Fig. 1

NET and DAT protein expression and ¹²³I-mIBG internalization in PHEO tumor biopsies and cellular mIBG internalization in HEK cells transfected with monoamine transporters. A Immunoblotting analysis of NET and DAT in PHEO tumor biopsies from patients. HEK-NET and HEK-DAT protein extracts were used as positive and negative controls for NET and DAT protein expression, and β-actin was used as a loading control. Quantification of immunoreactive signal was normalized with β-actin protein expression using the Image J software. B and C Illustration of the mRNA expression levels (normalized expression, in log2) of the indicated genes in one PHEO/PGL and one NB transcriptomic datasets analyzed by RNAseq from the R2: Genomics Analysis and Vizualization Platform (http://r2.amc.nl, MegaSampler analysis: Human Genome U133, Plus 2.0; MAS5.0 data normalization). D mIBG internalization in HEK-transfected cells incubated with mIBG 100 nM during 0, 1, and 4 h. Results were normalized with a BCA test. The experiments were performed three times in triplicate. Statistical analysis was performed through two-way ANOVA between the control (HEK) and each cell line. ****p < 0.0001; an between time points 1 and 4 h, ^##p < 0.01. p values are reported only when statistically significant (< 0.05). E Proteomic analysis of total protein fractions of HEK-transfected cells by LC–MS/MS. LFQ, label-free quantification. F and G Determination of NET and DAT Km and Vmax toward mIBG. HEK-NET/DAT results were normalized with a BCA test and performed three times in duplicates, with the mean values of each series recorded. Non-linear regression was drawn using GraphPad Prism’s Michaelis–Menten interpolation