Anti-miRNA-221 sensitizes human colorectal carcinoma cells to radiation by upregulating PTEN

Figure 2 miR-221 regulated expression of phosphatase and tensin homolog deleted on chromosome 10 in colorectal carcinoma-derived cells. A: Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) 3’-UTR site potentially targeted by miR-221 as predicted by Miranda; B: Luciferase activity assay showing direct interaction between miR-221 and PTEN 3’-UTR site. Firefly luciferase reporter activity in the presence of both pGL3-PTEN vector and pre-miR-221 or anti-miR-221 was compared with that of the controls. Luciferase activity in Caco2 cells cotransfected with pGL3-PTEN vector and pre-miR-221 was decreased markedly compared with the negative control. Luciferase activity in Caco2 cells transfected with anti-miR-221 was increased significantly compared with the negative control, ^bP < 0.01 vs control group; C: Western blotting showing PTEN protein expression in Caco2 cells transfected with pre-miR-221 or anti-miR-221. β-actin was used as a housekeeping gene to normalize PTEN protein expression. The relative PTEN protein levels normalized against β-actin are shown at the top of each panel; D: Real-time RT-PCR analysis showing PTEN mRNA expression in Caco2 cells transfected with pre-miR-221 or anti-miR-221. All the results are representative of three independent experiments.