Figure 2.

Expression of ISC and differentiation genes in SI-NETs in patients with Familial SI-NET. (A) Representative images of RNA-ISH of FFPE sections from an ileal SI-NET (patient F2) merging fluorescent and transmitted light images to visualize tumor cell location and indicated gene expression. Images show co-expression of Bmi1, HopX and NeuroD1 with TPH1 in the majority of the SI-NETs. There was no or negligible expression of Lgr5, Sox9 or Ngn3 mRNA in most of the TPH1+ tumors examined (See supplementary Tables). Expression of Bmi1, HopX and Sox9 was detected by fast red fluorescence (red) while expression of Lgr5, Ngn3 and NeuroD1 was detected by fast blue fluorescence (green). Expression of TPH1 was detected by either fast red (red) or fast blue (green) fluorescence. Scale bars, 10 μm. (B) Expression of ISC marker genes Lrig1and DCLK1 and differentiation marker genes GCG and Tac1 in the SI-NET cells. (Top left) Co-expression of Lrig1 and TPH1. (Top right) Co-expression of Lrig1 and DCLK1. (Bottom left) Co-expression of Tac1 and TPH1. (Bottom right) Absence of GCG expression in TPH1+ tumor cells. Expression of TPH1 and DCLK1 was detected by fast red fluorescence (red) and expression of Lrig1, Tac1 and GCG was detected by fast blue fluorescence (green). Scale bars in bottom right, 20 μm; for the rest, 10 μm. Representative RNA-ISH image for GCG was from patient F5. The images for Bmi1, Lrig1 and Tac1 were from patient F1 and the other images from patient F2.