Herein lie the crosstalk and regulation between AQP1 and Emmprin in SMMC7221 cells by means of siRNA technology and deglycosylation method. Firstly, HAQP1, rather than hAQP3, was selectively upregulated in SMMC7221 cells by FBS, flollowed by the upregulated expression of Emmprin. Emmprin gene silencing caused a remarkable change in the expression ofAQP1 gene, just like its downstream gene, MMP9, meanwhile the water permeability and cell migration were also descended prominently. Furthermore, when treated with tunicamycin, Emmprin was deglycosylated, which made the expression of AQP 1 significantly declined, followed by remarkably decreased cell membrane water permeability and cell migration. Taken together, all the data indicates the expression level and the modification of Emmprin by glycosylation are the key factors in regulating the expression of AQP1.
LI JiangZHANG Ai-liTONG QianZHANG Jun-fangLI Hai-jingZHAO BingMA Tong-huiLI Xiao-men
The authors investigated the regulation of human aquaporin I（hAQP1） and the involvement of aquaporin 1 （AQP 1） in the migration of human hepatocellular carcinoma SMMC-7221 cells using RNA intereference technology Firstly, two short hairpin RNA（shRNA） constructs in PBSU6 vector were reconstructed and their knockdown effects were identified in SMMC-7221 cells. Next, the involvement of endogenous hAQP1 in regulating the migration of SMMC-7221 cells was investigated via siRNA technology. HAQPI-shRNA can specifically inhibit AQP1 dependent osmotic water permeability. Meanwhile the migration of SMMC-7221 cells was inhibited remarkably after silencing AQP1 by performing transwell cell migration assay and in vitro wound healing assay. Furthermore, in the presence of an inhibitor HgCl2, the water permeability of the cell membrane was remarkably decreased, the expression of AQP1 was upregulated after HgCla treatment and the cell movement was decreased at the moment. Increased AQP1 cannot attenuate cell migration ability when cell membrane loses its water permeability function. This demonstrates that the cell migration was remarkably related to the transporting water function of cell membrane.
