BACKGROUND/ PURPOSE: The overexpression of multidrug resistance (MDR)-associated genes in primary untreated tumors has been proven to be associated with worse prognosis in various pediatric malignancies. This study compared the expression of 3 MDR-associated genes, MDR1, MDR-associated protein 1 (MRP1), and lung resistance-related protein (LRP), in pediatric tumors before and after chemotherapy to elucidate the mechanism of MDR during chemotherapy. METHODS: Surgical specimens of both primary and chemotherapy-treated tumors were obtained from 24 patients with pediatric malignancies (neuroblastoma [NB] 8; hepatoblastoma [HB] 8; Wilms tumor [WT] 4; rhabdomyosarcoma [RB] 4). The expression of MDR1, MRP1, and LRP was evaluated using the immunohistochemical staining. RESULTS: In primary tumors, MDR1 expression was observed in 6 NBs, 8 HBs, 3 WTs, and 3 RBs. MRP1 expression was observed in 3 NBs and 1 HB. LRP expression was not detected in any of the primary tumors. After chemotherapy, MDR1 expression was observed to increase in 5 NBs, 4 HBs, 2 WTs, and 3 RBs. MRP1 expression was newly observed or increased in 7 NBs, 4 HBs, and 3 RBs. LRP expression was newly observed in 3 HBs and 2 WTs. CONCLUSIONS: These results indicate that these 3 MDR-associated genes were upregulated after chemotherapy in various pediatric malignancies. These findings may be useful to understand the mechanism of drug resistance in pediatric malignancies.
BACKGROUND/ PURPOSE: The overexpression of multidrug resistance (MDR)-associated genes in primary untreated tumors has been proven to be associated with worse prognosis in various pediatric malignancies. This study compared the expression of 3 MDR-associated genes, MDR1, MDR-associated protein 1 (MRP1), and lung resistance-related protein (LRP), in pediatric tumors before and after chemotherapy to elucidate the mechanism of MDR during chemotherapy. METHODS: Surgical specimens of both primary and chemotherapy-treated tumors were obtained from 24 patients with pediatric malignancies (neuroblastoma [NB] 8; hepatoblastoma [HB] 8; Wilms tumor [WT] 4; rhabdomyosarcoma [RB] 4). The expression of MDR1, MRP1, and LRP was evaluated using the immunohistochemical staining. RESULTS: In primary tumors, MDR1 expression was observed in 6 NBs, 8 HBs, 3 WTs, and 3 RBs. MRP1 expression was observed in 3 NBs and 1 HB. LRP expression was not detected in any of the primary tumors. After chemotherapy, MDR1 expression was observed to increase in 5 NBs, 4 HBs, 2 WTs, and 3 RBs. MRP1 expression was newly observed or increased in 7 NBs, 4 HBs, and 3 RBs. LRP expression was newly observed in 3 HBs and 2 WTs. CONCLUSIONS: These results indicate that these 3 MDR-associated genes were upregulated after chemotherapy in various pediatric malignancies. These findings may be useful to understand the mechanism of drug resistance in pediatric malignancies.
Authors: V Ellerkamp; J Lieber; C Nagel; J Wenz; S W Warmann; J Fuchs; S Armeanu-Ebinger Journal: Pediatr Surg Int Date: 2012-12-25 Impact factor: 1.827
Authors: Alexander Dewerth; Timo Wonner; Justus Lieber; Verena Ellerkamp; Steven W Warmann; Jörg Fuchs; Sorin Armeanu-Ebinger Journal: Pediatr Surg Int Date: 2012-04-18 Impact factor: 1.827
Authors: I Iacobucci; A Ferrarini; M Sazzini; E Giacomelli; A Lonetti; L Xumerle; A Ferrari; C Papayannidis; G Malerba; D Luiselli; A Boattini; P Garagnani; A Vitale; S Soverini; F Pane; M Baccarani; M Delledonne; G Martinelli Journal: Blood Cancer J Date: 2012-03-09 Impact factor: 11.037