[Immunohistochemical analysis of a hypoxia-associated signature in melanomas with positive and negative sentinel lymph nodes : Hypoxia-associated signature of primary cutaneous melanomas]. / Immunhistochemische Analyse einer Hypoxie-assoziierten Signatur in Melanomen mit positivem und negativem Schildwächterlymphknoten : Hypoxie-assoziierte Signatur primär kutaner Melanome.

Metabolic reprogramming mediated by hypoxia-inducible factors and its downstream targets plays a crucial role in many human malignancies. Excessive proliferation of tumor cells under hypoxic conditions leads to metabolic reprogramming and altered gene expression enabling tumors to adapt to their hypoxic environment. Here we analyzed the metabolic signatures of primary cutaneous melanomas with positive and negative sentinel node status in order to evaluate potential differences in their metabolic signature. We found a positive correlation of the expression of glucose transporter 1 (GLUT-1) with tumor thickness and ulceration in all melanomas with subgroup analyses as well as in the subgroup with a negative sentinel node. Furthermore, the expression of vascular endothelial growth factor (VEGF) was positively correlated with the presence of ulceration in melanomas with positive sentinel node.

Vascular Endothelial Growth Factor Receptor-3 Expression Predicts Sentinel Node Status in Primary Cutaneous Melanoma.

This study analysed the expression of vascular endothelial growth factor-A (VEGF), VEGFR-2, and VEGFR-3 in primary cutaneous melanomas with positive and negative sentinel node status (SLN) (a total of 58 specimens divided into 2 groups of 29 for each status). The specimens were collected from the pathological archive of the department of Dermatology, Venereology and Allergology of the University Medical Center Heidelberg. A quantification score was developed for protein expression, by considering the percentage of positive melanoma cells (0: 0%, 1: up to 1%, 2: 2-10%, 3: 11-50%, and 4: > 50%) in relation to the intensity of staining (0: negative, 1: low, 2: medium, 3: strong). Tumoural VEGFR-3 expression (mean ± standard deviation) in SLN+ tumours (9.62 ± 3.09) was significantly stronger than in SLN- tumours (6.13 ± 3.87; p < 0.001). A binary logistic regression model proved VEGFR-3 expression and tumour thickness to be significant independent predictors of SLN. These data provide evidence that VEGFR-3 expression may play a critical role in the pathogenesis of malignant melanoma and that its investigation may help to improve the selection of patients with primary cutaneous melanoma for sentinel node biopsy.

Angiogenesis in Ocular and Extraocular Sebaceous Carcinoma.

To shed more light on the pathogenesis of sebaceous carcinoma, we analysed the expression of proteins related to angiogenesis in 18 ocular and 22 extraocular sebaceous carcinomas using a broad panel of immunohistochemical markers. To quantify the expression of D2-40, vascular endothelial growth factor, vascular endothelial growth factor receptor-2 and -3, we calculated a quantification score by considering the percentage of positive tumour cells (0=0%, 1=up to 1%, 2=2-10%, 3=11-50%, and 4=>50%) in relation to the staining intensity (0=negative, 1=low, 2=medium, and 3=strong). Additionally, lymphatic microvessel density in the D2-40 stained sections was counted. Vascular endothelial growth factor receptor-3 (quantification score 9.42 ± 2.94) was significantly more strongly expressed than vascular endothelial growth factor receptor-2 (quantification score 2.15 ± 2.42, p < 0.001). Furthermore, epidermal vascular endothelial growth factor expression was negatively correlated with the intratumoural lymphatic vessel density, and the ratio of small lymphatics to large lymphatics was much higher in intratumoural tissue than in paratumoural tissue and in intraindividual control tissue, suggesting a lymphangiogenetic potential of sebaceous carcinoma.

Merkel cell carcinoma induces lymphatic microvessel formation.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare, highly malignant neuroendocrine tumor of the skin characterized by frequent lymphatic metastasis. OBJECTIVE: We sought to identify lymphovascular anatomy and expression profiles of lymphangiogenic cytokines to give an opinion on lymphangiogenesis in MCC. METHODS: We studied lymphatic microanatomy and lymphangiogenic cytokines in 27 MCC by immunohistology or immunofluorescence (D2-40, lymphatic vessel endothelial hyaluronan receptor [LYVE-1], vascular endothelial growth factor [VEGF] receptor-3, VEGF-C, VEGF-D, Ki67/MiB-1, CD68/PG-M1, CD68/KP1, CD163), Merkel cell polyomavirus-specific polymerase chain reaction, and coanalysis with clinical and histologic data. RESULTS: We found a more than 3-fold increase in the mean density of absolute numbers of small lymphatic capillaries (diameter <10 µm) and a more than 8-fold increase in the median ratio of the number of small to large lymphatics (<10/≥10 µm) paratumorally compared with intraindividual controls. VEGF-C(+)CD68(+) CD163(+) cells (interpreted as M2 macrophages) could be identified as an important potentially lymphangiogenesis-inducing cell type. LIMITATIONS: Partially lacking follow-up data limited the analysis of the prognostic impact. CONCLUSIONS: Our findings strongly indicate lymphangiogenesis in MCC driven by VEGF-C(+)CD68(+) CD163(+) M2 macrophages.

Metabolic Signature of Atypical Fibroxanthoma and Pleomorphic Dermal Sarcoma: Expression of Hypoxia-inducible Factor-1α and Several of Its Downstream Targets.

Metabolic reprogramming mediated by hypoxia-inducible factors play a crucial role in many human cancers. HIF-1α is activated under hypoxic conditions and is considered a key regulator of oxygen homoeostasis during tumor proliferation under hypoxia. Aim of this research was to analyze the immunohistochemical expression of HIF-1α, VEGF-A, Glut-1, MCT4, and CAIX in atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS). 21 paraffin-embedded AFX and 22 PDS were analysed by immunohistochemistry, namely HIF-1α, VEGF-A (referred to as VEGF throughout the manuscript), Glut-1, MCT4, and CAIX. To quantify the protein expression, we considered the percentage of positive tumor cells (0: 0%, 1: up to 1%, 2: 2-10%, 3: 11-50%, 4: >50%) in relation to the staining intensity (0: negative, 1: low, 2: medium, 3: strong). HIF-1α expression (mean ± SD) in AFX (9.33±2.92) was significantly stronger than that in PDS (5.90±4.38; P= 0.007), whereas the expression of VEGF, Glut-1, MCT4, and CAIX did not show differences between AFX and PDS. When comparing all tumors without subgroup stratification, the expression of HIF-1α (P= 0.044) and MCT4 (P= 0.036) was significantly stronger in ulcerated tumors than in tumors without ulceration. Our findings provide the first evidence that HIF-1α-induced metabolic reprogramming may contribute to the pathogenesis of AFX and PDS. HIF-1α expression seems to be higher in AFX than in PDS, and ulcerated tumors show higher expression levels of HIF-1α and MCT4 irrespective of the diagnosis.

Hidradenitis suppurativa (acne inversa): early inflammatory events at terminal follicles and at interfollicular epidermis.

Hidradenitis suppurativa (acne inversa) is a chronic suppurative and scarring inflammatory disease with predilection in the apocrine gland-bearing areas. Histological investigations in the 1990s showed keratotic occlusion of the terminal follicle structure to be the initial cause. Our investigations describe and reproduce the morphology and try to figure out very early lesions of HS. A total of 262 operative specimens from 60 patients were investigated by routine histology and 11 operative specimens by immunohistochemistry: HS is dominated by a heterogeneous histological image. 82% of the surgical specimens showed mild or pronounced follicular hyperkeratosis, whereas an isotopic hyperplasia of follicular epithelium was evident in 77%. Pronounced perifolliculitis was seen in 68% and rupture of the follicle structure in 28%. Features which had not so far been described in detail were: epidermal psoriasiform hyperplasia (43%) and subepidermal interfollicular inflammatory infiltrate (78%). In all 11 specimens, immunohistochemical investigations showed a perifollicular and subepidermal inflammation of CD-3-, CD-4-, CD-68-, CD-79- and CD-8-cells, the latter with a striking selective epitheliotropism. To conclude, we could show follicular hyperkeratosis and lymphocytic perifollicular inflammation as early patterns in pathogenesis, whereas rupture of the follicle structure takes place later. Finally, it seems that there are two hot spots of inflammatory events (perifollicular and subepidermal) composed of a comparable inflammatory cell mixture. The CD-8 cell epitheliotropism (follicular and epidermal) described here and its influence in follicular hyperkeratosis, in hyperplasia of follicular epithelium and in epidermal psoriasiform hyperplasia will be of further interest, for instance, concerning early pharmacological intervention.

New mutation in the CYLD gene within a family with Brooke-Spiegler syndrome.

Brooke-Spiegler syndrome is a rare, autosomal dominant disease characterized by multiple skin appendage tumors caused by various mutations in the CYLD gene on chromosome 16q12-q13. We describe a family, in which we performed a molecular-genetic examination and found a new mutation in exon 19 in the CYLD gene leading to a frameshift. It is important to be aware of this syndrome and its pathogenesis as its phenotypic features can vary so that apparently different diseases are caused by the same genetic defect. In addition, there may be malignant transformation of the generally benign tumors, so that a timely diagnosis is essential for appropriate monitoring and therapy.

Frequent occurrence of RASSF1A promoter hypermethylation and Merkel cell polyomavirus in Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is one of the most aggressive cancers of the skin. It has recently been reported that integration of a Merkel cell polyomavirus (MCPyV) in receptor tyrosine phosphates type G (PTPRG) gene occurs in MCC, and that viral infections are associated with epigenetic silencing of tumor suppressor genes (TSG) in cancer. To examine whether a correlation between TSG inactivation and viral infection can be found in MCC, we investigated the promoter hypermethylation of RASSF1A, TP73, PTPRG, FHIT, and CDKN2A and the presence of MCPyV and SV40 in 98 MCC by PCR. Hypermethylation of RASSF1A was frequently found in 42 of 83 (51%) of MCC. Methylation of CDKN2A was present in 9 of 41 (22%) of MCC. Hypermethylation of TP73 (0%), PTPRG (4%), and FHIT (0%) was infrequent in MCC. Interestingly, MCPyV was found in 90 of 98 (92%) MCC, however, no SV40 signal was detected. No correlation between TSG hypermethylation and viral infection was found. Our results show frequent hypermethylation of RASSF1A and the presence of MCPyV in primary MCC, and that these events may contribute to the pathogenesis of MCC.

Palliative total skin electron beam therapy (TSEBT) for advanced cutaneous T-cell lymphoma.

Our aim was to analyze the effectiveness of palliative total skin electron beam therapy (TSEBT) in the management of advanced cutaneous T-cell non-Hodgkin's lymphoma (CTCL). Eighteen patients (median age 59 years) with advanced and therapy-refractory CTCL in stages IIB-IV were treated with TSEBT for the first time. The most common histological subtype was Mycosis fungoides (72%). All patients suffered from lymphoma-associated symptoms. Median daily fractions of 1 Gy were administered up to a median total dose of 25 Gy. The median follow-up period was 11 months. Nine patients (50%) achieved a complete response and seven patients (39%) had a limited response. The actuarial one-year progression-free survival was 24%. Four patients (22%) had continuing remission over a median period of six months. Lymphoma associated symptoms were improved in 16 patients (89%). The median overall survival after receiving TSEBT was 12 months, resulting in an actuarial one-year overall survival of 48%. Treatment related acute effects (grade 1 or 2) were observed in all patients during radiation therapy. Transient grade 3 epitheliolyses developed in five patients (28%), late skin effects (grade 1 and 2) in 16 patients (89%), and hypohidrosis was seen in six patients (33%). We conclude that TSEBT is a very efficient and tolerable palliative treatment for patients with advanced CTCL.

Cultivated keratinocytes express N-methyl-D-aspartate receptors of the NMDAR2D type.

N-methyl-D-aspartate receptors (NMDAR) can regulate the intracellular calcium concentration of keratinocytes (KC) and seem to be important for their growth and differentiation. The objective of this study was to identify the subtype(s) of this receptor expressed by KC in vitro. The mRNA was isolated from primary cultures of KC as well as from a KC cell line (HaCaT) and expression of the NMDAR subtypes determined by using RT-PCR. At the mRNA level, we found expression of only the constant NMDAR1 as well as the subtype NMDAR2D. In contrast to the other subtypes of NMDAR, NMDAR2D is characterized by low influence of magnesium to the receptor function. This characteristic is consistent with previously published functional investigations in KC. The identification of the NMDAR2D subtype in KC may be of value for the development of new therapeutic approaches.

Intratumoral DNA stem-line heterogeneity in superficial spreading melanoma.

BACKGROUND: In primary melanomas, data on the degree of intratumoral heterogeneity to date have been lacking. OBJECTIVE: Our purpose was to investigate intratumoral DNA stem-line heterogeneity in superficial spreading melanoma (SSM). METHODS: Multiple measuring fields of 54 SSMs (tumor thickness median 1.60 mm) were studied by DNA image cytometry to obtain data on the number of DNA stem lines per tumor, their ploidy characteristics, and intratumoral distribution. Results were compared with standard histopathological criteria. RESULTS: Twenty-three of 54 SSMs were found to have two or three distinct proliferating tumor cell stem lines (1.46 +/- 0.57 per tumor). Stem lines appeared spatially separated in 22 of 23 SMMs. At least 3 measuring fields per tumor were necessary to identify all stem lines with a likelihood of 95%. DNA heterogeneity correlated with tumor thickness, but occurred in 5 of 19 cases of pT1 melanoma. CONCLUSIONS: Primary SSMs can be regarded as potentially clonally unstable with a tendency for spatial separation of tumor cell stem lines.

Radiotherapy in multilocalized lymphedema-associated angiosarcoma.

We report an 80-year-old woman, suffering from a recurrence of a multilocalized lymphedema-associated angiosarcoma of the right arm. The tumor consisted of solid tumor cell formations and "classical" spongiform tumor complexes. In the tumor periphery, pathological endothelial cell proliferates on pre-existing dilated lymphatic capillaries were detectable, which, together with immunohistology (CD 31+/Desmoplakin-1-2.17+/CD 34-), supported the diagnosis of lymphangiosarcoma. Complete remission was achieved under radioimmunotherapy (54 Gy/Interferon beta). A further recurrence 3 months later outside the primary therapy fields was successfully treated with radiotherapy alone. During a follow-up observation period of 3 years, there was neither local recurrence nor metastasis. This case demonstrates for the first time the long-lasting efficacy of photon radiation in a case of histologically-defined lymphangiosarcoma. Further studies should elucidate the suitability of radio monotherapy as first-line therapy in lymphedema-associated angiosarcoma with lymphatic endothelium-like immunohistology.

Claudin11 Promoter Hypermethylation Is Frequent in Malignant Melanoma of the Skin, but Uncommon in Nevus Cell Nevi.

Epigenetic inactivation of tumor-related genes is an important characteristic in the pathology of human cancers, including melanomagenesis. We analyzed the epigenetic inactivation of Claudin 11 (CLDN11) in malignant melanoma (MM) of the skin, including six melanoma cell lines, 39 primary melanoma, 41 metastases of MM and 52 nevus cell nevi (NCN). CLDN11 promoter hypermethylation was found in 19 out of 39 (49%) of the primary MM and in 21 out of 41 (51%) of the MM metastases, but only in eight out of 52 (15%) of NCN (p = 0.001 and p = 0.0003, respectively). Moreover, a significant increase in the methylation level of CLDN11 from primary melanomas to MM metastases was revealed (p = 0.003). Methylation of CLDN11 was significantly more frequent in skin metastases (79%) compared to brain metastases (31%; p = 0.007). CLDN11 methylation was also found in five out of six MM cell lines (83%) and its promoter hypermethylation correlated with a reduced expression. Treatment of MM cell lines with a DNA methylation inhibitor reactivated CLDN11 transcription by its promoter demethylation. In summary, CLDN11 proved to be an epigenetically inactivated tumor related gene in melanomagenesis, and analysis of CLDN11 methylation level represents a potential tool for assisting in the discrimination between malignant melanoma and nevus cell nevi.

Expression of epidermal N-methyl-D-aspartate receptors (NMDAR1) depends on formation of the granular layer--analysis in diseases with parakeratotic cornification.

Ionotrope glutamate receptors of the N-methyl-D-aspartate (NMDA) receptor type are expressed on keratinocytes and influence the intracellular calcium concentration. The importance of NMDA receptors in pathophysiological processes in the skin is, however, still unclear. Epidermal distribution patterns of NMDA receptors were investigated in dermatoses with parakeratotic cornification (psoriasis vulgaris and verrucae vulgares) and compared to the expression of filaggrin. The expression of NMDA receptors (R1 component) in paraffin-embedded normal epidermis (n = 22), psoriasis vulgaris (n = 21) and verrucae vulgares (n = 23) was examined and evaluated by means of digital image analysis. For quantitative characterization of the distribution patterns, a quotient was formed of the expression in the stratum granulosum and stratum basale ("NMDA ratio"). The distribution of NMDAR1 was compared to the immunohistochemical expression of filaggrin. Additionally the expression of filaggrin was investigated in HaCaT cells after treatment with the NMDA receptor antagonist MK-801. NMDA receptors were demonstrated in the epidermis of all preparations. In healthy skin, the highest receptor density was found in the stratum granulosum. This distribution pattern was basically also present in the dermatoses examined. Thus, the occurrence of parakeratosis in psoriasis vulgaris, but not in verrucae vulgares, was characterized by a significant reduction in the NMDA ratio (reduced expression of NMDAR1 in the upper epidermis). The immunohistochemical distribution of filaggrin was similar to that of NMDAR1. In HaCaT cells MK-801 suppressed the expression of filaggrin. NMDA receptors are expressed in human epidermis under physiological conditions especially in the stratum granulosum. Their reduced expression within parakeratotic epidermis in psoriasis vulgaris may be evidence of impaired intracellular calcium influx in this disease.