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1.
Allelotype analysis of adult T-cell leukemia (ATL) was undertaken for the first time to identify chromosomal loci relevant to the development of acute/lymphomatous ATL. Loss of heterozygosity (LOH) was screened using 94 highly polymorphic microsatellite markers, distributed among all nonacrocentric, autosomal chromosomes. In each of the 22 cases, DNA obtained from their leukemic cells in acute/lymphomatous phase was compared with their constitutional DNA from mononuclear cells in chronic or remission phase. Allelic losses of at least on one chromosome arm occurred in 91% of the cases (20 individuals). Among 39 chromosome arms, allelic losses were observed on 31 arms at least for one sample. A high frequency of allelic loss (>30%) was seen on chromosome arms 6q (41%) and 17p (48%). The mean fractional allelic loss (FAL) was 0.109. These findings suggest that a novel tumor suppressor gene on chromosome arm 6q, as well as the p53 gene on chromosome arm 17p, probably have an important role in the development of acute/lymphomatous ATL.  相似文献   

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Several case-control studies identified common and atypical melanocytic nevi as major risk indicators for the development of cutaneous melanoma. The present investigation was planned to detect factors associated with the prevalence of these melanoma risk markers. Whole-body examination findings and interview data of 513 melanoma patients and 498 age- and sex-matched control subjects were analyzed. Existence of more than 50 common melanocytic nevi and the presence of atypical melanocytic nevi were significantly related to age and gender, with significantly elevated relative risk for their prevalence before the age of 60 and in males. Additionally, sunburns before the age of 20 were significantly associated with both more than 50 common melanocytic nevi (relative risk = 1.7) and the presence of atypical melanocytic nevi (relative risk = 1.5). Actinic lentigines were found more frequently with increasing age, and the presence of actinic lentigines was significantly related to a tendency of freckling in adolescence (relative risk = 2.0) and to two or more sunburns after the age of 20 (relative risk = 1.6). In conclusion, sunburns before the age of 20 contribute to the development of multiple melanocytic nevi and atypical melanocytic nevi. In adulthood, this type of sun exposure is associated with the development of actinic lentigines. The relative risk of developing cutaneous melanoma increases in association with the development of these benign melanocytic lesions.  相似文献   

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The c-kit gene encodes a transmembrane receptor that has tyrosine kinase activity. c-kit plays a role in hematopoiesis, gametogenesis, and melanogenesis. c-kit is found in melanocytes, and there is evidence that expression is lost in melanoma. We studied 85 melanocytic lesions for c-kit by immunohistochemical techniques using a monoclonal antibody. The lesions included banal nevi, junctional and compound nevi with melanocytic dysplasia, nontumorigenic radial growth phase melanoma, tumorigenic vertical growth phase melanoma, and metastatic melanoma. We found intense membrane staining in normal melanocytes and mast cells. Staining in compound nevi was strongest in junctional and superficial dermal components, whereas dermal nevi showed weak reactivity. Dysplastic nevi stained strongly, particularly in junctional cells. In melanoma, strong reactivity was most prominent in radial growth phase disease, but there was little or no staining in vertical growth phase and metastatic melanomas. In summary, c-kit protein is expressed in normal melanocytes, benign nevi, dysplastic nevi and nontumorigenic melanoma, but expression is lost in tumorigenic primary melanomas and metastases. The role of c-kit loss in advanced melanoma requires additional investigation.  相似文献   

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Frequent allelic losses on chromosome 9 are seen in a wide variety of human tumors; moreover, two genes (P16 and PTC) whose mutant alleles confer predispositions to some inherited cancer syndromes have been identified on this chromosome. Using 15 highly polymorphic microsatellite markers distributed on both arms of chromosome 9, we tested 96 primary breast carcinomas for allelic loss in order to define the locations of genes that might be involved in this type of tumor. Allelic loss was observed in 37 of the tumors (39%) and detailed deletion mapping identified target regions at 9p21, 9q22.3 and 9q33. Losses at 9q22.3 and 9q33 were correlated with the presence of lymph node metastasis, and allelic loss at 9q22.3 was observed more frequently in scirrhous tumors than in less aggressive histologic types. Therefore, inactivation of tumor suppressor genes in 9q22.3 and 9q33 regions might play a role in progression of breast cancers, especially in metastasis to lymph nodes and in development of scirrhous tumors.  相似文献   

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Substance P (SP) is a neuropeptide found in both the central and peripheral nervous system. In the skin, SP-containing neurons stimulate the release of histamine from connective tissue mast cells (MC). SP also can potentiate neoangiogenesis and induce dermal fibrosis. MC-derived histamine has potent vasoactive effects, is angiogenic, and promotes tissue fibroplasia. In addition to histamine, MC contain many other angiogenic factors and a variety of cytokines, growth factors, and proteolytic enzymes implicated in tissue remodeling, and normal as well as tumor-associated neoangiogenesis. Many MC-derived factors, including histamine, can enhance melanoma cell growth directly. MC often concentrate around cutaneous melanomas which also frequently are associated with angiogenesis and peritumoral fibrosis. The precise mediators of these responses have not been well defined. We evaluated by immunohistochemistry cutaneous lesions representing stages of progression of malignant melanoma and its precursor lesions for the expression of SP. SP was expressed in 17/25 (68%) primary invasive malignant melanomas, 2/5 (40%) metastatic melanomas, 6/10 (60%) melanomas in situ, 7/12 (58%) atypical (dysplastic) nevi, and 4/10 (40%) spindle and epithelioid cell (Spitz) nevi, but was not detected in any (0/11, 0%) acquired benign melanocytic nevi (p<0.05). Invasive melanomas were immunolabeled in both the intraepidermal and the dermal components of the lesions. For those atypical and Spitz nevi which expressed SP, most of the immunoreactive melanocytes were located at the dermal-epidermal junction overlying areas of papillary dermal fibrosis. The results show differential expression of SP among cutaneous melanocytic lesions and suggest that the expression of this neuropeptide together with other factors may contribute to some of the host responses associated with these lesions.  相似文献   

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To gain an insight into the genetic events underlying morphological phenotypes, we analysed 58 gastric carcinoma tissues for the genome-wide allelotype study using microsatellite markers. Based on a binomial distribution, loss of heterozygosity (LOH) that was significantly more frequent than expected (P<0.05) thus interpreted as nonrandom LOH selected during tumorigenesis. The overall extent of chromosomes undergoing LOH i.e. fractional allelic loss (FAL, the ratio of LOH-positive markers to the total number of informative markers) was measured in each tumor patient. Nonrandom LOH was found on 17p (48.0%), 18q (38.4%), 13q (38.1%) and 9p (36.4%). Overall, there were no significant phenotypes correlated with allelic loss on specific chromosome regions. Based on a bimodal distribution of FAL values with two peaks bordered by a mean of 0.233, tumors were classified into LOH-related (>0.233) and LOH-unrelated (<0.233) types. Among 24 patients with LOH-related tumors, increase in the infiltrative type of growth pattern was found to correspond with a significant trend of increasing FAL values. This study shows that the growth pattern of gastric carcinoma is correlated with FAL, suggesting that a malignant phenotype is influenced by LOH event.  相似文献   

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Spitz's nevi are acquired benign melanocytic skin tumors. Usually they are differentiated from nodular melanoma by clinical and histopathological criteria. Since Spitz's nevi are one of the most common simulators of nodular melanomas their bizarre histopathology may cause diagnostic confusion and make it difficult to differentiate these two melanocytic tumors. One of the histologic features shared by Spitz's nevus and nodular melanoma is prominent vascularity. The ability of malignant melanoma to induce angiogenesis is well established whereas benign melanocytic tumors do not have a prominent overall vascularity. The purpose of this study was to find out whether the degree of vascularity of nodular melanomas differs significantly from that of benign Spitz's nevi. In this study the number of microvessels and the vessel area were determined in 23 Spitz's nevi and 16 nodular melanomas. The number of microvessels and the vessel area were determined on Ulex Europaeus agglutinin I-stained sections by computer-assisted image analysis. Two methods of measurement were used, namely systematic and selective sampling. Measurement of the whole tumor specimen (systematic sampling) revealed a vessel count of 10.83/field (SD +/-5.97) for Spitz's nevi whereas nodular melanomas exhibited a significantly lower (p=0.04) vessel count of 6.44/field (SD +/-3.85). This difference was even more pronounced when the vessel area (Spitz's nevi: 17.85x10-4mm2, SD +/-10.32; nodular melanomas: 7.88x10-4mm2, SD +/-5.23) was investigated (p < 0.001). The difference in vessel area and vessel count was insignificant for areas exhibiting the greatest vascularity (selective sampling). Measurement of vessel count and vessel area lead us to conclude that Spitz's nevi have a significantly higher vascularity than do nodular melanomas. Our results thus indicate that angiogenesis in these pigmented lesions is not correlated with malignancy.  相似文献   

10.
Karyotypic and molecular data indicate that genetic alterations of the long arm of chromosome 11 (11q) are involved in the pathogenesis of malignant melanoma as well as of other malignancies. We have shown previously, by analysis of loss of heterozygosity (LOH), that a tumor-suppressor gene playing an important role in malignant melanoma is likely to be located within a 51-cM region at 11q23. Its loss appeared to be a late event in tumor progression and an indicator of a less favorable clinical outcome. To further test this hypothesis on a larger set of tumors and to refine the region(s) of common allelic loss, we analyzed 21 polymorphic microsatellite repeats on 11q. A PCR-based assay for LOH was used to study normal and tumor tissues from 53 individuals with primary cutaneous malignant melanoma or metastatic disease. Our findings indicate that in cutaneous malignant melanoma there are at least 2 distinct regions of common allelic loss on 11q, one of them centered around marker APOC3 at 11q23.1-q23.2 delineated by markers D11S1347 and D11S4142 and spanning approximately 5 Mb and a second 3-Mb region around marker D11S925 at 11q23.3 delineated by markers D11S528 and D11S1345. Both regions have been described as deletion targets or as being included within larger allelic deletions detected in several other common tumor types. Thus, these 2 putative melanoma-suppressor loci are likely to harbor tumor-suppressor genes relevant to tumorigenesis of melanoma and a number of other common human malignancies.  相似文献   

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The main objective of this study was to assess whether cutaneous malignant melanoma (CMM) shows a stronger relation with the melanocytic nevi count at the site where CMM was diagnosed than with the melanocytic nevi count at other sites, stratifying by histologic CMM type, in a southern Mediterranean population. Cases and controls were selected from a population in southern Spain in 1988-1993. The study population included 116 incident cases with non-familial CMM (International Classification of Diseases 9th Revision (ICD-9) code 172), and 116 controls matched 1:1 for sex and age (+/- 4 years). Data were collected by personal interview, and melanocytic nevi were counted over the entire body surface by clinical skin examination performed by a dermatologist. Crude and multiple risk factor-adjusted odds ratios and 95% confidence intervals were computed by conditional logistic regression analysis. After adjustment by skin type, unexposed skin color, and sun exposure, CMM was found to occur significantly more frequently in individuals with a high number of melanocytic nevi at the same site where CMM originated (odds ratio (OR) for >8 nevi = 12.0, 95% confidence interval (CI) 1.3-108.2). The ability to predict the number of melanocytic nevi on different anatomic sites on CMM, but excluding the CMM cases on each corresponding site, was also examined. A significant trend with the number of nevi on the anterior surface of thighs was found (OR for >4 nevi = 4.5, 95% CI 1.4-14.9). Melanocytic nevi count on the melanoma site was the variable most closely related to superficial spreading melanoma subtype (SSM) (OR for >8 nevi = 82.19, 95% CI 2.72-2,454). On the other hand, the number of melanocytic nevi on the melanoma site was unrelated to risk of CMM subtypes other than SSM. These results support the hypothesis that nevi are an important risk factor for melanoma, especially SSM, in populations with a darker ethnic background.  相似文献   

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BACKGROUND: A retrospective analysis of 40 patients diagnosed with melanoma of unknown primary site (MUP) was undertaken to analyze the etiology and clinical behavior of this presentation. METHODS: The patient records were located by a computer search of the Pigmented Lesion Clinic data base at the University of Pennsylvania. With the Cox proportional hazards model, the survival of the MUP patients with lymph node presentation was compared with that of patients with lymph node disease and a known concurrent primary melanoma. RESULTS: Sixty-five percent of the patients presented with lymph node metastasis only, 28% presented with visceral lesions, and 8% presented with subcutaneous nodules. The prevalence of dysplastic nevi was 22.5%. The overall 4-year survival rate for the 40 MUP patients was 55% +/- 9%. The 4-year survival (57% +/- 12%) of patients with lymph node presentation was compared with that of patients presenting with lymph node disease and a known concurrent primary melanoma (19 +/- 6%). Survival was significantly different between the groups (P = 0.008). This survival difference remained significant (P = 0.02) even after adjustments for number of positive lymph nodes, year of diagnosis, and age at diagnosis. CONCLUSIONS: This analysis revealed that MUP patients with lymph node metastasis survived significantly longer than patients diagnosed with lymph node metastasis concurrent with a known cutaneous primary melanoma. The prevalence of dysplastic nevi in the MUP patient series was intermediate between that reported among primary melanoma patients and that reported among population controls, suggesting the likelihood of a primary cutaneous origin for the metastatic melanoma.  相似文献   

13.
Recent evidence has implicated cyclins and cyclin-dependent kinases in the evolution and progression of various malignancies. We studied the immunohistochemical expression of cyclin A, cyclin B, and cyclin-dependent kinase p34cdc2 in a broad spectrum of benign and malignant melanocytic lesions. Formalin-embedded, parrafin-fixed tissue sections from 66 malignant melanomas (MM) and 60 benign nevi were examined for the expression of these cell-cycle proteins. The results were compared with the standard proliferative marker Ki-67 and mitotic index. MM showed significantly higher immunoreactivity for cyclin A, cyclin B, p34cdc2, and Ki-67 compared with benign nevi. Cyclin A, p34cdc2, and Ki-67 displayed strong co-expression in MM. Overexpression of cyclin A and p34cdc2 correlated with histological type, mitotic activity, Ki-67 index, tumor thickness, Clark's level, and clinical outcome in MM. In invasive MM, increased immunostaining of cyclin A and Ki-67 were associated with decreased patient survival. These findings indicate potential roles of mitotic cyclins and cyclin-dependent kinases in the pathogenesis and progression of malignant melanoma.  相似文献   

14.
Tenascin is a large extracellular matrix glycoprotein which is widely distributed in normal, hyperplastic and neoplastic tissues. Its function is unknown but it has been associated with the epithelial-stromal interactions, such as cell adhesion and movement which take place, e.g. in morphogenesis, cellular proliferation and neoplasia. In this study, we investigated tenascin expression in 70 benign, dysplastic and malignant melanocytic tumors by using immunohistochemistry and monoclonal anti-tenascin 143DB7C8 antibody on paraffin sections. In all types of benign nevi, both intradermal, compound and junctional, there was a moderate expression of tenascin at the dermoepidermal junction and in the papillary dermis. In dysplastic nevi, the fibrotic areas in the papillary dermis also showed a moderate staining for tenascin. Invasive malignant melanomas showed the strongest expression of tenascin. In addition to the staining at the dermo-epidermal junction and in the papillary dermis, there was a variable expression of tenascin in the reticular dermis. Intracytoplasmic tenascin was detected both in primary melanomas and melanoma metastases. In conclusion, we have shown that tenascin expression is moderately increased in benign and dysplastic melanocytic tumors and greatly increased in malignant melanomas and melanoma metastases. The function of tenascin may be related to the cellular-stromal interactions and it is possibly associated with the proliferation and spread of the melanocytic tumors.  相似文献   

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Congenital melanocytic nevi are benign lesions present at birth and considered to be caused by a maldevelopment of the neural crest. The malignant potential of the congenital melanocytic nevi have been extensively addressed by several authors, and malignant melanoma is the most frequent neoplasm arising in these lesions. The present report describes two patients with congenital melanocytic nevi in which malignant melanoma with undifferentiated areas showing rhabdomyoblastic differentiation developed. The findings suggest that these mixed neoplasms may be recapitulating the differentiation potential of the ectomesenchyme-neural crest cells. We advocate the term "melanoblastoma" when referring to them.  相似文献   

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Eleven uveal melanomas were analyzed using comparative genomic hybridization (CGH). The most abundant genetic changes were loss of chromosome 3, overrepresentation of 6p, loss of 6q, and multiplication of 8q. The smallest overrepresented regions on 6p and 8q were 6pter-->p21 and 8q24-->qter, respectively. Several additional gains and losses of chromosome segments were repeatedly observed, the most frequent one being loss of 9p (three cases). Monosomy 3 appeared to be a marker for ciliary body involvement. CGH data were compared with the results of chromosome banding. Some alterations, e.g., gains of 6p and losses of 6q, were observed with higher frequencies after CGH, while others, e.g., 9p deletions, were detected only by CGH. The data suggest some similarities of cytogenetic alterations between cutaneous and uveal melanoma. In particular, the 9p deletions are of interest due to recent reports about the location of a putative tumor-suppressor gene for cutaneous malignant melanoma in this region.  相似文献   

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Detailed deletion mapping of chromosome 6q has shown that the highest percentage of loss of heterozygosity (LOH) is located at 6q25-q27 and suggested that an ovarian cancer associated tumor suppressor gene may reside in this region. To further define the smallest region of common loss, we used 12 tandem repeat markers spanning a region no more than 18 cM, located between 6q25.1 and 6q26, to examine allelic loss in 54 fresh and paraffin embedded invasive ovarian epithelial tumor tissues. Loss of heterozygosity was observed more frequently at the loci defined by marker D6S473 (14 of 32 informative cases, 44%) and marker D6S448 (17 of 40 informative cases, 43%). Detailed mapping of chromosome 6q25-q26 in these tumor samples identified a 4 cM minimal region of LOH between markers D6S473 and D6S448 (6q25.1-q25.2). Loss of heterozygosity at D6S473 correlated significantly both with serous versus non-serous ovarian tumors (P=0.040) and with high grade versus low grade specimens (P=0.023). The results suggest that a 4 cM deletion unit located at 6q25.1-q25.2 may contain the putative tumor suppressor gene which may play a role in the development and progression of human invasive epithelial ovarian carcinomas (IEOC).  相似文献   

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Integrin alpha 2 beta 1 is a transmembrane protein receptor for collagen and laminin previously reported as a melanoma tumor progression antigen. alpha-Actinin is an actin-binding protein reported to interact with the cytoplasmic domain of the beta 1-integrin chain of alpha 2 beta 1. In vitro, both alpha 2 beta 1 and alpha-actinin play a role in melanoma cell motility. In turn, increased melanoma cell line motility (measured as mean migration rates), correlates with metastasis. To determine the in situ distribution of these proteins, we used monoclonal antibodies directed against the alpha 2-integrin subunit of alpha 2 beta 1 and alpha-actinin on frozen sections of 33 melanocytic proliferations, which included dermal nevi, primary melanomas, and metastatic melanomas. We found that the superficial portion of all of the melanocytic proliferations tested stained for alpha-actinin. In benign nevi and superficial spreading melanoma, there was a notable loss of staining for alpha-actinin in the cells in the deep reticular dermis. In contrast, alpha-actinin was present on almost all of the tumor cells in the nodular melanomas and the melanoma metastases. Tumors stained either uniformly positive or uniformly negative for alpha 2 beta 1; the expression of this protein correlated with the later stages of melanoma progression. Our findings suggest that alpha-actinin protein levels initially decrease and then increase during melanocytic tumor progression, whereas the alpha 2 subunit protein appears in the later stages of melanoma progression. The variable distribution of these proteins is evidence for the differential adhesive and motile properties of subpopulations of cells in melanocytic proliferations.  相似文献   

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