Figure 4.

FN matrix assembly in 3D culture correlates with aggregate compaction. P3, X5C5, X5C4, X5C2, and X5C0 cell lines were cultured as hanging drops for 16 h in the presence of 100 μg/ml exogenous rat plasma FN under tissue culture conditions. Aggregates were then harvested and the assembly of high-molecular-weight FN multimers was assessed as described in Figure 3. Matrix assembly of X5C5 cells in 3D culture was compared with P3 cells (A) and with the chimeric cells lines (B). Representative immunoblots are shown. Results for B were quantified by scanning densitometry using NIH Image software and expressed relative to the X5C5 cell line (C). A P3 signal was not detected and therefore, not included. The mean values ± SEM were calculated from at least three separate experiments. ^*Statistical significance (p ≤ 0.05 vs. X5C5 cells) as determined by a Student's unpaired t test.