DJ-1 enhances CRC tumor growth and metastasis in vivo. HCT116 cells were stably transfected with DJ-1 shRNA or negative control vector (NC), or stably transfected with DJ-1 cDNA or vector. a – c Transfected HCT116 cells were subcutaneously injected into nude mice and xenograft tumor growth was determined for 25 days or 45 days. Tumor mass images ( a ). Growth curves of tumor volumes ( b ). Tumor weight ( c ). n = 4. d Immunohistochemical staining of PCNA in xenografts from a . PCNA-positive cells were calculated. Scale bar, 100 μm. e Histopathology showing the lung metastases in mice and quantification of number of metastases following tail-vein injection. n = 6. * P