Inhibition of microRNA-21 increases radiosensitivity of esophageal cancer cells through phosphatase and tensin homolog deleted on chromosome 10 activation
Inhibition of microRNA-21 increases radiosensitivity of esophageal cancer cells through phosphatase and tensin homolog deleted on chromosome 10 activation
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抑制 microRNA-21 通过在 10 号染色体激活上删除的磷酸酶和张力蛋白同源物来增加食管癌细胞的放射敏感性。
DOI：
10.1111/j.1442-2050.2012.01389.x
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发表时间：
2013-11-01
影响因子：
2.6
通讯作者：
Zhang, X-Z.
中科院分区：
文献类型：
--
作者：
Huang, S.;Li, X-Q.;Zhang, X-Z.
食管鳞癌的放射抵抗是治疗的一大障碍。尽管已经证明microRNA-21（miR-21）可以作为食管鳞状细胞癌中的“癌基因”，但其在放射抗性中的作用仍然未被探索。本研究旨在探讨miR-21在食管鳞癌细胞放射抵抗中的作用及其可能机制。采用分次照射法建立食管鳞癌TE-1细胞系（TE-R60）。通过miRZip-21慢病毒转导，TE-1细胞中miR-21的表达稳定下调，将其重新命名为“anti-miR-21 TE-1细胞”。通过短干扰RNA在抗miR-21 TE-1细胞中敲低10号染色体上缺失的磷酸酶和张力蛋白同源物（PTEN）。采用实时定量逆转录聚合酶链反应（RT-PCR）或逆转录聚合酶链反应（RT-PCR）检测miR-21和PTEN mRNA的表达水平。Western blot检测PTEN、磷酸化Akt和Akt蛋白的表达水平。克隆形成实验分析细胞的放射敏感性。与亲本细胞相比，miR-21在建立的辐射抗性TE-R60细胞中过表达，并且PTEN被抑制（1.3倍和70.83%）。miR-21的抑制显著增加TE-1细胞的放射敏感性（P <0.05）和PTEN蛋白的表达（2.3倍）。 此外，在抗miR-21 TE-1细胞中，PTEN的下游靶标磷酸化Akt蛋白显著减少。在抗miR-21的TE-1细胞中敲除PTEN可消除miR-21抑制剂诱导的放射增敏作用（P <0.05）。 抑制miR-21可增加食管癌TE-1细胞的放射敏感性，这种作用可能是通过激活PTEN实现的。抑制miR-21可能成为提高食管癌放射敏感性的一种新的治疗策略。
The radioresistance of esophageal squamous cell carcinoma is a great obstacle to treatment. Although it has been demonstrated that microRNA-21 (miR-21) can act as an 'oncogene' in esophageal squamous cell carcinoma, its role in radioresistance remains unexplored. The aims of this study were to investigate the role of miR-21 in esophageal squamous carcinoma cells' radioresistance and to identify the possible mechanism. The relatively radioresistant esophageal squamous cancer TE-1 cells (TE-R60) was established by fractionated irradiation. By lentiviral transduction with miRZip-21, the miR-21 expression in TE-1 cells was stably downregulated, which was renamed as 'anti-miR-21 TE-1 cells.' The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) was knocked down in anti-miR-21 TE-1 cells through short interfering RNA. The expression level of miR-21 and PTEN messenger RNA were measured by quantitative real-time reverse transcription polymerase chain reaction or reverse transcription polymerase chain reaction. The expression level of PTEN, phospho-Akt, and Akt protein were detected by Western blot. Clongenic assay was used to analyze the cells' radiosensitivity. miR-21 was overexpressed, and PTEN was suppressed in established radioresistant TE-R60 cells compared with the parent cells (1.3-fold and 70.83%). The inhibition of miR-21 significantly increased the cells' radiosensitivity (P < 0.05) and the PTEN protein expression (2.3-fold) in TE-1 cells. In addition, phospho-Akt protein, downstream target of PTEN, reduced significantly in anti-miR-21 TE-1 cells. Knockdown of PTEN in anti-miR-21 TE-1 cells could abrogate the miR-21 inhibition-induced radiosensitization (P < 0.05). Inhibition of miR-21 increased radiosensitivity of esophageal cancer TE-1 cells, and this effect was possibly through the activation of PTEN. Inhibition of miR-21 may form a novel therapeutic strategy to increase the radiosensitivity of esophageal cancer.