Figure 4. Suppression of tumorigenicity of PC-3 by expression of miR-17*.

A, has-miR-17* was cloned in a Tet-on lentiviral vector and stably transected into PC-3 cells. The clone was tested by RFP screening under Dox- inductive conditions and then confirmed by measuring the expression of the three target genes using Western blots with β-actin normalization. B and C, the generated clone was injected into male nude mice to determine its tumorigenicity. The vehicle control was included. The number of days needed for tumor size to reach 500 mm³ is shown in (B) and calculated tumor growth rates in (C). D, total RNA and proteins were isolated from the tumor tissues and the level of miR-17* and corresponding activities of the three antioxidant proteins were quantified. Three samples (n = 3) were used in testing the generated miR-17* inducible clone (A). Nine vehicle control animals (n = 9) with or without DOX treatment and eighteen miR-17* expressed animals (n = 18) with or without DOX treatment were used to test the effect of miR-17* on tumor growth (B), (C), (D). * (p<0.05) and ** (p<0.01) indicate significances as compared to without DOX control (A) and (C).