Figure 3.

PAICS silencing retards CRC cell and tumor growth. (A) Immunoblot analysis using protein lysates from CRC cells, HCT116^p53-wt, HCT116^p53-null, and SW480^p53-mut, which were stably transfected with PAICS shRNAs, showed PAICS protein reduction as compared to cells transfected with NT shRNA. β-Actin was used as a loading control. Densitometric readings for Western Blots were calculated, and values were normalized relative to β-actin. These values are provided below the blots of the PAICS expression. The stable knockdown of PAICS in CRC cells reduced cell proliferation (B) and colony formation (C). (D) Representative images showing less invasion of PAICS-knockdown CRC cells through Transwell Matrigel membranes compared to cells treated with NT shRNA. (E) Phase-contrast microscopy images showing reduced formation of spheroids by CRC cells with PAICS knockdown compared with those transfected with NT shRNA; scale bar—1000 µm. (F) HCT116^p53-null cells transfected with PAICS shRNA1 or control NT shRNA were injected into NSG mice, and tumors were monitored at the indicated time points. A representative photograph showing tumors of two groups: those formed from cells transfected with control NT shRNA (n = 7) and those transfected with PAICS shRNA1 (n = 7). (G) A histogram showing tumor volumes and the weights of mouse xenografts (n = 7) +/- SD.