目的：探讨分化抑制因子1 基因（inhibitor of differentiation-1, Id1）和Id3 是否协同促进结肠癌SW620 细胞EMT和细胞的侵袭迁移能力及其可能的机制。方法：利用慢病毒载体构建Idl 和Id3 单或双基因敲减的结肠癌SW620 细胞，实验分为4组：SW620-Sh-Id1 组（转染shRNA-Id1）、SW620-Sh-Id3 组（转染shRNA-Id3）、SW620-Sh-Id1-Id3 组（共转染shRNA-Id1 和shRNAId3）、SW620-NC组（转染阴性空载慢病毒）。用qPCR 法和Western blotting 法分别检测敲减效果，显微镜下观察稳定下调Idl 和Id3 后SW620 细胞形态的变化，划痕愈合实验和Transwell 小室法检测SW620 细胞迁移和侵袭的变化，Western blotting 检测EMT标志分子及迁移、侵袭相关蛋白的表达。结果：成功构建了Idl 和Id3 单基因敲减与双基因敲减的结肠癌SW620 细胞株。（1）Idl和Id3 的敲除诱导SW620 细胞形态由上皮样向间质样转变；（2）与对照组相比，SW620-Sh-Id1 组和SW620-Sh-Id3 组SW620 细胞侵袭和迁移的能力显著下降(均P<0.05)；SW620-Sh-Id1-Id3 组细胞侵袭和迁移的能力较SW620-Sh-Id1 组和SW620-Sh-Id3 组也明显下降(均P<0.05)；（3）与对照组相比，SW620-Sh-Id1 组和SW620-Sh-Id3 组β-catenin、snail1 及MMP2 蛋白表达降低，上皮黏蛋白及TIMP2 蛋白表达增高(均P<0.05)；SW620-Sh-Id1-Id3 组与SW620-Sh-Id1 组和SW620-Sh-Id3 组相比，β-catenin、snail1 及MMP2蛋白表达也下降，同时上皮钙黏蛋白及TIMP2 蛋白表达也增高(均P<0.05)。结论：Id1 和Id3 可能通过诱导EMT协同影响结肠癌SW620 细胞侵袭与迁移的能力。

Objective: To investigate whether inhibitor of differentiation 1 gene (Id1) and Id3 gene can synergistically promote epithelial-mesenchymal transition (EMT), invasion and migration of colon cancer SW620 cells and to explore its underlying mechanisms.Methods: The SW620 cell strain with Idl or Id3 gene knockdown and the SW620 cell strain with Id1/Id3 gene double-knockdown were constructed by lentiviral vectors transfection. The SW620 cells were divided into four groups, which included SW620-Sh-Id1 group (transfected with shRNA-Id1), SW620-Sh-Id3 group (transfected with shRNA-Id3), SW620-Sh-Id1-Id3 group (transfected with shRNAId1 plus shRNA-Id3) and SW620-NC group (transfected with negative lentivirus). The efficiency of knockdown was detected by Realtime qPCR and Western blotting. The influence of stable knockdown of Idl or Id3 on cell morphological change was observed under a microscope. The changes of migration and invasion abilities of the SW620 cells were determined by wound healing assay and Transwell assay. EMT, invasion and migration related proteins were measured by Western blotting. Results: The SW620 cell strains with Idl and/or Id3 gene knockdown were successfully constructed. Idl and Id3 knockdown induced the epithelial-like to the mesenchymanl-like transformation of SW620 cells. (1) Compared with the control group, the invasion and migration abilities of the SW620 cells were significantly decreased in the SW620-Sh-Id1 group and SW620-Sh-Id3 group (all P<0.05). (2) Meanwhile, the invasion and migration abilities in the SW620-Sh-Id1-Id3 group were obviously weaker than the SW620-Sh-Id1 group and SW620-Sh-Id3 group (all P<0.05). (3)Compared with the control group, the SW620-Sh-Id1 group and SW620-Sh-Id3 group had a reduction in the protein expressions of β-catenin, snail1 and MMP2, and an increase in the protein expressions of E-cadherin and TIMP2 (all P<0.05). (4) Compared with the SW620-Sh-Id1 group and SW620-Sh-Id3 group , the protein expressions of β-catenin, snail1 and MMP2 were reduced, and the protein expressions of E-cadherin and TIMP2 were increased in the SW620-Sh-Id1-Id3 group (all P<0.05). Conclusion: Id1 and Id3 could synergistically influence invasion and migration of SW620 cells, possibly through inducing EMT.

国家自然科学基金资助项目（No. 81472720）