Effects of CXCL14 expression on human colorectal cancer cell proliferation. A, immunohistochemical staining of human colorectal tumor sections using CXCL14 and Ki67 antibodies. Bar, 25 μm. B, correlation between the expression levels of CXCL14 and Ki67 (n = 118; P < 0.01, two-tailed Spearman test coefficient: 0.502). C, endogenous CXCL14 mRNA and protein levels were determined by semi-quantitative RT-PCR and Western blotting in several colorectal cancer cell lines. D, CXCL14 was stably over-expressed in the SW620 subclones (clone 1 and clone 2). E-G, proliferation of SW620 cells stably expressing CXCL14 or mock vector was compared by BrdU incorporation assay (E), MTT assay (F), and colony formation assay (G), respectively. H, expression of CXCL14 in HCT116 cells was inhibited by transfection with shCXCL14. I-K, proliferation of HCT116 cells transfected with shCXCL14 or shNC was measured by BrdU assay (I), MTT assay (J), and colony formation assay (K), respectively. Error bars represent ± SD. Student’s t test was used for the statistical analyses. *, P < 0.05; **, P < 0.01.