FIG. 4.

Growth characteristics of AB605, AB606, and AB629 cell lines. (A) The growth rates and saturation densities of E1A 12S/E1B-156R-transfected BRK cells were comparable to those of A4 (expresses E1A 12S), AB7 (expresses E1), and AB120 (expresses E1A and E1B-55K) cells and higher than that of primary BRK cells. A total of 3 × 10⁴ cells were plated on six-well dishes in culture medium containing 5% fetal calf serum, and viable cells were counted every 48 h. The log₁₀ means of viable cells for duplicate dishes are shown. (B) AB605, AB606, and AB629 cells show different E1B-156R steady-state levels. Whole-cell extracts of all three cell lines were prepared, and the same amounts were used in immunoblotting. A Western blot assay of β-actin was included as a loading control. (C) The morphologies of AB605, AB606, and AB629 cells are altered in comparison to primary BRK cells and similar to A4 (E1A) and AB120 (E1A and E1B-55K) cells at subconfluency. The cells were plated on coverslips and photographed. Magnification, ×1,780 (phase-contrast microscopy).