Figure 6

Knockdown of P4HA2 suppresses tumor growth and metastasis in vivo . (A) Control or P4HA2-silenced (sh-P4HA2-1) MDA-MB-231/Luciferase cells were injected into the mammary fat pad in SCID mice. IVIS images show representative mice from each group (n = 6). (B) Tumor growth curve shows that knockdown of P4HA2 (sh-P4HA2-1) inhibited tumor growth in SCID mice (n = 6). (C) Tumor volume formed by p4HA2 knockdown (sh-P4HA2-1) cells was significantly reduced compared with control MDA-MB-231/Luc cells. Tumor volume was obtained by quantifying IVIS images. (D) Tumor sections were stained with hematoxylin and eosin. Arrows point to invasion area at primary tumor margins (scale bar, 200 μm). (E) Masson’s Trichrome staining of tumor sections (blue, collagen fibers; black, nuclei; red, cytoplasm). A significant amount of collagen fibers (arrows) were detected in the control tumors, but not in the P4HA2-silenced (sh-P4HA2-1) tumors (scale bar, 200 μm). The right bar graph is the quantification of Masson’s Trichrome staining results. (F) Mice received a tail vein injection of control or P4HA2 knockdown (sh-P4HA2-1) MDA-MB-231/Luc cells (n = 5). IVIS image showed lung metastasis of control and P4HA2-silenced (sh-P4HA2-1) MDA-MB-231 cells in SCID mice. Lung metastasis can be detected in control but not in the knockdown P4HA2 group (*p < 0.05). (G) Lung colonization was analyzed by hematoxylin and eosin staining. Arrows point to the tumor formed in control group lung tissue (Scale bar, 500 μm).