(a, b) Growth curves of WM983A, WM983B, A375P or A375M2 tumours grown intradermally in NXG mice. A375P endpoints considered at same-time and same-volume as A375M2. (c) Representative images and QuPath mark-up (map, red) of SOX10 staining and (d) quantification of dermal invasion in Day 42 WM983A and WM983B tumours grown intradermally in NXG mice. Dashed lines represent the boundary between proximal invasive front (PIF) and the distal invasive front (DIF). n= 8 and 8 mice, respectively. (e) Representative images and QuPath mark-up (map, red) of CITED1 staining and (f) quantification of dermal invading cells in Day 24 and Day 36 A375P tumours and Day 24 A375M2 tumours grown in NXG mice. n= 4, 4 and 8 mice, respectively. (g-j) Representative images (g,i) and percentage of tumour cell nuclei according to LAP1 intensity score (h,j) in the tumour body (TB) and invasive front (IF) of Day 55 WM983A (n = 8) and WM983B (n = 4) tumours (g,h) or in TB and IF of Day 33 A375P tumours (n = 8) and Day 33 A375M2 tumours (n = 8) grown subcutaneously in SCID mice. Significant p values shown for LAP1 score ‘3’. (k) Representative images and QuPath mark-up of GFP-NLS staining (map, red), (l) quantification of dermal invasion in Day 28 intradermal tumours (n= 10 in all conditions) and (m)
in-vitro proliferation curves of A375P cells stably expressing GFP-NLS LAP1B-mRuby3, GFP-NLS LAP1BΔ1-72-mRuby3, GFP-NLS LAP1BR563G-mRuby3, GFP-NLS LAP1C-mRuby3 and A375M2 GFP-NLS cells. n = 10 tumours per condition. In d, f, l, horizontal lines show the median and whiskers show minimum and maximum. P-values calculated by one-way ANOVA (f,l), two-way ANOVA (h,j), and unpaired t-test (d). **p<0.01, ***p<0.001, ****p<0.0001. Numerical data and exact p-values are available in the Source Data. In all cases, scale bars are 50 μm (10 μm in enlargements).