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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to measure cell mediated cytotoxicity to adherent growing cell lines in vitro more rapidly and conveniently, a fluorometric microassay was developed and results were compared with those obtained by the 51Cr release assay. The fluorometric method is based on the hydrolysis of the fluorochrome 4-methylumbelliferyl heptanoate (MUH) by intracellular esterases of viable cells. Melanoma cell monolayers were incubated with lymphokine activated killer (LAK) cells for 4 h at various effector: target (E:T) cell ratios (E:T = 16, 8, 4, 2:1). Thereafter surviving adherent melanoma cells were stained with MUH for 30 min and fluorescence was measured directly in a 96 well plate reader. For the calculation of LAK cell cytotoxicity fluorescence values were corrected for the number of nonspecifically detached tumor cells during the washes and the number of nonspecifically adherent LAK cells. Using identical target and effector cell preparations both assays showed a nearly proportional increase of percentage cytotoxicity with rising numbers of lymphocytes. Compared with the 51Cr release assay, however, higher cytotoxicity values were obtained with the fluorometric MUH microassay: 57% with MUH versus 26% with 51Cr and 39% versus 14% for cell lines StML-11 and SKMel-28, respectively (E:T ratio = 16:1). The higher cytotoxicity rates obtained with the fluorometric MUH microassay were not due to the additional 30 min staining with MUH or due to nonspecific hydrolysis of MUH by extracellular esterases released from damaged cells, as could be shown by a series of experiments. In conclusion, a simple and rapid fluorometric microassay has been developed showing reliable reproducibility and a higher sensitivity compared with the 51Cr release assay for the determination of cellular cytotoxicity to adherent growing cell lines, avoiding hazardous radioactive labels.
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PMID:A rapid and sensitive fluorometric microassay for determining cell mediated cytotoxicity to adherent growing cell lines. 143 Nov 56

Melanoma cells have surface markers that are expressed differently than in normal melanocytes and nevus cells. Monoclonal antibodies may define a phenotypic map of the various melanocytic lesions and can be used in immunohistopathology and immunoscintigraphy. Monoclonal antibodies directed against melanoma-associated glycoproteins and glycolipids are being tested for therapy. Rearrangements or deletions on chromosome 1, 6, and 7 are the most frequently observed cytogenetic abnormalities. Molecular studies have not given a clear picture. A subset of HRAS alleles has been reported to be associated with melanoma. NRAS activation by point mutation has been found in one fourth of the cases. Allele losses at different loci have been reported. Genetic linkage studies have given conflicting results on the presence of a gene for the melanoma-dysplastic nevus syndrome on the short arm of chromosome 1.
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PMID:Cellular and molecular biology of melanoma. 143 44

Southern travelling habits were recorded for 127 melanoma patients from southern parts of Sweden (the 56th latitude), 55 thyroid cancer patients, 100 non-Hodgkin's patients and 794 healthy controls from the same region. Melanoma patients were found to travel significantly more often south of the 45th latitude, as compared with patients with non-Hodgkin's lymphoma or thyroid carcinoma (RR = 2.2 for a difference of + 10 trips), and with the healthy controls (RR = 1.4 for a difference of + 10 trips). Considering men and women separately, the difference was significant only for men. Patients with melanoma had a higher educational level than the tumour controls and the healthy controls (p < 0.001 and p < 0.001 respectively). There was a significant correlation between high travelling frequency and high education. An increased risk related to southern travelling was present for patients with melanoma on the extremities and head and neck, as well as for patients with truncal melanoma. These findings support the concept that acute exposure to sunburn may be a risk factor for malignant melanoma.
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PMID:Southern travelling habits with special reference to tumour site in Swedish melanoma patients. 144 18

Normal human melanocyte proliferation and differentiation is dependent on stimulation of one of three growth factor/receptor systems. They are fibroblast growth factor (FGF), hepatocyte growth factor (HGF), and mast cell growth factor (MGF), which activate the FGF receptor, c-Met, and c-Kit, respectively, known to be receptor tyrosine kinases. In contrast, human melanoma cells from primary nodular and metastatic lesions grow autonomously partially because of inappropriate production of basic FGF (bFGF) and continuous activation of the bFGF-receptor kinase. Activation of transmembrane receptor tyrosine kinases in melanocytes stimulates not only proliferation but also the expression of pigmentation. Melanoma cells constitutively express several tyrosyl-phosphorylated proteins that in normal melanocytes are stimulated in response to growth factors. This high level of phosphorylation was not due to either the presence of constitutively active Kit kinase and Met kinase nor to the absence of any of several known protein tyrosine phosphatases. Because bFGF by itself does not transform melanocytes to melanomas, there must be additional cooperating factors that confer the malignant phenotype to pigment cells.
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PMID:Growth factors, receptor kinases, and protein tyrosine phosphatases in normal and malignant melanocytes. 144 4

Based on the clinicopathological classification of distinct stages of tumor progression in the melanocytic system, we have investigated the in vitro growth patterns and requirements of normal melanocytes and melanocytes isolated from different lesions of melanoma progression. Normal melanocytes depend on a combination of insulin-like growth factor (IGF-I) or insulin, 12-O-tetradecanoyl phorbol-13-acetate (TPA), alpha-melanocyte stimulating hormone (alpha-MSH), and basic fibroblast growth factor (bFGF) for in vitro proliferation. Nevus cells display a reduced need for TPA and are largely independent of bFGF. Both melanocytes and nevus cells have a finite lifespan in vitro and show no spontaneous transformation, whereas melanoma cells can be grown indefinitely in vitro. Cells from primary melanomas require only IGF-I or insulin for continuous growth, and metastatic melanoma cells can proliferate in base medium without addition of any growth factors or proteins. This progressive growth autonomy is paralleled by an increased competence for endogenous growth factor production. Among these growth factors, bFGF and melanoma growth-stimulatory activity (MGSA) act in an autocrine fashion. Melanoma-derived growth factors without apparent autocrine function, such as platelet-derived growth factor A and B (PDGF-A and PDGF-B) and transforming growth factor-alpha (TGF-alpha), might still be important for melanoma growth by stimulating surrounding normal fibroblasts, endothelial cells, or keratinocytes to secrete growth-promoting factors. The significance of growth factors such as transforming growth factor-beta (TGF-beta) and melanoma-inhibiting activity II (MIA II), which have a potentially negative autocrine function, remains unknown. The successful propagation of melanocytic cells of all stages of melanoma progression has yielded valuable insight into the mechanisms of growth regulation and malignant transformation.
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PMID:In vitro growth patterns of normal human melanocytes and melanocytes from different stages of melanoma progression. 144 12

Fotemustine is a new chloronitrosourea which is active against disseminated malignant melanoma (DMM), and especially against cerebral metastases (CM). This efficacy has been widely demonstrated through many phase II studies. A multicentre trial of monotherapy was undertaken in 153 evaluable French patients. A response rate (RR) of 24.2% (25.0% RR in CM; 31.8% in non-visceral metastases (NVM) was obtained. Three other phase II studies confirmed these results with respective objective RR of 16.7%, 20.0% and 47.0% and RR in CM of 8.3%, 14.3% and 60.0%. Fotemustine has also been used in combination with dacarbazine (DTIC), in patients with DMM. The RR among 103 patients was 27.2% (26.3% in CM, 37.5% in NVM), confirming the activity of fotemustine. The two drugs have also been administered sequentially, in order to exploit their synergism in interfering with the O6 alkyltransferase. Impressive RR have been achieved, especially in patients with visceral metastases (VM) but at the expense of a pulmonary toxicity that does not arise with other treatment schedules and which precludes its use outside of strictly conducted clinical trials.
Melanoma Res 1992 Sep
PMID:Fotemustine: an overview of its clinical activity in disseminated malignant melanoma. 145 Jun 67

Between 1983 and 1989 a phase II study was carried out by the EORTC Malignant Melanoma Cooperative Group in which postmenopausal women with advanced melanoma but a good performance status received tamoxifen, 40 mg per day, as a single agent. From 12 centres, 114 patients were registered of whom 107 appeared to be eligible and 102 evaluable. Seven died of progressive disease within 4 weeks, eight others had early progressive disease (of whom seven died within 7 weeks). The response rate was 4.9%, the complete response rate 1%. Without prior chemotherapy three of 58 responded, with prior chemotherapy two of 44. Except for one of 46 patients with lung metastases who experienced a PR of these metastases, all responders were patients with slowly growing small soft tissue metastases. We conclude that, because of the few side effects, tamoxifen can be recommended for (postmenopausal) patients who have only a small number of slowly growing metastases and who are not yet candidates for treatment with toxic drugs.
Melanoma Res 1992 Sep
PMID:Tamoxifen as a single agent for advanced melanoma in postmenopausal women. A phase II study of the EORTC Malignant Melanoma Cooperative Group. 145 Jun 68

The significance of the BANS location (upper Back, posterior Arm, Neck and Scalp) as a prognostic factor in patients with stage I melanoma is controversial. A meta-analysis performed by Weinstock et al. on their own and five comparable studies corroborated the hypothesis that this location is influential in the prognosis of intermediate thickness (0.76-1.69 mm) melanomas. Our study investigated the relationship between BANS subsites, thickness and prognosis in 1,082 stage I melanoma patients from two major Italian centres, Turin and Florence. A BANS primary was observed in 212 (19.5%) patients: recurrences occurred in 85 of them (40.1%) vs 309/870 non-BANS patients (35.5%). Overall survival probabilities were significantly shorter (p less than 0.01) in the BANS group (69.1% vs 76.7% at 5 years; 59% vs 68.5% at 10 years). The prognostic value of the BANS location was confirmed by a multivariate analysis using the Cox proportional hazards model. Stratification of BANS and non-BANS groups by thickness clusters showed a significant difference in both survival (p less than 0.001) and disease-free interval (p less than 0.05) in the 3.01-4.00 mm thickness subset, due to the greater incidence of distant and visceral metastases. In the 0.76-1.69 mm thickness range the significance was p = 0.06.
Melanoma Res 1992 Sep
PMID:BANS: a discussion of the problem. 145 Jun 69

Results obtained using a computerized image analysis system as an aid to clinical diagnosis of melanoma are reported. The system comprises a colour television camera connected through a digitizing board to a 386 personal computer. By means of original algorithms able to measure the shape, the colours and texture of a pigmented lesion of the skin, the system provides eight on/off indicators that are matched with the histological diagnosis to identify benign and malignant pigmented lesions. The chances that a given lesion is malignant increase with the increasing number of positive indicators. The training field of the system was constituted of images and data of 169 cutaneous lesions in 165 patients. Taking two positive indicators as the threshold between pigmented benign and malignant lesions, the efficiency of the system is 0.98, the positive predictive value is 0.45 and the negative predictive value is 0.95. These values were confirmed in a series of 44 pigmented lesions, 10 of which were melanoma, that constitute the present test series. The authors conclude that this computerized image analysis system should be regarded as a useful aid to diagnosis for a non-expert clinician. The system limit is transformation within a naevus.
Melanoma Res 1992 Sep
PMID:Results obtained by using a computerized image analysis system designed as an aid to diagnosis of cutaneous melanoma. 145 Jun 70

A unique in vivo approach to assessing the concentrations of 4-[10B]borono-L-phenylalanine (L-BPA), a melanoma targeting compound for boron neutron capture therapy (BNCT), was investigated using L-BPA labelled with positron-emitting 18F (half-life = 110 min), i.e., 4-[10B]borono-2-[18F]fluoro-L-phenylalanine (L-[18F]FBPA). High melanoma uptake of L-[18F]FBPA was reduced slightly by competition with L-BPA in the two animal models of the murine B16 melanoma and the melanotic Greene's melanoma No. 179 in hamsters. In mice given L-[18F]FBPA and L-BPA, the concentrations of 10B in B16 estimated from 18F radioactivity were lower than those measured by inductively coupled plasma-atomic emission spectroscopy. Lower estimated values were dependent on the time after injection and on the loading dose of L-BPA. The estimated 10B concentrations for Green's melanomas were comparable to the measured values. Positron emission tomography (PET) using L-[18F]FBPA allowed Greene's melanomas to be clearly visualized. In conclusion, when L-[18F]FBPA is used as a probe for L-BPA in BNCT of malignant melanomas, the melanoma can be localized and the 10B concentrations in tissues can be assessed in vivo using 18F radioactivity by PET.
Melanoma Res 1992 Sep
PMID:A unique in vivo assessment of 4-[10B]borono-L-phenylalanine in tumour tissues for boron neutron capture therapy of malignant melanomas using positron emission tomography and 4-borono-2-[18F]fluoro-L-phenylalanine. 145 Jun 71


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