Figure 3.

Inhibition of PC4 enhances the therapeutic effect of IR on NSCLC cell xenografts. PC‐9‐shPC4 and control PC‐9 cells (6 × 10⁶) were injected into the lower limb of female athymic nude mice. When the volume of a tumor reached 200 mm³, mice in the treatment groups were treated with 6 Gy IR. The xenograft tumors were removed on the 30th day in Mock and shPC4 groups, and on the 39th day on Mock + IR and shPC4 + IR groups. (A) Representative images showing xenografted tumors in null mice derived from PC‐9‐Mock and PC‐9‐shPC4 cells. (B) Tumor volumes of xenografts were measured by calipers every 3 days for 30–39 days. PC4 knockdown did not affect the growth of tumors in nontreatment groups (Mock and shPC4). Mean tumor volumes in Mock and shPC4 groups were 2149.7 ± 356.4 and 1999.7 ± 441.0 mm³, respectively (n = 5, P = 0.73, Student's t‐test). After treatment with 6 Gy IR (Mock + IR and shPC4 + IR groups), the mean tumor volume in the shRNA group was 116.0 ± 45.0 mm³, which was significantly smaller than 660.2 ± 282.1 mm³ in the Mock group (n = 5, P = 0.022, Student's t‐test). Values represent the mean tumor volume ± SE.