Figure 3.
Growth inhibition of U87MG glioblastoma cells by truncated Neu ectodomains. (A) Anchorage-independent growth assay. Cells (1,000–3,000 of each cell line) were seeded in soft agar dishes and cultured for 21–28 days. Colonies were then visualized and counted after staining. Each experiment was performed in triplicate. The mean degree of inhibition and standard error (SEM) observed in three independent experiments is shown. The U87/Nneu cell line is a control cell line that expresses full-length normal p185neu and exhibits increased transforming efficiency in vitro in these experiments. (B) Comparison of tumor growth in athymic mice between U87MG and U87MG cells expressing the N691stop form of Neu (U87/N691-B1) and (C) between U87MG and U87MG cells expressing the T691stop form of Neu (U87/T691-1). 106 cells of each cell line were injected intradermally on day 0 and tumor volume was recorded weekly. U87MG cells were injected on one side and the transfected cell line was injected into the contralateral side of the same animal. Data represents the mean and standard deviation (SD) of tumors derived from each cell line (U87MG, n = 19; U87/N691-B1, n = 9; U87/T691–1, n = 9).