Murine melanomas induce paracrine β-catenin signaling activation in tumor and TDLN DCs in vivo . A.Tumor-infiltrating DCs (TIDCs) isolated from Tyr::CreER;BrafCA;Ptenlox/lox primary melanomas exhibit increased expression levels of β-catenin target genes, including axin2, ccnd1, c-myc, and tcf-7, based on qrt-PCR relative to BMDCs derived from non-tumor bearing mice. Representative of 2 independent experiments. P value based on a two-way ANOVA. B. DCs isolated from tumor-draining lymph node (TDLN) tissues harvested from melanoma-bearing Tyr::CreER;BrafCA;Ptenlox/lox mice exhibit elevated expression levels of β-catenin target genes relative to distant LN tissues harvested from the same mice as well as LN tissues harvested from non-tumor-bearing cre- control mice. Representative of 2 independent experiments. P value based on a two-way ANOVA. C. β-catenin signaling activation in CD11c+ DCs derived from primary BRAFV600EPTEN-/- melanomas and TDLNs harvested from TCF/Lef1-EGFP reporter mice. Left, flow cytometry analysis and quantitation of GFP+CD11c+ DCs. Representative of 2 independent experiments. Right, immunofluorescence confocal microscopy of a GFP+CD11c+ DC isolated from a BRAFV600EPTEN-/- primary melanoma. D. Confocal microscopy of a resected BRAFV600EPTEN-/- melanoma resected from a TCF/Lef1-EGFP reporter mouse demonstrates a GFP-positive stromal infiltrate. Representative of 3 analyzed tumors. 60x. E. Left, Confocal immunofluorescence microscopy of TDLN tissue resected from TCF/Lef1-EGFP reporter mice demonstrates evidence of GFP+ lymph node cells. Center, TDLN tissue resected from wild type (WT) BRAFV600EPTEN-/- melanoma-bearing mice. Right, TDLN tissue from TCF/Lef1-EGFP reporter mice counterstained for CD11c expression shows evidence of GFP+CD11c+ DCs (arrows). Representative of 3 analyzed lymph nodes. 60x.