Fig. 2. DENND5A is variably expressed in familial melanomas and enriched in pigmented melanoma tissue.

a. Western blotting of DENND5A protein expression in tumors from familial melanomas from a Karolinska University Hospital-based registry since 2000. b. Quantification of relative DENND5A protein expression. Red dot represents DENND5A protein expression in melanoma (#355) derived from heterozygote (II:1). A dotted line is drawn across the DENND5A heterozygote as reference of potential DENND5A suppression. c. DENND5A mRNA expression in the Skin Cutaneous Melanoma (SKCM) cohort of The Cancer Genome Atlas is classified into ‘Normal-like’ and ‘Pigmentation’ subtype by applying ‘Pigmentation gene signature’ and then compared. (d-f). Spatial transcriptomic (ST) analysis on a cutaneous malignant melanoma (CMM). d. (left) Hematoxylin & Eosin stained CMM section and (right) higher magnification showing the pigmentation from the section. Scale bar: 1 cm (left), 0.25 cm (right). e. ST microarray on CMM section with barcoded spots of 100 μm diameter and 200 μm center-to-center distance. f. A density plot of DENND5A expression ran by trendsceek in the same section, with the regions of significantly elevated DENND5A expression marked red. g. A matrix of ultraviolet (UV)-related alterations (CC>TT in red; dpC>T, C>T transition at dipyrimidines, in pink) from all the Cancer Genome Atlas (TCGA) skin cutaneous melanomas (SKCM), arising from both chronic (CSD) and non-chronic (non-CSD) sun-exposed body sites (n=38). Sample types (primary or metastatic), body sites (CSD, or non-CSD) and detected DENND5A somatic variants are color-coded and then sorted after DENND5A mRNA expression. h. Proportion of UV signature (CC>TT transitions) from DENND5A^High (top 15) and DENND5A^Low (lowest 15) mRNA are compared and shown as mean ± S.E.M.; Two-tailed, Unpaired t test (c, h).