Vitiligo is an autoimmune disease of the skin that results in disfiguring white spots. There are no FDA-approved treatments for vitiligo, and most off-label treatments yield unsatisfactory results. Vitiligo patients have increased numbers of autoreactive, melanocyte-specific CD8+ T cells in the skin and blood, which are directly responsible for melanocyte destruction. Here we report that gene expression in lesional skin from vitiligo patients reveals an IFN-γ-specific signature, including the chemokine CXCL10. CXCL10 is elevated in both vitiligo patient skin and serum and CXCR3, its receptor, is expressed on pathogenic T cells. To address the function of CXCL10 in vitiligo, we employed a mouse model of disease that also exhibits an IFN-γ-specific gene signature, expression of CXCL10 in the skin, and upregulation of CXCR3 on antigen-specific T cells. Mice that receive Cxcr3−/− T cells develop minimal depigmentation, as do mice lacking Cxcl10 or treated with CXCL10 neutralizing antibody. CXCL9 promotes autoreactive T cell global recruitment to the skin but not effector function while, in contrast, CXCL10 is required for effector function and localization within the skin. Surprisingly, CXCL10 neutralization in mice with established, widespread depigmentation induces reversal of disease, evidenced by repigmentation. These data identify a critical role for CXCL10 in both the progression and maintenance of vitiligo, and thereby support inhibiting CXCL10 as a targeted treatment strategy.

UNC-6 netrin, a laminin-related protein secreted from neuroglia and neurons along the ventral midline, orients migrating cells and pioneering growth cones on the nematode epidermis. UNC-5, a cell surface protein expressed on motile cells and pioneer axons, orients movements away from UNC-6 sources. UNC-40, a homolog of the cell surface proteins DCC (Deleted in Colorectal Cancer) and neogenin, is also expressed on motile cells and pioneer neurons. UNC-40 acts cell autonomously to orient movement toward UNC-6 sources. For cells coexpressing UNC-5, it helps orient movement away from UNC-6 sources. Finally, UNC-40 helps determine the dorsoventral position of cells undergoing purely longitudinal migrations. Together with the recent report that DCC is a netrin receptor in vertebrates, our results suggest that UNC-40 is a component of UNC-6 receptors on motile cells.

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Melanoma is one of the most aggressive cancers affecting humans. Although early melanomas are curable with surgical excision, metastatic melanomas are associated with high mortality. The mechanism of melanoma development, progression, and metastasis is largely unknown. In order to uncover genes unique to melanoma cells, we used high-density DNA microarrays to examine the gene expression profiles of metastatic melanoma nodules using benign nevi as controls. Over 190 genes were significantly overexpressed in metastatic melanomas compared with normal nevi by at least 2-fold. One of the most abundantly expressed genes in metastatic melanoma nodules is osteopontin (OPN). Immunohistochemistry staining on tissue microarrays and individual skin biopsies representing different stages of melanoma progression revealed that OPN expression is first acquired at the step of melanoma tissue invasion. In addition, blocking of OPN expression by RNA interference reduced melanoma cell numbers in vitro. Our observations suggest that OPN may be acquired early in melanoma development and progression, and may enhance tumor cell growth in invasive melanoma.

Purpose: The collagen triple helix repeat containing 1 (CTHRC1) is a promigratory protein first found to be expressed during rat tissue repair process. Recent preliminary results revealed CTHRC 1 mRNA in melanoma and breast cancer. However, the full significance of CTHRC1 to human carcinogenesis remains unclear. This study is to further characterize the clinical and functional relevance of CTHRC1in melanoma and other human solid cancers. Experimental Design: First, semiquantitative immunohistochemistry analysis was done on 304 clinically annotated, paraffin-embedded biopsies representing different stages of melanoma progression. Then, short interfering RNA was used to inhibit expression of CTHRC1 protein for migration analysis on cultured melanoma cells. Finally, the CTHRC1 expression was surveyed in 310 samples representing 19 types of human solid cancers. Results: In benign nevi and noninvasive melanoma biopsies, there was little CTHRC1 protein expression. In contrast, in invasive primary melanomas, there was a significant increase of CTHRC1protein (P < 0.01, m 2 test). There was a further increase of CTHRC1protein in metastatic melanoma specimens compared with nonmetastatic lesions (P < 0.01, m 2 test). In addition, inhibition of CTHRC1 expression resulted in decreased cell migration in vitro. Finally, transcription survey in 19 types of human solid cancers revealed aberrant CTHRC1 expression in 16 cancer types, especially cancers of the gastrointestinal tract, lung, breast, thyroid, ovarian, cervix, liver, and the pancreas. Conclusions: Aberrant expression of CTHRC1 is widely present in human solid cancers and seems to be associated with cancer tissue invasion and metastasis. It potentially plays important functional roles in cancer progression, perhaps by increasing cancer cell migration.

This study was designed to characterize the direct effects of hyperglycemia on plasminogen activator inhibitor-1 (PAI-1) expression in cultured vascular smooth muscle cells. Glucose induced dose-and time-dependent increases of PAI-1 mRNA expression in rat aortic smooth muscle (RASM) cells in vitro. Using a series of luciferase reporter gene constructs containing PAI-1 5-flanking sequence (from ؊6.4 kilobase to ؊42 base pairs (bp)) transfected into RASM, we found that glucose (25 mM) consistently induced a 4-fold increase in luciferase activity, with the response localized to sequence between ؊85 and ؊42 bp. Mutagenesis of two putative Sp1-binding sites located in the region of interest essentially obliterated the glucose-response. Electrophoretic mobility shift assays with radiolabeled oligonucleotides containing the two putative Sp1-binding sites from PAI-1 promoter and nuclear extracts from RASM cells revealed that glucose treatment markedly changed the mobility pattern of the major protein-DNA complexes. Supershift assay showed that transcription factor Sp1 was present in the complexes under control and hyperglycemic conditions. These results suggest that glucose regulates PAI-1 gene expression in RASM cells through an effect on two adjacent Sp1 sites located between ؊85 and ؊42 bp of the PAI-1 5-flanking region and that the release of a transcriptional repressor from the Sp1 complexes may explain the activation of the PAI-1 gene under high glucose conditions in RASM cells.

Growth cones in developing nervous systems encounter a sequence of extracellular cues during migration. In theory, a growth cone can navigate by selectively expressing or activating surface receptor(s) that recognize extracellular cues appropriate to each migratory phase. Using the simple Caenorhabditis elegans nervous system, we attempted to demonstrate that path selection by migrating growth cones can be predictably altered by ectopic expression of a single receptor. The unc-5 gene of C. elegans encodes a unique receptor of the immunoglobulin superfamily (UNC-5), required cell-autonomously to guide growth cone and mesodermal cell migrations in a dorsal direction on the epidermis. We report here that the UNC-5 receptor induces dorsally oriented axon trajectories when ectopically expressed in the touch receptor neurons which normally extend pioneer axons longitudinally or ventrally on the epidermis. These errant trajectories depend on unc-6, which encodes a putative epidermal path cue, just as normal dorsally oriented axon trajectories do (such as those of certain motor neurons), suggesting that UNC-5 acts to reorient the touch cell growth cones by using its normal guidance mechanisms. These results support previous evidence that UNC-5 and UNC-6 play instructive rules in guiding growth cone migrations on the epidermis in C. elegans, and indicate that pioneering growth cones, which normally migrate in different directions, may use equivalent intracellular signalling mechanisms for guidance.

The lack of a specific marker differentiating early mycosis fungoides (eMF) from benign inflammatory dermatitis presents significant difficulties in the assessment and management of suspected MF patients, which often leads to delayed diagnosis and improper medical approaches. To address this, an investigation was carried out to characterize positive identification markers for eMF by comparing eMF lesions with healthy skin and benign inflammatory dermatitis, using high-throughput genomic transcription profiling. A total of 349 genes were differentially expressed in eMF lesions compared with normal skin. These genes belong to pathways associated with inflammation, immune activation, and apoptosis regulation. Most of them (N=330) also demonstrated significant upregulation in chronic dermatitis, making them nonideal markers for eMF. Among them, 19 genes with specific enrichment in eMF lesions were identified that showed no significant upregulation in chronic dermatitis. Two of them, TOX and PDCD1, showed high discrimination power between eMF lesions and biopsies from benign dermatitis by RNA expression. Furthermore, TOX demonstrated highly specific staining of MF cells in eMF skin biopsies in immunohistochemistry and immunofluorescence, including the early epidermotropic cells in Pautrier's microabscesses. This study demonstrates the potential of eMF-enriched genes, especially TOX, as molecular markers for histological diagnosis of eMF, which currently is a major diagnostic challenge.