In vivo primary tumor growth and lymph node metastasis of 468-CON, 468-OPN and 468-ΔTC cells. (A)Transfected cell lines were injected into the mammary fat pad of female nude mice using 1 × 106 cells/mouse and 12 mice/group. Tumors were measured weekly in two dimensions for twelve weeks using standard calipers and the tumor volume was estimated using the formula: [volume = 0.52 × (width)2 × (length)]. Growth data are presented as mean +/- SEM. (B)Average tumor latency (time to reach 500 mm3) is represented as mean +/- SEM. (C)Mean lymph node metastatic burden (% of lymph node occupied by tumor) +/- SEM. At twelve weeks post-injection mice were sacrificed and assessed for lymph node metastasis. Tissue sections from primary lymph nodes (LN) were subjected to H&E staining and read by an experienced pathologist in a blinded fashion. γ = 468-ΔTC significantly different from 468-CON (p < 0.01), Φ = 468-OPN significantly different from 468-CON (p < 0.05), θ = 468-ΔTC significantly different from 468-OPN (p < 0.05), * = sig. different than corresponding treatment of 468-CON (p < 0.01); δ = sig. different than corresponding treatment of 468-OPN (p < 0.05).