Genomic and clinical analysis of amplification of the 13q31 chromosomal region in alveolar rhabdomyosarcoma: a report from the Children's Oncology Group.

Autor: Reichek JL; Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA., Duan F, Smith LM, Gustafson DM, O'Connor RS, Zhang C, Dunlevy MJ, Gastier-Foster JM, Barr FG
Jazyk: angličtina
Zdroj: Clinical cancer research : an official journal of the American Association for Cancer Research [Clin Cancer Res] 2011 Mar 15; Vol. 17 (6), pp. 1463-73. Date of Electronic Publication: 2011 Jan 10.
DOI: 10.1158/1078-0432.CCR-10-0091
Abstrakt: Purpose: This study determined the molecular characteristics and clinical significance of amplification of the 13q31 chromosomal region in alveolar rhabdomyosarcoma (ARMS), an aggressive pediatric cancer with frequent PAX3-FOXO1 and PAX7-FOXO1 gene fusions.
Experimental Design: The 13q31 amplicon was localized in an initial panel of ARMS cases using oligonucleotide arrays. A fluorescence in situ hybridization assay for this localized region was designed, and applied to more ARMS cases to determine the frequency and distribution of amplification. Quantitative reverse transcription-PCR assays were applied to measure gene expression. The clinical significance of copy number and expression was determined with Kaplan-Meier and Cox proportional hazard models.
Results: We localized the 13q31 amplicon to a 0.15 Mb region containing the MIR17HG gene encoding the polycistronic microRNA cluster, miR-17-92. This amplicon is present in 23% of ARMS cases with a marked preference for PAX7-FOXO1-positive cases. In tumors with 13q31 amplification, there is significantly increased expression of 5 of 6 microRNA's within the miR-17-92 cluster (miR-17, miR-19a, miR-19b, miR-20a, and miR-92a). In addition, a subset of nonamplified tumors with copy number-independent overexpression of all 6 microRNA's was identified. In clinical analyses, there was a significantly worse outcome associated with increased expression of the 5 microRNA's described above in 13q31-amplified cases when compared to nonamplified cases. There was also an improved outcome in 13q31-amplified cases with lower expression of these microRNA's.
Conclusions: 13q31 amplification and expression of the miR-17-92 cluster provide novel markers for identifying good and poor prognostic subsets of PAX7-FOXO1-positive ARMS.
(©2011 AACR.)
Databáze: MEDLINE