Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.10.3.1 (tyrosinase)
 9,065 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The presence of tyrosinase mRNA in the peripheral blood cells of melanoma patients has been recently studied as a possible marker of haematogenous dissemination. However, considerable variations in the rates of detection have been noted. We determined the presence of tyrosinase mRNA-positive circulating cells using reverse transcriptase-polymerase chain reaction (RT-PCR) in 35 patients with stage I melanoma, two patients with stage II melanoma and two patients with stage III melanoma. Among the patients with stage 1, 13 were tested before and after surgery (< 1 h). Twenty healthy subjects served as negative controls. Out of the melanoma patients, the tyrosinase gene was expressed in three of the 52 samples tested. Tyrosinase mRNA was present in the circulating cells of only one patient with stage I melanoma after intra-congenital naevi resection. However, two other stage I patients developed rapidly lethal metastasis within the following 6 months, despite the lack of detectable tyrosinase mRNA. None of stage II patients were positive for the tyrosinase transcripts, while both patients with stage III melanoma showed enzyme expression. Our results confirm those of previous studies, showing that a small proportion of stage I melanoma patients have tyrosinase-positive circulating cells. Moreover, the lack of tyrosinase mRNA detection in the blood does not necessarily exclude metastatic progression. Therefore, this study indicates that the detection of tyrosinase mRNA-positive circulating cells by RT-PCR is not a predictive biomarker of a metastasis risk in patients with stage I melanoma.
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PMID:The detection of tyrosinase mRNA in the peripheral blood of stage I melanoma patients is not of clinical relevance in predicting metastasis risk and survival. 1080 11

Sentinel node (SN) mapping and biopsy seems at present the best way to assess the nodal status in cutaneous melanoma without removing the lymphatic chain. The procedure is minimally invasive, safe and low cost, and allows selection of patients who can benefit from elective node dissection. From March 1997 up to July 1999 we examined 112 SNs excised after lymphatic mapping from 95 patients (48 males and 47 females) with stage I cutaneous melanoma affecting the trunk or limbs. Of these, 88 SNs from 74 patients were submitted to polymerase chain reaction (PCR) in order to detect tyrosinase mRNA. A new antibody (anti-tyrosinase, Clone T311, IgG2a type, Lab Vision Corporation) was used to detect nodal micrometastases. The search for micrometastases was histologically positive in 15 SNs and negative in 97. The 88 SNs examined using molecular biology were positive in 40 cases and negative in 48. In 28 only the PCR was positive. The new antibody used to detect micrometastases was shown to be very useful. Cases positive on both conventional histology and PCR were Clark level II or more and were thicker than 0.6 mm. No difference with regard to site or sex was observed. Lymphoedema and hypersensitivity reactions, nor the inability to work, did not occur. Only patients with histologically proven micrometastases underwent elective node dissection. Cases positive only on molecular biology were submitted to close follow-up.
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PMID:Detection of nodal micrometastases using immunohistochemistry and PCR in melanoma of the arm and trunk. 1193 Jan 11