Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.10.3.1 (tyrosinase)
9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum tyrosinase activity has been measured by adapting the [3]tyrosine assay for tyrosinase and significant elevations of serum tyrosinase activity were found in patients with malignant melanoma. In contrast to findings in a study which utilized [14C]tyrosine, augmented levels of tyrosinase activity were not observed in sera from patients with other malignancies, including subjects with carcinoma of the breast. The results of the examinations for soluble tyrosinase activity in human malignant melanoma tissue-cultured lines were all positive, whereas human cell lines from carcinoma of the breast, carcinoma of the colon and sarcoma uniformly showed no activity. The method employed for detecting tyrosinase activity holds promise as a specific diagnostic test and may be valuable for monitoring the response to clinical treatment of patients with malignant melanoma.
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PMID:Tyrosinase activity in the sera of patients with malignant melanoma: method and specificity. 41 60

In order to clarify the histogenesis of clear cell sarcoma of tendons and aponeuroses (CCS), two cases of human and one nude mouse-transplanted CCS line were studied using an ultrastructural and enzyme cytochemical approach. Most of the tumour cells obtained from the primary and transplanted CCS demonstrated melanosomes in various stages of development within the cytoplasm, whereas no melanosomes could be identified in the metastatic CCS. However, cholinesterase and tyrosinase activities could be demonstrated not only in the melanotic primary and transplanted CCS but also in the amelanotic metastatic CCS. The results therefore support the hypothesis that CCS is a soft tissue tumour derived from the neural crest.
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PMID:Neural crest origin of clear cell sarcoma of tendons and aponeuroses. Ultrastructural and enzyme cytochemical study of human and nude mouse-transplanted tumours. 249 78

A clear cell sarcoma (CCS) cell line, designated as NCS-1, was established in monolayer culture from a xenograft line originating from a metastatic CCS. Marked karyotypic aberrations and tumorigenicity in nude mice revealed the malignant derivation of the NCS-1 cell line. These cells contained abundant glycogen and were amelanotic by light microscopy. By electron microscopy, however, melanosomes in various developmental stages were seen, and some of them were partially melanized. The electron microscopic dopa reaction revealed the presence of tyrosinase activity. Enzyme-linked immunoadsorbent assay revealed that NCS-1 cells expressed a 75-kDa glycoprotein which was identified as a marker of highly differentiated melanoma cells. From these results, NCS-1 cells were found to retain both cytochemical and morphological properties of CCS. Application of NCS-1 cells to a panel of monoclonal antibodies recognizing melanocytic differentiation antigens showed that they corresponded approximately to highly differentiated melanoma cells. In conclusion, the present study strongly supports the close relationship between CCS and malignant melanoma.
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PMID:Establishment and characterization of a clear-cell sarcoma (malignant melanoma of soft parts) cell line. 806 Jan 55

The aim of this study was to characterize a metastasizing soft tissue tumor in a dog, which clinically, grossly and histologically showed a close resemblance to human clear cell sarcoma, a soft tissue variant of malignant melanoma. Ultrastructurally, melanosomes were found, indicating a melanocytic origin of the tumor. Using reverse-transcription polymerase chain reaction, expression of the gene encoding tyrosinase was determined in tumor cells. With this first case of canine clear cell sarcoma, as well as the earlier report from our laboratory on amelanotic melanomas in the cat, we demonstrate that expression of the tyrosinase gene may occur in a broader range of less differentiated melanocytic tumors in different species, including man.
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PMID:Tyrosinase gene expression in clear cell sarcoma indicates a melanocytic origin: insight from the first reported canine case. 1059 69

Many attempts have been made to develop a suitable animal model to study more effectively the aetiology, pathogenesis, diagnosis and therapy of intraocular (uveal) melanoma. Uveal melanoma may spontaneously occur in some animals, including dogs, cats, horses, rats, mice, birds and fish. The histological features, metastatic behaviour and unpredictable nature of occurrence of these uncommon spontaneous tumours detract from their suitability as a model. Several methods have been developed to induce intraocular melanoma chemically or by radiation in laboratory animals. Some of these induced tumours resemble human uveal melanoma, although the majority originate from the retinal pigment epithelium. Uveal proliferations have been biologically induced by feline leukaemia/sarcoma virus and simian virus 40, although the presence of virus in tumour cells and extraocular tumours resulting from shed virus detract from the utility of this model. Inoculation of tissue culture hamster, murine or human melanoma cells into animal eyes has the advantage that the inoculation site and size of inoculum can be controlled. Disadvantages include the immune suppression necessary for tumour growth in some models as well as the fact that many of the melanoma cell lines are of cutaneous origin. Transgenic murine models have been developed using the promoter region of the tyrosinase gene to target expression of oncogenes in melanin-producing cells. Spontaneous intraocular pigmented tumours and distant metastases may occur, although many, if not all, of the intraocular tumours arise in the retinal pigment epithelium.
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PMID:Animal models of uveal melanoma. 1089 Mar 73

Angiomyolipoma has a unique immunophenotype with co-expression of muscle-specific actin and melanocytic markers such as HMB-45 and Melan-A. The most recently developed melanocytic markers, microphthalmia transcription factor and tyrosinase, have not been studied in the diagnosis of angiomyolipoma. We tested 29 renal angiomyolipomas (21 classic histology, 4 epithelioid variants, 2 lipomatous variants, and 2 leiomyomatous variants) with an immunohistochemical panel, including microphthalmia transcription factor, tyrosinase, HMB-45, Melan-A, and muscle-specific actin. Results were compared with 15 renal cell carcinomas (9 conventional types, 6 with sarcomatoid change), 2 leiomyosarcomas, 5 liposarcomas, and 1 unclassified high-grade sarcoma. Microphthalmia transcription factor expression was seen in 22 of 29 angiomyolipomas, one renal cell carcinoma, and one well-differentiated liposarcoma (that is, 2 of 23 non-angiomyolipomas; sensitivity 75%, specificity 91%). Tyrosinase expression was seen in 4 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 14%, specificity 100%). HMB-45 was positive in 24 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 83%, specificity 100%). Melan-A was expressed by 25 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 86%, specificity 100%). Muscle-specific actin was expressed by 29 of 29 angiomyolipomas and 2 of 23 non-angiomyolipomas (both leiomyosarcomas; sensitivity 100%, specificity 91% [100% excluding leiomyosarcomas]). Microphthalmia transcription factor showed the most widespread staining in angiomyolipoma (50% of cases staining more than half of the tumor cells) followed by Melan-A (24% of cases staining more than 50%). Only three cases showed positivity for all four melanocytic markers, while in one case each only microphthalmia transcription factor and Melan-A were positive. We conclude that microphthalmia transcription factor, but not tyrosinase immunostaining, has a sensitivity and specificity that rivals those of the established markers, HMB-45 and Melan-A, in the diagnosis of angiomyolipoma. Our data supports the use of a panel in difficult cases that includes antibodies to microphthalmia transcription factor, either Melan-A or HMB-45, and muscle-specific actin to provide the best mix of high sensitivity, high specificity, nuclear and cytoplasmic immunolocalization, and widespread staining of cells within a given tumor.
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PMID:Immunohistochemical study of microphthalmia transcription factor and tyrosinase in angiomyolipoma of the kidney, renal cell carcinoma, and renal and retroperitoneal sarcomas: comparative evaluation with traditional diagnostic markers. 1114 53

Primary sinonasal tract mucosal malignant melanomas are uncommon tumors that are frequently misclassified, resulting in inappropriate clinical management. A total of 115 cases of sinonasal tract mucosal malignant melanoma included 59 females and 56 males, 13-93 years of age (mean 64.3 years). Patients presented most frequently with epistaxis (n = 52), mass (n = 42), and/or nasal obstruction (n = 34) present for a mean of 8.2 months. The majority of tumors involved the nasal cavity (n = 34), septum alone, or a combination of the nasal cavity and sinuses (n = 39) with a mean size of 2.4 cm. Histologically, the tumors were composed of a variety of cell types (epithelioid, spindled, undifferentiated), frequently arranged in a peritheliomatous distribution (n = 39). Immunohistochemical studies confirmed the diagnosis of sinonasal tract mucosal malignant melanomas with positive reactions for S-100 protein, tyrosinase, HMB-45, melan A, and microphthalmia transcription factor. Sinonasal tract mucosal malignant melanomas need to be considered in the differential diagnosis of most sinonasal malignancies, particularly carcinoma, lymphoma, sarcoma, and olfactory neuroblastoma. Surgery accompanied by radiation and/or chemotherapy was generally used. The majority of patients developed a recurrence (n = 79), with 75 patients dying with disseminated disease (mean 2.3 years), whereas 40 patients are either alive or had died of unrelated causes (mean 13.9 years). A TNM-type classification separated by anatomic site of involvement and metastatic disease is proposed to predict biologic behavior.
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PMID:Sinonasal tract and nasopharyngeal melanomas: a clinicopathologic study of 115 cases with a proposed staging system. 1271 45

Ovarian malignant melanoma (MM), primary or metastatic, is an extremely rare tumor and in the absence of a previous diagnosis can represent a diagnostic challenge. We present the clinicopathologic and immunohistochemical features of 23 cases seen in our institution over a period of 40 years (1962-2001). The patients' age ranged from 14 to 53 years (mean 35.7 years). Ethnicity was known in 19 patients: 14 white, 4 Hispanic, and 1 black. A previous history of MM was definitively obtained in 14 patients; in these cases, the interval between the primary MM and the ovarian metastasis ranged from 15 to 228 months (mean 77.7 months). The tumor was unilateral in 19 and bilateral in 4 cases. The tumor size ranged from 4.5 to 23 cm (average 10 cm); the melanoma arising in a cystic teratoma was 0.2 mm in thickness. The tumor was grossly pigmented in 8 cases (35%). The architectural pattern was nodular (8 cases), diffuse (6 cases), nodular and diffuse (5 cases), nested (3 cases), and lentiginous arising in a teratoma (1 case). Follicle-like spaces were seen in 8 cases, pseudo-glandular areas in 1 case, pseudo-myxoid areas in 1 case, and cords in 1 case. The tumor cell type was epithelioid in 19 cases, spindled in 2 cases, mixed epithelioid and spindled in 1 case, and small cell in 1 case. Nucleoli were prominent in 18 cases, and nuclear inclusions were present but rare in the majority of cases. Nuclear grooves were seen in 3 cases. Necrosis was extensive in 8 cases, focal in 10 cases, and was absent in 5 cases. In 8 cases, initial diagnoses included sex cord stromal tumor, germ cell tumor, sarcoma, or undifferentiated carcinoma. S-100 was positive in 18 of 19 cases, HMB-45 in 17 of 20 cases, MART-1 in 13 of 15 cases, tyrosinase in 10 of 15 cases, and Mitf in 8 of 14 cases. Inhibin was positive in 3 of 14 cases. Calretinin was focally positive in 1 of 12 cases. Treatment performed in 18 of the cases are as follows: oophorectomy with/without chemotherapy (10); total abdominal hysterectomy with bilateral salpingo-oophorectomy with/without chemotherapy (6); vaginal hysterectomy, bilateral salpingo-oophorectomy, and chemotherapy (1); and total abdominal hysterectomy with salpingo-oophorectomy (1). Follow-up ranging from 2 to 96 months was available in 18 patients. All but one had metastases in other organs, most often in the lungs. Thirteen patients died of disease (range 2-76 months), 3 are alive with disease (6-18 months), and 2 have no evidence of disease at 24 and 96 months; one was the patient with melanoma arising within a teratoma. In conclusion, MM involving the ovary is a rare disease, predominantly seen in women of reproductive age, and is associated with a poor prognosis. The tumor is most often metastatic from another site and is unilateral in most cases. Nodular or diffuse pattern and epithelioid cell type are most frequently seen, and the tumor can be mistaken for germ cell and sex cord stromal tumors. S-100 is the most sensitive marker. MART-1 was positive in the few cases that were negative with HMB-45. Inhibin can be focally positive in some cases.
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PMID:Malignant melanoma involving the ovary: a clinicopathologic and immunohistochemical study of 23 cases. 1516 69

A clear cell sarcoma, arising primarily in the ileum of a 35-year-old man, is reported. Histologically, the neoplasm infiltrated the full thickness of the intestinal wall. It consisted of strands and sheets of round to spindle-shaped cells with clear to eosinophilic cytoplasm, vesicular nuclei and prominent nucleoli. Vascular invasion was present at diagnosis. Tumour cells expressed S-100 protein, melan-A and tyrosinase. They were negative for HMB45, CD117, cytokeratins, epithelial membrane antigen, smooth muscle actin, desmin, CD31, CD34, chromogranin and synaptophysin. Reverse transcription-polymerase chain reaction analysis performed on paraffin-embedded tissue showed EWS-ATF1 fusion transcripts representative of the t(12;22) (q13;q12) clear cell sarcoma reciprocal translocation. The patient, who developed liver metastases 2 months after diagnosis, died of disease at 15 months. This case demonstrates that the gastrointestinal tract is a potential site for primary clear cell sarcoma of soft tissues, and, furthermore, that cytogenetics and/or molecular techniques play a central role in the diagnosis.
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PMID:Primary clear cell sarcoma of the ileum: an uncommon and misleading site. 1602 14

Clear cell sarcoma (CCS) is a high grade soft tissue sarcoma with a distinct molecular profile and with morphological features resembling those of melanoma. CCS has been rarely described in other locations other than the soft tissues, including the gastrointestinal tract. In this study, we report a case of CCS arising in the ileum of a 31-year-old woman. Histologically, the tumor involved the entire thickness of the intestinal wall. Tumor cells were polygonal or fusiform, with clear or eosinophilic cytoplasm, arranged in a uniform nested to fascicular growth pattern. Immunohistochemical studies revealed strong positivity for vimentin and S-100 protein. HMB-45, Melan-A, tyrosinase, cytokeratins, EMA, smooth muscle actin, CD34, CD31, CD117, CD99, synaptophysin, chromogranin A, CD56, and NSE were negative. Fluorescence in situ hybridization analysis demonstrated the presence of a t(12;22)(q13;q12) translocation, the diagnostic hallmark of CCS of soft parts. The present case, together with a detailed review of the literature on this topic, demonstrates that the gastrointestinal tract is a possible site of CCS of soft tissues and that making a reliable diagnosis of this tumor requires cytogenetic or molecular diagnostic investigations.
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PMID:Clear cell sarcoma of the ileum: report of a case and review of literature. 1763 26


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