Determination of 17q gain in patients with neuroblastoma by analysis of circulating DNA.
ABSTRACT Retrospective studies have demonstrated the prognostic impact of genomic profiles in neuroblastoma (NB). Segmental chromosome alterations have been found useful for identifying tumors with a high risk of relapse. As the gain of chromosome arm 17q is the most frequent chromosome alteration reported in NB primary tumors, we evaluated the presence of this 17q gain in the peripheral blood of patients with NB.
Using duplex quantitative real-time PCR, we quantified simultaneously MPO (17q.23.1) and a reference gene, p53, and Survivin (17q25) and p53. MPO and Survivin copy numbers were evaluated as MPO/p53 and Survivin/p53 ratios in 142 serum or plasma samples in which 17q status had been determined by array-based comparative genomic hybridization (aCGH) or multiplex ligation-dependent probe amplification (MLPA).
In patients <18 months of age, serum-based determination of 17q gain in DNA sequences had good specificity (94.4%) and 58.8% sensitivity (P < 0.001). In contrast, for patients over 18 months of age, the approach exhibited moderate specificity (71.4%) and 51.2% sensitivity (P = ns). Similar results were observed in patients with tumors without MYCN amplification.
Our results show that 17q gain determination in circulating DNA is possible and suggest that this non-invasive test could be useful for very young children when no reliable information on genomic alterations is obtained by aCGH or MPLA analysis of tumor samples This test is complementary to previously developed techniques for detecting circulating MYCN DNA sequences.
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ABSTRACT: Introduction: The hallmark of neuroblastoma is its clinical and biological heterogeneity, with the likelihood of cure varying widely according to age at diagnosis, extent of disease and tumor biology. We hope this review will be useful for understanding part of the unfamiliar neuroblastoma codex. Areas covered: In the first part of this review, the authors summarize the currently used prognostic factors for risk-adapted therapy, with the focus on clinical management of neuroblastoma patients. In the second part, the authors discuss the evolving prognostic factors for future treatment schemes. A search of online medical research databases was undertaken focusing especially on literature published in the last six years. Expert opinion: Harnessing the synergy of the various forms of data, including clinical variables and biomarker profiles, would allow mathematical predictive models to be built for the individual patient, which could eventually become molecular targets of specific therapies.Expert Opinion on Medical Diagnostics 11/2012; 6(6):555-567.
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ABSTRACT: MicroRNAs (miRNAs) are deregulated in a variety of human cancers, including neuroblastoma, the most common extracranial tumor of childhood. We previously reported a signature of 42 miRNAs to be highly predictive of neuroblastoma outcome. One miRNA in this signature, miR-542, was downregulated in tumors from patients with adverse outcome. Re-analysis of quantitative PCR and next-generation sequencing transcript data revealed that miR-542-5p as well as miR-542-3p expression is inversely correlated with poor prognosis in neuroblastoma patients. We, therefore, analyzed the function of miR-542 in neuroblastoma tumor biology. Ectopic expression of miR-542-3p in neuroblastoma cell lines reduced cell viability and proliferation, induced apoptosis and downregulated Survivin. Survivin expression was also inversely correlated with miR-542-3p expression in primary neuroblastomas. Reporter assays confirmed that miR-542-3p directly targeted Survivin. Downregulating Survivin using siRNA copied the phenotype of miR-542-3p expression in neuroblastoma cell lines, while cDNA-mediated ectopic expression of Survivin partially rescued the phenotype induced by miR-542-3p expression. Treating nude mice bearing neuroblastoma xenografts with miR-542-3p-loaded nanoparticles repressed Survivin expression, decreased cell proliferation and induced apoptosis in the respective xenograft tumors. We conclude that miR-542-3p exerts its tumor suppressive function in neuroblastoma, at least in part, by targeting Survivin. Expression of miR-542-3p could be a promising therapeutic strategy for treating aggressive neuroblastoma. © 2014 Wiley Periodicals, Inc.International Journal of Cancer 07/2014; · 6.20 Impact Factor