Regulation of the growth and pulmonary metastasis of breast cancer cells by PRDX6 in in vivo studies. The growth curves for different MDA-MB-231 (a) and MDA-MB-435 (b) cells in an in vivo proliferation assay. Photomicrographs of micrometastases (arrow) in lung sections obtained from mice bearing parental (a), vector-transfected (b), PRDX6-transfected (c) and PRDX6 knockdown (d) groups for MDA-MB-231 (c) and MDA-MB-435 (d) cells (H & E; × 200). (e) Metastasis numbers per lung in parental, vector-transfected, PRDX6-transfected and PRDX6 knockdown groups at week 8 for MDA-MB-435 cells. The relative protein expression of PRDX6, uPAR, Ets-1, MMP-9, RhoC and TIMP-2 was normalized to the signal intensity of β-actin for MDA-MB-231 (f) and MDA-MB-435 (g) cells. MMP, matrix metalloproteinase; PRDX, peroxiredoxin; TIMP, tissue inhibitor of MMP; uPAR, urokinase-type plasminogen activator receptor; Ets-1, E26 transformation-specific-1; RhoC, ras homolog gene family member C.