FIG. 2.
EBV infection enhances anchorage-independent growth of breast cancer cells. MCF7, MCF7-A, and MCF7-Neor cells, as well as BT474, BT474-A, and BT474-Neor cells, were seeded in 6-cm dish in culture medium containing 0.33% low-melting-temperature agarose over a 0.5% agarose layer and culture for 2 weeks. Colonies were then stained with 0.05% crystal violet, and colonies larger than 60 μm were counted. (A) Photomicrographs show a representative size distribution of MCF7, MCF7-A, MCF7-Neor, BT474, BT474-A, and BT474-Neor colonies. Bar, 100 μm. (B) The number of colonies is expressed as a percentage of the number of colonies in parental controls. Results from three independent experiments were averaged and are presented as means ± standard error as shown. The Student's t test was used to determine the significance of enhancement ★, P < 0.05.