Restoration of tumor suppressor miR-34 inhibits human p53-mutant gastric cancer tumorspheres.
Restoration of tumor suppressor miR-34 inhibits human p53-mutant gastric cancer tumorspheres.
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DOI：
10.1186/1471-2407-8-266
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发表时间：
2008-09-21
期刊：
影响因子：
3.8
通讯作者：
Xu L
中科院分区：
文献类型：
--
作者：
Ji Q;Hao X;Meng Y;Zhang M;Desano J;Fan D;Xu L
微小RNA（microRNAs，miRNAs）通过调节细胞增殖和/或细胞死亡参与肿瘤的发生，其中一些作为癌基因或抑癌基因发挥作用。最近发现microRNA miR-34是p53的直接靶点，在p53通路的下游作为肿瘤抑制因子发挥作用。miR-34靶向Notch、HMGA 2和Bcl-2，这些基因参与癌症干细胞的自我更新和存活。miR-34在胃癌中的作用尚未见报道。在这项研究中，我们研究了miR-34恢复对p53突变的人胃癌细胞和潜在的靶基因表达的影响。用miR-34模拟物转染人胃癌细胞或用miR-34-MIF慢病毒表达系统感染人胃癌细胞，并通过使用Bcl-2 3 'UTR报告基因的miR-34报告基因测定进行验证。通过蛋白质印迹和mRNA定量实时RT-PCR评估潜在靶基因表达。通过细胞生长测定、细胞周期分析、半胱天冬酶-3活化和细胞毒性测定以及肿瘤球形成和生长来评估miR-34恢复的作用。miR-34修复的人胃癌Kato III细胞降低了靶基因Bcl-2、Notch和HMGA 2的表达。Bcl-2 3 'UTR报告基因检测结果显示转染的miR-34具有功能性，证实Bcl-2是miR-34的直接靶点。具有高水平Bcl-2的miR-34化学致敏的Kato III细胞的恢复，但不具有低水平Bcl-2的MKN-45细胞。miR-34损害细胞生长，使细胞聚集在G1期，增加caspase-3活化，并且更显著地抑制肿瘤球形成和生长。我们的研究结果表明，在p53缺陷的人胃癌细胞中，功能性miR-34的恢复抑制细胞生长并诱导化疗增敏和凋亡，表明miR-34可以恢复p53功能。miR-34的恢复抑制肿瘤球的形成和生长，据报道这与癌症干细胞的自我更新相关。miR-34介导的自我更新抑制机制似乎与直接调节下游靶点Bcl-2、Notch和HMGA 2有关，表明miR-34可能参与胃癌干细胞自我更新/分化决策。我们的研究表明，肿瘤抑制基因miR-34的恢复可能为p53突变型胃癌提供一种新的分子治疗方法。
MicroRNAs (miRNAs), some of which function as oncogenes or tumor suppressor genes, are involved in carcinogenesis via regulating cell proliferation and/or cell death. MicroRNA miR-34 was recently found to be a direct target of p53, functioning downstream of the p53 pathway as a tumor suppressor. miR-34 targets Notch, HMGA2, and Bcl-2, genes involved in the self-renewal and survival of cancer stem cells. The role of miR-34 in gastric cancer has not been reported previously. In this study, we examined the effects of miR-34 restoration on p53-mutant human gastric cancer cells and potential target gene expression. Human gastric cancer cells were transfected with miR-34 mimics or infected with the lentiviral miR-34-MIF expression system, and validated by miR-34 reporter assay using Bcl-2 3'UTR reporter. Potential target gene expression was assessed by Western blot for proteins, and by quantitative real-time RT-PCR for mRNAs. The effects of miR-34 restoration were assessed by cell growth assay, cell cycle analysis, caspase-3 activation, and cytotoxicity assay, as well as by tumorsphere formation and growth. Human gastric cancer Kato III cells with miR-34 restoration reduced the expression of target genes Bcl-2, Notch, and HMGA2. Bcl-2 3'UTR reporter assay showed that the transfected miR-34s were functional and confirmed that Bcl-2 is a direct target of miR-34. Restoration of miR-34 chemosensitized Kato III cells with a high level of Bcl-2, but not MKN-45 cells with a low level of Bcl-2. miR-34 impaired cell growth, accumulated the cells in G1 phase, increased caspase-3 activation, and, more significantly, inhibited tumorsphere formation and growth. Our results demonstrate that in p53-deficient human gastric cancer cells, restoration of functional miR-34 inhibits cell growth and induces chemosensitization and apoptosis, indicating that miR-34 may restore p53 function. Restoration of miR-34 inhibits tumorsphere formation and growth, which is reported to be correlated to the self-renewal of cancer stem cells. The mechanism of miR-34-mediated suppression of self-renewal appears to be related to the direct modulation of downstream targets Bcl-2, Notch, and HMGA2, indicating that miR-34 may be involved in gastric cancer stem cell self-renewal/differentiation decision-making. Our study suggests that restoration of the tumor suppressor miR-34 may provide a novel molecular therapy for p53-mutant gastric cancer.
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DOI：
10.1186/bcr920
发表时间：
2004
期刊：
Breast cancer research : BCR
影响因子：
--
作者：
Dontu G;Jackson KW;McNicholas E;Kawamura MJ;Abdallah WM;Wicha MS
通讯作者：
Wicha MS
影响因子：
11.2
作者：
Corsten, Maarten F.;Miranda, Rafael;Shah, Khalid
通讯作者：
Shah, Khalid
影响因子：
12.4
作者：
Eramo, A.;Lotti, F.;De Maria, R.
通讯作者：
De Maria, R.
影响因子：
64.8
作者：
He, Lin;He, Xingyue;Hannon, Gregory J.
通讯作者：
Hannon, Gregory J.
影响因子：
11.2
作者：
Li, Chenwei;Heidt, David G.;Simeone, Diane M.
通讯作者：
Simeone, Diane M.