title: Complete in vivo reversal of the multidrug resistance phenotype by jet-injection of anti-MDR1 short hairpin RNA-encoding plasmid DNA.
abstract: Triggering the RNA interference (RNAi) pathway by inducing the expression of short hairpin RNA (shRNA) molecules has become a promising tool for efficient silencing of a given gene in gene therapy applications. In this study, shRNA encoding DNA was utilized to reverse the classical MDR1/P-glycoprotein (MDR1/P-gp)-mediated multidrug resistance (MDR) phenotype in vivo. For the first time, the nonviral jet-injection technology was applied for delivering naked shRNA-vector constructs for direct intratumoral in vivo transfer. The highly efficient anti-MDR1 shRNA expression vectors were applied twice in the human MDR1/P-gp overexpressing MaTu/ADR cancer xenograft-bearing mice, and twice in the corresponding drug-sensitive parental MaTu tumor xenograft bearing mice as well. Two days after anti-MDR1 shRNA vector injection, the expression level of the MDR1 messenger RNA (mRNA) was decreased by more than 90% and the corresponding MDR1/P-gp protein was no longer detectable in the tumors. Two jet-injections of anti-MDR1 shRNA vectors into the tumors, combined with two intravenous (IV) administrations of doxorubicin, were sufficient to achieve complete reversal of the drug-resistant phenotype. The data show that jet-injection delivery of shRNA-expressing vectors is effective in reversing MDR1/P-gp-mediated MDR in vivo, and is therefore a promising strategy for making tumors with an MDR1/Pgp-dependent MDR phenotype revert to a drug-sensitive state.
authors: 1Max-Delbrück-Center for Molecular Medicine, Berlin, Germany.
authors: Ulrike
authors: U
authors: Stein
authors: Wolfgang
authors: W
authors: Walther
authors: Alexandra
authors: A
authors: Stege
authors: Alexander
authors: A
authors: Kaszubiak
authors: Iduna
authors: I
authors: Fichtner
authors: Hermann
authors: H
authors: Lage
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D004273:DNA, Neoplasm / Q000008:administration & dosage* / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D015552:Injections, Intralesional; D007277:Injections, Jet; D008325:Mammary Neoplasms, Experimental / Q000235:genetics* / Q000378:metabolism / Q000628:therapy; D051379:Mice; D008819:Mice, Nude; D010641:Phenotype; D010957:Plasmids / Q000008:administration & dosage*; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000008:administration & dosage* / Q000235:genetics
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D004273:DNA, Neoplasm; D012333:RNA, Messenger; D012334:RNA, Neoplasm