title: Targeted delivery of microRNA-29b by transferrin-conjugated anionic lipopolyplex nanoparticles: a novel therapeutic strategy in acute myeloid leukemia.
abstract: OBJECTIVE
  miR-29b directly or indirectly targets genes involved in acute myeloid leukemia (AML), namely, DNMTs, CDK6, SP1, KIT, and FLT3. Higher miR-29b pretreatment expression is associated with improved response to decitabine and better outcome in AML. Thus, designing a strategy to increase miR-29b levels in AML blasts may be of therapeutic value. However, free synthetic miRs are easily degraded in bio-fluids and have limited cellular uptake. To overcome these limitations, we developed a novel transferrin-conjugated nanoparticle delivery system for synthetic miR-29b (Tf-NP-miR-29b).
  
  
  METHODS
  Delivery efficiency was investigated by flow cytometry, confocal microscopy, and quantitative PCR. The expression of miR-29b targets was measured by immunoblotting. The antileukemic activity of Tf-NP-miR-29b was evaluated by measuring cell proliferation and colony formation ability and in a leukemia mouse model.
  
  
  RESULTS
  Tf-NP-miR-29b treatment resulted in more than 200-fold increase of mature miR-29b compared with free miR-29b and was approximately twice as efficient as treatment with non-transferrin-conjugated NP-miR-29b. Tf-NP-miR-29b treatment significantly downregulated DNMTs, CDK6, SP1, KIT, and FLT3 and decreased AML cell growth by 30% to 50% and impaired colony formation by approximately 50%. Mice engrafted with AML cells and then treated with Tf-NP-miR-29b had significantly longer survival compared with Tf-NP-scramble (P = 0.015) or free miR-29b (P = 0.003). Furthermore, priming AML cell with Tf-NP-miR-29b before treatment with decitabine resulted in marked decrease in cell viability in vitro and showed improved antileukemic activity compared with decitabine alone (P = 0.001) in vivo.
  
  
  CONCLUSIONS
  Tf-NP effectively delivered functional miR-29b, resulting in target downregulation and antileukemic activity and warrants further investigation as a novel therapeutic approach in AML.
authors.affiliation: Molecular, Cellular and Developmental Biology, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Huang
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schwind
authors.forename: Bo
authors.initials: B
authors.lastname: Yu
authors.forename: Ramasamy
authors.initials: R
authors.lastname: Santhanam
authors.forename: Hongyan
authors.initials: H
authors.lastname: Wang
authors.forename: Pia
authors.initials: P
authors.lastname: Hoellerbauer
authors.forename: Alice
authors.initials: A
authors.lastname: Mims
authors.forename: Rebecca
authors.initials: R
authors.lastname: Klisovic
authors.forename: Alison R
authors.initials: AR
authors.lastname: Walker
authors.forename: Kenneth K
authors.initials: KK
authors.lastname: Chan
authors.forename: William
authors.initials: W
authors.lastname: Blum
authors.forename: Danilo
authors.initials: D
authors.lastname: Perrotti
authors.forename: John C
authors.initials: JC
authors.lastname: Byrd
authors.forename: Clara D
authors.initials: CD
authors.lastname: Bloomfield
authors.forename: Michael A
authors.initials: MA
authors.lastname: Caligiuri
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lee
authors.forename: Ramiro
authors.initials: R
authors.lastname: Garzon
authors.forename: Natarajan
authors.initials: N
authors.lastname: Muthusamy
authors.forename: Ly James
authors.initials: LJ
authors.lastname: Lee
authors.forename: Guido
authors.initials: G
authors.lastname: Marcucci
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D000077209:Decitabine; D015536:Down-Regulation; D015870:Gene Expression; D015973:Gene Expression Regulation, Leukemic; D055785:Gene Knockdown Techniques; D018014:Gene Transfer Techniques; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000628:therapy*; D019787:Linoleic Acid / Q000737:chemistry; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D010714:Phosphatidylethanolamines / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D034622:RNA Interference; D014168:Transferrin / Q000737:chemistry*; D023041:Xenograft Model Antitumor Assays
chemical_list: C410262:1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine; D000964:Antimetabolites, Antineoplastic; C532045:MIRN29a microRNA, human; D035683:MicroRNAs; D010714:Phosphatidylethanolamines; D014168:Transferrin; D011092:Polyethylene Glycols; D000077209:Decitabine; D019787:Linoleic Acid; D004248:DNA (Cytosine-5-)-Methyltransferases; D001374:Azacitidine