Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lymph node metastasis is the most important prognostic factor in colon cancer. However, more accurate screening for metastasis than that afforded by conventional pathology remains elusive. We have employed a reverse transcriptase-polymerase chain reaction (RT-PCR) assay for a matrix metalloproteinase (MMP), 'matrilysin', because this gene is epithelial-specific and consistently expressed in colorectal cancer cells. The sensitivity of this assay was examined with the matrilysin-producing rectal cancer cell line 'CaR-1'. Matrilysin mRNA was detected in this system when more than 10(4) matrilysin-positive cells existed in a lymph node of ordinary size. Fourteen of 15 (93%) primary colon cancers and none of the surrounding normal tissues expressed matrilysin. All 10 histologically-positive lymph nodes were positive for matrilysin, while of 60 histologically-negative lymph nodes, eight were positive for matrilysin. When the additional sequential sectioning and histological re-examination was performed on five of these eight 'matrilysin-positive, but histologically-negative' lymph nodes, micrometastases were detected in three. Only one of the lymph nodes that were histologically-positive, but negative by matrilysin assay was from a patient with colon cancer in which matrilysin was not detected. In conclusion, RT-PCR assay for matrilysin is a sensitive method for detecting occult metastases in patients with colon cancer, and may complement histologic examination.
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PMID:Detection of regional lymph node metastases in colon cancer by using RT-PCR for matrix metalloproteinase 7, matrilysin. 950 72

Matrilysin, a member of matrix metalloproteinase family, is believed to play a significant role in the growth and proliferation of colon cancer cells. Overexpression of the matrilysin gene has been shown to correlate with Dukes' stage and increased metastatic potential in colorectal cancer. The aim of this study was to evaluate the effect of preoperative high-dose radiotherapy (25 Gy in five fractions over 5 days) on matrilysin (MMP-7) gene expression, in patients with resectable rectal cancer, by a quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). Biopsy samples of tumour (n=30) and distant normal mucosa (n=12) from 15 patients were obtained pre- and post-radiotherapy. Messenger (m)RNA was extracted from all of the tissue samples and reverse transcribed to double-stranded cDNA. Quantitative RT-PCR was performed to study the effect of preoperative radiotherapy on matrilysin gene expression in both the tumour and normal mucosal specimens. Matrilysin mRNA values were expressed relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) for each sample. In 14 out of 15 cases, matrilysin mRNA was detected in the cancerous tissue. Although all six normal mucosal specimens expressed matrilysin mRNA, the levels were approximately 10-fold lower compared with those seen in the paired tumour samples. Preoperative radiotherapy led to a significant 6- to 7-fold increase (P=0.001) in the expression of matrilysin mRNA in rectal cancer tissue. In contrast, there was no significant change in the matrilysin mRNA expression of normal mucosal specimens post-radiotherapy. Preoperative high-dose radiotherapy upregulates matrilysin gene expression in rectal cancer. Matrilysin inhibition may be a useful preventive or therapeutic adjunct to radiotherapy in rectal cancer.
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PMID:Effect of preoperative radiotherapy on matrilysin gene expression in rectal cancer. 1187 42

Oxaliplatin (L-OHP) is a new platinum analogue that has shown antitumour activity against colon cancer both in vitro and in vivo and is now used in the chemotherapeutic treatment of metastatic colon and rectal cancer. L-OHP like cisplatin (CDDP), is detoxified by glutathione (GSH)-related enzymes and forms platinum (Pt)-DNA adducts lesions that are repaired by the nucleotide excision repair system (NER). We investigated the cytotoxicity and the pharmacology of L-OHP and CDDP on a panel of six colon cell lines in vitro. We showed that GSH and glutathione S-transferase (GST) activity were not correlated to oxaliplatin cytotoxicity. Pt-DNA adducts formation and repair were correlated with CDDP, but not with L-OHP cytotoxicity. The determination of ERCC1 and XPA expression, two enzymes of the NER pathway, by reverse transcriptase-polymerase chain reaction (RT-PCR), demonstrated that ERCC1 expression was predictive of L-OHP sensitivity (r(2)=0.67, P=0.02) and XPA level after oxaliplatin exposure was also correlated to L-OHP IC(50) (r(2)=0.5; P=0.04). The knowledge of such correlations could help predict the sensitivity of patients with colon cancer to L-OHP.
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PMID:Cellular determinants of oxaliplatin sensitivity in colon cancer cell lines. 1250 67

Recurrence is a significant clinical problem for patients with rectal cancer treated with adjuvant chemoradiation. Previous studies have suggested that determining intratumoral gene expression of key genes may be helpful in predicting clinical outcome of patients with gastrointestinal malignancies undergoing chemotherapy. The role of molecular predictors for prediction of recurrence in the setting of adjuvant chemoradiotherapy is not well established. The present study was designed to identify a genetic profile that would be associated with recurrence in patients with rectal cancer treated with adjuvant chemoradiation therapy. A retrospective study with a longitudinal cohort and a cross-sectional cohort of 67 patients with locally advanced rectal cancer who underwent cancer resection, followed by 5-fluorouracil (5-FU) plus pelvic radiation was conducted. Total RNA was extracted from formalin-fixed, paraffin-embedded, laser-captured-microdissected tissue. We determined mRNA levels of genes involved in the 5-FU pathway (thymidylate synthase, dihydropyrimidine dehydrogenase), DNA-repair (excision-repair cross-complementing factor 1, Rad51), angiogenesis/radiation sensitivity [vascular endothelial growth factor (VEGF)] and radio-sensitivity [epidermal growth factor receptor (EGFR)] in tumor tissue and tumor-adjacent normal tissue by quantitative reverse transcriptase-polymerase chain reaction. In univariate analysis, only intratumoral gene expression level of VEGF (P = 0.055) was associated with recurrence, whereas elevated mRNA expression levels of thymidylate synthase (P = 0.008), VEGF (P = 0.023) and EGFR (P = 0.004) in tumor-adjacent normal tissue were significantly associated with recurrence. Multivariate analysis using recursive partitioning indicated that distinct groups of recurrence could be defined by elevated mRNA expression levels of VEGF, EGFR in tumor-adjacent normal tissue, and Rad51 in tumor tissue. These data suggest that the genetic profile of the tumor-adjacent normal tissue may be associated with treatment failure, indicating that tumor microenvironment may be more important in the development of recurrence of rectal tumors than formerly expected.
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PMID:Gene expression in tumor-adjacent normal tissue is associated with recurrence in patients with rectal cancer treated with adjuvant chemoradiation. 1684 24

The significance of dissecting the lateral pelvic lymph node (LN) for lower rectal cancer remains controversial. We detected the lateral sentinel node (SN) by indocyanine green (ICG) and micrometastases using carcinoembryonic antigen (CEA)-specific reverse transcriptase-polymerase chain reaction (RT-PCR). Twenty-five patients who underwent curative surgery with a dissection of the lateral pelvic LNs between 2003 and 2005 were examined. We investigated the existence of lateral SNs and any associations between pathological metastases and micrometastases by RT-PCR. Lateral SNs were detected in 7 (28%) of the 25 patients. The number of lateral SNs was 13 LNs, or 1.9 nodes per case. Of the 25 cases, 7 had lateral LN metastases based on pathological examinations in dissected lateral LNs. Three cases had massive lateral LN swelling by pre-operative pelvic CT and the SNs were not detected in them. The SNs were detected in two cases and were negative based on pathological examinations and positive according to a genetic diagnosis. SNs were detected in one case, which was positive based on pathological examinations and a genetic diagnosis. SN was not detected in one case. There were five SNs in which CEA was positive by RT-PCR, though only one of them was positive based on pathological examinations. No SNs were observed that were negative based on a genetic diagnosis, but were positive according to the pathological diagnosis. We detected the lateral SNs using ICG. The sensitivity of identifying lateral LN metastasis was improved by the use of a genetic diagnosis. However, the detection rate was still low, therefore we need to develop a new method for detecting SNs.
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PMID:Evaluation of the lateral sentinel node by indocyanine green for rectal cancer based on micrometastasis determined by reverse transcriptase-polymerase chain reaction. 1881 13

Despite the development of new treatment options based on the molecular characterization of colorectal cancer, 20% of patients present de novo metastatic disease, whereas 30-40% of patients who receive curative treatment relapse during follow up. Herein, we report 2 cases with rectal cancer that developed uncommon sites of metastasis; the first patient had an isolated breast metastasis, while the second patient developed bone marrow infiltration with synchronous brain metastases. In order to evaluate the uncommon metastatic pattern of rectal cancer, we detected and enumerated circulating tumor cells (CTCs) using both immunofluorescence and real-time reverse transcriptase polymerase chain reaction in these patients' peripheral blood. The procedure revealed the presence of CTCs, positive for CEACAM5 but negative for epithelial phenotype (EpCAM-), that might explain the patients' metastatic potential and survival.
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PMID:Brain and bone marrow metastases from rectal cancer. 3189 4