FIG. 1.
Effects of E2A-HLF protein expression in FL5.12 cells. (A) Immunoblot analysis with an HLF(C) antiserum of five independent E2A-HLF-positive, G418-resistant transfected pools of FL5.12 cells and an empty vector-transfected cell pool, all cultured in the presence (even-numbered lanes) or absence (odd-numbered lanes) of 100 μM ZnSO4. (B) Growth of FL5.12 cells induced to express the E2A-HLF protein, together with growth of control cells transfected with an empty vector. Cells growing exponentially in IL-3-supplemented medium for 16 h in the presence or absence of zinc were adjusted to 5 × 105 cells per ml on day 0 and cultured without IL-3 for 15 days. The growth factor was reintroduced to the cultures on day 15 (arrow). The shaded region indicates the ranges of cell counts for E2A-HLF-transfected pools in the absence of zinc and control cells in the presence or absence of the metal. Each symbol represents a discrete pool of E2A-HLF-transfected, G418-resistant cells; open circles, pool 104; open triangles, pool 112; open squares, pool 116; closed circles, pool 120; and open diamonds, pool 122. (C) Cell cycle phase distribution of a representative pool of transfected cells (pool 116; open squares in panel B) expressing E2A-HLF in the presence (+) or absence (−) of zinc, as determined from DNA histograms obtained by propidium iodide staining and flow cytometry.