Fig. 5

Effects of butyrate on PKM2 and HSP90β protein in colon tissues of different transformation stages. a, c Representative blots of PKM2 and HSP90β protein in paired normal and tumor colon tissue after treatment with 10 mM butyrate for 12 h. Cytosolic extracts from the different tissue types have been analyzed by Western blot using specific antibodies. β-actin served as internal loading control. b, d Protein expression ratios (fold changes) of PKM2 and HSP90β in paired normal and tumor colon tissue after treatment with 10 mM butyrate for 12 h compared to the respective gene expression ratios. Sample material from donors was simultaneously treated with butyrate (12 h) for subsequent mRNA (qPCR) and protein expression analysis (Western blot). Results are presented in a patient (P)-wise manner, sorted by age of the patients. The small letter further differentiates between males (m) and females (f). The symbols (filled triangle, open square minus) denote the change in expression after butyrate treatment when compared to the medium control (fold change). No protein fold change could be determined for the tumor samples of patients P12 (PKM2) and P19 (HSP90β). Ratios equal to 1 indicate no expression differences between butyrate- and non-butyrate-treated (medium) tissues (n = 13)