TY - JOUR A1 - Kneitz, Hermann A1 - Rose, Christian A1 - Glutsch, Valerie A1 - Goebeler, Matthias T1 - Recurrence of a cellular blue nevus with satellitosis — a diagnostic pitfall with clinical consequences JF - Dermatopathology N2 - Blue nevus is a benign melanocytic lesion, typically asymptomatic and of unknown etiology. Several histologic and clinical variants have been distinguished, the most frequent being common blue nevus, cellular blue nevus, and combined blue nevus. Although melanocytic nevi with a satellite lesion are usually suggestive of locally advanced malignant melanoma, very few cases of blue nevi with satellite lesions have been reported. The diagnosis of common or cellular blue nevi is generally straightforward; however, the presence of structures such as irregular edges or satellitosis are highly suggestive for malignancy, and differential diagnoses such as locally advanced malignant melanoma and malignant blue nevus should be considered. Recurrent blue nevi can display atypical features not seen in the primary lesion, such as pleomorphism and mitotic activity. They usually tend to follow a benign course; however, in some cases, recurrence may indicate malignant transformation. We here report the unique case of a 64-year-old woman with a recurrent cellular blue nevus accompanied by satellite lesions. Such a biological behavior resulting in a clinical presentation as a melanoma-like lesion is a rarity in blue nevus and has not been described before. KW - common blue nevus KW - cell rich blue nevus KW - satellitosis KW - immunohistochemistry KW - skin Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297436 SN - 2296-3529 VL - 9 IS - 4 SP - 361 EP - 367 ER - TY - JOUR A1 - Leikam, C A1 - Hufnagel, AL A1 - Otto, C A1 - Murphy, DJ A1 - Mühling, B A1 - Kneitz, S A1 - Nanda, I A1 - Schmid, M A1 - Wagner, TU A1 - Haferkamp, S A1 - Bröcker, E-B A1 - Schartl, M A1 - Meierjohann, S T1 - In vitro evidence for senescent multinucleated melanocytes as a source for tumor-initiating cells JF - Cell Death and Disease N2 - Oncogenic signaling in melanocytes results in oncogene-induced senescence (OIS), a stable cell-cycle arrest frequently characterized by a bi-or multinuclear phenotype that is considered as a barrier to cancer progression. However, the long-sustained conviction that senescence is a truly irreversible process has recently been challenged. Still, it is not known whether cells driven into OIS can progress to cancer and thereby pose a potential threat. Here, we show that prolonged expression of the melanoma oncogene N-RAS\(^{61K}\) in pigment cells overcomes OIS by triggering the emergence of tumor-initiating mononucleated stem-like cells from senescent cells. This progeny is dedifferentiated, highly proliferative, anoikis-resistant and induces fast growing, metastatic tumors. Our data describe that differentiated cells, which are driven into senescence by an oncogene, use this senescence state as trigger for tumor transformation, giving rise to highly aggressive tumor-initiating cells. These observations provide the first experimental in vitro evidence for the evasion of OIS on the cellular level and ensuing transformation. KW - reactive oxygen KW - human melanoma KW - MITF KW - cancer KW - skin KW - DNA damage KW - kappa-B KW - oncogene-induced senescence KW - cellular senescence Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-148718 VL - 6 IS - e1711 ER - TY - JOUR A1 - Schatton, Tobias A1 - Yang, Jun A1 - Kleffel, Sonja A1 - Uehara, Mayuko A1 - Barthel, Steven R. A1 - Schlapbach, Christoph A1 - Zhan, Qian A1 - Dudeney, Stephen A1 - Mueller, Hansgeorg A1 - Lee, Nayoung A1 - de Vries, Juliane C. A1 - Meier, Barbara A1 - Beken, Seppe Vander A1 - Kluth, Mark A. A1 - Ganss, Christoph A1 - Sharpe, Arlene H. A1 - Waaga-Gasser, Ana Maria A1 - Sayegh, Mohamed H. A1 - Abdi, Reza A1 - Scharffetter-Kochanek, Karin A1 - Murphy, George F. A1 - Kupper, Thomas S. A1 - Frank, Natasha Y. A1 - Frank, Markus H. T1 - ABCB5 Identifies Immunoregulatory Dermal Cells JF - Cell Reports N2 - Cell-based strategies represent a new frontier in the treatment of immune-mediated disorders. However, the paucity of markers for isolation of molecularly defined immunomodulatory cell populations poses a barrier to this field. Here, we show that ATP-binding cassette member B5 (ABCB5) identifies dermal immunoregulatory cells (DIRCs) capable of exerting therapeutic immunoregulatory functions through engagement of programmed cell death 1 (PD-1). Purified Abcb5\(^+\) DIRCs suppressed T cell proliferation, evaded immune rejection, homed to recipient immune tissues, and induced Tregs in vivo. In fully major-histocompatibility-complex-mismatched cardiac allotransplantation models, allogeneic DIRCs significantly prolonged allograft survival. Blockade of DIRC-expressed PD-1 reversed the inhibitory effects of DIRCs on T cell activation, inhibited DIRC-dependent Treg induction, and attenuated DIRC-induced prolongation of cardiac allograft survival, indicating that DIRC immunoregulatory function is mediated, at least in part, through PD-1. Our results identify ABCB5\(^+\) DIRCs as a distinct immunoregulatory cell population and suggest promising roles of this expandable cell subset in cellular immunotherapy. KW - mesenchymal stem cells KW - P-glycoprotein KW - regulatory T cells KW - maintain immune homeostasis KW - malignant melanoma KW - in vivo KW - skin KW - generation KW - transplant KW - tolerance Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-149989 VL - 12 SP - 1564 EP - 1574 ER - TY - JOUR A1 - Stolpmann, K. A1 - Brinkmann, J. A1 - Salzmann, S. A1 - Genkinger, D. A1 - Fritsche, E. A1 - Hutzler, C. A1 - Wajant, H. A1 - Luch, A. A1 - Henkler, F. T1 - Activation of the aryl hydrocarbon receptor sensitises human keratinocytes for CD95L-and TRAIL-induced apoptosis JF - Cell Death & Disease N2 - In this study, we have analysed the apoptotic effects of the ubiquitous environmental toxin benzo[ a] pyrene (BP) in HaCaT cells and human keratinocytes. Although prolonged exposure to BP was not cytotoxic on its own, a strong enhancement of CD95 (Fas)-mediated apoptosis was observed with BP at concentrations activating the aryl hydrocarbon receptor (AhR). Importantly, the ultimately mutagenic BP-metabolite, that is, (+)-anti-BP-7,8-diol-9,10-epoxide (BPDE), failed to enhance CD95-mediated cell death, suggesting that the observed pro-apoptotic effect of BP is neither associated with DNA adducts nor DNA-damage related signalling. CD95-induced apoptosis was also enhanced by beta-naphtoflavone, a well-known agonist of the AhR that does not induce DNA damage, thus suggesting a crucial role for AhR activation. Consistently, BP failed to sensitise for CD95L-induced apoptosis in AhR knockdown HaCaT cells. Furthermore, inhibition of CYP1A1 and/or 1B1 expression did not affect the pro-apoptotic crosstalk. Exposure to BP did not increase expression of CD95, but led to augmented activation of caspase-8. Enhancement of apoptosis was also observed with the TRAIL death receptors that activate caspase-8 and apoptosis by similar mechanisms as CD95. Together, these observations indicate an interference of AhR signalling with the activity of receptor-associated signalling intermediates that are shared by CD95 and TRAIL receptors. Our data thus suggest that AhR agonists can enhance cytokine-mediated adversity upon dermal exposure. KW - CD95 KW - HaCaT cells KW - growth-factor receptor KW - cell death KW - mitochondrial dysfunction KW - mediated apoptosis KW - FAS KW - dermatitis KW - pathways KW - skin KW - progression KW - aryl hydrocarbon receptor (AhR) KW - apoptosis KW - benzo[a]pyrene KW - human keratinocytes Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133501 VL - 3 IS - e388 ER -