Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 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

Last year the Melanoma Group of the European Organization for Research and Treatment of Cancer (EORTC-MG) completed accrual (1418 patients) for trial EORTC 18952, a three-arm phase III trial evaluating adjuvant therapy with two different intermediate doses of interferon (IFN) alfa-2b versus observation for stage IIB-III melanoma. About 25% of the patients entered the trial with tumor-positive sentinel nodes (SNs). Prognosis was significantly better in SN-positive patients than in patients with palpable regional node involvement (P < .00001). Subsequently the EORTC-MG embarked on two large phase III trials of adjuvant therapy based on the tumor status of the SN. In trial EORTC 18961 for stage II melanoma, GM2-KLH/QS-21 vaccination is compared with observation (1300 patients); in trial EORTC 18991 for stage III melanoma, 5-year treatment with pegylated interferon alfa-2b (PEG-Intron) is compared with observation (900 patients). Translational research projects will compare SN assessment by hematoxylin and eosin (H&E) staining, immunohistochemistry (IHC), and reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the relative accuracy of each method and its correlation to relapse and survival of patients with stage II melanoma. In stage III patients, a similar workup of the most proximal nonsentinel node in the full lymph-node dissection specimen will indicate the accuracy of each methodology to detect nodal metastasis beyond the SN and the prognostic significance thereof. These findings will be correlated to the results of sequential blood testing by RT-PCR and by tumor marker assays for S100, TA90, and angiostatin. In addition, tumor-positive and tumor-negative SNs will be assessed for activated cytotoxic T lymphocytes and downregulation of dendritic cell functions.
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PMID:The EORTC melanoma group translational research program on prognostic factors and ultrastaging in association with the adjuvant therapy trials in stage II and stage III melanoma. European Organization for Research and Treatment of Cancer. 1159 96