DNA damage sensor protein hRad9, a novel molecular target for lung cancer treatment.
DNA damage sensor protein hRad9, a novel molecular target for lung cancer treatment.
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DOI：
10.3892/or_00000108
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发表时间：
2008
期刊：
影响因子：
4.2
通讯作者：
Takeshi Yuki;Y. Maniwa;T. Doi;K. Okada;W. Nishio;Y. Hayashi;Y. Okita
中科院分区：
文献类型：
--
作者：
Takeshi Yuki;Y. Maniwa;T. Doi;K. Okada;W. Nishio;Y. Hayashi;Y. Okita
DNA损伤传感器蛋白被认为是DNA损伤检查点信号通路的上游组分，并且是细胞周期控制和诱导凋亡所必需的。hRad 9作为检查点信号传导的上游调节剂发挥重要作用。在我们以前的研究中，我们证实了hRad 9在经皮切除的非小细胞肺癌（NSCLC）标本中肿瘤细胞核中的显著积累。我们还发现，在肺癌细胞中产生功能性hRad 9蛋白的能力是完整的，这一发现表明hRad 9将是导致NSCLC生存和进展的途径中的重要组成部分。将靶向hRad 9的小干扰RNA转染人肺腺癌A549和PC 3细胞。在hRad 9敲低后，通过中性红摄取试验测量转染细胞的细胞毒性，并通过流式细胞术检查照射细胞的G2-M期阻滞。在hRad 9表达下调的癌细胞中观察到显著的细胞毒性。我们还通过Western blot分析检测了Chk 1磷酸化的抑制。这表明hRad 9沉默导致肿瘤细胞中DNA损伤检查点信号传导途径的损害。流式细胞术表明G2-M期细胞群减少，这一观察结果与几项研究的发现一致，这些研究表明hRad 9是G2-M停滞所必需的。总之，目前的研究表明，靶向癌细胞中hRad 9的RNA干扰导致DNA损伤检查点信号通路受损，这似乎是维持肿瘤细胞增殖所必需的，并诱导细胞死亡。因此，hRad 9有可能成为肺癌治疗的一个新的分子靶点。
DNA damage sensor proteins are recognized as upstream components of the DNA damage checkpoint signaling pathway and are required for cell cycle control and the induction of apoptosis. hRad9 plays an important role as an upstream regulator of checkpoint signaling. In our previous studies, we confirmed the significant accumulation of hRad9 in the nuclei of tumor cells in surgically-resected non-small cell lung cancer (NSCLC) specimens. We also found that the capacity to produce a functional hRad9 protein was intact in lung cancer cells, a finding which suggests that hRad9 would be a vital component in the pathways that lead to the survival and progression of NSCLC. Small interfering RNA targeting hRad9 was transfected into human lung adenocarcinoma A549 and PC3 cells. After the hRad9 knockdown, the cytotoxicity of the transfected cells was measured by a neutral red uptake test, and the G2-M arrest of irradiated cells was examined by flow cytometry. Significant cytotoxicity was observed in the cancer cells in which hRad9 expression was down-regulated. We also detected the inhibition of Chk1 phosphorylation by Western blot analysis. This suggested that hRad9 silencing leads to the impairment of the DNA damage checkpoint signaling pathway in tumor cells. Flow cytometry indicated a reduced population of cells in the G2-M phase, an observation consistent with the findings of several studies that indicated that hRad9 is necessary for G2-M arrest. In conclusion, the current study demonstrated that RNA interference targeting hRad9 in cancer cells leads to the impairment of the DNA damage checkpoint signaling pathway, which appears to be essential for maintaining tumor cell proliferation, and induces cell death. Therefore, hRad9 may be a novel molecular target for lung cancer treatment.