Fig. 5

Analysis of SAMHD1 and p21^Cip1 gene expression in HCTp53^+/+ and HCT116 p53^−/− cells. 2.5 × 10⁵ cells of non-cycling HCT 116 p53^+/+ and HCT116 p53^−/− cells cultured in DMEM with 0.5% FBS (Un-infected), and were infected with 0.5 ml 2.5 × 10⁷ copies/ml retrovirus for 4 h, 8 h and 16 h. RNA were extracted from cells harvested, and then analyzed by p21^Cip1 TaqMan real time PCR (a), SAMHD1 TaqMan real time PCR (b). The copy numbers of mRNA were normalized to reference gene GAPDH. p53, p21^Cip1, SAMHD1, phospho-SAMHD1 (Thr592) and β-actin proteins were analyzed by Western blot (c) . p-value of Student’s t-test is indicated. p value < 0.01 is indicated by **