Epithelial α5(IV) supports tumor cell growth and tumorigenicity.

<p>(A) RT-PCR analysis of α5(IV) knockdown efficiency in A549 cells. (B-D) Knockdown of α5(IV) in A549 cells significantly impaired cell proliferation (B), migration (C) and anchorage-independent cell growth (D). Data are presented as mean ± SD. (E) Growth kinetics of xenograft tumors from A549 cells expressing scramble control (sh<i>Scram</i>) (n = 5) or <i>COL4A5</i> (sh<i>COL4A5</i>-2) (n = 6) shRNAs. (F) H&E, anti-Ki67, anti-cleaved caspase-3, or anti-CD31 immunohistochemical staining on xenograft tumor sections. No apoptotic signal was evident in both groups. (G and H) Quantitative proliferative indices (G) and microvascular density (MVD) (H) were measured. Data are presented as mean ± SEM. **P < 0.01, ***P < 0.001. NS: not significant. Scale bars: 200μm.