Gene expression profiling to monitor therapeutic and adverse effects of antisense therapies for Duchenne muscular dystrophy.
OBJECTIVE
The objective of this study was to assess the utility of the gene expression profiling technique for the preclinical evaluation of drug efficacy and safety, taking a new therapeutic approach for Duchenne muscular dystrophy (DMD) as an example.


METHODS
Muscles from dystrophin-deficient (mdx) mice, a well-characterized animal model for DMD, were injected with antisense constructs that restore the open reading frame in the Dmd gene. Synthetic antisense oligonucleotides (AONs) complexed with different carriers to enhance cellular uptake and recombinant adeno-associated virus (rAAV)-expressed antisense sequences were evaluated. Muscular gene expression profiles were analyzed on oligonucleotide microarrays.


RESULTS
Polyethylenimine (PEI)-complexed AONs restored the reading frame slightly more effectively than uncomplexed, F127- or Optison-complexed AONs. However, PEI induced the expression of many immune genes, reflecting an aggravation of the inflammation present in untreated mdx mice. Expression profiles in Optison and F127-injected muscles were similar to those of saline treated muscles, implying that these carriers did not evoke adverse responses. Due to moderate levels of exon skipping, a significant shift toward wild-type expression levels was not detected. Injection with rAAV vectors resulted in much higher production of dystrophin and greatly improved the histological appearance of the muscle. Depending on the efficacy of the treatment, the expression of genes previously shown to be elevated in muscular dystrophies, partly or completely returned to wild-type expression levels. Reductions in inflammation and fibrosis were among the most prominent changes observed.


CONCLUSIONS
Expression profiling is a powerful tool for the evaluation of both desired and adverse effects of new pharmacological therapies. It is sensitive and detects changes that are not histologically visible. In addition, its ability to simultaneously monitor a large number of different biological processes not only reduces the number of different assays required in preclinical research and clinical trials, but may also assist in the early detection of potential side effects.
't Hoen
Peter A C
PA
Leiden University Medical Center, Center for Human and Clinical Genetics, Room S-04-003, Postbus 9600, 2300 RC Leiden, The Netherlands. p.a.c.hoen@lumc.nl
van der Wees
Caroline G C
CG
Aartsma-Rus
Annemieke
A
Turk
Rolf
R
Goyenvalle
Aurélie
A
Danos
Olivier
O
Garcia
Luis
L
van Ommen
Gert-Jan B
GJ
den Dunnen
Johan T
JT
van Deutekom
Judith C T
JC
D000818:Animals; D015153:Blotting, Western; D004337:Drug Carriers; D005091:Exons / Q000235:genetics; D020869:Gene Expression Profiling; D007150:Immunohistochemistry; D051379:Mice; D018101:Mice, Inbred mdx; D020388:Muscular Dystrophy, Duchenne / Q000188:drug therapy* / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction
D004337:Drug Carriers; D016376:Oligonucleotides, Antisense; D012313:RNA