Meinhard Schiller

Malignant Melanoma S3-Guideline "Diagnosis, Therapy and Follow-up of Melanoma"

This first German evidence-based guideline for cutaneous melanoma was developed under the auspices of the German Dermatological Society (DDG) and the Dermatologic Cooperative Oncology Group (DeCOG) and funded by the German Guideline Program in Oncology. The recommendations are based on a systematic literature search, and on the consensus of 32 medical societies, working groups and patient representatives. This guideline contains recommendations concerning diagnosis, therapy and follow-up of melanoma. The diagnosis of primary melanoma based on clinical features and dermoscopic criteria. It is confirmed by histopathologic examination after complete excision with a small margin. For the staging of melanoma, the AJCC classification of 2009 is used. The definitive excision margins are 0.5 cm for in situ melanomas, 1 cm for melanomas with up to 2 mm tumor thickness and 2 cm for thicker melanomas, they are reached in a secondary excision. From 1 mm tumor thickness, sentinel lymph node biopsy is recommended. For stages II and III, adjuvant therapy with interferon-alpha should be considered after careful analysis of the benefits and possible risks. In the stage of locoregional metastasis surgical treatment with complete lymphadenectomy is the treatment of choice. In the presence of distant metastasis mutational screening should be performed for BRAF mutation, and eventually for CKIT and NRAS mutations. In the presence of mutations in case of inoperable metastases targeted therapies should be applied. Furthermore, in addition to standard chemotherapies, new immunotherapies such as the CTLA-4 antibody ipilimumab are available. Regular follow-up examinations are recommended for a period of 10 years, with an intensified schedule for the first three years.

Immune response modifiers – mode of action

Abstract:  The innate immune system governs the interconnecting pathways of microbial recognition, inflammation, microbial clearance, and cell death. A family of evolutionarily conserved receptors, known as the Toll‐like receptors (TLRs), is crucial in early host defense against invading pathogens. Upon TLR stimulation, nuclear factor‐κB activation and the interferon (IFN)‐regulatory factor 3 pathway initiate production of pro‐inflammatory cytokines, such as interleukin‐1 and tumor necrosis factor‐α, and production of type I IFNs (IFN‐α and IFN‐β), respectively. The innate immunity thereby offers diverse targets for highly selective therapeutics, such as small molecular synthetic compounds that modify innate immune responses. The notion that activation of the innate immune system is a prerequisite for the induction of acquired immunity raised interest in these immune response modifiers as potential therapeutics for viral infections and various tumors. A scenario of dermal events following skin cancer treatment with imiquimod presumably comprises (i) an initial low amount of pro‐inflammatory cytokine secretion by macrophages and dermal dendritic cells (DCs), thereby (ii) attracting an increasing number type I IFN‐producing plasmacytoid DCs (pDCs) from the blood; (iii) Langerhans cells migrate into draining lymph nodes, leading to an increased presentation of tumor antigen in the draining lymph node, and (iv) consequently an increased generation of tumor‐specific T cells and finally (v) an accumulation of tumoricidal effector cells in the treated skin area. The induction of predominately T helper (Th)1‐type cytokine profiles by TLR agonists such as imiquimod might have further benefits by shifting the dominant Th2‐type response in atopic diseases such as asthma and atopic dermatitis to a more potent Th1 response.

α-Melanocyte-Stimulating Hormone Counteracts the Suppressive Effect of UVB on Nrf2 and Nrf-Dependent Gene Expression in Human Skin

Human skin is constantly exposed to UV light, the most ubiquitous environmental stressor. Here, we investigated the expression and regulation of Nrf1-3, transcription factors crucially involved in protection against oxidative stress in human skin cells in vitro, ex vivo, and in situ. In particular, we examined whether alpha-MSH, a UV-induced peptide, is capable of modulating Nrf2 and Nrf-dependent gene expression. Nrf1, -2, and -3 were found to be expressed in various cutaneous cell types in vitro. Surprisingly, UVB irradiation at physiological doses (10 mJ/cm(2)) reduced Nrf2 and Nrf-dependent gene expression in normal keratinocytes and melanocytes in vitro as well as ex vivo in skin organ cultures. alpha-MSH alone significantly increased Nrf2 as well as Nrf-dependent heme oxygenase-1, gamma-glutamylcysteine-synthetase, and glutathione-S-transferase Pi gene expression in both keratinocytes and melanocytes. This effect of alpha-MSH occurred at physiological doses and was due to transcriptional induction, mimicked by the artificial cAMP inducer forskolin, and blocked by protein kinase A pathway inhibition. In silico promoter analysis of Nrf2 further identified several putative binding sites for activator protein 1 and cAMP response element-binding protein, transcription factors typically activated by alpha-MSH. Importantly, alpha-MSH prevented or even overcompensated the UVB-induced suppression of Nrf2 and Nrf-dependent genes not only in normal keratinocytes and melanocytes in vitro but also in skin organ cultures. These findings, for the first time, show regulation of Nrf2 and Nrf-dependent genes by alpha-MSH. Our data also highlight a novel facet in the cytoprotective and antioxidative effector mechanisms of alpha-MSH and perhaps of related melanocortin peptides.

α‐melanocyte–stimulating hormone suppresses bleomycin‐induced collagen synthesis and reduces tissue fibrosis in a mouse model of scleroderma: Melanocortin peptides as a novel treatment strategy for scleroderma?

OBJECTIVE Recently, we found that human dermal fibroblasts (HDFs) express melanocortin 1 receptors (MC-1R) that bind alpha-melanocyte-stimulating hormone (alpha-MSH). In search of novel therapies for scleroderma (systemic sclerosis [SSc]), we used the bleomycin (BLM) model to investigate the effects of alpha-MSH on collagen synthesis and fibrosis. METHODS Collagen expression in HDFs was determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analyses. Signal transduction studies included pharmacologic blockade, immunofluorescence analysis, Western blotting, and reporter-promoter assays. Oxidative stress was measured by fluorescence-activated cell sorter analysis, and anti-oxidative enzyme levels were determined by real-time RT-PCR and Western blot analyses. The effect of alpha-MSH in the BLM mouse model of scleroderma was assessed by histologic, immunohistochemical, real-time RT-PCR, and protein analyses. Expression of MC-1R and pro-opiomelanocortin (POMC) in skin and HDF samples from patients with SSc was determined by RT-PCR and compared with that in samples from normal controls. RESULTS Treatment with alpha-MSH (and related peptides) suppressed BLM-induced expression of type I and type III collagen in HDFs, and this effect was cAMP-dependent. Neither BLM nor alpha-MSH altered Smad signaling, but antioxidants inhibited BLM-induced collagen expression in vitro. In addition, alpha-MSH suppressed BLM-induced oxidative stress and enhanced the expression of superoxide dismutase 2 (SOD2) and heme oxygenase 1 (HO-1). In the BLM mouse model, alpha-MSH reduced skin fibrosis and collagen content and increased tissue levels of SOD2 and HO-1. In skin and HDFs from patients with SSc, both MC-1R and POMC messenger RNAs were detected, but there were no differences compared with healthy controls. CONCLUSION Alpha-melanocyte-stimulating hormone and related peptides that exert their effects via MC-1R may provide a novel antifibrogenic therapeutic tool for the treatment of fibrotic diseases such as scleroderma.

Neoadjuvant Imatinib in Advanced Primary or Locally Recurrent Dermatofibrosarcoma Protuberans: A Multicenter Phase II DeCOG Trial with Long-term Follow-up

Purpose: Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous tumor. COL1A1–PDGFB gene fusion is frequent in DFSP, rendering tumor cell proliferation and survival dependent on PDGFRβ (platelet-derived growth factor receptor β) signaling. This trial investigated imatinib as neoadjuvant treatment of DFSP, including long-term follow-up. Experimental Design: The primary endpoint of this multicenter phase II trial was response; secondary endpoints were safety, tumor relapse, and response biomarkers. Patients with advanced primary or locally recurrent DFSP and measurable disease by RECIST (response evaluation criteria in solid tumors) were eligible and received imatinib 600 mg/d until definitive surgery with histopathologic proof of tumor-free margins. Results: Sixteen patients received imatinib, and 14 patients were evaluable for all endpoints. Median treatment duration was 3.1 months; median tumor shrinkage was 31.5%. Best overall response was 7.1% complete response (CR), 50.0% partial response (PR), 35.7% stable disease, and 7.1% progressive disease (PD). Toxicity was moderate with 25.0% grade 3 and 4 events. During a median follow-up of 6.4 years, one patient developed secondary resistance to imatinib but responded to second-line sunitinib. This patient also presented local recurrence, distant metastasis, and death from DFSP. Exploratory analysis showed that response to imatinib was associated with decreased tumor cellularity and formation of strong hyalinic fibrosis. Weak PDGFRB phosphorylation and pigmented-type DFSP were associated with nonresponse. Additional to PDGFRB, the kinases EGFR and insulin receptor were found activated in a high percentage of DFSPs. Conclusion: The neoadjuvant use of imatinib 600 mg/d in DFSP is efficacious and well tolerated. Long-term follow-up results do not definitely support smaller surgical margins after successful imatinib pretreatment, and presume that secondary resistance to imatinib might promote accelerated disease progression. Clin Cancer Res; 20(2); 499–510. ©2013 AACR.

Increased cAMP Levels Modulate Transforming Growth Factor-β/Smad-induced Expression of Extracellular Matrix Components and Other Key Fibroblast Effector Functions

cAMP is a key messenger of many hormones and neuropeptides, some of which modulate the composition of extracellular matrix. Treatment of human dermal fibroblasts with dibutyryl cyclic AMP and forskolin antagonized the inductive effects of transforming growth factor-β (TGF-β) on the expression of collagen, connective tissue growth factor, tissue inhibitor of matrix metalloproteinase-1, and plasminogen activator inhibitor type I, four prototypical TGF-β-responsive genes. Increased intracellular cAMP prevented TGF-β-induced Smad-specific gene transactivation, although TGF-β-mediated Smad phosphorylation and nuclear translocation remained unaffected. However, increased cAMP levels abolished TGF-β-induced interaction of Smad3 with its transcriptional co-activator cAMP-response element-binding protein (CREB)-binding protein (CBP)/p300. Overexpression of the transcriptional co-activator CBP/p300 rescued Smad-specific gene transcription in the presence of cAMP suggesting that sequestration of limited amounts of CBP/p300 by the activated cAMP/CREB pathway is the molecular basis of this inhibitory effect. These findings were extended by two functional assays. Increased intracellular cAMP levels suppressed the inductive activity of TGF-β to contract mechanically unloaded collagen lattices and resulted in an attenuation of fibroblast migration of mechanically induced cell layer wounds. Of note, cAMP and TGF-β synergistically induced hyaluronan synthase 2 (HAS2) expression and hyaluronan secretion, presumably via putative CREB-binding sites adjacent to Smad-binding sites within the HAS2 promoter. Our findings identify the cAMP pathway as a potent but differential and promoter-specific regulator of TGF-β-mediated effects involved in extracellular matrix homeostasis.

Predisposing factors of actinic keratosis in a North-West German population.

The growing incident rates of skin cancer and their corresponding precursor lesions, e.g. actinic keratosis (AK), among Caucasians have become an important public health problem. A multicenter case-control study was conducted to identify the risk factors of AK of a prototypical Central European population. The study population comprised a total of 331 cases and 383 controls. Using multivariate analysis we identified ten independent variables predicting the AK risk. The five most crucial were age (OR 1.11; 95% CI 1.08-1,14), gender (OR 3.92; 95% CI 2.42-6.36), history of previous skin malignancies (OR 6.47; 95% CI 3.21-13.03), pale skin phototype (OR 2.5; 95% CI 1.53-4.06), and sun exposure for occupational reasons (OR 1.72; 95% CI 1.01-2.92). Additionally, sun exposure for recreational reasons, denial of the use of sunscreens, painful sunburn episodes before the age of 20, and a familial history of skin malignancies are also significant independent correlates of AK. Our epidemiological data suggest that constitutional susceptibility and sunlight exposure are equally involved in the onset of AK. Additional prophylactic and educational efforts should focus on increasing sun protection policies and educational programs especially aimed at outdoor workers, men, fair skinned individuals and patients with a history of previous skin malignancies. These measures should be able to reduce the excessive incidence rates of AK among Caucasians in Central Europe.

Intracellular retention of cytosine arabinoside triphosphate in blast cells from children with acute myelogenous and lymphoblastic leukemia

The importance of the cellular pharmacokinetics of cytarabine triphosphate (ara-CTP) with regard to therapeutic efficacy is well established. In vitro and in vivo monitoring of pharmacokinetic parameters of leukemic blast cells were initiated in order to contribute to the pharmacological basis of optimal ara-C treatment strategies. Peripheral or bone marrow blast cells from 66 leukemic patients [51 acute myelogenous leukemia (ALL), 15 acute lymphoblastic leukemia (AML) were separated and incubated with ara-C for 1 hour and in ara-C-free medium for another 3 hours, and the intracellular formation and retention of ara-CTP was measured. In eight children who received continuous ara-C infusion for induction treatment, the ara-CTP concentration in circulating blast cells was monitored in vivo. The in vitro values observed in this assay corresponded to the cellular levels monitored in vivo. The ara-CTP retention differed clearly among the individual groups, as classified by immunophenotype at the time of the initial diagnosis: non-T-ALL 67+/-25% (x+/-SD, n=33), T-ALL 37+/-15% (n=8), and AML 34+/-18% (n=14). The difference in ara-CTP retention between non-T-All and AML (P<0.05) as well as T-ALL (P<0.05) was significant. There was a tendency toward lower ara-CTP retention in relapsed as compared with newly diagnosed ALL, but the difference was not significant. The maximal accumulation of ara-CTP (after 1 hour incubation) was comparable in AML, T-ALL, non-T-ALL, and blast cells from children in relapse. The observed similarity of cellular accumulation in all groups and the significantly more rapid decrease in T-ALL and AML provide the pharmacokinetic rationale supporting the prolonged infusion duration for ara-C in these subgroups as an alternative to the intensification by high-dose ara-C schedules with short-term infusion.

Characterization of a polyclonal antibody raised against the human melanocortin-1 receptor.

ABSTRACT: We have generated a polyclonal antibody raised against a synthetic peptide corresponding to the amino acids 2–18 of the extracellular, N‐terminal domain of the human melanocortin‐1 receptor (MC‐1R). Specificity of the affinity‐purified anti‐MC‐1R antibody was confirmed by dot blot analysis with the an‐tigenic peptide. The antibody detected MC‐1R antigenicity on the surface of normal human melanocytes and WM35 melanoma cells, as shown by FACS and immunofluorescence analysis. The antibody was suitable for immunoperoxidase staining of deparaffinized skin sections, revealing prominent MC‐1R staining of a cutaneous melanoma as opposed to undiseased skin in which normal melanocytes were only occasionally immunoreactive. Distinct adnexal structures in normal skin also displayed MC‐1R immunostaining. Specificity of the MC‐1R immunoreactivity in each technique was confirmed by preabsorption with the immunogenic peptide, omission, or substitution of the primary antibody with preimmune serum. Our results provide a baseline for future studies on MC‐1R expression in diseased human skin.

Significant Risk of a Second Melanoma in Patients with a History of Melanoma but No Further Predisposing Factors

It is a well-accepted fact that melanoma patients are prone to develop further melanomas. In a cohort of 535 melanoma patients, we determined the incidence of second melanomas, as well as risk factors known to be associated with melanoma development. A retrospective analysis of patients regularly consulting our melanoma care unit revealed second or even further melanomas in 5.6% (n = 30). When compared to the overall population, melanoma patients have at least a 30-fold increased risk for the development of a second melanoma. Twenty of these 30 patients revealed none of the known predisposing conditions for multiple melanomas.