Effects of MYCN Antisense Oligonucleotide Administration on Tumorigenesis in a Murine Model of Neuroblastoma
Background: Human MYCN (hMYCN) oncogene amplification is a powerful predictor of treatment failure in childhood neuroblastoma, and dysregulation of hMYCN protein expression appears to be critically involved in the pathogenesis of this disease. We used hMYCN antisense (AS) oligonucleotides to investi...
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| Published in: | JNCI : Journal of the National Cancer Institute Vol. 95; no. 18; pp. 1394 - 1403 |
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| Main Authors: | , , , , , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Cary, NC
Oxford University Press
17-09-2003
Oxford Publishing Limited (England) |
| Subjects: | |
| Online Access: | Get full text |
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| Summary: | Background: Human MYCN (hMYCN) oncogene amplification is a powerful predictor of treatment failure in childhood neuroblastoma, and dysregulation of hMYCN protein expression appears to be critically involved in the pathogenesis of this disease. We used hMYCN antisense (AS) oligonucleotides to investigate, both in vitro and in vivo, the therapeutic potential of inhibiting hMYCN expression. Methods: We transiently transfected human neuroblastoma IMR-32 cells, which have an amplified hMYCN gene, with fluorescently labeled hMYCN AS or scrambled (SCR) control oligonucleotides and used fluorescence-activated cell sorting to enrich for cell populations containing different levels of the oligonucleotides. We used fluorescence immunocytochemistry or reverse transcription polymerase chain reaction to assay gene expression levels and trypan blue exclusion to assay growth inhibition in the cell populations. We examined the effects of continuous treatment for 6 weeks with AS or SCR oligonucleotides via subcutaneously implanted microosmotic pumps on tumor growth in a transgenic mouse model of hMYCN-induced neuroblastoma (n = 20 mice per group). All statistical tests were two-sided. Results: IMR-32 cells treated with AS oligonucleotides had approximately half as much hMYCN protein and cell proliferation as either SCR oligonucleotide–transfected or mock-transfected controls; the differences were statistically significant. Transgenic mice treated with AS oligonucleotides had lower tumor incidence and statistically significantly lower tumor mass than SCR-treated or untreated control mice. Compared with control treatments, AS oligonucleotide treatment in vitro and in vivo was associated with decreased expression of hMYCN and putative hMYCN target genes but not with that of closely related genes. Several AS oligonucleotide–treated mice developed tumors contralateral to the site of oligonucleotide administration, whereas SCR oligonucleotide–treated or untreated mice displayed bilateral tumor growth. Conclusions: Decreased expression of hMYCN protein is achievable with the use of AS oligonucleotide treatment, even in the presence of hMYCN oncogene amplification. Antisense strategies targeting the hMYCN oncogene in vivo decrease mouse neuroblastoma tumorigenesis. Investigation of their clinical effect in children with neuroblastoma is warranted. |
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| Bibliography: | istex:99390EC2E7E22E6521E2BBA178B623F3F3F0FDF6 ark:/67375/HXZ-9VG9PWZM-F Correspondence to: Michelle Haber, PhD, Children’s Cancer Institute Australia for Medical Research, High St., P.O. Box 81, Randwick, NSW, Australia 2031 (e-mail: m.haber@unsw.edu.au). local:0951394 PII:1460-2105 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
| ISSN: | 0027-8874 1460-2105 |
| DOI: | 10.1093/jnci/djg045 |