Expression of DNA damage response proteins in gastric cancer: Comprehensive protein profiling and histological analysis
Expression of DNA damage response proteins in gastric cancer: Comprehensive protein profiling and histological analysis
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DOI：
10.3892/ijo.2018.4238
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发表时间：
2018-03-01
影响因子：
5.2
通讯作者：
Naito, Zenya
中科院分区：
文献类型：
--
作者：
Arai, Hiroki;Wada, Ryuichi;Naito, Zenya
胃癌是日本癌症相关死亡的第三大原因。本研究的目的是通过全面的蛋白质分析来确定与胃癌生物学有关的因素。采用液相色谱-串联质谱法对 17 例胃癌病例的福尔马林固定石蜡包埋标本进行蛋白质分析。通路分析和正交偏最小二乘判别分析表明核糖核蛋白、异质核核糖核蛋白、白细胞介素结合因子2 (ILF2)、KU70和KU80的显着表达，这些蛋白参与DNA损伤反应(DDR)。因此，采用免疫组化方法检测42例胃癌中KU70、ILF2、CHK1和CHK2的表达和磷酸化水平。所有病例中 ILF2 和 CHK1 的表达均不受影响。 2例CHK2不表达且不磷酸化。尽管有蛋白质表达，但 KU70 和 CHK2 的磷酸化似乎分别在 1 例和 4 例中受损。 42 例中有 7 例 (17%) DDR 似乎受损。这 7 例中有 2 例（29%）复发，而其余 35 例中有 2 例（6%）复发。进一步检测4个胃癌细胞系中KU70、ILF2、CHK1、CHK2和TP53的表达水平。暴露于紫外线辐射后，3 个细胞系的表达和磷酸化水平均异常。仅在一种细胞系中检测到 CHK1 和 CHK2 的正常连续磷酸化、TP53 的上调以及暴露于紫外线辐射后细胞凋亡的增加，这表明 DDR 和 TP53 的保留功能对于细胞命运的决定是必要的。因此表明DDR在胃癌的病理学中发挥重要作用。
Gastric cancer is the third major cause of cancer-related mortality in Japan. The aim of this study was to identify a factor implicated in the biology of gastric cancer by comprehensive protein profiling. Protein profiling was carried out by liquid chromatography-tandem mass spectrometry, using formalin-fixed paraffin-embedded specimens of 17 gastric cancer cases. Pathway analysis and orthogonal partial least square-discriminant analysis suggested the significant expression of ribonucleoproteins, heterogeneous nuclear ribonucleoproteins, interleukin binding factor 2 (ILF2), KU70 and KU80, which are involved in DNA damage response (DDR). Thus, the expression and phosphorylation levels of KU70, ILF2, CHK1 and CHK2 were examined by immunohistochemistry in 42 cases of gastric cancer. The expressions of ILF2 and CHK1 were unaffected in all cases. The expression and phosphorylation of CHK2 were absent in 2 cases. Despite the expression of proteins, the phosphorylation of KU70 and CHK2 appeared to be impaired in 1 and 4 cases, respectively. In 7 out of 42 cases (17%), DDR appeared to be impaired. Recurrence was noted in 2 out of these 7 cases (29%), whereas the recurrence was noted in 2 out of the remaining 35 cases (6%). The expression levels of KU70, ILF2, CHK1, CHK2 and TP53 were further examined in 4 gastric cancer cell lines. The expression and phosphorylation levels following exposure to ultraviolet radiation were abnormal in the 3 cell lines. The normal consecutive phosphorylation of CHK1 and CHK2, the upregulation of TP53 and an increase in apoptotic cell death following exposure to ultraviolet radiation was detected only in one cell line, suggesting that the preserved functions of DDR and TP53 are necessary for the determination of cell fate. It is thus suggested that DDR plays an important role in the pathobiology of gastric cancers.