ABSTRACT
@# 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 βcatenin, 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.