Thrombospondins 2, a novel p53 target gene regulates proliferation of prostate cancer cells

Abstract

Objective To investigate whether thrombospondins 2 (THBS2) promotes prostate cancer cells proliferation and is regulated by p53. Methods After inhibiting the expression of p53 by interfering RNA (RNAi) in C4-2 cells using Lipofectamine 2000, the mRNA and protein expression levels were assessed by real-time quantitative polymerase chain reaction (Real-time PCR) and Western blotting. After transfecting GFP-p53 into 293T cells according to the manufacturer’s instruction, the expression level of THBS2 was assessed by Western blotting. After knocking down EAF2 by RNAi in C4-2 cells, proliferation was tested by bromodeoxyuridine incorporation assay (BrdU). Then, the BrdU assay was repeated after transfecting GFP-THBS2. Results The mRNA and protein expression levels were significantly increased after transfection of small interfering RNA (siRNA) against p53. Moreover, proliferation was further decreased from (19.7±1.6)% to (13.2±0.9)% (P=0.000). At the meantime, after transfection of GFP-THBS2, proliferation was further increased from (19.2±1.5)% to (36.0±1.3)% (P=0.011). Conclusion Our findings suggest that p53 regulates the mRNA and protein expression level of THBS2, and THBS2 could regulate proliferation ability of C4-2 cells. Key words: Prostate cancer; p53; Thrombospondins 2