Adhesion of different cell cycle human hepatoma cells to endothelial cells and roles of integrin beta1.
OBJECTIVE
To investigate the adhesive mechanical properties of different cell cycle human hepatoma cells (SMMC-7721) to human umbilical vein endothelial cells (ECV-304), expression of adhesive molecule integrinbeta1 in SMMC-7721 cells and its contribution to this adhesive course.


METHODS
Adhesive force of SMMC-7721 cells to endothelial cells was measured using micropipette aspiration technique. Synchronous G1 and S phase SMMC-7721 cells were achieved by thymine-2-deoxyriboside and colchicines sequential blockage method and double thymine-2-deoxyriboside blockage method, respectively. Synchronous rates of SMMC-7721 cells and expression of integrinbeta1 in SMMC-7721 cells were detected by flow cytometer.


RESULTS
The percentage of cell cycle phases of general SMMC-7721 cells was 11.01% in G2/M phases, 53.51% in G0/G1 phase, and 35.48% in S phase. The synchronous rates of G1 and S phase SMMC-7721 cells amounted to 74.09% and 98.29%, respectively. The adhesive force of SMMC-7721 cells to endothelial cells changed with the variations of adhesive time and presented behavior characteristics of adhesion and de-adhesion. S phase SMMC-7721 cells had higher adhesive forces than G1 phase cells ((307.65+/-92.10) x 10(-10) N vs (195.42+/-60.72) x 10(-10) N, P<0.01). The expressive fluorescent intensity of integrinbeta(1) in G(1) phase SMMC-7721 cells was depressed more significantly than the values of S phase and general SMMC-7721 cells. The contribution of adhesive integrinbeta1 was about 53% in this adhesive course.


CONCLUSIONS
SMMC-7721 cells can be synchronized preferably in G1 and S phases with thymine-2-deoxyriboside and colchicines. The adhesive molecule integrinbeta1 expresses a high level in SMMC-7721 cells and shows differences in various cell cycles, suggesting integrin beta1 plays an important role in adhesion to endothelial cells. The change of adhesive forces in different cell cycle SMMC-7721 cells indicates that S phase cells play predominant roles possibly while they interact with endothelial cells.
Song
Guan-Bin
GB
Key Laboratory for Biomechanics and Tissue Engineering of the State Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044, China. song9973@tom.com
Qin
Jian
J
Luo
Qing
Q
Shen
Xiao-Dong
XD
Yan
Run-Bin
RB
Cai
Shao-Xi
SX
D006528:Carcinoma, Hepatocellular / Q000098:blood supply* / Q000276:immunology; D002448:Cell Adhesion; D002453:Cell Cycle / Q000502:physiology*; D002460:Cell Line; D045744:Cell Line, Tumor; D004730:Endothelium, Vascular / Q000166:cytology / Q000502:physiology*; D006801:Humans; D019012:Integrin beta1 / Q000502:physiology*; D008113:Liver Neoplasms / Q000098:blood supply / Q000276:immunology; D014471:Umbilical Veins
D019012:Integrin beta1