[摘要] 目的：探讨上皮细胞转化序列2（epithelial cell transforming 2，ECT2）基因在人胰腺导管腺癌（pancreatic ductal adenocarcinoma，PDAC）中的表达及其对胰腺癌细胞增殖、凋亡的影响。方法：采集2018 年7 月至2019 年3 月在海军军医大学附属长海医院病理科PDAC及相应癌旁样本各35 例。通过GEO数据库中人胰腺癌基因表达谱筛选差异表达基因，采用TCGA数据分析该基因在PDAC中的表达及与患者生存的相关性。以qPCR及免疫组化在人PDAC样本中验证了ECT2 mRNA及蛋白的表达。以siRNA干扰人胰腺癌细胞系PANC-1 中ECT2 基因的表达，CCK-8 增殖实验检测肿瘤细胞增殖，流式细胞术检测对胰腺癌细胞凋亡的影响，最后WB检测凋亡相关蛋白的变化。结果：生物信息学分析筛选出胰腺癌中差异表达基因ECT2，TCGA数据库分析发现其在癌组织中高表达（t=4.005，P<0.05）并与生存显著相关（P<0.01）。mRNA（1.01±0.06 vs 4.25±0.12，t=24.09，P<0.01）及蛋白水平验证其在人PDAC样本中高表达。干扰ECT2 基因后，其细胞增殖受到明显抑制（P<0.01）、他莫昔芬诱导的细胞凋亡显著增加（P<0.01），同时影响凋亡相关蛋白BAX及BCL-2 的表达。结论：ECT2 基因在人PDAC中高表达并与患者生存相关，其增加了胰腺癌细胞的增殖及抗凋亡能力。本结果为探讨ECT2 作为胰腺癌预后判断及治疗新靶点提供了实验依据。

[Abstract] Objective: To investigate the expression of ECT2 (epithelial Transforming sequence 2) gene in human pancreatic ductal adenocarcinoma (PDAC) and its effect on the proliferation and apoptosis of pancreatic cancer cells. Methods: Carcinoma tissues and corresponding para-carcinoma tissues from 35 PDAC patients at Changhai Hospital Affiliated to Naval Medical University from July 2018 to March 2019 were collected for this study. The differentially expressed genes in pancreatic cancer were screened out by using Gene Expression Omnibus (GEO) Database. Then, the related gene expression in PDAC and its relation with patients’survival were analyzed by The Cancer Genome Atlas (TCGA) database. QPCR and immunohistochemistry were used to verify the mRNA and protein expressions of ECT2 in human PDAC samples. To explore the effect of ECT2 on the biological behaviors of pancreatic cancer cells, si-RNA was used to silence the ECT2 gene in pancreatic cancer PANC-1 cells, and CCK-8 proliferation assay and Flow cytometry were used to detect the proliferation and apoptosis rate of PANC-1 cells after ECT2 silence. Finally,the expressions of apoptosis-related proteins were detected by WB. Results: The differentially expressed gene-ECT2, was screened out by analyzing the gene expression profiles of human pancreatic cancer in GEO database. TCGA database analysis showed that ECT2 was highly expressed in pancreatic cancer tissues (t=4.005, P<0.05) and significantly correlated with patients’survival (P<0.01). Moreover, it is also verified that ECT2 was highly expressed in PDAC tissues at mRNA (1.01±0.06 vs 4.25±0.12; t=24.09，P<0.01) and protein level. After ECT2 silence in PANC-1 cells, the proliferation rate was decreased (P<0.01), while the Tamoxifeninduced apoptosis rate was increased (P<0.01), and the expressions of apoptosis-related proteins (BAX and Bcl-2) were also affected.Conclusion: ECT2 is highly expressed in human pancreatic ductal adenocarcinoma and is related with patients’survival.ECT2 promotes the proliferation and apoptosis resistance of pancreatic cancer cells, providing the basis for exploring ECT2 as a new target for the prognostic judgment and treatment of pancreatic cancer.

上海市青年科技启明星计划资助(No. 19QA1411300)