Department of Gastroenterological Surgery, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
Int J Oncol. 2010 Nov;37(5):1105-11. doi: 10.3892/ijo_00000762.
Ankyrin repeat and SOCS box-containing 9 (ASB9) is involved in the negative regulation of cytokine signaling. However, its biological function is largely undefined. The aim of this study was to assess the value and role of ASB9 as an indicator of prognosis in colorectal cancer (CRC). In order to demonstrate the importance of ASB9 expression for predicting the prognosis of CRC, we analyzed the ASB9 mRNA expression in 125 paired cases of CRC and non-cancerous regions and the protein expression by immunohistochemistry. To investigate the role of ASB9 in vitro, we performed proliferation and invasion assay with small interfering RNA against ASB9. ASB9 mRNA expression was higher in CRC tissue than corresponding normal tissue (P=0.0282). Patients expressing low levels of ASB9 had a poorer overall survival rate than those expressing high levels (P=0.0301), indicating that decreased ASB9 expression was an independent prognostic factor. The immunohistochemical study revealed that ASB9 was predominantly expressed in cancer cells. A multivariate analysis showed that ASB9 expression status was an independent prognostic factor of overall survival (relative risk, 4.09; 95% confidence interval, 1.47-11.88; P=0.007). In an invasion assay, ASB9 siRNA-transfected cells showed significantly high invasiveness. The results of the present study suggest that ASB9 is a useful prognostic marker for CRC.
锚蛋白重复和 SOCS 盒蛋白 9（ASB9）参与细胞因子信号的负调控。然而，其生物学功能在很大程度上尚未确定。本研究旨在评估 ASB9 作为结直肠癌（CRC）预后指标的价值和作用。为了证明 ASB9 表达对于预测 CRC 预后的重要性，我们分析了 125 对 CRC 组织和非癌组织中的 ASB9 mRNA 表达，并通过免疫组织化学检测蛋白表达。为了研究 ASB9 在体外的作用，我们使用针对 ASB9 的小干扰 RNA 进行了增殖和侵袭测定。CRC 组织中的 ASB9 mRNA 表达高于相应的正常组织（P=0.0282）。表达低水平 ASB9 的患者总生存率低于表达高水平 ASB9 的患者（P=0.0301），表明 ASB9 表达降低是独立的预后因素。免疫组织化学研究表明，ASB9 主要在癌细胞中表达。多因素分析显示，ASB9 表达状态是总生存率的独立预后因素（相对风险，4.09；95%置信区间，1.47-11.88；P=0.007）。在侵袭测定中，转染 ASB9 siRNA 的细胞表现出明显的高侵袭性。本研究的结果表明，ASB9 是 CRC 的一种有用的预后标志物。
