Liu Yanlong, Yang Yanmei, Xu Hui, Dong Xinshu
Department of Colorectal Surgery, Affiliated Tumor Hospital, Harbin Medical University, Harbin, China.
Diagn Mol Pathol. 2010 Dec;19(4):194-200. doi: 10.1097/PDM.0b013e3181e202f2.
Increasing experimental evidence suggests that USP22 plays a crucial role in the pathologic processes of epithelial malignancies and other solid tumors. BMI-1, p16INK4a, p14ARF, cyclin D2, and c-Myc have been implicated in the regulation of the cell cycle mediated by USP22 in cell culture experiments. In this study, we examined whether these in vitro findings can be extrapolated to the in vivo situation.
We measured the expression of USP22 and the candidate targets such as BMI-1, c-Myc, cyclin D2, p16INK4a, p14ARF by quantitative real time-polymerase chain reaction, Western blotting, and immunostaining in a series of 43 colorectal carcinomas (CRCs) and correlated the data with several clinicopathologic variables.
The frequency of overexpression (4-fold expression analysis) was 37.0% for USP22, 48.9% for BMI-1, 48.9% for c-Myc, and 58.0% for cyclinD2, respectively. Statistical correlation analysis at the mRNA level showed USP22 to be significantly correlated with BMI-1 (r=0.889, P<0.0001), c_Myc (r=0.573, P<0.0001), and cyclin D2 (r=0.872, P<0.0001), but not p16IN K4a (r=0.222, P=0.153) or p14Are (r=-0.154, P=0.325) by quantitative real time-polymerase chain reaction. These findings were confirmed by the Western blotting assay. Furthermore, the k-means cluster analysis showed that CRCs with high mRNA expression of USP22, BMI-1, c-Myc, and cyclin D2 were significantly correlated with the advanced AJCC stage (P=0.01) associated with poor prognosis.
The findings of this study supported dysregulation of a proposed functional pathway by upregulation of gene products in primary CRC.
越来越多的实验证据表明，USP22在上皮恶性肿瘤和其他实体瘤的病理过程中起关键作用。在细胞培养实验中，BMI-1、p16INK4a、p14ARF、细胞周期蛋白D2和c-Myc参与了由USP22介导的细胞周期调控。在本研究中，我们检测了这些体外研究结果是否能外推至体内情况。
我们通过定量实时聚合酶链反应、蛋白质印迹法和免疫染色，检测了43例结直肠癌（CRC）中USP22及其候选靶点如BMI-1、c-Myc、细胞周期蛋白D2、p16INK4a、p14ARF的表达，并将数据与多个临床病理变量进行关联分析。
USP22、BMI-1、c-Myc和细胞周期蛋白D2的过表达频率（4倍表达分析）分别为37.0%、48.9%、48.9%和58.0%。mRNA水平的统计相关性分析显示，通过定量实时聚合酶链反应，USP22与BMI-1（r=0.889，P<0.0）、c-Myc（r=0.573，P<0.0001）和细胞周期蛋白D2（r=0.872，P<0.0001）显著相关，但与p16INK4a（r=0.222，P=0.153）或p14ARF（r=-0.154，P=0.325）无关。蛋白质印迹分析证实了这些结果。此外，k均值聚类分析显示，USP22、BMI-1、c-Myc和细胞周期蛋白D2 mRNA高表达的CRC与预后不良的晚期美国癌症联合委员会（AJCC）分期显著相关（P=0.01）。
本研究结果支持原发性CRC中基因产物上调导致功能通路失调。
