MiR-1178在胰腺导管腺癌中的表达及其意义

Correlation between miR-1178 expression and clinicopathological significance in human pancreatic cancer

目的探讨miR－1178在胰腺导管腺癌中的表达及其临床意义。方法收集2004年1月至2008年12月北京协和医院收治的经病理科确诊的胰腺导管腺癌及配对癌旁组织手术标本87例。利用原位杂交的方法检测石蜡标本中miR－1178的表达水平，分析miR－1178与胰腺导管腺癌患者临床病理资料及预后的关系。通过脂质体及慢病毒转染胰腺癌细胞株，观察miR－1178对胰腺癌细胞侵袭及增殖能力的影响。建立裸鼠皮下移植瘤模型，接种4周后切取肿瘤测量体积和重量。分别采用Student t检验、秩和检验、χ2检验等方法对组间数据进行统计学分析；采用Cox回归进行单因素及多因素分析。结果72例胰腺癌患者获得完整随访资料。胰腺癌组织中miR－1178高表达率为69.4%（50/72），配对癌旁组织中miR－1178高表达率为15.3%（11/72）（χ2＝43.26，P〈0.05）。miR－1178高表达组中淋巴结转移为58.0%（29/50），低表达组中淋巴结转移为31.8%（7/22）（χ2＝4.189，P＝0.041）。单因素及多因素分析结果发现，miR－1178是胰腺导管腺癌患者的独立预后因素（HR＝2.364，95%CI：1.114～5.019，P＝0.025）。Transwell实验结果显示，miR－1178过表达后AsPC－1侵袭细胞数目[（177.0±19.8）个]多于对照组[（119.7±15.9）个]（χ2＝8.21，P〈0.05）。裸鼠皮下移植瘤增殖实验结果表明，过表达miR－1178组肿瘤体积[（5 122.4±760.2）mm3]大于对照组[（1 976.8±601.8）mm3 ]（t＝2.413，P〈0.05）；过表达miR－1178组肿瘤重量[（1.55±0.21）g]大于对照组[（0.67±0.17）g]（t＝2.960，P〈0.05）。与对照组相比，miR－1178过表达组的FAK、MMP－9蛋白表达水平明显增加（P〈0.05）。结论miR－1178在胰腺导管腺癌组织中呈高表达，与胰腺癌患者预后相关。miR－1178能促进胰腺癌的增殖及侵袭，其分子机制可能与Stub1/FAK/MMP－9通路的异常活化有关。

ObjectiveTo test the expression of miR-1178 in pancreatic cancer and study its clinicopathological significance and mechanism.MethodsThe expression of miR-1178 in 87 paired paraffin pancreatic ductal adenocarcinoma specimens and adjacent non- cancerous pancreatic tissue diagnosed by Pathology Department of Peking Union Medical College Hospital was detected by hybridization in situ. The relationship between the expression of miR-1178 and clinicopathological characters was analyzed.miR-1178 mimics and inhibitor were used to further detect the close relationship among miR-1178 and cancer invasion. Establish a nude mice subcutaneously transplanted tumor model, 4 weeks after vaccination for tumor volume and weight measurement.Student t-test, rank sum test, and χ2 test was used respectively to compare the data between two groups. Cox regression was adopted to improve the single factor and multiple factors analysis.ResultsThe results of hybridization in situ showed the expression of miR-1178 was increased in 72 cases with pancreatic cancer compared to that in paired normal pancreatic tissues （50/72 vs. 11/72, χ2=43.26, P〈0.05）. miR-1178 expression was positively associated with tumor lymph node stage （χ2=4.189, P=0.041）. Univariate and multivariate analysis revealed that miR-1178 was an independent adverse prognostic indicator for patients with pancreatic cancer （HR=2.364, 95%CI： 1.114-5.019, P=0.025）. Transwell assay indicated the over-expression of miR-1178 increased the number of AsPC-1 cells that penetrated the ECM-coated membrane （177.0±19.8 vs. 119.7±15.9）（χ2=8.21, P〈0.05）. For the in vivo experiment, overexpression of miR-1178 significantly promoted tumor growth, compared with control group （tumor volume： （5 122.4±760.2）mm3vs. （1 976.8±601.8）mm3, t=2.413, P〈0.05; tumor weight： （1.55±0.21）g vs. （0.67±0.17）g, t=2.960, P〈0.05）. Over-expression of miR-1178 down-regulated the expression of Stub1 and elevated the expression of FAK/MMP-9 signal pathway（P〈0.05）.ConclusionsMiR-1178 is overexpressed in pancreatic cancer, and is effective for predicting patients′ prognosis. MiR-1178 regulate Stub1/FAK/MMP-9 signal pathway and promote the invasion of AsPC-1 cells.