CDX2在十二指肠癌中的表达及生物学功能研究

Expression and biological function of CDX2 in duodenal adenocarcinoma

目的探讨尾侧型同源转录因子2(CDX2)在十二指肠癌中的表达情况及生物学功能。方法收集40例十二指肠癌手术切除石蜡样本,构建组织芯片后通过免疫组织化学法检测CDX2的表达。构建CDX2过表达质粒和靶向CDX2小分子干扰RNA(CDX2-siRNA),转染结肠癌CaCO_(2)细胞和十二指肠癌HuTu-80细胞,实时定量PCR和Western blotting检测转染效率,CCK-8实验检测细胞增殖能力,划痕实验检测细胞迁移能力,流式细胞仪检测细胞周期和细胞凋亡情况。结果CDX2阳性染色主要定位于细胞核,十二指肠癌组织中CDX2的阳性率为65%,低于癌旁非肿瘤组织的84%(P<0.05)。CDX2表达下降后CaCO_(2)和HuTu-80细胞的增殖能力明显增强(P<0.05),CDX2的外源性过表达显著抑制了肠癌细胞的增殖能力(P<0.05)。敲减CDX2后肠癌细胞的迁移能力明显上升,而上调CDX2后肠癌细胞的迁移能力明显下降(P<0.05)。过表达CDX2后G_(0)/G_(1)期细胞比例增加(P<0.05),S期细胞比例减少(P<0.05);而敲减CDX2后G_(0)/G_(1)期细胞比例减少(P<0.05),G_(2)/M期细胞比例增加(P<0.05)。与对照组相比,过表达CDX2后凋亡细胞比例增加(P<0.05),而敲减CDX2后凋亡细胞比例减少(P<0.05)。结论CDX2在十二指肠癌发生发展过程中表达下降或者缺失,发挥了抑癌基因的功能。CDX2或可成为预测十二指肠癌发生、发展和治疗方案选择的重要标志物。

Objective To investigate the expression and biological function of caudal homologous transcription factor 2(CDX2)in duodenal adenocarcinoma.Methods Paraffin samples were collected from 40 cases of duodenal adenocarcinoma.Tissue microarray was constructed,and the expression of CDX2 was detected by immunohistochemistry.CDX2 overexpressed plasmid and small interfering RNA targeting CDX2(CDX2-siRNA)were constructed and transfected into colon cancer CaCO2 cells and duodenal cancer HuTu-80 cells.Transfection efficiency was detected by qPCR and Western blotting.Cell proliferation was detected by CCK-8 assay,cell migration was detected by scab assay,and cell cycle and apoptosis were detected by flow cytometry.Results CDX2 positive staining was mainly located in the nucleus,and the positive rate of CDX2 in duodenal carcinoma tissues was 65%,significantly lower than 84%in non-tumor tissues adjacent to carcinoma(P<0.05).The proliferation of CaCO2 and HuTu-80 cells was significantly increased after CDX2 expression was decreased(P<0.05),and the exogenous overexpression of CDX2 significantly inhibited the proliferation of colorectal cancer cells(P<0.05).The migration ability of colorectal cancer cells increased significantly after CDX2 knockdown,but decreased significantly after CDX2 up-regulation(P<0.05).After CDX2 overexpression,the proportion of G_(0)/G_(1) phase cells was significantly increased(P<0.05),and the proportion of S phase cells was significantly decreased(P<0.05),while after CDX2 knockdown,the proportion of G_(0)/G_(1) phase cells was significantly decreased(P<0.05),and the proportion of G_(2)/M phase cells were significantly increased(P<0.05).Compared with the control cells,proportion of apoptotic cells increased significantly after CDX2 overexpression(P<0.05),while proportion of apoptotic cells decreased significantly after CDX2 knockdown(P<0.05).Conclusion The expression of CDX2 is decreased or lost in the development of duodenal adenocarcinoma,which functions as a tumor suppressor.The CDX2 expression is expected to be an important marker for predicting the occurrence,development and treatment of primary duodenal adenocarcinoma.