MiR-214 increases the sensitivity of breast cancer cells to tamoxifen and fulvestrant through inhibition of autophagy.
MiR-214 increases the sensitivity of breast cancer cells to tamoxifen and fulvestrant through inhibition of autophagy.
复制标题
MiR-214通过抑制自噬增加乳腺癌细胞对他莫昔芬和氟维司群的敏感性
DOI：
10.1186/s12943-015-0480-4
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发表时间：
2015-12-15
期刊：
影响因子：
37.3
通讯作者：
Qu X
中科院分区：
文献类型：
--
作者：
Yu X;Luo A;Liu Y;Wang S;Li Y;Shi W;Liu Z;Qu X
背景他莫昔芬（TAM）和氟维司群（FUL）是雌激素受体阳性（ER+）乳腺癌患者的主要药物。然而，内分泌抵抗的发展是成功治疗的障碍。我们的目的是探讨内分泌抵抗的机制和克服TAM和FUL抵抗的治疗策略。方法在ER+和雌激素/TAM敏感的MCF7细胞和抗雌激素抵抗的MCF7/LCC9细胞中进行实验。通过 RT-qPCR 和蛋白质印迹法测定乳腺癌细胞和人乳腺癌组织标本中 miR-214 和解偶联蛋白 2 (UCP2) 的表达。通过荧光探针单丹酰尸胺 (MDC) 检查细胞自噬，并通过共聚焦显微镜鉴定 GFP-LC3-II 阳性点状。通过Annexin V-FITC/PI染色测定凋亡细胞。通过预测工具、靶蛋白表达和荧光素酶报告基因测定确定miR-214的潜在调控靶点。结果4-OHT/FUL治疗导致乳腺癌细胞凋亡和自噬的诱导。自噬可能是内分泌抵抗 4-OHT 或 FUL 的主要原因。 MiR-214 通过抑制自噬增加乳腺癌细胞对 4-OHT/FUL 诱导的细胞凋亡的敏感性。重要的是，通过 RT-qPCR 检测的人乳腺癌组织标本中 miR-214 和 UCP2 之间建立了负相关。 UCP2 被确定为 miR-214 的直接靶标。对MCF7/LCC9细胞的进一步研究表明，内分泌抵抗可能是由于PI3K-Akt-mTOR通路的激活引起的，从而通过UCP2的过表达诱导自噬。结论MiR-214通过靶向UCP2抑制自噬，增加乳腺癌细胞对TAM和FUL的敏感性。 MiR-214 显示出作为克服 ER+乳腺癌内分泌耐药的新型治疗策略的潜力。
BackgroundTamoxifen (TAM) and fulvestrant (FUL) are the major drugs for patients with estrogen receptor-positive (ER+) breast cancers. However, the development of endocrine resistance is the impediment for successful treatment. We aimed to explore the mechanisms of endocrine resistance and therapeutic strategy for overcoming resistance against TAM and FUL.MethodsExperiments were performed in ER+and estrogen/TAM-sensitive MCF7 cells and antiestrogen-resistant MCF7/LCC9 cells. The expression of miR-214 and uncoupling protein 2 (UCP2) was determined by RT-qPCR and Western blot in breast cancer cells and human breast cancer tissue specimens. Cell autophagy was examined by fluorescent probe monodansyl cadaverine (MDC) and GFP-LC3-II-positive punctate identified by confocal microscopy. Apoptotic cells were determined by Annexin V-FITC/PI staining. The potential regulatory target of miR-214 was determined by prediction tool, target protein expression and luciferase reporter assay.Results4-OHT/FUL treatment resulted in induction of apoptosis as well as autophagy in breast cancer cells. Autophagy might be the major cause of endocrine resistance to 4-OHT or FUL. MiR-214 increased the sensitivity of breast cancer cells to the 4-OHT/FUL-induced apoptosis through inhibition of autophagy. Importantly, a negative correlation was established between miR-214 and UCP2 in human breast cancer tissue specimens assayed by RT-qPCR. UCP2 was identified to be a direct target of miR-214. Further study in MCF7/LCC9 cells indicated that endocrine resistance might arise from activation of the PI3K-Akt-mTOR pathway, thereby inducing autophagy by overexpression of UCP2.ConclusionMiR-214 increased the sensitivity of breast cancer cells to TAM and FUL through inhibition of autophagy by targeting UCP2. MiR-214 shows potential as a novel therapeutic strategy for overcoming endocrine resistance in ER+breast cancers.