D'Angelo Edoardo, Zanon Carlo, Sensi Francesca, Digito Maura, Rugge Massimo, Fassan Matteo, Scarpa Marco, Pucciarelli Salvatore, Nitti Donato, Agostini Marco
Department of Surgical, Oncological and Gastroenterological Sciences, University of Padua, Padua, Italy.
Nanoinspired Biomedicine Lab, Pediatric Research Institute - Fondazione Città della Speranza, Padua, Italy.
J Clin Pathol. 2018 Apr;71(4):344-350. doi: 10.1136/jclinpath-2017-204690. Epub 2017 Sep 4.
Curative surgery remains the primary form of treatment for locally advanced rectal cancer (LARC). Recent data support the use of preoperative chemoradiotherapy (pCRT) to improve the prognosis of LARC with a significant reduction of local relapse and an increase of overall survival. Unfortunately, only 20% of the patients with LARC present complete pathological response after pCRT, whereas in 20%-40%, the response is poor or absent.
We investigated the expression level of miR-194 in n=38 patients with LARC using our public microRNA (miRNA) expression dataset. miR-194 expression was further validated by real-time quantitative PCR (qRT-PCR) and in situ hybridisation (ISH). Protein-protein interaction network and pathway enrichment analysis were performed on miR-194 targets.
Using biopsy samples collected at diagnosis, mir-194 was significantly upregulated in patients responding to treatment (p value=0.016). The data was confirmed with qRT-PCR (p value=0.0587) and ISH (p value=0.026). Protein-protein interaction network and pathway enrichment analysis reveal a possible mechanism of susceptibility to pCRT involving Wnt pathway via its downstream mediator TRAF6. Finally, we interrogated the Comparative Toxicogenomics Database database in order to identify those chemical compounds able to mimic the biological effects of miR-194 as new possible therapeutic option in LARC treatment. The present study combining miRNA expression profiling with integrative computational biology identified miR-194 as predictive biomarker of response to pCRT. Using known and predicted drug mechanism of action, we then identified possible chemical compounds for further in vitro validation.
根治性手术仍然是局部晚期直肠癌（LARC）的主要治疗方式。近期数据支持术前放化疗（pCRT）的应用，其可改善LARC的预后，显著降低局部复发率并提高总生存率。遗憾的是，只有20%的LARC患者在pCRT后出现完全病理缓解，而20%-40%的患者反应较差或无反应。
我们使用公开的微小RNA（miRNA）表达数据集，调查了38例LARC患者中miR-194的表达水平。通过实时定量聚合酶链反应（qRT-PCR）和原位杂交（ISH）进一步验证miR-194的表达。对miR-194的靶标进行蛋白质-蛋白质相互作用网络和通路富集分析。
利用诊断时采集的活检样本，mir-194在治疗有反应的患者中显著上调（p值=0.016）。该数据经qRT-PCR（p值=0.0587）和ISH（p值=0.026）证实。蛋白质-蛋白质相互作用网络和通路富集分析揭示了一种对pCRT敏感的可能机制，该机制通过其下游介质TRAF6涉及Wnt通路。最后，我们查询了比较毒理基因组学数据库，以确定那些能够模拟miR-194生物学效应的化合物，作为LARC治疗中可能的新治疗选择。本研究将miRNA表达谱分析与综合计算生物学相结合，确定miR-194为pCRT反应的预测生物标志物。利用已知和预测的药物作用机制，我们随后确定了可能的化合物用于进一步的体外验证。
