Differential expression of ABC transporters (MDR1, MRP1, BCRP) in developing human embryos

Three ABC transporters (MDR1, MRP1, BCRP), belonging to the family of multidrug resistance (MDR) proteins, play a crucial role in the protection mechanisms during embryogenesis and mediate drug resistance in cancer cells. The distribution of these transporters in the serie of human embryonal/fetal intestine, liver and kidneys of various stages of IUD by indirect two-step immunohistochemical method was investigated. The organand age-specific expression patterns of these transporters were depicted and compared with the expression in adult organs. The evaluation of intestine and liver samples demonstrate differences in expression pattern of ABC transporters during IUD. On the contrary, in kidneys the age-specific localization was not observed. However, the increasing positivity from the kidney surface towards deeper, more differentiated parts was observed. We also speculate that the differences in distribution of these transporters during IUD reflect their vulnerability to different drugs and toxins. Hopefully, our findings may contribute to elucidation of the role of multidrug resistance (MDR) pathways during IUD.