SNAI2 modulates colorectal cancer 5-fluorouracil sensitivity through miR145 repression.
SNAI2 modulates colorectal cancer 5-fluorouracil sensitivity through miR145 repression.
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DOI：
10.1158/1535-7163.mct-14-0207
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发表时间：
2014-11
影响因子：
5.7
通讯作者：
Camp ER
中科院分区：
文献类型：
--
作者：
Findlay VJ;Wang C;Nogueira LM;Hurst K;Quirk D;Ethier SP;Staveley O'Carroll KF;Watson DK;Camp ER
上皮-间质转化（EMT）与各种恶性肿瘤的不良治疗结果相关，并与miRNA-145表达呈负相关。因此，我们假设SNAI2 （Slug）可能通过抑制结直肠癌（CRC）中miR-145介导5FU化疗耐药，从而代表了一个新的治疗靶点，以增强当前的CRC治疗策略。与亲代DLD1结肠癌细胞相比，5fu耐药（5FUr） DLD1细胞表现出EMT的特征，包括侵袭和迁移增强>2倍（p<0.001）， E-Cadherin表达抑制，SNAI2表达增加2倍。与对照空载体细胞相比，SNAI2 （DLD1/SNAI2; HCT116/SNAI2）稳定表达的DLD1和HCT116细胞也表现出EMT特征，如E-Cadherin减少，miR-145表达显著降低。基于miR-145荧光素酶启动子实验，我们证明了SNAI2在DLD1和HCT116细胞中抑制miR-145启动子的活性。此外，异位表达SNAI2细胞系表现出5FU敏感性降低，相反，miR-145替代显著增强了5FU敏感性。在高SNAI2和低miR-145水平亲本SW620结肠癌细胞系中，直接用短发夹序列抑制SNAI2和miR-145替代治疗均可降低Vimentin表达并增加体外5FU敏感性。在治疗前直肠癌患者活检样本中，低miR-145表达水平与对基于5FU的新辅助放化疗的不良反应相关。这些结果表明，SNAI2:miR-145通路可能代表CRC的一个新的临床治疗靶点，并可能作为对放化疗的反应预测因子。
Epithelial-to-mesenchymal transition (EMT) has been associated with poor treatment outcomes in various malignancies and is inversely associated with miRNA-145 expression. Therefore, we hypothesized that SNAI2 (Slug) may mediate 5FU chemotherapy resistance through inhibition of miR-145 in colorectal cancer (CRC) and thus, represents a novel therapeutic target to enhance current CRC treatment strategies. Compared to parental DLD1 colon cancer cells, 5FU-resistant (5FUr) DLD1 cells demonstrated features of EMT, including >2-fold enhanced invasion (p<0.001) and migration, suppressed E-Cadherin expression, and 2-fold increased SNAI2 expression. DLD1 and HCT116 cells with stable expression of SNAI2 (DLD1/SNAI2; HCT116/SNAI2) also demonstrated EMT features such as the decreased E-Cadherin, as well as significantly decreased miR-145 expression, as compared to control empty vector cells. Based on a miR-145 luciferase promoter assay, we demonstrated that SNAI2 repressed activity of the miR-145 promoter in the DLD1 and HCT116 cells. In addition, the ectopic expressing SNAI2 cell lines demonstrated decreased 5FU sensitivity and conversely, miR-145 replacement significantly enhanced 5FU sensitivity. In the parental SW620 colon cancer cell line with high SNAI2 and low miR-145 levels, inhibition of SNAI2 directly with short hairpin sequence for SNAI2 and miR-145 replacement therapy both decreased Vimentin expression and increased in vitro 5FU sensitivity. In pre-treatment rectal cancer patient biopsy samples, low miR-145 expression levels correlated with poor response to neoadjuvant 5FU based chemoradiation. These results suggested that the SNAI2:miR-145 pathway may represent a novel clinical therapeutic target in CRC and may serve as a response predictor to chemoradiation therapy.