title: Downregulation of Plk1 expression by receptor-mediated uptake of antisense oligonucleotide-loaded nanoparticles.
abstract: Human serum albumin (HSA) nanoparticles represent a promising tool for targeted drug delivery to tumor cells. The coupling of the antibody trastuzumab to nanoparticles uses the capability of human epidermal growth factor receptor 2 (HER2)-positive cells to incorporate agents linked to HER2. In our present study, we developed targeted nanoparticles loaded with antisense oligonucleotides (ASOs) against polo-like kinase 1 (Plk1). We evaluated the receptor-mediated uptake into HER2-positive and -negative breast cancer and murine cell lines. We performed quantitative real-time PCR and Western blot analyses to monitor the impact on Plk1 expression in HER2-positive breast cancer cells. Antibody-conjugated nanoparticles showed a specific targeting to HER2-overexpressing cells with cellular uptake by receptor-mediated endocytosis and a release into HER2-positive BT-474 cells. We observed a significant reduction of Plk1 mRNA and protein expression and increased activation of Caspase 3/7. Thus, this is the first report about ASO-loaded HSA nanoparticles, where an impact on gene expression could be observed. The data provide the basis for the further development of carrier systems for Plk1-specific ASOs to reduce off-target effects evoked by systemically administered ASOs and to achieve a better penetration into primary and metastatic target cells. Treatment of tumors using trastuzumab-conjugated ASO-loaded HSA nanoparticles could be a promising approach to reach this goal.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medicine, Johann Wolfgang Goethe-University, D-60590 Frankfurt, Germany. Birgit.Spaenkuch@t-online.de
authors.forename: Birgit
authors.initials: B
authors.lastname: Spänkuch
authors.forename: Isabel
authors.initials: I
authors.lastname: Steinhauser
authors.forename: Heidrun
authors.initials: H
authors.lastname: Wartlick
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kurunci-Csacsko
authors.forename: Klaus I
authors.initials: KI
authors.lastname: Strebhardt
authors.forename: Klaus
authors.initials: K
authors.lastname: Langer
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D015536:Down-Regulation; D016503:Drug Delivery Systems; D004355:Drug Stability; D006801:Humans; D051379:Mice; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000378:metabolism; D012709:Serum Albumin / Q000737:chemistry; D000068878:Trastuzumab; D000097869:Polo-Like Kinase 1
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D053148:Caspase 3; D053179:Caspase 7; D018797:Cell Cycle Proteins; D016376:Oligonucleotides, Antisense; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D012709:Serum Albumin; D000068878:Trastuzumab; D000097869:Polo-Like Kinase 1; C490219:PLK4 protein, human; C496126:PLK2 protein, human