Figure 3.

Consequences of PKM2 knockdown to morphology, survival, and colony formation ability of 786-O cells. (A) Evaluation of the effect of PKM2 knockdown on viability (determined using IncuCyte ZOOM™ live cell imaging system) of kidney cancer 786-O cells following treatment with indicated siRNAs at concentrations ranging from 5 to 100 nM for 72 h. At a concentration of 100 nM for 72 h, si156 significantly reduced the survival of 786-O cells as compared with other groups. (B) Morphology of untransfected and transfected 786-O cells captured at 100× magnification. Morphological changes were prominent after PKM2 knockdown as compared with normal and negative control cells. (C) Representative photographs of colony formation assay of 786-O cells transfected with indicated PKM2 siRNAs in six-well plates captured at 100× magnification. All cell colonies were visually recorded and counted under a light microscope. No differences in colony number were observed between normal and negative control cells as compared with si156-, si155-, and si27-transfected cells. Knockdown of PKM1 and PKM2 by siPK reduced the colony number. (D) Quantitative analysis of colony number. Representative data of three independent experiments are shown. One-way ANOVA was used to compare means of different groups. Differences between means were considered significant at p < 0.05 using Tukey’s multiple comparison test; *** p < 0.001 as compared with normal control cells. si27, si155, and si156: experimental siRNAs targeting PKM2 mRNA; siPK: commercially available siRNA targeting both PKM1 and PKM2 mRNAs (positive control); and siCT (siControl): siRNA targeting the firefly luciferase gene (negative control).