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Biomedical subjects

H Pehamberger

Publications and source records attributed to H Pehamberger.

At least 37 records · Page 2Linked to original sources
PubMed2001

Cisplatin and carboplatin combination as second-line chemotherapy in dacarbazine-resistant melanoma patients.

High-dose cisplatin regimens have been shown to be highly active in advanced melanoma patients but are associated with unacceptable side effects. In order to increase the platinum dose but avoid severe side effects, we treated 15 dacarbazine (DTIC)-resistant metastatic melanoma patients with a combination regimen of cisplatin (100 mg/m2) and carboplatin (200 mg/m2), two platinum analogues with a similar mode of action but a different toxicity pattern. After a mean follow-up period of 10.7 months (range 4-18 months), two patients (13.3%) achieved complete remission and two patients (13.3%) showed partial remission, giving an overall response rate of 26.4% (95% confidence interval [CI] 4.2-49%). Furthermore, three patients (20%; 95% CI 0-40.2%) experienced stable disease. The median duration of response was 7.1 months (95% CI 4.2-10.0 months), and the median overall survival was 12.5 months (95% CI 5.8-19.2 months), with eight patients still alive. The main side effects were haematological (leukopenia/thrombocytopenia World Health Organization [WHO] grade I-IV; anaemia WHO grade I-III), gastrointestinal (WHO grade I-III), neurological (WHO grade I-II) and renal (WHO grade I) toxicity. Nevertheless, except in one patient, side effects did not result in discontinuation of therapy. Despite the small number of patients treated in this preliminary study, we believe that combining cisplatin and carboplatin represents a novel, active and well-tolerated therapeutic option as second-line chemotherapy in DTIC-resistant advanced melanoma patients.

Adult↗
PubMed2001

MART-1/Melan-A and tyrosinase transcripts in peripheral blood of melanoma patients: PCR analyses and follow-up testing in relation to clinical stage and disease progression.

The use of tyrosinase-based polymerase chain reaction (PCR) tests for the detection of circulating tumour cells in the blood of melanoma patients has led to highly controversial results. We here report on the analysis of 120 blood samples from 76 stage I to IV melanoma patients using a new MART-1/Melan-A PCR system in conjunction with the tyrosinase-specific assay reported in the literature. While there were no positive results in localized disease (stages I and II), identification of specific PCR products in stage III melanoma patients was restricted to the MART-1/Melan-A tests, with positive results in 11% (two out of 19) of the blood specimens analysed. Stage IV melanoma patients presented with the highest incidence of detectable mRNA levels, with positive results for tyrosinase in 38% (12 out of 32) and for MART-1/Melan-A in 22% (seven out of 32). By delineating 64 follow-up specimens covering sampling periods of up to 33 weeks, stable mRNA expression profiles were identified in nearly 95%. Four patients, however, showed PCR changes towards positive MART-1/Melan-A expression that were linked to metastatic melanoma progression. Taken together, PCR tests for tyrosinase and MART-1/Melan-A seem to lack sufficient detection frequencies for the routine monitoring of melanoma disease. Regarding the link between MART-1/Melan-A seroconversion and the development of metastatic disease, further studies are needed to clarify the clinical value of this observation.

Adult↗
PubMed2000

Chemosensitisation of malignant melanoma by BCL2 antisense therapy.

BACKGROUND: Chemoresistance of malignant melanoma has been linked to expression of the proto-oncogene BCL2. Antisense oligonucleotides (ASO) targeted against BCL2 mRNA decreased BCL2 protein concentrations, increased tumour-cell apoptosis, and led to tumour responses in a mouse xenotransplantation model when combined with systemic dacarbazine. This phase I-II clinical study investigated the combination of BCL2 ASO (augmerosen, Genasense, G3139) and dacarbazine in patients with advanced malignant melanoma expressing BCL2. METHODS: In a within-patient dose-escalation protocol, 14 patients with advanced malignant melanoma were given augmerosen intravenously or subcutaneously in daily doses of 0.6-6.5 mg/kg plus standard dacarbazine treatment (total doses up to 1000 mg/m2 per cycle). Toxicity was scored by common toxicity criteria. Plasma augmerosen concentrations were assayed by high-performance liquid chromatography. In serial tumour biopsy samples, BCL2 protein concentrations were measured by western blotting and tumour-cell apoptosis was assessed. FINDINGS: The combination regimen was well tolerated, with no dose-limiting toxicity. Haematological abnormalities were mild to moderate. Lymphopenia was common, but no febrile neutropenia occurred. Higher doses of augmerosen were associated with transient fever. Four patients had liver-function abnormalities that resolved within 1 week. Steady-state plasma concentrations of augmerosen were attained within 24 h, and increased with administered dose. By day 5, daily doses of 1.7 mg/kg and higher led to a median 40% decrease in BCL2 protein in melanoma samples compared with baseline, concomitantly with increased tumour-cell apoptosis, which was greatly increased after dacarbazine treatment. Six patients have shown antitumour responses (one complete, two partial, three minor). The estimated median survival of all patients now exceeds 12 months. INTERPRETATION: Systemic administration of augmerosen downregulated the target BCL2 protein in metastatic cancer. Such downregulation of BCL2, combined with standard anticancer therapy, offers a new approach to the treatment of patients with resistant neoplasms.

Adult↗
PubMed2000

Frequency and characteristics of enlarging common melanocytic nevi.

OBJECTIVE: To analyze the frequency and characteristics of enlarging common melanocytic nevi. DESIGN: Cohort study using digital epiluminescence microscopy (ELM) for documentation and follow-up, with a median follow-up interval of 11.4 months. SETTING: A dermatology department at a university hospital in Vienna, Austria. PATIENTS: One thousand six hundred twelve melanocytic nevi appearing clinically as common nevi, obtained from 385 patients (mean [+/-SD] age, 34.2 +/- 14.8 y; 55.6% female). INTERVENTIONS: Follow-up examination and documentation by digital ELM. MAIN OUTCOME MEASURES: Frequency of enlarging nevi according to age and comparison of ELM features observed in enlarging and nonenlarging nevi. RESULTS: Enlargement was found in 5.3% (n = 86) of nevi. The frequency of enlarging nevi was inversely related to age (P<.001), in that enlarging nevi were common in patients younger than 20 years and relatively rare in older age groups. Epiluminescence microscopy revealed a peripheral rim of brown globules in 48.8% (n = 42) of enlarging nevi. In contrast, a peripheral rim of brown globules was found in only 0.7% (n = 11) of nevi without enlargement (P<.001). Enlarging nevi that were excised in children and adolescents showed no histological signs of atypia. In older age groups, 48.1% of excised enlarging nevi that were clinically diagnosed as common nevi showed some histological signs of atypia. None of the excised enlarging lesions was histologically diagnosed as melanoma. CONCLUSIONS: The frequency of enlarging common nevi is inversely related to age. In the absence of clinical signs of atypia, enlargement alone does not indicate malignancy. A peripheral rim of brown globules is a characteristic ELM feature of symmetrically enlarging melanocytic nevi.

Adult↗
PubMed2000

Bcl-2 antisense oligonucleotides (G3139) inhibit Merkel cell carcinoma growth in SCID mice.

Merkel cell carcinoma was first described in 1972 by Toker and is an aggressive neuroendocrine skin tumor with a high metastatic potential. Merkel cell carcinoma is thought to derive from the neuroendocrine (Merkel) cells of the skin, although in contrast to fetal and especially adult Merkel cells, Merkel cell carcinomas express high levels of the Bcl-2 oncoprotein. Bcl-2 is capable of blocking programmed cell death and has been shown to play an important role in normal cell turnover, tumor biology, and chemoresistance. High Bcl-2 expression leading to prolonged survival of cells may therefore be of importance in the biological and clinical characteristics of Merkel cell carcinoma. In a SCID mouse xenotransplantation model for human Merkel cell carcinoma, we investigated the influence of the bcl-2 antisense oligonucleotide G3139 (Genta) on tumor growth in comparison with control oligonucleotides or cisplatin. Bcl-2 antisense treatment, targeting the first six codons of the bcl-2 mRNA, resulted in either a dramatic reduction of tumor growth or complete remission, whereas reverse sequence and two-base mismatch control oligonucleotides or cisplatin had no significant antitumor effects compared with saline-treated controls. Apoptosis was enhanced 2.4-fold in the bcl-2 antisense treated tumors compared with the saline-treated group, and no other treatment showed a comparable increase in apoptosis. Our findings suggest that bcl-2 antisense treatment may be a novel approach to improve treatment outcome of human Merkel cell carcinoma.

Animals↗
PubMed2000

Effects of betulinic acid alone and in combination with irradiation in human melanoma cells.

Recently, betulinic acid was identified as a highly selective inhibitor of human melanoma growth and was reported to induce apoptosis in these cells. We have investigated the growth-inhibitory properties of this compound alone and in combination with ionizing radiation in a panel of established human melanoma cell lines as well as in normal human melanocytes. Betulinic acid strongly and consistently suppressed the growth and colony-forming ability of all human melanoma cell lines investigated. In combination with ionizing radiation the effect of betulinic acid on growth inhibition was additive in colony-forming assays. Betulinic acid also induced apoptosis in human melanoma cells as demonstrated by Annexin V binding and by the emergence of cells with apoptotic morphology. The growth-inhibitory action of betulinic acid was more pronounced in human melanoma cell lines than in normal human melanocytes. Notably, despite the induction of apoptosis, analysis of the expression of Bcl-2 family members in betulinic-acid-treated cells revealed that expression of the anti-apoptotic protein Mcl-1 was induced. Furthermore, the antiproliferative action of betulinic acid seemed to be independent of the p53 status. The properties of betulinic acid make it an interesting candidate, not only as a single agent but also in combination with radiotherapy. We conclude that the strictly additive mode of growth inhibition in combination with irradiation suggests that the two treatment modalities may function by inducing different cell death pathways or by affecting different target cell populations.

Antineoplastic Agents, Phytogenic↗
PubMed2000

Follow-up of melanocytic skin lesions with digital epiluminescence microscopy: patterns of modifications observed in early melanoma, atypical nevi, and common nevi.

BACKGROUND: Digital epiluminescence microscopy (DELM) has been reported to be a useful technique for the follow-up of melanocytic nevi. One of the promises of this technique is to identify modifications over time that indicate impending or incipient malignancy and to facilitate surveillance of melanocytic skin lesions, particularly in patients with multiple clinically atypical nevi. OBJECTIVE: Our purpose was to report on patterns of modifications over time observed in benign melanocytic skin lesions and melanoma. METHODS: A total of 1862 sequentially recorded DELM images of melanocytic lesions from 202 patients (mean age, 36.1 years; 54.0% female patients) with multiple clinically atypical nevi were included in the analysis. The median follow-up interval was 12. 6 months. Melanocytic lesions with substantial modifications over time (enlargement, changes in shape, regression, color changes or appearance of ELM structures known to be associated with melanoma) were excised and referred to histopathologic examination. RESULTS: A total of 75 melanocytic skin lesions (4.0%) from 52 patients (mean age, 33.3 years; 63.5% female patients) showed substantial modifications over time and were excised and referred to histopathologic examination. Eight changing lesions were histologically diagnosed as early melanomas. These lesions frequently showed focal enlargement associated with a change in shape as well as appearance of ELM structures that are known to be associated with melanoma. In contrast, the majority of benign changing lesions (common and atypical nevi) showed symmetric enlargement without substantial structural ELM changes. Six of the 8 patients in whom melanoma developed were unaware of the fact that the lesion had changed over time. CONCLUSION: We demonstrate that follow-up of melanocytic lesions with DELM helps to identify patterns of morphologic modifications typical for early melanoma. DELM may therefore serve as a useful tool to improve the surveillance of patients with multiple atypical nevi.

Adult↗
PubMed2000

Erythropoietin receptor expression in human melanoma cells.

Erythropoietin is well known for its role in the control of erythropoiesis, where it acts by binding to its cognate receptor (EpoR) on the surface of erythroid progenitor cells. Here we present the novel finding that the EpoR is also expressed in cells of the melanocytic lineage. It is expressed in transformed cell lines established from normal melanocytes and also in established human melanoma cell lines derived from melanoma metastases, but not in normal primary human melanocytes. The analysis of individual subclones isolated from spontaneously transformed melanocytes revealed that approximately 50% of all the clones examined expressed the EpoR. Further analysis of the individual growth characteristics of EpoR-positive and EpoR-negative clones indicated that, under standard cell culture conditions, expression of the receptor did not affect cell growth. Expression of this receptor is consequently most likely driven by an event that is associated with, but not absolutely required for, the transformed phenotype. While the definite function of this receptor in melanoma cells is still unknown and additional studies are required, our findings support the hypothesis that the EpoR may serve as a progression marker for human melanoma. This observation might be useful in the early diagnosis of melanoma.

Cell Division↗
PubMed2000

Computer-aided epiluminescence microscopy of pigmented skin lesions: the value of clinical data for the classification process.

Early melanoma is often difficult to differentiate from benign pigmented skin lesions (PSLs). Digital epiluminescence microscopy (DELM) and automated image analysis could represent possible aids for inexperienced clinicians. We designed an automated computerized image analysis system that has the potential for use as an additional tool for the differentiation of melanoma from dysplastic naevi and common naevi. The PC-based pilot system was attached to a common DELM system as the image source. Digital images of PSLs were automatically segmented and a panel of 107 morphological parameters were measured. Additionally, seven clinical parameters were evaluated and used as an additional source of information. Neural networks were then trained to distinguish melanoma from benign PSLs. One class of networks was trained solely based on the morphometric features, whereas the second class of networks was trained on the combination of morphometric and clinical features. The automatic segmentation algorithm was correct in 96% of cases. Using three-way receiver operating characteristic (ROC) analysis, for networks trained solely on morphometric features the volume under surface (VUS) was 0.617 (SD 0.036). The performance was significantly better for networks trained on the combination of both morphometric and clinical features (VUS = 0.682, SD 0.035). In a dichotomous model, distinguishing benign lesion (common naevi + dysplastic naevi) from melanoma, the area under the curve (AUC) from two-way ROC analysis was 0.942 (SD 0.018) for networks trained solely on morphometric features and 0.968 (SD 0.012) for those trained on the combination of clinical and morphometric data (P= NS). Automated feature extraction from PSLs and the training of neural networks as classifiers has thus shown satisfactory performance in a large scale experiment. The addition of clinical data significantly increases the diagnostic performance for distinguishing three classes of lesions (i.e. common naevi, dysplastic naevi and melanoma). Such integrated systems hold promise as a decision aid for the diagnosis of PSLs.

Algorithms↗
PubMed2000

Influenza virus NS1 protein counteracts PKR-mediated inhibition of replication.

The availability of an influenza virus NS1 gene knockout virus (delNS1 virus) allowed us to establish the significance of the biological relationship between the influenza virus NS1 protein and double-stranded-RNA-activated protein kinase (PKR) in the life cycle and pathogenicity of influenza virus. Our results show that the lack of functional PKR permits the delNS1 virus to replicate in otherwise nonpermissive hosts, suggesting that the major function of the influenza virus NS1 protein is to counteract or prevent the PKR-mediated antiviral response.

Animals↗
PubMed1999

Novel Ras antagonist blocks human melanoma growth.

During past decades, knowledge of melanoma biology has increased considerably. Numerous therapeutic modalities based on this knowledge are currently under investigation. Advanced melanoma, nevertheless, remains a prime example of poor treatment response that may, in part, be the consequence of activated N-Ras oncoproteins. Besides oncogenic Ras, wild-type Ras gene products also play a key role in receptor tyrosine kinase growth factor signaling, known to be of importance in oncogenesis and tumor progression of a variety of human neoplasms, including malignant melanoma; therefore, it is reasonable to speculate that a pharmacological approach that curtails Ras activity may represent a sensible approach to inhibit melanoma growth. To test this concept, the antitumor activity of S-trans, trans-farnesylthiosalicylic acid (FTS), a recently discovered Ras antagonist that dislodges Ras from its membrane-anchoring sites, was evaluated. The antitumor activity of FTS was assessed both in vitro and in vivo in two independent SCID mouse xenotransplantation models of human melanoma expressing either wild-type Ras (cell line 518A2) or activated Ras (cell line 607B). We show that FTS (5-50 microM) reduces the amounts of activated N-Ras and wild-type Ras isoforms both in human melanoma cells and Rat-1 fibroblasts, interrupts the Ras-dependent extracellular signal-regulated kinase in melanoma cells, inhibits the growth of N-Ras-transformed fibroblasts and human melanoma cells in vitro and reverses their transformed phenotype. FTS also causes a profound and statistically significant inhibition of 518A2 (82%) and 607B (90%) human melanoma growth in SCID mice without evidence of drug-related toxicity. Our findings stress the notion that FTS may qualify as a novel and rational treatment approach for human melanoma and possibly other tumors that either carry activated ras genes or rely on Ras signal transduction more heavily than nonmalignant cells.

Animals↗
PubMed1999

Influence of MUC18/MCAM/CD146 expression on human melanoma growth and metastasis in SCID mice.

The cell surface glycoprotein MUC18MCAM/CD146 was originally defined as a marker of melanoma progression and has been suspected to be directly linked to the metastatic process of this malignancy. In order to address this question, 2 MCAM negative human melanoma cell lines, SK-2 and XP44RO(Mel), were transfected with MCAM-encoding cDNA. Surface MCAM expression on SK-2 and XP44RO(Mel) transfectants was similar to that observed in naturally occurring MCAM positive human melanoma cells and transfectants demonstrated MCAM-dependent increase in homotypic adhesion in vitro. The growth behavior of 7 MCAM transfectants and their respective vector controls was evaluated in SCID mice. Tumor size at 4-5 weeks after s.c. implantation was highly variable, but did not correlate with MCAM expression. Despite massive primary tumor formation at the injection site, no spontaneous metastasis was observed with any of the investigated MCAM transfectants. The influence of MCAM expression on lung metastases formation in an experimental metastasis assay was system dependent, converting only XP44RO(Mel) transfectants into metastatic cells, although increased homotypic adhesion, leading to formation of tumor cell clusters, was observed with transfectants of both cell lines in vitro. Our findings indicate that MCAM expression of human melanoma cells has an influence on later stages of the metastatic process only, namely, extravasation and establishment of new foci of growth, but is per se not sufficient for this process.

Animals↗
PubMed1999

Immunotherapy of metastatic malignant melanoma by a vaccine consisting of autologous interleukin 2-transfected cancer cells: outcome of a phase I study.

We performed a phase I trial to evaluate the safety and tolerability of repeated skin injections of IL-2-transfected autologous melanoma cells into patients with advanced disease. Cell suspensions, propagated from excised metastases, were IL-2 gene transfected by adenovirus-enhanced transferrinfection and X-irradiated prior to injection. Vaccine production was successful in 54% of the patients. Fifteen patients (37%) received two to eight skin vaccinations of either 3 x 10(6) (intradermal) or 1 x 10(7) (half intradermal, half subcutaneous) transfected melanoma cells per vaccination (secreting 140-17,060 biological response modifier program units of IL-2/10(6) cells/24 hr). Analyses of safety and efficacy were carried out in 15 and 14 patients, respectively. Overall, the vaccine was well tolerated. All patients displayed modest local reactions (erythema, induration, and pruritus) and some experienced flu-like symptoms. Apart from newly appearing (4 of 14) and increasing (5 of 14) anti-adenovirus and newly detectable anti-nuclear antibody titers (1 of 15), recipients developed de novo or exhibited increased melanoma cell-specific delayed-type hypersensitivity (DTH) reactions (8 of 15) and vitiligo (3 of 15) and showed signs of tumor regression (3 of 15). This supports the idea of a vaccine-induced or -amplified anti-cancer immune response. None of the patients exhibited complete or partial regressions, but five of them experienced periods of disease stabilization. Three of these individuals received more than the four planned vaccinations and their mean survival time was 15.7 +/- 3.5 months as compared to 7.8 +/- 4.6 months for the entire patient cohort. These data indicate that IL-2-producing, autologous cancer cells can be safely administered to stage IV melanoma patients and could conceivably be of benefit to patients with less advanced disease.

Adult↗
PubMed1999

Farnesylthiosalicylic acid inhibits the growth of human Merkel cell carcinoma in SCID mice.

Merkel cell carcinoma (MCC) is a neuroendocrine malignancy showing poor response to a variety of therapeutic strategies. We evaluated the antitumor activity of S-trans, trans-farnesylthiosalicylic acid (FTS), a new inhibitor of Ras signal transduction, in a newly established SCID mouse xenotransplantation model for human MCC (seven animals per group). FTS injected intraperitoneally at 5 mg/kg per day for 2 weeks up-regulated the tumor suppressor p53 and induced tumor cell apoptosis in established MCCs growing subcutaneously in SCID mice. These effects led to a statistically significant inhibition of MCC growth (P<0.002). The mean tumor weights following FTS or control treatment were 0.32+/-0.15 g and 1.08+/-0.29 g, respectively. There was no evidence of FTS related toxicity at the effective dose used. Our findings stress the notion that FTS may qualify as a novel and rational treatment approach for MCC and possibly for other tumors that rely on tyrosine kinase signaling.

Aged↗
PubMed1999

Reevaluation of the ABCD rule for epiluminescence microscopy.

BACKGROUND: Epiluminescence microscopy (ELM) provides for increased accuracy in the clinical diagnosis of pigmented skin lesions (PSL). It is based on pattern analysis of ELM criteria, which requires experience. The recently introduced application of the ABCD score to ELM facilitates this by permitting lesion evaluation on the basis of predefined clinical criteria. OBJECTIVE: The present study was performed to evaluate the diagnostic performance of the ABCD rule for ELM in pigmented skin lesions testing dermatologists with varying skills from novice to expert. METHODS: Two hundred fifty electronic images of randomly selected, histologically proven PSL including 41 early melanomas (16.4%) were presented to the raters, and each image was scored according to the rules of the ABCD score and rated without the guidance of a scoring system on a scale from 1 = definitely benign to 5 = definitely melanoma. RESULTS: Our data show that the application of the ABCD rule significantly enhances diagnostic ability in less experienced dermatologists compared with rating without the guidance of a scoring system. In contrast, the diagnostic accuracy of dermatologists who are moderately to greatly experienced is not improved by use of the ABCD rule. CONCLUSION: Our experiments indicate that the application of the ABCD rule to ELM introduced by Stolz et al represents a useful enhancement for diagnosis of pigmented skin lesions in less experienced users. However, the method does fail to detect melanomas with 100% accuracy. Therefore further effort has to be made to make the diagnosis of melanoma easier and more accurate.

Clinical Competence↗
PubMed1999

Morphologic changes of pigmented skin lesions: a useful extension of the ABCD rule for dermatoscopy.

BACKGROUND: Epiluminescence microscopy (ELM) significantly increases the early diagnosis of pigmented skin lesions (PSL) using established criteria and pattern analysis. The ABCD rule for dermatoscopy (ie, ELM) provides a simplified approach to the interpretation of ELM images on the basis of asymmetry (A), border (B), color (C), and dermatoscopic structure (D). OBJECTIVE: We set out to determine whether the diagnostic accuracy of the ABCD scoring algorithm can be significantly improved by incorporating information about morphologic changes of the lesion observed and provided by the patient. METHODS: We prospectively collected 356 small pigmented skin lesions (< 1 cm) including 73 (20.5%) melanomas. Before excision all patients were asked whether the lesion had changed in size, color, or shape within the last year or whether they experienced any sign of ulceration or spontaneous bleeding. ELM images of the lesions were evaluated according to the ABCD rule for dermatoscopy to yield a semiquantitative score. Accuracy of diagnosis was evaluated in terms of sensitivity, specificity, and area under receiver operating characteristic curves (AUC). RESULTS: The frequency of reported changes was significantly higher for melanomas than benign PSL (65.8% vs 29.7%, P < .001). In a multivariate model morphologic change was a significant independent predictor of malignancy (odds ratio = 3.17, 95% confidence interval [CI]: 1.96 to 5.14, P < .001). The mean final score achieved when using the enhanced ABCD-E criteria including morphologic change (E) was significantly higher for melanomas (5.7, 95% CI: 5.3 to 6.0) than benign PSL (2.9, 95% CI: 2.8 to 3.1, P < .001). Diagnostic accuracy was significantly higher when the lesions were evaluated by the enhanced ABCD-E criteria as compared with the standard ABCD score (AUC(ABCD) = 0.87 vs AUC(ABCD-E) = 0.90; P = .006). CONCLUSION: Information about morphologic changes of PSL as reported by the patient is a useful extension of the ABCD rule for dermatoscopy.

Adult↗
PubMed1999

Deletions of the region 17p11-13 in advanced melanoma revealed by cytogenetic analysis and fluorescence in situ hybridization.

The significance of the p53 tumour-suppressor gene in the oncogenesis of a variety of malignant tumours has been demonstrated over recent years. However, the role of p53 in human malignant melanoma is still unclear. Therefore, we investigated melanoma metastases from 11 patients cytogenetically and with fluorescence in situ hybridization (FISH) after short-term culture, employing a p53 region-specific probe for 17p13.1 and a probe detecting the centromere of chromosome 17. Furthermore, paraffin-embedded tissue samples from nine of these patients were investigated immunohistochemically for expression of the p53 protein. Deletions of the short arm of chromosome 17 were seen in six melanomas in cytogenetic analysis. With FISH, three malignant melanomas had clones with only one p53-allele and an additional four malignant melanomas showed a reduced number of signals at the p53 tumour-suppressor gene locus compared with signals for the centromeric region of chromosome 17. This was confirmed by immunohistochemistry. Our results suggest that the 17p11-13 region is frequently deleted in malignant melanomas and that p53 or other genes located on this band might contribute to the malignant potential of advanced melanoma.

Chromosome Deletion↗