title: Partial correction of the dwarf phenotype by non-viral transfer of the growth hormone gene in mice: Treatment age is critical.
abstract: Non-viral transfer of the growth hormone gene to different muscles of immunodeficient dwarf (lit/scid) mice is under study with the objective of improving phenotypic correction via this particular gene therapy approach. Plasmid DNA was administered into the exposed quadriceps or non-exposed tibialis cranialis muscle of lit/scid mice followed by electroporation, monitoring several growth parameters. In a 6-month bioassay, 50μg DNA were injected three times into the quadriceps muscle of 80-day old mice. A 50% weight increase, with a catch-up growth of 21%, together with a 16% increase for nose-to-tail and tail lengths (catch-up=19-21%) and a 24-28% increase for femur length (catch-up=53-60%), were obtained. mIGF1 serum levels were ~7-fold higher than the basal levels for untreated mice, but still ~2-fold lower than in non-dwarf scid mice. Since treatment age was found to be particularly important in a second bioassay utilizing 40-day old mice, these pubertal mice were compared in a third bioassay with adult (80-day old) mice, all treated twice with 50μg DNA injected into each tibialis cranialis muscle, via a less invasive approach. mIGF1 concentrations at the same level as co-aged scid mice were obtained 15days after administration in pubertal mice. Catch-up growth, based on femur length (77%), nose-to-tail (36%) and tail length (39%) increases was 40 to 95% higher than those obtained upon treating adult mice. These data pave the way for the development of more effective pre-clinical assays in pubertal dwarf mice for the treatment of GH deficiency via plasmid-DNA muscular administration.
authors.affiliation: Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN), Cidade Universitária, São Paulo, SP, Brazil.
authors.forename: Eliza
authors.initials: E
authors.lastname: Higuti
authors.affiliation: Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN), Cidade Universitária, São Paulo, SP, Brazil; Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark.
authors.forename: Cláudia R
authors.initials: CR
authors.lastname: Cecchi
authors.affiliation: Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN), Cidade Universitária, São Paulo, SP, Brazil; Lillehei Heart Institute, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Nélio A J
authors.initials: NA
authors.lastname: Oliveira
authors.affiliation: Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN), Cidade Universitária, São Paulo, SP, Brazil.
authors.forename: Eliana R
authors.initials: ER
authors.lastname: Lima
authors.affiliation: Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN), Cidade Universitária, São Paulo, SP, Brazil.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Vieira
authors.affiliation: Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Aagaard
authors.affiliation: Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Jensen
authors.affiliation: Genetic-Endocrinology Unit (LIM25), Endocrinology Department, University of São Paulo School of Medicine (FMUSP), São Paulo, SP, Brazil.
authors.forename: Alexander A L
authors.initials: AA
authors.lastname: Jorge
authors.affiliation: Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN), Cidade Universitária, São Paulo, SP, Brazil.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bartolini
authors.affiliation: Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN), Cidade Universitária, São Paulo, SP, Brazil. Electronic address: cnperoni@ipen.br.
authors.forename: Cibele N
authors.initials: CN
authors.lastname: Peroni
mesh_terms: D000367:Age Factors; D000818:Animals; D004392:Dwarfism / Q000235:genetics*; D005260:Female; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D006128:Growth / Q000235:genetics / Q000502:physiology; D013006:Growth Hormone / Q000008:administration & dosage / Q000235:genetics*; D007273:Injections, Intramuscular; D051379:Mice; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D010641:Phenotype; D018013:Receptors, Neuropeptide / Q000235:genetics; D018017:Receptors, Pituitary Hormone-Regulating Hormone / Q000235:genetics
chemical_list: D018013:Receptors, Neuropeptide; D018017:Receptors, Pituitary Hormone-Regulating Hormone; D013006:Growth Hormone; C048250:somatotropin releasing hormone receptor
keywords: Gene therapy; Growth hormone gene; Immunodeficient dwarf mice; Non-viral gene transfer; Treatment age; mIGF1