588 Essential role of periostin in inflammation-associated melanoma progression in human and mouse F Ohno 1 , T Nakahara 1 , M Nakahara 1 , S Nunomura 2 , K Izuhara 2 and M Furue 1 1 Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan and 2 Department of Bio- molecular Sciences, Saga Medical School, Saga, Japan It is widely accepted that chronic inflammation initiates and promotes carcinogenesis and tumor progression in various cell types. However, such a paradigm has not been fully investigated in melanoma. Stromal expression of periostin (S-periostin) is one of the clues to link “inflammation” to “melanoma progression”, because 1) S-periostin is induced in various cutaneous inflammation, 2) S-periostin is involved in tolerogenic M2 macrophage induction, and 3) S-periostin is associated with histological grading of human melanoma. In this study, we first evaluated the prognostic value of S-periostin and found that the intensity of S-peri- ostin was indeed a significant, unfavorable prognostic factor for melanoma (N¼94) and that it was also significantly associated with the number of infiltrated M2 macrophages. In murine chronic inflammation model, S-periostin was induced by repeated application of 1% trini- trochlorobenzene every other day for 2 weeks. We then inoculated B16 melanoma cells intradermally into the normal or inflamed murine skin. Three weeks after the inoculation, tumor size in the inflamed skin was significantly larger than that in control skin. Although the number of infiltrated CD3+ T cells was comparable between two groups, significantly more number of CD163+ M2 macrophages were recruited in the melanomas in the inflamed skin than those in control skin. Notably, peritumoral S-periostin was significantly enhanced in the inflamed skin than control. Moreover, periostin receptor aVb5 integrin was expressed in B16 melanoma cells and periostin significantly upregulated the migration of B16 melanoma cells in vitro. These findings stress a critical role of S-periostin in human and murine melanoma progression and probably prognosis. Furthermore, S-periostin may be implicated in inflam- mation-associated melanoma progression. 589 N-myc downstream regulated gene 1(NDRG1) promotes proliferation and differentiation of infantile hemangioma cells J Byun, H An and H Yoon Dermatology, INHA University School of Medicine, Incheon, Korea (the Republic of) Infantile hemangioma (IH), the most common vascular tumor in infants, is characterized by during the first weeks to months of a child’s life, followed by a spontaneous involution over 10 years. However, its cellular origin and biological signals for uncontrolled growth are poorly understood, and specific pharmacological treatment is unavailable. Recently, we evaluated differences of mRNA expression and protein levels of FOXO1, NDRG1 and RICTOR between proliferating and involuting IH endothelial cells. We found that FOXO1 was decreased and NDRG1 was increased in IH endothelial cells during proliferation phase. Here, we investi- gated the effects of NDRG1 and FOXO1 expression in IH endothelial cells. Downregulation of NDRG1 expression in IH endothelial cells by siRNA transfection decreased differentiation of endothelial cells. Increased FOXO1 expression correlated with decreased expression of differentiation markers. Thus, our findings indicate that NDRG1 and FOXO1 are potential targets for regulating IH proliferation. 590 G protein-coupled oestrogen receptor (GPER) is expressed in melanoma and may predict survival benefit M Fa ´bia ´n 2 , P Balogh 1 , F Rencz 3 , V Brodszky 3 , J Ha ´rsing 2 , T Krena ´cs 1 , K Ne ´meth 2 and S Ka ´rpa ´ti 2 1 1st Department of Pathology, Semmelweis University, Budapest, Hungary, 2 Department of Dermatology, Semmelweis University, Budapest, Hungary and 3 Corvinus University, Buda- pest, Hungary The presence of GPER has been demonstrated in various solid tumours. In this study we aimed to investigate the presence and distribution of GPER in melanoma samples. Formalin-fixed paraffin embedded melanoma tissues from 43 patients (n¼22 females and n¼21 males, mean age 33 years and 34 years) have been selected for immunohistochemical analysis. Univariate Cox proportional regression analysis was used to determine the hazards of developing local and distant metastasis. GPER was expressed in melanomas collected from either sexes (women: 22.7 % vs. men: 33.3 %; p¼0.4383). The Breslow thickness of GPER positive tu- mours appeared to be lower compared to GPER negative melanomas in both genders (meanÆSD 0.82Æ0.61 vs. meanÆSD 1.77Æ1.55), but reached statistical significance only in males (meanÆSD 0.54Æ0.18 vs. meanÆSD 1.91Æ1.56, p¼0.0256). The mitotic rate corre- lated inversely with GPER expression, as demonstrated by comparison of GPER positive and negative samples in all patients combined (meanÆSD 1.30Æ1.57 vs. meanÆSD 4.90Æ5.58; p¼0.0260) and in men (meanÆSD 0.50Æ0.84 vs. meanÆSD 4.93Æ5.28; p¼0.0326). There was no association between the presence of ulceration and GPER expression. By univariate Cox proportional hazards model, the hazards of developing metastases was lower (HR¼0.029,95%CI 0-8.979) in GPER positive cases compared to GPER negative patients. In conclusion, we detected cytoplasmic GPER expression in a significant subset of melanoma cases, regardless of sex. The receptor positivity was associated in both women and men with lower Breslow thickness, lower mitotic rate and lower hazards of metastasis. This suggests that GPER expression may have a positive prognostic role in melanoma outcome. Confir- matory studies on a larger cohort of patients are needed. 591 PUVA induces a shift in systemic T-cell function and Treg activity in lesional skin of MF patients PA Vieyra-Garcia 1,2 , R Fink-Puches 1,2 , S Porkert 2 , R Lang 2 , S Po ¨ chlauer 2 , G Ratzinger 2 ,A Tanew 2 , S Selhofer 2 , P Sator 2 , L Cerroni 1,2 , A Hofer 1,2 , A Gruber-Wackernagel 1,2 , FJ LEGAT 1,2 and P Wolf 1,2 1 Dermatology, Medical University of Graz, Graz, Austria and 2 Austrian PUVA study group, Graz, Austria Although mycosis fungoides (MF) is the skin-restricted form of cutaneous T-cell lymphoma, systemic levels of proinflammatory mediators may reflect disease severity, increase risk for comorbidities and serve as a biomarker to assess response to therapy. We studied a cohort of 28 early stage MF patients treated with PUVA. Blood and skin samples were taken at baseline and throughout therapy to evaluate serum cytokine levels, effector T-cell proliferation and number of Tregs in blood and lesional skin. Twenty of the patients (71%) had a complete clinical/histological response. After 12-16 weeks of PUVA, the percentage of blood circu- lating Tregs increased from 5.2 to 7.8% (ie, 50% increase) and remained higher compared to baseline for up to 48 weeks. The suppressive function of Tregs did not change substantially after PUVA. The proliferative capacity of effector T-cells (CD4+ CD25-) decreased by two-fold and remained consistently low for up to 36 weeks. In MF lesional skin, the expression of Treg- associated molecules like CTLA4, Foxp3, GITR and TGF-b was higher compared with skin of healthy donors. The expression of these molecules decreased significantly after PUVA. Serum analyses at baseline showed that MF patients had an abnormal systemic secretion of cytokines with increased levels of Eotaxin 1/2, a Th2 chemoattractant of eosinophils and basophiles, MMP-1 and soluble IL-2R, a known reporter of disease activity. Serum levels of APRIL, a homeostatic modulator of autoantibody secretion, were lower in MF patients compared with healthy donors. This work suggests that PUVA triggers a shift of inflammatory mediators increasing Tregs in circulation but lowering the expression of Treg molecules in lesional skin that may deprive the neoplastic cells from external activating signals. 592 Clinical, dermoscopic and confocal features of nevi and melanomas in a multiple primary melanoma patient with the MITF p.E318K homozygous mutation S Bassoli 2 , C Pellegrini 1 , C Longo 2 , L Di Nardo 1 , F Farnetani 2 , G Pellacani 2 and M Fargnoli 1 1 DISCAB, University of L’Aquila, L’Aquila, Italy and 2 Dermatology and Venerology, University of Modena-Reggio Emilia, Modena-Reggio Emilia, Italy The MITF gene is a transcription factor acting as a master gene of melanocyte homeostasis. The p.E318K MITF mutation has been associated with an increased melanoma risk and development of multiple primary melanomas (MPM). In all previous studies on melanoma, the p.E318K variant has been always reported in a heterozygous status. Herein, we report a MPM patient who carried the p.E318K mutation in homozygosis, describing the dermoscopic and confocal features of his melanomas and melanocytic nevi. Dermoscopic and confocal images of melanomas and nevi were obtained by DermLite-PhotoÒ(3Gen, California) and VivastackÒ (Vivascope Ò1500, Ger- many), respectively. Mutational screening of all exons of CDKN2A, exon 2 of CDK4, exon 10 of MITF, the entire open reading frame of MC1R and genotyping of the p.S270N POT1 mutation were carried out by sequencing on germline DNA. The first melanoma was dermoscopically characterized by a peripheral atypical network, areas of negative pigment network and different degrees of pinkish and grey pigmentation. At the confocal examination, a severe cyto-architec- tural atypia was observed, with polymorphous cells and atypical melanocytic nests at the junc- tional layer. The second melanoma was characterized by an irregular brown network with a widespread negative pigment network. Confocal examination showed intraepidermal and junc- tional atypical melanocytic proliferation and architectural disarray. Two main dermoscopic nevus patterns were observed: a hypopigmented type with a predominant dermal-congenital pattern and a pigmented type with a predominant reticular/homogenous pattern. Sequencing data revealed the presence of the *500C>G polymorphism in CDKN2A, a homozygous p.E318K mutation in MITF and the p.R160W variant in MC1R. No mutations were found in CDK4 and POT1 genes. Of note, this is the first case of the MITF p.E318K mutation occurring in homozy- gosis in melanoma. 593 The Expression of Dedicator of cytokinesis I (Dock180) and engulfment and cell motility 1 (ELMO1) in G361 melanoma cells M Cho and J Bae Department of dermatology, Soonchunhyang university hospital, Seoul, Korea (the Republic of) Melanoma is resistant to all available therapies and has been challenging the scientific community for decades. The Rho family of small guanosine triphosphates (GTPases), including Rac1, is a key regulator of actin cytoskeletal dynamics and plays a role in relaying signals to downstream effectors that regulate cell migration and invasion. The dedicator of cytokinesis I, also known as Dock180, superfamily of proteins was identified as novel, un- conventional guanine nucleotide exchange factors (GEF) for Rho GTPases. In particular, Dock180 requires binding to engulfment and cell motility 1 (ELMO1) to achieve nucleotide exchange on Rac1. Therefore we hypothesized that Dock180 and Elmo1 may be involved in cancer progression by alternating the apoptosis and cell migration of melanoma cells. We assessed the role of Dock180 and Elmo1 in human malignant melanoma cell line G361 with siRNA through western blot analysis, apoptosis assay, cell proliferation assay and wound healing assay. G361 cells transfected with a siRNA containing target specific sequences for Dock180 downregulated Dock180 expression and significantly attenuated ELMO1 protein levels while having no effect on Rac1 protein levels. However, siRNA for ELMO1 inhibited ELMO1 expression and downregulated Rac1 protein expression without alteration of Dock180 protein expression. Increased rate of apoptosis was found in G361 cells after transfection with Dock180- and ELMO1-specific siRNA. Silencing of both Dock180 and ELMO1 significantly decreased cell migration of G361 cells and the levels of pERK1/2 and pAKT. These results showed that Dock180 and ELMO1 stimulate cancer cell proliferation and migration by regulating Rac1. We present that Dock180 and ELMO1 are functionally related to pathophysiology of cancer and suggest that Dock180 and ELMO1 can be potential targets for treatment and/or prevention of the skin cancers. Melanoma and Other Skin Cancers | ABSTRACTS www.jidonline.org S293