Mcl-1 as a potential therapeutic target for human hepatocelluar carcinoma
Mcl-1 as a potential therapeutic target for human hepatocelluar carcinoma
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DOI：
10.1007/s11596-016-1614-7
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发表时间：
2016-07
期刊：
影响因子：
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通讯作者：
Qin Yu;Zhao-yu Liu;Qiong Chen;Junhao Lin
中科院分区：
文献类型：
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作者：
Qin Yu;Zhao-yu Liu;Qiong Chen;Junhao Lin
肝细胞癌（HCC）是癌症相关死亡率的主要原因，部分原因是其对化疗药物的高耐药性。抗凋亡Mcl-1表达已被报道为各种类型肿瘤中的抗性因子。本研究通过检测Mcl-1在肝癌细胞和肝癌组织中的表达及其与p53的关系，探讨Mcl-1基因作为肝癌治疗分子靶点的可能性。应用免疫组化法检测30例HCC标本中Mcl-1和p53的表达。用RT-PCR和Western blotting检测肝癌细胞株Mcl-1的表达。采用RNA干扰技术或特异性磷脂酰肌醇-3激酶（PI 3 K）抑制剂LY 294002对Mcl-1进行单药治疗，并与丝裂霉素C（MMC）联合治疗肝癌细胞株HepG 2。MTT法和流式细胞仪检测细胞存活率和凋亡率。最后，分别用Mcl-1 siRNA、Mcl-1表达质粒和野生型p53表达质粒转染各种肝癌细胞系后，检测Mcl-1或p53表达的变化。Mcl-1蛋白在肝癌组织中的表达明显高于癌旁肝组织。Mcl-1在HepG 2和Hep 3B细胞中表达显著，在SMMC 7721细胞中表达较弱，而在L02细胞中不表达。P53蛋白在肝癌组织中也有过表达，且与Mcl-1的表达有显著相关性。通过RNAi或LY 294002沉默Mcl-1下调Mcl-1表达，并导致细胞活力降低和凋亡增加。MMC与Mcl-1 RNAi或LY 294002联合应用具有明显的化疗增敏作用。在HepG 2细胞中，Mcl-1 siRNA对p53的表达无影响;在L02细胞中，转染Mcl-1表达质粒对p53的表达无影响。此外，Mcl-1在Hep 3B细胞中的表达在转染野生型p53表达质粒后也没有显著变化。结论：Mcl-1在肝癌组织中过表达。沉默Mcl-1使肝癌细胞对化疗敏感的机制可能不是由于p53表达上调，而是通过Mcl-1/p53相互作用使p53功能障碍。Mcl-1可能成为肝癌基因治疗的潜在靶点。
Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality in part due to its high resistance to chemotherapeutic drugs. The anti-apoptotic Mcl-1 expression has been reported as a resistance factor in various types of tumors. Here, we investigated the expression of Mcl-1 in hepatoma cells and HCC tissues and its relationship with p53, and analyzed the possibility of the gene as a molecular target for HCC therapy. HCC specimens of 30 patients were examined by immunohistochemistry for Mcl-1 and p53 expression. Mcl-1 expression in hepatoma cell lines was measured by RT-PCR and Western blotting. The suppression of Mcl-1 by RNA interference or specific phosphatidylinositol-3 kinase (PI3K) inhibitor, LY294002, was evaluated as monotherapy, and it was combined with mitomycin C (MMC) in treating hepatoma cell line HepG2. Cell viability and apoptosis were assessed by MTT and FACS analysis. Finally, changes of Mcl-1 or p53 expression in various hepatoma cell lines were examined after transfection with Mcl-1 siRNA, the Mcl-1 expression plasmid, or the wide-type p53 expression plasmid, respectively. Mcl-1 protein was remarkably enhanced in HCC tissues as compared with adjacent non-tumor liver tissues. In addition, Mcl-1 was prominently expressed in HepG2 and Hep3B cells, weakly in SMMC7721 cells, and not in L02 cells. P53 protein was also overexpressed in HCC tissues and there was a significant correlation between the expression of p53 and Mcl-1. Silencing Mcl-1 by RNAi or LY294002 downregulated Mcl-1 expression and led to decreased cell viability and increased apoptosis. Combination of MMC and Mcl-1 RNAi or LY294002 exhibited a significant chemosensitizing effect. The expression of p53 was not influenced by Mcl-1 siRNA in HepG2 cells or transfection with the Mcl-1 expression plasmid in L02 cells. Furthermore, the expression of Mcl-1 in Hep3B cells was also not significantly changed after transfection with the wild-type p53 expression plasmid. It is concluded that Mcl-1 is overexpressed in HCC tissues. The mechanisms by which silencing Mcl-1 sensitizes hepatoma cells towards chemotherapy may be not attributed to the upregulated expression of p53 but the dysfunction of p53 through Mcl-1/p53 interaction. Mcl-1 may be a potential target of gene therapy for HCC.