Article Figures & Data
Figures
- FIGURE 1.
Down-regulation of PER2 by siRNA in vitro increases β-catenin and cyclin D and accelerates cell growth in colon cancer cell lines compared with control siRNA cultures. Representative Western blots (A and C) and quantitation of protein abundance (B and D), relative to actin content, show that reducing PER2 results in an increase in β-catenin and cyclin D protein in HCT116 and SW480 colon cancer cell lines. Down-regulation of PER2 also accelerates cell growth of HCT116 (E) and SW480 (F) cell lines compared with control siRNA–treated cultures (representative growth experiment). Findings are similar among three experiments. Points, mean; bars, SE. *, P < 0.03, compared with control conditions.
- FIGURE 2.
Increase in cyclin D and acceleration of cell growth caused by PER2 down-regulation is prevented when β-catenin expression is down-regulated by siRNA in vitro compared with control siRNA cultures. Representative Western blots (A and B) are shown with the siRNA treatment listed at the left top and proteins detected on the right with quantitation of protein abundance (C and D), relative to actin content. Columns, mean of three independent experiments; bars, SE. In HCT116 (A, B, and E) and SW480 (C, D, and F) colon cancer cell lines, down-regulation of PER2 alone increases cyclin D protein and cell growth, and this PER2-associated change in cyclin D and cell growth is prevented when β-catenin expression is simultaneously down-regulated. *, P < 0.01, compared with control conditions.
- FIGURE 3.
β-Catenin transcriptional activity by TOPFLASH assay in human HEK293 kidney cells. PER2 overexpression (o/e) decreased and PER2 down-regulation (siRNA) increased β-catenin/TCF transcriptional activity compared with control cultures (equal to one). Means of four to five experiments are shown. *, P < 0.05.
- FIGURE 4.
β-Catenin and cyclin D levels in small intestinal mucosa and colon polyps are increased in Per2m/m mice compared with wild-type mice. Small intestinal mucosa from 15-wk-old wild-type and Per2m/m mice was isolated during the mid-activity phase and homogenized for protein analysis. Representative Western blots of individual mice (A) with quantitation of protein abundance (B), relative to control tubulin content (five mice/genotype), show an increase in β-catenin and cyclin D (β-catenin target gene) proteins in the mucosa of Per2m/m mice. C. Colon polyp numbers and frequency in 15-wk-old wild-type, Per2m/+, and Per2m/m mice. *, P < 0.05, for Per2m/m compared with wild-type.
- FIGURE 5.
Homozygous Per2 inactivation increases small intestinal polyp and colonic polyp numbers in 10-wk-old ApcMin/+ mice. A. Total and small-sized (<1 mm) small intestinal polyps, but not large-sized (>1 mm) small intestinal polyps, are higher in ApcMin/+Per2m/m mice compared with ApcMin/+ mice. *, P < 0.001. B. Distribution of total small intestinal polyps throughout the proximal (duodenum), first and second jejunum, and distal (ileum) segments of the small intestine shows higher numbers in ApcMin/+Per2m/m compared with ApcMin/+ mice in the second, third, and fourth segments of the intestine. *, P < 0.01. C. Total colonic polyp numbers are higher in ApcMin/+Per2m/m compared with ApcMin/+ mice (P = 0.025). Small intestinal polyp numbers and distribution, and colonic polyp numbers did not differ between ApcMin/+Per2m/+ and ApcMin/+ mice. Columns, mean; bars, SE.
Additional Files
Supplementary Data, Wood, et al.
Files in this Data Supplement:
Volume 6, Issue 11
