Table 3

In situ mRNA and immunohistochemical analysis of VEGF, VEGF receptor flk-1, and microvessel density in LNCaP and selected variants

Mice were injected with 2 × 106 cells and necropsied 5 weeks after injection. Five different areas of three separate tumors were analyzed. Values are means ± SD of 15 determinations of each cell line. Statistical comparisons were performed using Tukey’s honestly significant difference test.
Cell lineVEGF (ISH)aVEGF (IHC)bflk-1cCD31d
LNCaP89 ± 17.5173.3 ± 23.0124.6 ± 21.612.4 ± 3.5
LNCaP-Pro563 ± 14.7141.2 ± 38.1126.1 ± 20.05.8 ± 2.2
LNCaP-LN3152.2 ± 28.5200.5 ± 28.3156.5 ± 20.616.4 ± 4.2
Tukey’s honestly significant difference test Ps
 LNCaP vs. LNCaP-Pro50.1170.0110.9730.001
 LNCaP vs. LNCaP-LN30.0010.0230.0010.001
 LNCaP-LN3 vs. LNCaP-Pro50.0010.0010.0010.001
  • a VEGF mRNA density was evaluated by computer-assisted image analysis and is expressed as the ratio of the intensity of tumor ISH to that of the normal glandular epithelium, normalized to poly(dT) expression. The differences between LNCaP and LNCaP-LN3 (P = 0.001) and between LNCaP-LN3 and LNCaP-Pro5 (P = 0.001) were significant.

  • b VEGF cytoplasmic staining was evaluated by computer-assisted image analysis and is expressed as a ratio of the tumor expression to normal prostatic glandular epithelial cell expression. The differences between LNCaP and LNCaP-Pro5 (P = 0.011), between LNCaP and LNCaP-LN3 (P = 0.023), and between LNCaP-LN3 and LNCaP-Pro5 (P = 0.001) were significant.

  • c flk-1 cytoplasmic staining in endothelial cells was evaluated by computer-assisted image analysis and is expressed as a ratio of tumor vascular endothelium expression to normal glandular vascular endothelium expression. The differences between LNCaP and LNCaP-LN3 and between LNCaP-LN3 and LNCaP-Pro5 were significant (P = 0.0001 for both comparisons).

  • d CD31 staining reflecting microvessel density was counted under ×200 magnification in 0.739-mm2 fields. The differences between LNCaP and LNCaP-Pro5, between LNCaP and LNCaP-LN3, and between LNCaP-LN3 and LNCaP-Pro5 were significant (P = 0.0001 for each comparison).