Fig. 4: Netrin-1 signaling inhibits the progression of precancer PanIN lesions.

a, b 3D maximum intensity projection of CK19 immunostaining in 6.5-week-old KIC mice treated with anti-Netrin-1 antibody (αNetrin-1) or isotype control (Iso-antibody). CK19 labels both pancreatic ducts and their ramifications (asterisks), as well as PanIN lesions (arrows). Scale bar: 500 µm. c Quantification of PanIN lesions per mm³ following anti-Netrin-1 (αNet) or isotype (Iso) treatment. Data: mean ± SEM; n  =  3 mice/group; 6 (Iso) and 5 (αNet) ROIs were analyzed. Unpaired t-test, two-tailed. d, e 2D optical sections showing low- (d) and high-grade (e) PanIN lesions. PanINs were labeled with CK19, and pancreatic tissue was visualized by autofluorescence (AF). Insets: 3D maximum intensity projections of CK19⁺ signal. Scale bars: 100 µm (d), 200 µm (e). f Proportions of low- and high-grade PanIN lesions following anti-Netrin-1 (αNet) or isotype (Iso) treatment. n  = 3 mice/group; 20 (Iso) and 41 (αNet) PanINs analyzed. Data are shown as percentage. Chi-squared, two-tailed. g, h IHC for Sox9 and KI67 in PanIN lesions from KIC mice treated with isotype (g) or anti-Netrin-1 (h) antibodies. Scale bar: 50 µm. i Proportion of Sox9⁺ cells expressing KI67 in PanIN lesions following anti-Netrin-1 (αNet) or isotype (Iso) treatment. Data: mean ± SEM. n  =  3 mice/group; 20 (Iso) and 19 (αNet) PanINs analyzed. Unpaired t-test, two-tailed. j Summary of findings and proposed model: Reactivation of the neurodevelopmental Netrin-1/DCC signaling pathway promotes hyperinnervation of non-malignant pancreatic lesions by sympathetic nerve terminals. This process may initiate a negative feedback loop that restrains lesion progression to higher grades by limiting cell proliferation. p-values are indicated in the figure (ns: p > 0.05). Source data are provided as a Source Data file.