Fig 10.

SRp20 overexpression is tumorigenic in nude mice. (A-B) HeLa cells with reduced SRp20 expression are less competent at inducing tumors. HeLa cells (1 × 10⁶) with or without SRp20 knockdown were implanted subcutaneously, and the tumor diameter (A) was measured on the indicated days. The tumor weight (B) was recorded when the animals were sacrificed on day 22. Data are means ± SE from 10 animals in each group (P < 0.01 for tumor size at each time point and P < 0.05 for tumor weight, t test). (C) Tumors from HeLa cells treated with NS or SRp20 siRNAs and implanted into both sides of the mice (L, left; R, right). Tumors from five animals from each group are shown. (D-E) MEF 3T3 tet-off cells with SRp20 overexpression are tumorigenic. MEF 3T3 tet-off cells (3 × 10⁶) stably transfected with an empty vector only or a T7-SRp20 vector were grown in doxycycline-free medium and then implanted subcutaneously, and the tumor diameter (D) and weight (E) were measured as described above. Data are means ± SE from 5 animals in each group (P < 0.001 for both tumor size at each time point and weight). (F) Tumors from MEF3T3 tet-off cells with or without T7-SRp20 expression implanted into the left or right side. (G) A model for SRp20 regulation of cell cycle progression and tumorigenesis. SRp20 regulates the expression of FoxM1, Cdc25B, and PLK1 and controls cell apoptosis. Green ovals: cells; orange circles: nuclei; bars: genomes.