Wolfgang Tilgen

Increased Serum Concentration of Angiogenic Factors in Malignant Melanoma Patients Correlates With Tumor Progression and Survival

PURPOSE To determine the predictive value of the angiogenic serum factors angiogenin, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and interleukin-8 (IL-8) for the prognosis of patients with malignant melanoma. PATIENTS AND METHODS Angiogenin, VEGF, bFGF, and IL-8 were measured in sera of 125 melanoma patients with different stages of disease and with or without current therapy including interferon alfa and different cytostatics in comparison with 30 healthy controls using enzyme-linked immunosorbent assay. RESULTS Serum levels of angiogenin, VEGF, bFGF, and IL-8 were significantly increased in melanoma patients compared with healthy controls. Elevated serum concentrations of VEGF, bFGF, and IL-8 were associated with advanced disease stages and tumor burden. Cytostatic therapy of patients was accompanied by increased serum levels of angiogenin, bFGF, and IL-8. As shown by univariate analysis, elevated serum levels of VEGF (P = .0001 and .0036), bFGF (P < .00005 and < .00005), and IL-8 (P < .00005 and < .00005) were strongly correlated with a poor overall and progression-free survival, respectively. Multivariate analysis revealed stage of disease (P = .0238), tumor burden (P = .0347), VEGF (P = .0036), bFGF (P = .0252), and IL-8 (P = .0447) as independent predictive factors of overall survival. Tumor burden (P = .0081), VEGF (P = .0245), and IL-8 (P = .0089) were found as independent predictive factors of progression-free survival. CONCLUSION Our data suggest that the angiogenic serum factors VEGF, bFGF, and IL-8 are useful predictive markers for overall and progression-free survival in melanoma patients.

Challenge and promise: roles for clusterin in pathogenesis, progression and therapy of cancer

Clusterin (CLU) has been implicated in various cell functions involved in carcinogenesis and tumour progression. There are two known CLU protein isoforms generated in human cells. A nuclear form of CLU protein (nCLU) is proapoptotic, and a secretory form (sCLU) is prosurvival. CLU expression has been associated with tumorigenesis of various malignancies, including tumours of prostate, colon, and breast. Furthermore, CLU expression is modulated by many factors that are believed to regulate tumour growth and/or apoptosis, including 1,25-dihydroxyvitamin D3, transforming growth factor beta-1, ultraviolet radiation, and IR. sCLU upregulation appears to be a general molecular stress response. Presently, preliminary results indicate that therapeutic modalities targeting CLU may be effective in cancer treatment. However, such strategies should make sure that nCLU is not eliminated or reduced. This review summarizes our present understanding of the importance of CLU in various physiological functions including tumour growth, and discusses its relevance to future cancer therapy.

Detection of circulating melanoma cells by specific amplification of tyrosinase complementary DNA is not a reliable tumor marker in melanoma patients : a clinical two-center study

PURPOSE Recently, the reverse-transcription polymerase chain reaction (RT-PCR) of tyrosinase messenger RNA (mRNA) was reported to be a useful tool for the detection of circulating tumor cells in the peripheral blood of melanoma patients. Our aim was to evaluate critically the diagnostic value of this marker by investigating a significant number of patients in different stages of the disease in a two-center study. PATIENTS AND METHODS Different techniques of blood collection, RNA isolation, and RT-PCR were compared, and the detectability of tyrosinase mRNA was tested using nine different melanoma cell lines. The sensitivity of the method was confirmed by blood spiking experiments and the specificity by restriction enzyme analysis. Subsequently, a total of 153 blood samples from 137 individuals (30 healthy subjects, five basal cell carcinoma, and 102 melanoma patients) were investigated. RESULTS The detection level of melanoma cells differed between the cell lines tested. However, we could reproducibly detect single melanoma cells by spiking whole blood samples from healthy volunteers. One of 43 patients with primary melanoma (2.3%), zero of 15 patients with regional metastasis (0%), and 12 of 44 patients with advanced disease (27.3%) were found to be RT-PCR positive. All blood samples obtained from controls and patients with basal cell carcinoma were tyrosinose mRNA negative. CONCLUSION Our data support the recent doubts that the detection of circulating tumor cells in melanoma patients using the tyrosinase mRNA RT-PCR is not sensitive enough to be used either as a melanoma progression marker in early stages of the disease or to monitor therapy in advanced stages of the disease.

Analysis of the Vitamin D System in Cervical Carcinomas, Breast Cancer and Ovarian Cancer

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is the biologically active metabolite of vitamin D and has been shown to regulate the growth of various cell types. There are two principal enzymes involved in the formation of circulating 1,25(OH)2D3 from vitamin D, the vitamin D 25-hydroxylase (25-OHase) and the 1alpha-hydroxylase (1alpha-OHase). Recently, extrarenal activity of 1alpha-OHase has been reported in various cell types. The aim of this study was to analyze expression of VDR and the main enzymes involved in the synthesis and metabolism of calcitriol in gynecological malignancies and corresponding normal tissue. Expression of VDR, 25-OHase, 1alpha-OHase, and 24-OHase was analyzed in breast carcinomas (BC), ovarian cancer (OC), cervix carcinomas (CC) and normal corresponding tissues using real-time PCR and specific hybridization probes as well as using immunohistochemistry. RNA for VDR, 1alpha-OHase, 24-OHase and 25-OHase was up-regulated in breast cervical and ovarian carcinomas as compared to normal tissue. VDR immunoreactivity was increased in breast and ovarian cancer and in cervix carcinomas as compared to normal corresponding tissue. Our findings indicate that cervical carcinomas, breast cancer and ovarian cancer may be considered as potential targets for prevention or therapy with new vitamin D analogs that exert little or no calcemic side effects or by pharmacological modulation of 1,25(OH)2D3 synthesis and metabolism in these tumor cells.

L1 adhesion molecule (CD 171) in development and progression of human malignant melanoma

The L1 adhesion molecule (CD171) plays an important role in axon guidance and cell migration in the nervous system. In the human, L1 is expressed on tumors derived from neurocrest and on certain carcinomas. We have analyzed immunohistochemically L1 expression on paraffin embedded specimens of acquired melanocytic nevi, primary cutaneous melanomas, and cutaneous and lymph node metastases of malignant melanomas. We found an increase in L1 immunoreactivity in malignant melanomas and metastases of malignant melanomas as compared to acquired melanocytic nevi that was statistically significant (P<0.05). Additionally, a correlation of L1 immunoreactivity with histological data of prognostic value such as Clark level and the expression of alphav-integrins was found. We detected soluble L1 in the conditioned medium of cultivated melanoma cells but only in 1/40 serum samples from a panel of melanoma patients representing various stages of disease. Our findings suggest that the presence of L1 might contribute to tumor progression by promoting cell adhesion and migration.

Temozolomide in Combination With Interferon-Alfa Versus Temozolomide Alone in Patients With Advanced Metastatic Melanoma: A Randomized, Phase III, Multicenter Study from the Dermatologic Cooperative Oncology Group

PURPOSE Temozolomide (TMZ) has shown efficacy in metastatic melanoma equal to that of dacarbazine (DTIC), the standard chemotherapeutic agent for melanoma. As the combination with interferon-alfa (IFN-alpha) appears superior to single-agent DTIC regarding response rates, the purpose of this study was to compare TMZ alone and TMZ plus IFN-alpha in terms of objective response (OR), overall survival, and safety in a prospective, randomized, multicenter trial. PATIENTS AND METHODS Two hundred ninety-four patients with untreated stage IV metastatic melanoma (American Joint Committee on Cancer staging system) were randomly assigned to receive either oral TMZ alone (200 mg/m2/day; days 1 through 5 every 28 days) or in combination with subcutaneous IFN-alpha (5 MU/m2; days 1, 3, and 5 every week). RESULTS Two hundred eighty-two patients were eligible for an intent-to-treat analysis, 271 patients were treated per protocol. In the TMZ + IFN-alpha arm, 33 (24.1%) of 137 patients responded to therapy (partial or complete remission) whereas in the monotherapy arm, in 18 (13.4%) of 134 patients, a response was evident. Thus, the response rate was significantly higher in the combination arm (P = .036). Median survival time was 8.4 months for patients treated with TMZ (95% CI, 7.07 to 9.27) and 9.7 months for those treated with the combination (95% CI, 8.26 to 11.18; P = .16). Dose modifications and interval prolongations due to hematologic toxicity were significantly more frequent in the TMZ + IFN-alpha arm (P < .001). CONCLUSION In metastatic melanoma treatment with TMZ + IFN-alpha leads to a significantly superior OR rate compared to treatment with TMZ alone, which did not translate into prolonged survival in our study population.

Present concepts and future outlook: Function of peroxisome proliferator-activated receptors (PPARs) for pathogenesis, progression, and therapy of cancer

Peroxisome proliferator‐activated receptors (PPARs) are members of the nuclear receptor superfamily of transcriptional regulators that regulate lipid, glucose, and amino acid metabolism. In recent studies it also has been shown that these receptors are implicated in tumor progression, cellular differentiation, and apoptosis and modulation of their function is therefore considered as a potential target for cancer prevention and treatment. PPAR ligands and other agents influencing PPAR signalling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in a variety of human cancers and could represent a potential novel strategy to inhibit tumor carcinogenesis and progression. This review summarizes the currently available data on the roles of PPARs in relation to the processes of cell differentiation and carcinogenesis as well as their role as promising future therapeutic targets. J. Cell. Physiol. 212: 1–12, 2007.

Short German guidelines: Malignant melanoma

Malignant melanoma is a malignant tu-mor which arises from melanocytic cellsand primarily involves the skin. For thebalance of these guidelines, the termsmalignant melanoma and melanoma willbe used interchangeably, because thereare no benign melanomas. Melanomascan also arise in the eye (conjunctiva anduvea), meninges and on various mucosalsurfaces. While melanomas are usuallyheavily pigmented, there are also amela-notic tumors. Even small tumors have atendency towards metastasis and thus arelatively unfavorable prognosis. Melan-omas account for 90% of the deaths as-sociated with cutaneous tumors. The incidence of melanoma is increasingworldwide in white populations, especi-ally where fair-skinned peoples receiveexcessive sun exposure. In central Europethe incidence is 10 – 12 / 100,000yearly; in the USA, 10-25 / 100,000yearly; and in Australia the highest inci-dence, 50-60 / 100,000 yearly. In indivi-duals with more pigmentation (Asians,Africans) melanomas are uncommonand almost always found on either acralor mucosal surface. Individuals withlarge numbers of melanocytic nevi andthose with melanoma precursors (dyspla-stic nevi, congenital nevi) are at greaterrisk. The inheritance of melanoma is po-lygenic; 5-10% of melanomas appear inmelanoma-prone families. In addition tothese genetic and constitutional factors,the most important exogenous factor isexposure to UV irradiation. The relativeroles of toxic substances, medicationsand hormones (pregnancy, oral contra-ceptives) are controversial. The immunestatus of the patient plays a major role indetermining the course of melanoma, asnumerous examples of spontaneous re-gression or of rapid progression in im-munosuppressed individuals bear testi-mony.A number of different types of melano-mas can be identified clinically and hi-stologically. Some tumors either repre-sent mixed forms or are not classifiable.Examples of special forms are amelanoticmelanomas, mucosal melanomas, andother extracutaneous melanomas, whichtogether account for about 5% of allmelanomas.

Peroxisome proliferator-activated receptors (PPARs) and the human skin: importance of PPARs in skin physiology and dermatologic diseases.

Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily that regulate lipid, glucose, and amino acid metabolism. More recently, PPARs and corresponding ligands have been shown in skin and other organs to regulate important cellular functions, including cell proliferation and differentiation, as well as inflammatory responses. These new functions identify PPARs and corresponding ligands as potential targets for the treatment of various skin diseases and other disorders.It has been shown that in inflammatory skin disorders, including hyperproliferative psoriatic epidermis and the skin of patients with atopic dermatitis, the expression of both PPARα and PPARγ is decreased. This observation suggests the possibility that PPARα and PPARγ activators, or compounds that positively regulate PPAR gene expression, may represent novel NSAIDs for the topical or systemic treatment of common inflammatory skin diseases such as atopic dermatitis, psoriasis, and allergic contact dermatitis. Moreover, recent findings indicate that PPAR-signaling pathways may act as a promising therapeutic target for the treatment of hyperproliferative skin diseases including skin malignancies. Studies in non-diabetic patients suggest that oral thiazolidinediones, which are synthetic ligands of PPARγ, not only exert an antidiabetic effect but also may be beneficial for moderate chronic plaque psoriasis by suppressing proliferation and inducing differentiation of keratinocytes; furthermore, they may even induce cell growth arrest, apoptosis, and terminal differentiation in various human malignant tumors. It has been reported that PPARα immunoreactivity is reduced in human keratinocytes of squamous cell carcinoma (SCC) and actinic keratosis (AK), while PPARδ appears to be upregulated. Additionally, the microvessel density is significantly higher in AK and SCC that express high levels of PPARδ. PPARδ has been demonstrated to have an anti-apoptotic role and to maintain survival and differentiation of epithelial cells, whereas PPARα and PPARγ activators induce differentiation and inhibit proliferation and regulate apoptosis. In melanoma, the growth inhibitory effect of PPARγ activation is independent of apoptosis and seems to occur primarily through induction of cell cycle arrest in the G1 phase of the cell cycle or induction of re-differentiation. PPARα activation causes inhibition of migration of melanoma cells and anchorage-independent growth, whereas primary tumor growth remains unaltered. In clinical trials of gemfibrozil, a PPARα ligand, significantly fewer patients treated with this lipid-lowering drug were diagnosed with melanoma as compared to those in the control group.In conclusion, an increasing body of evidence indicates that PPAR signaling pathways may represent interesting therapeutic targets for a broad variety of skin disorders, including inflammatory skin diseases such as psoriasis and atopic dermatitis, and skin malignancies.

In vitro Drug Sensitivity Predicts Response and Survival after Individualized Sensitivity-Directed Chemotherapy in Metastatic Melanoma: A Multicenter Phase II Trial of the Dermatologic Cooperative Oncology Group

Purpose:In vitro sensitivity assays are promising tools to predict the individual outcome of different chemotherapy regimens. However, a direct association between in vitro and in vivo chemosensitivity has to be shown by clinical studies. This multicenter phase II trial was aimed to investigate the efficacy of a sensitivity-directed, first-line chemotherapy in metastasized melanoma patients, and to prove an association between in vitro sensitivity and therapy outcome. Patients and Methods: The primary study end point was objective response; secondary end points were safety, overall survival, and progression-free survival. Viable tumor cells obtained from metastatic lesions were tested for chemosensitivity to seven single drugs and five drug combinations using an ATP-based luminescence viability assay. Results: Out of 82 recruited patients (intention-to-treat), 57 received assay-directed chemotherapy and 53 were evaluable for all study end points (per protocol). The drug combinations used were gemcitabine + treosulfan, paclitaxel + cisplatin, paclitaxel + doxorubicin, and gemcitabine + cisplatin. The per protocol population could be divided into 22 (42%) chemosensitive and 31 (58%) chemoresistant patients by an arbitrary chemosensitivity index. Objective response was 36.4% in chemosensitive patients compared with 16.1% in chemoresistant patients (P = 0.114); progression arrest (complete response + partial response + stable disease) was 59.1% versus 22.6% (P = 0.01). Chemosensitive patients showed an increased overall survival of 14.6 months compared with 7.4 months in chemoresistant patients (P = 0.041). Conclusion:In vitro chemosensitivity testing may be worthy of further exploration to see if it could be a useful tool to predict the outcome of melanoma patients treated with a sensitivity-directed chemotherapy. Therefore, these preliminary results will be evaluated by a planned phase III trial using a randomized, standard-regimen controlled setting.