miR-762 activation confers acquired resistance to gefitinib in non-small cell lung cancer
miR-762 activation confers acquired resistance to gefitinib in non-small cell lung cancer
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DOI：
10.1186/s12885-019-6416-4
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发表时间：
2019-12-10
期刊：
影响因子：
3.8
通讯作者：
Yue, Wanxia
中科院分区：
文献类型：
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作者：
Ge, Peng;Cao, Lei;Yue, Wanxia
背景：表皮生长因子受体(EGFR)-酪氨酸激酶抑制剂(TKIs)(如吉非替尼)目前仍是激活EGFR突变的晚期非小细胞肺癌(NSCLC)患者的一线治疗药物。然而，对吉非替尼的获得性耐药经常发生，其机制不明，显著降低了治疗效果。先前的miRNA微阵列分析显示，在对吉非替尼耐药的NSCLC细胞中，保守的oncomiR-762的表达水平显著上调。因此，我们旨在阐明miR-762在Gefitinib耐药机制中的作用及其可能的机制。方法：采用RT-qPCR方法检测MIR-762在Gefitinib耐药非小细胞肺癌组织和细胞中的表达。用药理学和生物化学方法研究了IL-6对miR-762表达的潜在调节作用。采用四甲基偶氮唑盐比色法、细胞凋亡法和异种移植模型评价miR-762对吉非替尼敏感性的影响。结果：miR-762在对吉非替尼耐药的非小细胞肺癌组织和细胞中表达上调，提示化疗后预后不良。IL-6信号诱导的MIR-762上调显著提高了NSCLC细胞的存活率，并使NSCLC细胞对吉非替尼诱导的细胞死亡无反应。我们最终提供的证据表明，miR-762的致癌作用主要是通过转录后抑制ABR在吉非替尼耐药的NSCLC细胞中介导的。结论：我们的研究结果为进一步在复发的EGFR突变的NSCLC患者中测试miR-762抑制和ABR修复共同治疗以治疗对抗EGFR-TKIs耐药机制的异质性提供了理论基础。
Background: Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) (e.g. gefitinib) currently remain the first-line treatment for patients with advanced non-small-cell lung cancer (NSCLC) with activating EGFR mutation. However, acquired resistance to gefitinib, which occurs frequently through unidentified mechanisms, significantly attenuate therapeutic effectiveness. Previous miRNA microarray analysis reveals that expression levels of a conserved oncomiR miR-762 are significantly upregulated in gefitinib-resistant NSCLC cells. We therefore aim to elucidate the role and underlying mechanisms of miR-762 during the pathogenesis of gefitinib resistance.Methods: miR-762 expression in gefitinib-resistant NSCLC tissues and cells was evaluated using RT-qPCR. The potential regulation of miR-762 expression by IL-6 was studied using pharmacological and biochemical approaches. Effects of miR-762 manipulation on sensitivity to gefitinib was assessed using MTT, apoptotic ELISA and xenograft model. Finally, the posttranscriptional regulation of active BCR related protein (ABR) by miR-762 was determined using luciferase assay and site-directed mutagenesis.Results: miR-762 expression was upregulated in gefitinib-resistant NSCLC tissues and cells, and this upregulation predicted a poor post-chemotherapy prognosis in NSCLC patients. miR-762 upregulation, induced by IL-6 signaling, significantly enhanced cell survival and rendered NSCLC cells unresponsiveness to gefitinib-elicited cell death. We finally provided the evidence that the oncogenic effect of miR-762 was mediated mainly through posttranscriptional repression of ABR in gefitinib-resistant NSCLC cells.Conclusions: Our findings provide a rationale for future efforts testing miR-762 inhibition and ABR restoration cotreatment in patients with recurrent EGFR mutant NSCLC to therapeutically combat the heterogeneity of EGFR-TKIs resistance mechanisms.