Roles of XB130, a novel adaptor protein, in cell cycle progression of gastric cancer cells via regulation of c-Myc

接头蛋白可以参与各种细胞功能的调节，这取决于它们相互作用的伙伴的功能作用。我们已经克隆了一个新的接头蛋白XB130，它被认为是酪氨酸激酶介导的信号转导的底物和调节器，并参与控制甲状腺和肺癌细胞的增殖和凋亡。然而，其在胃肠道肿瘤中的表达和作用尚未被研究。在本研究中，我们试图确定XB130在胃和食道癌细胞中的作用，并检测其表达情况和对上消化道癌症患者预后的影响。通过对XB130 siRNA进行基因敲除实验，我们发现XB130通过c-Myc和p21调控胃和食道癌细胞的细胞周期进程。免疫组织化学分析显示，71.2%的食管癌组织中有XB130的表达，且XB130在细胞核中的表达是一个独立的预后因素。本研究发现XB130是上消化道肿瘤的一个重要预后因子，并有可能作为一种新的介质和/或生物标志物出现。

Adaptor proteins can participate in the regulation of various cellular functions, depending on the functional role of their interacting partners. We have cloned a novel adaptor protein, XB130, which has been implicated as a substrate and regulator of tyrosine kinase-mediated signaling and in controlling cell proliferation and apoptosis in thyroid and lung cancer cells. However, its expression and role in gastrointestinal cancer have not been investigated. In the present study, we sought to determine the role of XB130 in gastric and esophageal cancer cells and examine its expression and effects on the prognosis of patients with upper gastrointestinal cancer. Using knockdown experiments with XB130 siRNA, we found that XB130 regulate cell cycle progression via c-Myc and p21 in gastric and esophageal cancer cells. Immunohistochemical analysis revealed that expression of XB130 in cancer tissue was observed in 71.2% of patients with esophageal cancer, and that XB130 expression in the nucleus was an independent prognostic factor. The present study leads to the discovery of XB130 as an important prognostic factor in upper gastrointestinal cancer, and has the potential to present as a novel mediator and/or biomarker.