Effect of tissue factor on colorectal cancer stem cells

Background/Aim: Tissue factor (TF) expression increases cancer stem cell (CSC) activity in breast and lung cancer. There are ongoing studies focused on targeting CSCs via anti-TF treatment, for breast and lung cancer therapy. Herein, the aim was to determine whether targeting TF could have an anti-CSC therapeutic role in colorectal cancer (CRC). Materials and Methods: Evaluation of colonosphere-forming efficiency (CFE) and aldehyde dehydrogenase (ALDH) expression level was used to quantify CSC activity in two CRC cell lines, after TF knockdown (TFKD) or TF over-expression (TFOE). Results: TFKD resulted in increased levels of ALDH in SW620 (1.31±0.04-fold, p<0.001) and DLD-1 (1.63±0.14-fold, p=0.04) cells. CFE was increased in SW620 (1.21±0.23% vs. 2.03±0.29%, p=0.01) and DLD-1 (0.41±0.12% vs. 0.68±0.9%, p=0.01) cells. Conversely, TFOE decreased ALDH expression (0.72±0.04-fold, p=0.001) and CFE (0.33±0.05% vs. 0.66±0.14%, p=0.006) in DLD-1, but had no impact on SW620 cells. Conclusion: In the examined CRC cell lines, TF expression was inversely related to CSC activity suggesting that anti-TF therapies may not have a role in CRC treatment.