Translational Paediatric Oncology, National Cancer Research Institute (IST), Genoa, Italy.
BMC Cancer. 2009 Dec 15;9:441. doi: 10.1186/1471-2407-9-441.
Neuroblastoma is the most common, pediatric, extra-cranial, malignant solid tumor. Despite multimodal therapeutic protocols, outcome for children with a high-risk clinical phenotype remains poor, with long-term survival still less than 40%. Hereby, we evaluated the potential of non-coding RNA expression to predict outcome in high-risk, stage 4 neuroblastoma.
We analyzed expression of 481 Ultra Conserved Regions (UCRs) by reverse transcription-quantitative real-time PCR and of 723 microRNAs by microarrays in 34 high-risk, stage 4 neuroblastoma patients.
First, the comparison of 8 short- versus 12 long-term survivors showed that 54 UCRs were significantly (P < 0.0491) over-expressed in the former group. For 48 Ultra Conserved Region (UCRs) the expression levels above the cut-off values defined by ROC curves were strongly associated with good-outcome (OS: 0.0001 <P < 0.0185, EFS: 0.0001 <P < 0.0491). Then we tested the Transcribed-UCR (T-UCR) threshold risk-prediction model on an independent cohort of 14 patients. The expression profile of 28 T-UCRs was significantly associated to prognosis and at least 15 up-regulated T-UCRs are needed to discriminate (P < 0.0001) short- from long-survivors at the highest sensitivity and specificity (94.12%). We also identified a signature of 13 microRNAs differently expressed between long- and short-surviving patients. The comparative analysis of the two classes of non-coding RNAs disclosed that 9 T-UCRs display their expression level that are inversely correlated with expression of 5 complementary microRNAs of the signature, indicating a negative regulation of T-UCRs by direct interaction with microRNAs. Moreover, 4 microRNAs down-regulated in tumors of long-survivors target 3 genes implicated in neuronal differentiation, that are known to be over-expressed in low-risk tumors.
Our pilot study suggests that a deregulation of the microRNA/T-UCR network may play an important role in the pathogenesis of neuroblastoma. After further validation on a larger independent set of samples, such findings may be applied as the first T-UCR prognostic signature for high-risk neuroblastoma patients.
神经母细胞瘤是最常见的小儿颅外恶性实体瘤。尽管采用了多模式治疗方案，但高危临床表型患儿的预后仍然较差，长期生存率仍低于 40%。因此，我们评估了非编码 RNA 表达在高危 4 期神经母细胞瘤中的预测预后价值。
我们对 34 例高危 4 期神经母细胞瘤患者进行了 481 个超保守区（UCRs）的逆转录定量实时 PCR 分析和 723 个 microRNAs 的微阵列分析。
首先，对 8 例短生存与 12 例长生存患者的比较表明，前者有 54 个 UCRs 表达显著升高（P<0.0491）。对于 48 个 UCRs，ROC 曲线定义的截值以上的表达水平与良好预后强烈相关（OS：0.0001<P<0.0185，EFS：0.0001<P<0.0491）。然后，我们在另一个 14 例患者的独立队列中测试了转录 UCR（T-UCR）风险预测模型。28 个 T-UCR 的表达谱与预后显著相关，至少需要 15 个上调的 T-UCR 来区分（P<0.0001）短生存与长生存者，具有最高的敏感性和特异性（94.12%）。我们还鉴定了一个在长生存与短生存患者之间差异表达的 13 个 microRNAs 的特征。对两类非编码 RNA 的比较分析表明，9 个 T-UCR 的表达水平与其互补的签名 microRNAs 的表达水平呈负相关，表明 T-UCRs 通过与 microRNAs 的直接相互作用而受到负调控。此外，在长生存者肿瘤中下调的 4 个 microRNAs 靶向 3 个参与神经元分化的基因，这些基因在低危肿瘤中过度表达。
我们的初步研究表明，microRNA/T-UCR 网络的失调可能在神经母细胞瘤的发病机制中发挥重要作用。在更大的独立样本集上进一步验证后，这些发现可作为高危神经母细胞瘤患者的首个 T-UCR 预后标志物。
