Disturbance in the regulation of miR 17-92 cluster on HIF-1-α expression contributes to clinically relevant radioresistant cells: an in vitro study
Disturbance in the regulation of miR 17-92 cluster on HIF-1-α expression contributes to clinically relevant radioresistant cells: an in vitro study
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DOI：
10.1007/s10616-019-00364-9
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发表时间：
2020-01
期刊：
影响因子：
2.2
通讯作者：
Mehryar Habibi Roudkenar;Motoi Fukumoto;A. Roushandeh;Youshikazu Kuwahra;Yusuke Uroshihara;H. Harada;M. Fukumoto
中科院分区：
文献类型：
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作者：
Mehryar Habibi Roudkenar;Motoi Fukumoto;A. Roushandeh;Youshikazu Kuwahra;Yusuke Uroshihara;H. Harada;M. Fukumoto
细胞辐射抵抗是影响肿瘤放射治疗效果的主要障碍之一。为了阐明HIF-1α和miR-17-92在难治性放射抵抗细胞中的表达意义，也为了研究这些分子作为克服放射抵抗癌症的新的治疗手段的潜在应用，本研究进行了这项研究。临床相关的放射抵抗(CRR)细胞系是通过长期暴露于X射线的分割辐射而建立起来的。相应地，通过基因芯片分析和实时定量RT-PCR寻找与CRR表型相关的miRNA。HIF-1α在CRR细胞中下调，miR17-92簇在CRR细胞中过表达。在亲本细胞中，miR17-3p的表达分别被特异性抑制剂抑制，miR19a的表达被模拟物增强。HIF-1α在亲代细胞中的过表达或在CRR细胞中HIF-1α的下调不参与放射抵抗。然而，当HIF-1α被基因修饰为在常氧条件下结构性表达时，它被呈现为对细胞的保护。外源性miR17-92簇在CRR细胞中的过表达导致HIF-1α表达取消，并恢复了对电离辐射的增敏。亲本细胞中miR-17-3p的表达减弱对其具有辐射保护作用。总体而言，CRR细胞中miR17-92簇的微调去调节可能是照射后CRR细胞中HIF-1α积聚的原因。
Cellular radioresistance is one of the major obstacles to the effectiveness of cancer radiotherapy. In an attempt to elucidate the implication of HIF-1α and miR-17-92 expressions in refractory radioresistant cells and also in order to study the potential applications of these molecules as novel therapeutic modalities to overcome radioresistant cancers, the current study was conducted. Clinically relevant radioresistant (CRR) cells from human cancer cell lines were established by exposing to long-term fractionated radiation of X-rays. Correspondingly, microarray analysis and real time RT-PCR were performed to find miRNA involved in the CRR phenotype. HIF-1α was down-regulated and miR17-92 cluster was overexpressed in CRR cells by transfection. The expression of miR 17-3p was inhibited by specific inhibitors and miR 19a was enforced by mimics, respectively in parental cells. Overexpression of HIF-1α in parental cells or down regulation of HIF-1α in CRR cells were not involved in radioresistance. However, when HIF-1α was genetically modified to constitutively express under normoxia condition, it was rendered for protection to cells. Exogenous overexpression of miR 17-92 cluster in CRR cells resulted in abolition of HIF-1α expression and restored sensitizations to ionizing radiation. Attenuated expression of miR-17-3p in parental cells protected them from irradiation. Overall, fine-tune deregulation of miR 17-92 cluster in CRR cells might account for the accumulation of HIF-1α in the CRR cells following exposure to irradiation.