and activation of monocytes may be hopeful to augment the therapeutic efficiency of anti-P-glycoprotein antibody. For clinical use, construction of human moAb, overcoming tumor heterogeneity, and protection of normal tissue by specifically targeting the tumor cells should be essential.