Discrimination of Dysplastic Nevi from Common Melanocytic Nevi by Cellular and Molecular Criteria.

Dysplastic nevi (DNs), also known as Clark's nevi or atypical moles, are distinguished from common melanocytic nevi by variegation in pigmentation and clinical appearance, as well as differences in tissue patterning. However, cellular and molecular differences between DNs and common melanocytic nevi are not completely understood. Using cDNA microarray, quantitative RT-PCR, and immunohistochemistry, we molecularly characterized DNs and analyzed the difference between DNs and common melanocytic nevi. A total of 111 probesets (91 annotated genes, fold change > 2.0 and false discovery rate < 0.25) were differentially expressed between the two lesions. An unexpected finding in DNs was altered differentiation and activation of epidermal keratinocytes with increased expression of hair follicle-related molecules (keratin 25, trichohyalin, ribonuclease, RNase A family, 7) and inflammation-related molecules (S100A7, S100A8) at both genomic and protein levels. The immune microenvironment of DNs was characterized by an increase of T helper type 1 (IFNγ) and T helper type 2 (IL13) cytokines as well as an upregulation of oncostatin M and CXCL1. DUSP3, which regulates cellular senescence, was identified as one of the disease discriminative genes between DNs and common melanocytic nevi by three independent statistical approaches and its altered expression was confirmed by immunohistochemistry. The molecular and cellular changes in which the epidermal-melanin unit undergoes follicular differentiation as well as upregulation of defined cytokines could drive complex immune, epidermal, and pigmentary alterations.

Gene expression profiling of the leading edge of cutaneous squamous cell carcinoma: IL-24-driven MMP-7.

The precise mechanisms governing invasion at the leading edge of squamous cell carcinoma (SCC) and its subsequent metastasis are not fully understood. We aimed to define the cancer-related molecular changes that distinguish noninvasive tumor from invasive SCC. To this end, we combined laser capture microdissection with complementary DNA (cDNA) microarray analysis. We defined invasion-associated genes as those differentially regulated only in invasive SCC nests, but not in actinic keratosis or in situ SCC, compared with normal epidermis. There were 383 upregulated and 354 downregulated genes in the "invasion set." SCC invasion was characterized by aberrant expression of various proteolytic molecules. We noted increased expression of MMP7 and IL-24 in invasive SCC. IL-24 induced the expression of matrix metallopeptidase 7 (MMP7) in SCC cells in culture. In addition, blocking of MMP7 by a specific antibody significantly delayed the migration of SCC cells in culture. These results suggest a possible contribution of IL-24 to SCC invasion via enhancing focal expression of MMP7, although IL-24 has been suggested to have antitumor growth effects in other cancer types. Identification of regional molecular changes that regulate cancer invasion may facilitate the development of new targeted treatments for aggressive cancer.

Identification of anaplastic lymphoma kinase as a potential therapeutic target in Basal Cell Carcinoma.

The pathogenesis of BCC is associated with sonic hedgehog (SHH) signaling. Vismodegib, a smoothened inhibitor that targets this pathway, is now in clinical use for advanced BCC patients, but its efficacy is limited. Therefore, new therapeutic options for this cancer are required. We studied gene expression profiling of BCC tumour tissues coupled with laser capture microdissection to identify tumour specific receptor tyrosine kinase expression that can be targeted by small molecule inhibitors. We found a >250 fold increase (FDR<10-4) of the oncogene, anaplastic lymphoma kinase (ALK) as well as its ligands, pleiotrophin and midkine in BCC compared to microdissected normal epidermis. qRT-PCR confirmed increased expression of ALK (p<0.05). Stronger expression of phosphorylated ALK in BCC tumour nests than normal skin was observed by immunohistochemistry. Crizotinib, an FDA-approved ALK inhibitor, reduced keratinocyte proliferation in culture, whereas a c-Met inhibitor did not. Crizotinib significantly reduced the expression of GLI1 and CCND2 (members of SHH-pathway) mRNA by approximately 60% and 20%, respectively (p<0.01). Our data suggest that ALK may increase GLI1 expression in parallel with the conventional SHH-pathway and promote keratinocyte proliferation. Hence, an ALK inhibitor alone or in combination with targeting SHH-pathway molecules may be a potential treatment for BCC patients.

CD200 upregulation in vascular endothelium surrounding cutaneous squamous cell carcinoma.

OBJECTIVE: To characterize the presence of CD200 and CD200 receptor (CD200R) in the human cutaneous squamous cell carcinoma (SCC) microenvironment and to define a possible role for the CD200 axis in immune evasion by SCC. DESIGN: Gene expression in SCC vs normal skin was studied. Laser capture microdissection was used to determine differential expression of CD200 in normal skin vs actinic keratosis vs SCC in situ vs invasive SCC. Immunofluorescence microscopy was used to define expression of CD200R on macrophages, myeloid dendritic cells, natural killer cells, and T cells in SCC vs normal skin. The effects of SCC supernatant on induction of CD200 in human blood endothelial cells was also examined. SETTING: Academic Medical Center with an established Section of Mohs and Dermatologic Surgery and an active Cutaneous Biology Research Program. PARTICIPANTS: Surgical discard tissue from deidentified patients and samples of normal skin from healthy volunteers were used in this study. MAIN OUTCOME MEASURES: Expression of CD200 on SCC-associated blood vessels; expression of CD200 receptor on SCC-associated macrophages and T cells; and induction of CD200 on endothelial cells by SCC supernatants. RESULTS: CD200 gene and message were upregulated in SCC stroma. Immunostaining revealed a higher number of CD200(+) cells in SCC stroma than in normal dermis (180.8 cells/mm(2) vs 24.6 cells/mm(2)) (P<.01). CD200 was further identified mainly on blood vessel endothelium in SCC. Tumor supernatant was able to induce CD200 expression on human dermal blood endothelial cells in culture. CD200R was identified on macrophages and dendritic cells in SCC microenvironment. CONCLUSIONS: CD200 expression on local blood vessels may promote tumor progression by suppressing CD200R myeloid cells during diapedesis. These data highlight a previously unrecognized mechanism of immune evasion by SCC and may provide guidance for the development of targeted therapy.

Cutaneous manifestations of gastrointestinal disease: part II.

The gastrointestinal (GI) and cutaneous organ systems are closely linked. In part I of this continuing medical education article, the intricacies of this relationship were explored as they pertained to hereditary polyposis disorders, hamartomatous disorders, and paraneoplastic disease. Part II focuses on the cutaneous system's links to inflammatory bowel disease and vascular disorders. An in-depth analysis of inflammatory bowel disease skin findings is provided to aid dermatologists in recognizing and facilitating early consultation and intervention by gastroenterologists. Cutaneous signs of inflammatory bowel disease include fissures and fistulae, erythema nodosum, pyoderma gangrenosum, pyostomatitis vegetans, oral aphthous ulcers, cutaneous polyarteritis nodosa, necrotizing vasculitis, and epidermolysis bullosa acquisita. Additional immune-mediated conditions, such as diverticulitis, bowel-associated dermatosis-arthritis syndrome, Henoch-Schönlein purpura, dermatitis herpetiformis, and Degos disease, in which the skin and GI system are mutually involved, will also be discussed. Genodermatoses common to both the GI tract and the skin include Hermansky-Pudlak syndrome, pseudoxanthoma elasticum, Ehlers-Danlos syndrome, hereditary hemorrhagic telangiectasia, and blue rubber bleb nevus syndrome. Kaposi sarcoma is a neoplastic disease with lesions involving both the skin and the gastrointestinal tract. Acrodermatitis enteropathica, a condition of zinc deficiency, likewise affects both the GI and dermatologic systems. These conditions are reviewed with updates on the genetic basis, diagnostic and screening modalities, and therapeutic options. Finally, GI complications associated with vascular disorders will also be discussed.

Cutaneous manifestations of gastrointestinal disease: part I.

Cutaneous findings are not uncommonly a concomitant finding in patients afflicted with gastrointestinal (GI) diseases. The dermatologic manifestations may precede clinically evident GI disease. Part I of this 2-part CME review focuses on dermatologic findings as they relate to hereditary and nonhereditary polyposis disorders and paraneoplastic disorders. A number of hereditary GI disorders have an increased risk of colorectal carcinomas. These disorders include familial adenomatous polyposis, Peutz-Jeghers syndrome, and juvenile polyposis syndrome. Each disease has its own cutaneous signature that aids dermatologists in the early diagnosis and detection of hereditary GI malignancy. These disease processes are associated with particular gene mutations that can be used in screening and to guide additional genetic counseling. In addition, there is a group of hamartomatous syndromes, some of which are associated with phosphatase and tensin homolog (PTEN) gene mutations, which present with concurrent skin findings. These include Cowden syndrome, Bannayan-Riley-Ruvalcaba syndrome, and Cronkhite-Canada syndrome. Finally, paraneoplastic disorders are another subcategory of GI diseases associated with cutaneous manifestations, including malignant acanthosis nigricans, Leser-Trélat sign, tylosis, Plummer-Vinson syndrome, necrolytic migratory erythema, perianal extramammary Paget disease, carcinoid syndrome, paraneoplastic dermatomyositis, and paraneoplastic pemphigus. Each of these disease processes have been shown to be associated with an increased risk of GI malignancy. This underscores the important role of dermatologists in the diagnosis, detection, monitoring, and treatment of these disorders while consulting and interacting with their GI colleagues.

Post-therapeutic relapse of psoriasis after CD11a blockade is associated with T cells and inflammatory myeloid DCs.

UNLABELLED: To understand the development of new psoriasis lesions, we studied a group of moderate-to-severe psoriasis patients who experienced a relapse after ceasing efalizumab (anti-CD11a, Raptiva, Genentech). There were increased CD3(+) T cells, neutrophils, CD11c(+) and CD83(+) myeloid dendritic cells (DCs), but no increase in CD1c(+) resident myeloid DCs. In relapsed lesions, there were many CD11c(+)CD1c(-), inflammatory myeloid DCs identified by TNFSF10/TRAIL, TNF, and iNOS. CD11c(+) cells in relapsed lesions co-expressed CD14 and CD16 in situ. Efalizumab induced an improvement in many psoriasis genes, and during relapse, the majority of these genes reversed back to a lesional state. Gene Set Enrichment Analysis (GSEA) of the transcriptome of relapsed tissue showed that many of the gene sets known to be present in psoriasis were also highly enriched in relapse. Hence, on ceasing efalizumab, T cells and myeloid cells rapidly enter the skin to cause classic psoriasis. TRIAL REGISTRATION: Clinicaltrials.gov NCT00115076.

The human cutaneous squamous cell carcinoma microenvironment is characterized by increased lymphatic density and enhanced expression of macrophage-derived VEGF-C.

Metastases from primary cutaneous squamous cell carcinoma (SCC) account for the majority of the ∼10,000 non-melanoma skin cancer deaths in the United States annually. We studied lymphangiogenesis in human SCC because of the potential link to metastasis. SCC samples were stained for lymphatic endothelial vessel marker LYVE-1 and positive cells were counted and compared with cells in normal skin. Gene set enrichment analysis and reverse transcription (RT)-PCR were performed on SCC, on adjacent non-tumor-bearing skin, and on normal skin to determine the differential expression of lymphangiogenesis-associated genes. Laser capture microdissection (LCM) was performed to isolate tumor cells and tumor-associated inflammatory cells for further gene expression analysis. Immunofluorescence was performed to determine the source of vascular endothelial growth factor-C (VEGF-C) in the tumor microenvironment. We found increased lymphatic density and reorganized lymphatic endothelial vessels in the dermis immediately adjacent to SCC nests. RT-PCR confirmed the presence of VEGF-C in skin immediately adjacent to SCC. LCM confirmed the increased expression of VEGF-C, the SCC inflammatory infiltrate. The presence of CD163(+)/CD68(+)/VEGFC(+) cells and absence of VEGF-C expression by CD3(+) or CD11C(+) cells suggested that VEGF-C is derived from tumor-associated macrophages. Clarification of mechanisms governing SCC-mediated lymphangiogenesis may identify potential targets for therapeutic intervention against aggressive or inoperable disease.

Personalized medicine in psoriasis: developing a genomic classifier to predict histological response to Alefacept.

BACKGROUND: Alefacept treatment is highly effective in a select group patients with moderate-to-severe psoriasis, and is an ideal candidate to develop systems to predict who will respond to therapy. A clinical trial of 22 patients with moderate to severe psoriasis treated with alefacept was conducted in 2002-2003, as a mechanism of action study. Patients were classified as responders or non-responders to alefacept based on histological criteria. Results of the original mechanism of action study have been published. Peripheral blood was collected at the start of this clinical trial, and a prior analysis demonstrated that gene expression in PBMCs differed between responders and non-responders, however, the analysis performed could not be used to predict response. METHODS: Microarray data from PBMCs of 16 of these patients was analyzed to generate a treatment response classifier. We used a discriminant analysis method that performs sample classification from gene expression data, via "nearest shrunken centroid method". Centroids are the average gene expression for each gene in each class divided by the within-class standard deviation for that gene. RESULTS: A disease response classifier using 23 genes was created to accurately predict response to alefacept (12.3% error rate). While the genes in this classifier should be considered as a group, some of the individual genes are of great interest, for example, cAMP response element modulator (CREM), v-MAF avian musculoaponeurotic fibrosarcoma oncogene family (MAFF), chloride intracellular channel protein 1 (CLIC1, also called NCC27), NLR family, pyrin domain-containing 1 (NLRP1), and CCL5 (chemokine, cc motif, ligand 5, also called regulated upon activation, normally T expressed, and presumably secreted/RANTES). CONCLUSIONS: Although this study is small, and based on analysis of existing microarray data, we demonstrate that a treatment response classifier for alefacept can be created using gene expression of PBMCs in psoriasis. This preliminary study may provide a useful tool to predict response of psoriatic patients to alefacept.