Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Reverse-transcriptase polymerase chain reaction (RT-PCR) with multiple markers has been demonstrated to be highly sensitive in detecting metastatic cells in peripheral blood of malignant melanoma (MM) patients, and the circulating MM cells to be significantly correlated with disease stages. We further evaluated the presence of specific PCR-positive mRNA markers in peripheral blood as well as in regional nodes as an expression of tumor progression. Peripheral blood samples from 317 MM patients with either localized (n = 219) or metastatic (n = 98) disease were processed to obtain total cellular RNA. RT-PCR was performed using tyrosinase (TYR), p97, and MelanA/MART1 as mRNA markers. PCR products were analyzed by gel electrophoresis and Southern blot hybridization. In addition, paraffin-embedded samples of histologically proven tumor-negative lymph nodes from the subset of patients with localized disease were analyzed by RT-PCR, using radiolabeled primers for TYR and MelanA/MART1. The presence of mRNA markers was significantly correlated with tumor burden with a good correlation between risk of recurrence (evaluated in stage I-III patients) and increasing number of PCR-positive markers (p = 0.0002). Currently, for each patient, PCR results obtained at different times during follow-up are being analyzed, and any variation in the number of PCR-positive markers is being correlated to the clinical status. Molecular screening of histologically negative nodes for the presence of metastatic MM cells is also under evaluation. Preliminary assessment of a subset of MM patients with higher risk of recurrence will require longer follow-up in order to define the role of RT-PCR in monitoring these patients.
 ...
PMID:Clinical significance of PCR-positive mRNA markers in peripheral blood and regional nodes of malignant melanoma patients. Melanoma Cooperative Group. 1109 47

Reverse transcriptase-polymerase chain reaction (RT-PCR)-mediated detection of melanoma cells may be a prognostic factor for disease outcome. We investigated the presence of melanoma cells in lymphatic drainage and blood in melanoma patients after lymph node dissection (LND) via the highly sensitive multimarker (MM) RT-PCR assay. We collected 24-h lymph fluid (LY) and peripheral blood (BL) from 107 stage III melanoma patients after radical LND (59 axillary and 48 ilioinguinal LND). Tyrosinase, MART1 and uMAGE mRNA levels were determined by RT-PCR to detect melanoma cells, and the presence of at least one marker signified a positive result. All patients underwent follow-up (median for survivors, 21 months, range: 4-37 months). Forty patients (37.4%) were positive for LY MM RT-PCR and 28 (26.2%) were positive based on BL MM RT-PCR. No differences for disease-free survival (DFS) curves according to BL MM RT-PCR were observed, but we found significant differences in the estimated 24-month DFS rate for patients with at least one marker and those without any marker in lymph fluid [18.9% (95% confidence interval: 1.4-37.5%) and 42.1% (95% confidence interval: 29.7-54.5%), median: 9.9 and 15.3 months, respectively] (P=0.04). Detection of multiple markers in lymph fluid correlated with shorter DFS. Approximately 37% of lymph fluid after radical LND were positive by MM RT-PCR, which correlated significantly with early melanoma recurrences and shorter survival. The LY MM RT-PCR seems to be an effective prognostic tool for stage III melanoma patients. The MM RT-PCR analysis of single peripheral blood sample in these patients did not have additional prognostic value.
 ...
PMID:Molecular staging by multimarker reverse transcriptase-polymerase chain reaction assay of lymphatic drainage and blood from melanoma patients after lymph node dissection. 1862 8

Sentinel lymph node (SLN) biopsy has become integral in the staging of patients with melanoma, and entails detailed histologic examination with immunohistochemistry. Reverse transcriptase-polymerase chain reaction (RT-PCR) for tyrosinase transcripts has been used to increase sensitivity but requires a dedicated piece of tissue that does not undergo histologic examination. We developed a nested RT-PCR assay for tyrosinase applicable on paraffin-embedded tissue and applied this to a series of SLNs from pediatric patients with melanoma. Thirty-six SLNs from 4 females and 4 males were included in the study. Eight lymph nodes with reactive changes were included as controls. SLNs were examined histologically and immunohistochemically for S100, tyrosinase, and MART1. Seven patients had between 1 and 4 morphologically-positive SLNs and one patient had negative SLNs (HISTO+; 12/36, 33%). Three lymph nodes were excluded from molecular analysis owing to inadequate RNA, and 29 of the remaining 33 nodes were positive (MOL+; 88%). All patients had at least 1 SLN positive by RT-PCR. Twelve were HISTO+/MOL+; 17 were HISTO-/MOL+; and 4 were HISTO-/MOL-. All control lymph nodes were negative for tyrosinase transcripts. The application of RT-PCR for tyrosinase to paraffin-embedded tissue significantly increased the number of positive SLNs and upstaged one patient from negative to positive. The prognostic implications of such findings require further investigation, especially in the pediatric age group. Nonetheless, this technique provides a useful tool to determine the clinical significance of RT-PCR positivity in melanoma SLNs.
 ...
PMID:Increased detection of metastatic melanoma in pediatric sentinel lymph node biopsies using RT-PCR on paraffin-embedded tissue. 2057 43