Bernhard Lange-Asschenfeldt

Tumor lymphangiogenesis predicts melanoma metastasis to sentinel lymph nodes

Cutaneous melanoma is a common melanocytic neoplasm that can quickly metastasize to regional lymph nodes. Currently, prognosis is determined by measuring tumor thickness but more reliable markers for metastatic spread are urgently needed. We investigated whether the extent of tumor lymphangiogenesis can predict melanoma metastasis to sentinel lymph nodes. We quantified the extent of tumor lymphangiogenesis, as well as other factors, in excised primary tumors and in sentinel lymph node biopsy samples from 45 patients with primary cutaneous melanoma. The results were correlated with histological and clinical outcome. Primary melanomas from patients whose tumors had metastasized to the sentinel lymph nodes contained prominent ‘hot spots’ of increased lymphatic vessel density, compared to nonmetastatic tumors. Multivariate risk analysis revealed that the lymphatic vascular area of primary melanomas, an index of tumor lymphangiogenesis, was the most sensitive prognostic marker for sentinel lymph node metastasis, and was even able to more accurately predict which tumors were metastatic to sentinel lymph nodes than the currently used method of measuring tumor thickness. Highly lymphangiogenic melanomas maintained their lymphangiogenic activity after metastasis to the sentinel lymph node. The extent of tumor lymphangiogenesis is a highly sensitive (83%) and specific (89%) prognostic marker of lymph node metastasis. Assessment of lymphangiogenesis in primary melanomas may be a more effective approach than the currently used technique of measuring tumor thickness in selecting patients with early metastatic disease for aggressive therapy.

VEGF-A promotes tissue repair-associated lymphatic vessel formation via VEGFR-2 and the α1β1 and α2β1 integrins

Vascular endothelial growth factor‐A (VEGF‐A) is strongly up‐regulated in wounded cutaneous tissue and promotes repair‐associated angiogenesis. However, little is known about its role in lymphatic regeneration of the healing skin. We studied wound healing in transgenic mice that overexpress VEGF‐A specifically in the epidermis and in wild‐type mice in the absence or presence of inhibitors of VEGF‐A signaling. Surprisingly, transgenic overexpression of VEGF‐A in the skin promoted lymphangiogenesis at the wound healing site, whereas systemic blockade of VEGFR‐2 prevented lymphatic vessel formation. Studies in cultured lymphatic endothelial cells revealed that VEGF‐A induced expression of the α1 and α2 integrins, which promoted their in vitro tube formation and their haptotactic migration toward type I collagen. VEGF‐A‐induced lymphatic endothelial cord formation and haptotactic migration were suppressed by anti‐α1 and anti‐α2 integrin blocking antibodies, and systemic blockade of the α1 and α2 integrins inhibited VEGF‐A‐driven lymphangiogenesis in vivo. We propose that VEGF‐A promotes lymphatic vasculature formation via activation of VEGFR‐2 and that lineage‐specific differences of integrin receptor expression contribute to the distinct dynamics of wound‐associated angiogenesis and lymphangiogenesis.

Thrombospondin‐1 suppresses wound healing and granulation tissue formation in the skin of transgenic mice

The function of the endogenous angiogenesis inhibitor thrombospondin‐1 (TSP‐1) in tissue repair has remained controversial. We established transgenic mice with targeted overexpression of TSP‐1 in the skin, using a keratin 14 expression cassette. TSP‐1 transgenic mice were healthy and fertile, and did not show any major abnormalities of normal skin vascularity, cutaneous vascular architecture, or microvascular permeability. However, healing of full‐thickness skin wounds was greatly delayed in TSP‐1 transgenic mice and was associated with reduced granulation tissue formation and highly diminished wound angiogenesis. Moreover, TSP‐1 potently inhibited fibroblast migration in vivo and in vitro. These findings demonstrate that TSP‐1 preferentially interfered with wound healing‐associated angiogenesis, rather than with the angiogenesis associated with normal development and skin homeostasis, and suggest that therapeutic application of angiogenesis inhibitors might potentially be associated with impaired wound vascularization and tissue repair.

Activation of the tie2 receptor by angiopoietin-1 enhances tumor vessel maturation and impairs squamous cell carcinoma growth.

The distinct roles of angiopoietin (Ang)-1 and Ang2, counteracting ligands for the endothelium-specific Tie2 receptor, in tumor development and progression have remained poorly understood. We investigated the expression of Ang1 and Ang2 during multistep mouse skin carcinogenesis and in human squamous cell carcinoma (SCC) xenografts. Expression of Ang2, but not of Ang1, was up-regulated in angiogenic tumor vessels already in early stages of skin carcinogenesis and was also strongly increased in SCCs. Stable overexpression of Ang1 in human A431 SCCs resulted in a more than 70% inhibition of tumor growth, associated with enhanced Tie2 phosphorylation levels, as compared with low levels in control transfected tumors. No major changes in the vascular density, vascular endothelial growth factor mRNA and protein expression, and vascular endothelial growth factor receptor-2 phosphorylation levels were observed in Ang1-expressing tumors. However, the fraction of tumor blood vessels with coverage by alpha-smooth muscle actin-positive periendothelial cells was significantly increased, indicative of an increased vascular maturation status. These findings identify an inhibitory role of Ang1/Tie2 receptor-mediated vessel maturation in SCC growth and suggest that up-regulation of its antagonist, Ang2, during early-stage epithelial tumorigenesis contributes to the angiogenic switch by counteracting specific vessel-stabilizing effects of Ang1.

The Angiogenesis Inhibitor Thrombospondin-1 Inhibits Acute Cutaneous Hypersensitivity Reactions

There is increasing evidence that vascular remodeling and endothelial cell activation promote acute and chronic inflammation. Thrombospondin 1 (TSP-1) is a potent endogenous angiogenesis inhibitor thought to play an important role in maintaining cutaneous vascular quiescence. We first investigated TSP-1 expression in human and contact hypersensitivity (CHS) reactions and found that TSP-1 was upregulated in the inflamed skin of patients and in mice. To elucidate the function of TSP-1 in cutaneous inflammation, we induced CHS reactions in the skin of mice with targeted epidermal TSP-1 overexpression in TSP-1-deficient mice and in wild-type mice. We found decreased edema formation, angiogenesis, and inflammatory infiltrate in the inflamed skin of TSP-1 transgenic mice. Conversely, TSP-1-deficient mice exhibited an enhanced and prolonged inflammation, characterized by increased edema formation, enhanced vascular remodeling, and increased neutrophilic infiltrate, when compared with wild-type mice. Moreover, we found strong upregulation of the proinflammatory cytokines IL-1beta, macrophage inflammatory protein 2, and tumor necrosis factor-alpha in the inflamed skin of TSP-1-deficient mice. Our results indicate that TSP-1 downregulates cutaneous delayed-type hypersensitivity reactions by acting on several distinct pathways mediating skin inflammation.

Treatment of multiple, multiform actinic keratoses on the head with imiquimod 5% cream

The objective of this non-controlled interventional clinical study was to evaluate the efficacy of imiquimod in the treatment of fields with multiple, multiform AK. 180 office-based dermatological practices in Germany participated. Patients with clinically typical, visible AK lesions on the head were treated with 5% imiquimod cream 3 times per week for 4 weeks followed by a 4 week treatment pause. If lesions were still present, a second treatment course of treatment (COT) was given. Complete clearance rate, i.e. no clinically visible AK lesions in the treatment area, was the main outcome measure. 829 patients were enrolled. The complete clearance rate was 40.5% after the first COT and 68.9% overall. Altogether, 85.4% of the 7,427 baseline lesions were cleared. Patients with hyperkeratotic/hypertrophic lesions showed comparable responses. Local skin reactions were the most commonly reported adverse effects, causing discontinuation in only 4 patients. Severity of the local skin reactions was a strong predictor of the outcome. Patients with multiple multiform AK on the head can be successfully and safely treated with topical imiquimod in daily practice. Assurance of patient understanding that treatment success is closely correlated to proper drug administration is important.

Anaphylactic reaction caused by the UVA absorber disodium phenyl dibenzimidazole tetrasulfonate

Sir, Adverse reactions from sunscreen ingredients have been increasingly reported, including allergic and irritant contact dermatitis, phototoxic and photoallergic reactions, contact urticaria and even severe anaphylactic reactions (1). UV filters, the active sunscreen components, are more frequently being added to cosmetic products such as lipsticks and moisturizing creams. Moreover, the variety of fragrances, emollients, preservatives and waterproofing additives in these products is infinitely increasing. We here report the first case of a severe generalized anaphylactic reaction caused by the UVA filter disodium phenyl dibenzimidazole tetrasulfonate (PDBT), recently approved for use in the European market.

Serum levels of hepatocyte growth factor as a potential tumor marker in patients with malignant melanoma.

Serum markers can be important tools for prognostic classification and treatment monitoring in cancer patients. The MAP-kinase pathway, which is upregulated in the majority of melanoma patients, can be activated by hepatocyte-growth factor (HGF) through the proto-oncogene c-MET. The aim of this study was to evaluate the predictive and prognostic value of circulating HGF in terms of treatment outcome and survival compared with a widely established serum marker, protein S-100B, in patients with advanced metastatic melanoma. HGF and S-100B were measured in serum samples of 101 patients with metastatic melanoma (American Joint Committee on Cancer stage IV) before and after treatment and 50 patients with stage I/II melanoma. HGF and S-100B correlated significantly with the stage of disease (P=0.032 and P<0.001, respectively). In stage IV melanoma patients, baseline serum levels of HGF and S-100B were significantly associated with treatment response (P=0.012 and 0.006, respectively). Furthermore, the Cox regression analysis confirmed that serum levels of HGF and S-100B proved to have a significant prognostic impact on progression-free survival (hazard ratio=1.39 and 1.29, respectively) and overall survival (hazard ratio=1.27 and 1.29, respectively) in advanced metastatic melanoma patients. In melanoma patients, serum levels of HGF and S-100B correlate significantly with the stage of disease. In stage IV melanoma, both markers are prognostic factors and correlate significantly with progression-free survival and overall survival. Measurement of serum HGF levels might be a useful additional tool in the management of melanoma patients.

A case of Schöpf-Schulz-Passarge syndrome caused by c.1135C>T WNT10A missense mutation

An 86-year-old female patient was referred to our clinic for evaluation of plantar erosions. She reported a lifelong history of palmoplantar keratoderma, which, in recent years, had evolved into painful hyperkeratotic papules and erosions, as well as oligodontia of primary and permanent teeth, and massive palmoplantar hyperhidrosis, which had disappeared in early adulthood. Her medical records revealed that numerous neurocutaneous fi bromas (on the trunk) had been excised over the years. At the age of 50, a squamous cell carcinoma had been removed from the right palm. The patient was born to healthy parents, with no known ectodermal abnormalities or consanguineous background.

Herpes zoster in an infant without postnatal varicella infection

We report the case of a five-month-old female infant who presented with a two-day history of small blisters on the abdomen and the right thigh. At the time of examination, the infant was in good general health and exhibited ageappropriate development without any signs of pain or fever. Her medical history did not reveal any evidence of a prior varicella infection. Up to this point, the infant had received all vaccinations recommended in the Austrian immunization schedule (rotavirus, diphtheria, tetanus, pertussis, polio, Haemophilus influenza type b, hepatitis B, pneumococci); the MMR vaccination (recommended after the 10th month of life according to the Austrian immunization schedule) was yet to be administered. Clinically, the patient showed grouped vesicles on an erythematous base that were clearly confined to dermatomes T12–L2 (right side) (Figure 1). Using polymerase chain reaction, the diagnosis was confirmed by the detection of varicella-zoster virus (VZV) nucleic acids. Serum VZV IgG was elevated (201 mU/mL; normal value < 149 mU/mL); VZV IgM was within normal limits. Humoral or cellular immune deficiency was ruled out by measuring the various subclasses of serum immunoglobulins, as well as by another pediatric consult. Over the course of seven days, the infant subsequently received an oral acyclovir suspension (15 mg/kg, five times daily). Topical therapy initially included a zinc lotion, later panthenol ointment (Bepanthen®). Follow-up ten days after the start of treatment showed significant clinical improvement with only minor persistent erythema in the area previously covered by vesicles (dermatomes T12–L2 right side). Upon repeated questioning of the patient’s mother, an Indian migrant, and review of her medical history, we were able to ascertain a (documented) mild VZV infection with a polymorphous rash (at typical location) in the 4th gestational week.