Figure 6. Long-term effect of elevated level of cyclin A1 on growth and angiogenesis phenotype of xenograft tumors in mice.

MCF-7 cells stable expressing pcDNA–cyclin A1 or pcDNA vectors were subcutaneous implanted into female nude mice with E2 supplementation. (A, B) Representative microphotographs of xenograft tumor sections stained with Haematoxylin and Eosin are shown. (C, D) Representative pictures show the xenograft tumors stained with antibody against human CD31, the CD31 positive vessels are indicated. The control tumor “control-pcDNA” and cyclin A1 expressing tumors “cyclin A1-pcDNA” are indicated. (E) Growth curves of the two groups of xenograft tumors are indicated. The time is indicated in x-axis and tumor volume in mm³ is indicated in y-axis. (F) Quantification of the tumor vascularizations in cyclin A1 expressing xenograft tumors “cyclin A1-pcDNA” and in control xenograft tumors “control-pcDNA”. The numbers of CD31-positive blood vessels in the central vs. edge regions of the tumor areas are shown. P values are indicated. Mean ± SD represents three independent experiments. (G–N) Xenograft tumors from “cyclin A1-pcDNA” and “control-pcDNA” groups were immunostained with antibodies against VEGF, VEGFR1, ER-α and Ki67. The representative microphotographs are shown.