Figure 5.

Murine (4T1) tumor cell morphology is changed and adhesion is enhanced in type III collagen (Col3)–null microenvironments. A: Morphology of 4T1–green fluorescent protein (GFP) cells co-cultured with Col3^+/+ and Col3^−/− fibroblasts in serum-free media for 48 hours. Four different littermate embryonic fibroblast pairs were analyzed (three representative pairs shown). B: Images of 4T1-GFP cells after 2 hours in co-culture with Col3^+/+ and Col3^−/− fibroblasts. C: Quantitative analysis of five different littermate embryonic fibroblast pairs (three representative pairs shown in B), evaluated in triplicate culture wells (five images per well). D: 4T1-GFP cells were allowed to attach for 2 hours to tissue culture plastic wells coated with the following: 0.5 μg/cm² Col3; a 50:50 mixture of Col1 and Col3 (Col1/3, 50:50; total collagen = 0.5 μg/cm²); 0.5 μg/cm² Col1; or a 100:50 mixture of Col1 and Col3 (Col1/3, 100:50; total collagen = 0.75 μg/cm²). Attached cells were fixed and stained with crystal violet and read at OD 570. Data represent means ± SD of three independent experiments (C and D). ^∗∗P < 0.01 via a paired Student's t-test (for comparisons between 4T1 cells on Col3^+/+ and Col3^−/− fibroblasts; C); ^∗P < 0.05, ^∗∗P < 0.01 via one-way analysis of variance, followed by Tukey post hoc test (for comparisons between Col3, Col1/3, and Col1; D). Original magnification, ×10 (A and B).