目的：探讨Krüppel 样转录因子9（KLF9）在胰腺癌中的表达并探讨其与胰腺癌患者临床病理参数、预后的关系。方法： 收集200 例配对的胰腺癌组织与癌旁组织标本，分别用RT-PCR（28 对）、Western blot（4 对）和免疫组化（全部标本）检测KLF9 的表达，分析KLF9 的表达水平与患者临床病理参数以及生存率的关系。结果：RT-PCR 结果显示，在28 例配对标本中，21 例（75%）胰腺癌组织中KLF9 mRNA 的表达水平明显低于其癌旁正常胰腺组织。Western blot 结果显示，与癌旁正常胰腺组织比较，胰腺癌组织中KLF9 蛋白表达水平明显下调。免疫组化显示，在胰腺癌组织中KLF9 的染色强度明显减弱。与患者临床病理参数关系分析结果显示，KLF9 的表达水平与肿瘤的分化程度（P=0.008）和血管侵犯（P=0.006）有关。生存分析显示，KLF9 阳性表达患者1、2、3 年总生存率明显高KLF9 阴性表达患者（41%、31%、16% vs. 18%、6%、6%）、中位生存时间明显长于KLF9 阴性表达患者（21.05 个月vs. 11.82 个月）（均P<0.05）。结论：KLF9 在胰腺癌中表达下调，且可能与不良预后密切相关。
Krüppel-like transcription factor 9 expression in pancreatic cancer and its clinical significance
Objective: To investigate the expression of Krüppel-like transcription factor 9 (KLF9) in pancreatic cancer tissue and its association with clinicopathologic features and prognosis of pancreatic cancer patients. Methods: The specimens of 200 paired pancreatic cancer and adjacent pancreatic tissues were collected. The KLF9 expressions in these specimens were determined by RT-PCR (28 pairs), Western blot (4 pairs), and immunohistochemical staining (all specimens), respectively, and the relations of KLF9 expressions with clinicopathologic features and postoperative survival of the patients were also analyzed. Results: The results of RT-PCR showed that the KLF9 mRNA expression level in pancreatic cancer tissue was remarkably lower than that in its adjacent pancreatic tissue in 21 of 28 paired specimens (75%). The results of Western blot showed that the KLF9 protein expression was obviously down-regulated in pancreatic cancer tissue compared with its adjacent pancreatic tissue. The results of immunohistochemical staining showed the KLF9 expression intensity was remarkably weaker in pancreatic cancer tissue than that in adjacent pancreatic tissue. The results of analyses of the relationship between KLF9 expression and clinicopathologic variables showed that the KLF9 expression level was significantly related to degree of tumor differentiation (P=0.008) and vascular invasion (P=0.006). Survival analysis showed that the 1-, 2- and 3-year overall survival rate in patients with positive KLF9 expression was significant higher than that in patients with negative KLF9 expression (41%, 31%, 16% vs. 18%, 6%, 6%), and the median survival time in patients with positive KLF9 expression was significant longer than that in patients with negative KLF9 expression (21.05 months vs. 11.82 months) (all P<0.05). Conclusion: KLF9 expression is decreased in pancreatic cancer, which is closely related to malignant unfavorable prognosis.