Figure 1. STRAP knockdown increases the sensitivity of colorectal cancer (CRC) cells to drug treatment.
A. shSTRAP#1 and control clones were treated with 5-Fluorouracil (5-FU) or Oxaliplatin for 24 hours as indicated. The percentage of cells entering apoptosis was determined by flow cytometry using FITC-labeled annexin-V staining. B. Whole-cell lysates from control and STRAP knockdown clones treated with 5-FU or Oxaliplatin for 48 hours were subjected to western blot analyses using anti-cleaved Caspase-3 (C. CP3) antibody with β-actin as loading control. C and D. HCT116 and DLD-1 clones (STRAP-KD and control) were implanted subcutaneously into the flank regions of nude mice. When the tumors reached 100 mm3, drug treatment was initiated. Each group consisted of eight animals. After 4 weeks, mice were euthanized, tumor volumes were measured, and growth curves were plotted. The fold changes at the bottom represent the mean change in final tumor volume of the untreated group divided by the mean tumor volume of the treated group in the same category of animals. E. Representative Hematoxylin-Eosin (HE) stained images are shown. The expression of STRAP, Ki67 and cleaved Caspase-3 in the tumor from HCT116 clones was detected by IHC (magnification: X40). F. Scatter plots of mRNA expressions (log2) of STRAP versus mRNA expression levels of BMI1, CD24, CD44, EPCAM, ITGB1, and PSEN1 in colon adenocarcinoma (n=193) from TCGA dataset were plotted. P values and R2 are displayed.