The Role of Pr otein Synthesis in the Adhesion of Chinese Hamster Lung Cells


Abstract: In order to determine the effect of endogenous protein synthesis on CHL cell adhesion, the initial attachment of these cells to tissue culture dishes was measur ed in the pr esence of 1µgml -1 emetine, in which protein synthesis was inhibited by 97% as determined by labeling the cells with [ 3 5 S]-methio-nine. In the pr esence of this drug, 80% of cells were able to adhere after 2 hours of incubation at 37 o C, while, during the same period, 97% of the contr ol cells became attached. Cells str engthen their adhesion foll owinginitial attachment, spreading and growth. Hence, the adhesion str engths of CHL cells that wer e gr own for 24 hours in the presence of cycloheximide, or emetine, or both were measured quantitatively using a convering laminar flow chamber . The inhibition of protein synthesis by the above drug(s) reduced cell adhesion str ength. Hence, the levels of critical shear str ess of detachment of the cells were 8.1 8 ±1.0 3 N m -2 , 6.7 0 ±0.3 0 N m-2 , and 5.6 6 ±.0.3 6 N m-2 , respectively , while that of the control cells was 10.48±0.78Nm -2 . Before subculturing CHL cells in the presence of these drug(s), pre-treatment of the cells with the same protein synthesis inhibitor further reduced the cell adhesion strength. Thus, with a pre treatment of cycloheximide, emetine and both emetine and cycloheximide the levels of critical shear stress of the detachment of cells were 4.84±0.54Nm -2 , 4.20±0.2Nm -2 , and 3.4±0.7Nm -2 , respectively . These results indicate that cells not require protein synthesis only for initial cell attachment, but also to gain the maximum possible adhesion strength. Key W ords: Protein synthesis, emetine, cell adhesion.


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