miR-302a Inhibits Metastasis and Cetuximab Resistance in Colorectal Cancer by Targeting NFIB and CD44
miR-302a Inhibits Metastasis and Cetuximab Resistance in Colorectal Cancer by Targeting NFIB and CD44
复制标题
miR-302a 通过靶向 NFIB 和 CD44 抑制结直肠癌的转移和西妥昔单抗耐药性
DOI：
10.7150/thno.36605
复制
发表时间：
2019-01-01
期刊：
影响因子：
12.4
通讯作者：
Zhao, Xiaodi
中科院分区：
文献类型：
--
作者：
Sun, Lina;Fang, Ying;Zhao, Xiaodi
前言：转移和耐药是结直肠癌（CRC）患者预后不良的主要原因。然而，CRC发展为转移性和耐药特征的表观遗传调控机制仍不清楚。本研究旨在探讨miR-302 a在结直肠癌转移和分子靶向耐药中的作用及其分子机制。方法：采用qPCR和荧光原位杂交技术分析miR-302 a在结直肠癌细胞系和患者组织微阵列中的表达。在体外和体内评估miR-302 a在转移和西妥昔单抗（CTX）抗性中的作用。进行生物信息学预测算法和荧光素酶报告基因测定以鉴定NFIB和CD 44 3 '-UTR中的miR-302 a结合区。进行染色质免疫沉淀测定以检查ITGA 6启动子区域中的NFIB占有率。进行免疫印迹以鉴定miR-302 a改变的EGFR介导的途径。结果：miR-302 a在结直肠癌细胞和组织中的表达经常降低，特别是在CTX耐药细胞和患者来源的异种移植物中。降低的miR-302 a水平与CRC患者的总体生存率差相关。miR-302 a过表达抑制了CRC细胞的转移并恢复了CTX反应性，而miR-302 a沉默则产生了相反的效果。NFIB和CD 44被鉴定为miR-302 a的新靶点。miR-302 a抑制NFIB的转移促进作用，NFIB在生理上激活ITGA 6转录。miR-302 a通过抑制CD 44诱导的癌症干细胞样特性和EGFR介导的MAPK和AKT信号传导恢复CTX反应性。这些结果与临床观察结果一致，表明miR-302 a表达与CRC标本中其靶标的表达呈负相关。结论：我们的研究结果表明，miR-302 a通过分别靶向NFIB和CD 44，作为CRC转移和CTX耐药的多方面调节剂。我们的研究暗示miR-302 a是CRC的候选预后预测因子和治疗剂。
Introduction: Metastasis and drug resistance contribute substantially to the poor prognosis of colorectal cancer (CRC) patients. However, the epigenetic regulatory mechanisms by which CRC develops metastatic and drug-resistant characteristics remain unclear. This study aimed to investigate the role of miR-302a in the metastasis and molecular-targeted drug resistance of CRC and elucidate the underlying molecular mechanisms. Methods: miR-302a expression in CRC cell lines and patient tissue microarrays was analyzed by qPCR and fluorescence in situ hybridization. The roles of miR-302a in metastasis and cetuximab (CTX) resistance were evaluated both in vitro and in vivo. Bioinformatic prediction algorithms and luciferase reporter assays were performed to identify the miR-302a binding regions in the NFIB and CD44 3'-UTRs. A chromatin immunoprecipitation assay was performed to examine NFIB occupancy in the ITGA6 promoter region. Immunoblotting was performed to identify the EGFR-mediated pathways altered by miR-302a. Results: miR-302a expression was frequently reduced in CRC cells and tissues, especially in CTX-resistant cells and patient-derived xenografts. The decreased miR-302a levels correlated with poor overall CRC patient survival. miR-302a overexpression inhibited metastasis and restored CTX responsiveness in CRC cells, whereas miR-302a silencing exerted the opposite effects. NFIB and CD44 were identified as novel targets of miR-302a. miR-302a inhibited the metastasis-promoting effect of NFIB that physiologically activates ITGA6 transcription. miR-302a restored CTX responsiveness by suppressing CD44-induced cancer stem cell-like properties and EGFR-mediated MAPK and AKT signaling. These results are consistent with clinical observations indicating that miR-302a expression is inversely correlated with the expression of its targets in CRC specimens. Conclusions: Our findings show that miR-302a acts as a multifaceted regulator of CRC metastasis and CTX resistance by targeting NFIB and CD44, respectively. Our study implicates miR-302a as a candidate prognostic predictor and a therapeutic agent in CRC.