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:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have analysed the capacity of the 11 phase-variable, opacity-associated (Opa) proteins encoded by Neisseria gonorrhoeae MS11 to mediate traversal across polarized monolayers of the human colonic carcinoma T84 cell line. Gonococci expressing either the heparan sulphate proteoglycan (HSPG) binding Opa protein (Opa50) or no Opa protein (Opa-) did not interact with the apical pole of T84 monolayers, whereas the 10 variant Opa proteins previously shown to bind CD66 receptors were found to mediate efficient gonococcal adherence and transepithelial traversal. Consistent with this, T84 cells were shown by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblotting to co-express CD66a (BGP), CD66c (NCA) and CD66e (CEA). The recruitment of CD66 receptors by Opa-expressing gonococci indicates their involvement in mediating adherence to the surface of T84 cells, and these bacterial interactions could be inhibited completely using polyclonal antibodies cross-reacting with all of the CD66 proteins co-expressed on T84 cells. Consistent results were obtained when Opa proteins were expressed in Escherichia coli, suggesting that the Opa-CD66 interaction is sufficient to mediate bacterial traversal. Transcytosis of Opa-expressing N. gonorrhoeae or E. coli did not disrupt the barrier function of infected monolayers, as indicated by a sustained transepithelial electrical resistance (TEER) throughout the course of infection, and confocal laser scanning and electron microscopy both suggest a transcellular rather than a paracellular route of traversal across the monolayers. Parallels between the results seen here and previous work done with organ cultures confirm that T84 monolayers provide a valid model for studying neisserial interactions with the mucosal surface, and suggest that CD66 receptors contribute to this process in vivo.
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PMID:Opa binding to cellular CD66 receptors mediates the transcellular traversal of Neisseria gonorrhoeae across polarized T84 epithelial cell monolayers. 982 30

Anaplastic thyroid carcinoma is a rapidly growing, aggressive neoplasm affecting the elderly which does not respond to most of the therapies. We established cultured cell lines from four untreated tumors. The cultures grew in a monolayer of spindle-shaped cells in three cell lines and of small polygonal cells in one line, having relatively long doubling times and chromosomal abnormalities. The xenotransplantation of the lines in athymic nude mice produced tumors with a histology similar to the original tumors. The immunocytochemical staining showed the expression of PCNA, HLA-class 1, cytokeratin, vimentin and FAS (fatty acid synthase) but not CEA, desmin or P-glycoprotein. The lines secreted TPA, IL-6, IL-8 and few or no thyroid-related hormones in the culture supernatant. One cell line produced G-CSF. The chemosensitivity assay revealed intrinsic drug resistance to nine out of 11 antineoplastic agents. The reverse transcriptase-polymerase chain reaction (RT-PCR) detected MRP (multidrug resistance-associated protein) mRNA but not mdr (multidrug resistance protein)-1 and mdr-3 mRNAs. This finding indicates that the multidrug resistance of these lines is mediated by a P-glycoprotein-unrelated mechanism. The RT-PCR also presented FAS mRNA in all the lines, and IL-6 and IL-8 mRNAs in some of the lines.
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PMID:Biological characteristics and chemosensitivity profile of four human anaplastic thyroid carcinoma cell lines. 1168 81

In small-cell lung carcinoma (SCLC) tumour cell contamination of leukaphereses is unknown. The present study was performed to define appropriate markers for reverse transcriptase polymerase chain reaction (RT-PCR), then to assess the contamination rate of leukaphereses and corresponding bone marrow samples. Immunocytochemistry (ICC) and RT-PCR methods were also compared. Among the 33 patients included, analyses were performed in 16 who had multiple leukaphereses and 17 who had only bone marrow. Leukapheresis products and bone marrow were analysed by ICC using several specific monoclonal antibodies against neural-cell adhesion molecule (N-CAM), epithelial glycoprotein (EGP-40) and cytokeratins (CK). Samples were also analyzed by RT-PCR for expression for N-CAM, synaptophysin, neuron-specific enolase, chromogranin, cytokeratin-18/-19, CEA, EGP-40, apomucin type 1 (MUC-1) and human endothelial cell-specific molecule (ESM-1). Using ICC staining, contaminating tumour cells were detected in 34% of leukaphereses (27% in patients with limited disease and 43% in those with extensive disease). N-CAM was the most reliable marker for detection of contamination. For RT-PCR, CK-19 and CEA were the only appropriate markers. Positive signal rate in leukaphereses increased to 78% (89% for patients with limited disease and 67% for extensive disease). In bone marrow, both techniques were in agreement whereas in leukaphereses, RT-PCR was better than ICC. A high rate of tumour cell contamination was demonstrated not only in bone marrow but also in leukaphereses from SCLC patients. The most appropriate technique was RT-PCR mainly in patients with limited disease.
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PMID:High tumour contamination of leukaphereses in patients with small cell carcinoma of the lung: a comparison of immunocytochemistry and RT-PCR. 1174 93

Bone marrow is a prognostically relevant indicator organ for micrometastasis. In the present study, real time quantitative reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect disseminated gastric cancer cells in bone marrow. We compared CEA, CK18 and CK20 expression using four gastric cancer cell lines and three normal tissue cell lines in order to select the most appropriate marker for detection of disseminated gastric cancer cell in bone marrow. CK20 proved to be the most promising marker since the expression level of normal cell lines was extremely low and about 50--100-fold differences were found between gastric carcinoma cell lines and normal tissue cell lines. We also screened bone-marrow RNA of 47 patients with gastric cancers, using this system. Among the three markers we tested, with only about CK20 could we find that 27 of 47 patients were positive. Though long-term clinical follow up studies are needed to evaluate the clinical significance of this method, real time quantitative RT-PCR is sensitive and quantitative for detection of micrometastasis in bone marrow.
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PMID:Detection of disseminated cancer cells in bone marrow of gastric cancer using real time quantitative reverse transcriptase polymerase chain reaction. 1240 64

Four carcinoembryonic antigen-related cell adhesion molecule (CEACAM)s, i.e. CEA, CEACAM1, CEACAM6 and CEACAM7, are localized to the apical glycocalyx of normal colonic epithelium and have been suggested to play a role in innate immunity. The expression of these molecules in colon carcinoma cells was studied at the mRNA and protein levels after treatment with interferon-gamma (IFN-gamma), interleukin-1beta, live bacteria or lipopolysaccharide. The colon carcinoma cell lines LS174T and HT-29 were studied in detail using real-time quantitative reverse transcriptase-polymerase chain reaction, immunoflow cytometry and immunoelectron microscopy. IFN-gamma, but not the other agents, modified expression of CEA, CEACAM1 and CEACAM6. None of the agents upregulated CEACAM7 expression. Two expression patterns were seen. HT-29 cells, which initially showed low quantities of mRNAs and proteins, displayed marked upregulation of both mRNAs and proteins. LS174T cells transcribed stable high levels of mRNA before and after treatment. Additionally, IFN-gamma induced increased cell surface expression of CEA, CEACAM1 and CECAM6. IFN-gamma has two important effects on the expression levels of the CEA family molecules in colon epithelial cells: direct upregulation of CEACAM1 and promotion of cell differentiation resulting in increased expression of CEA and CEACAM6 and decreased expression of CEACAM7.
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PMID:Interferon-gamma tempers the expression of carcinoembryonic antigen family molecules in human colon cells: a possible role in innate mucosal defence. 1463 19

Circulating cell detection using reverse transcriptase-polymerase chain reaction (RT-PCR) techniques has been studied as a new prognostic factor in colorectal cancer patients. With the view of enhancing detection sensitivity, we developed a new multiplex RT-PCR assay for circulating cell detection based on the expression of carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5; formerly CEA) and CEACAM7 (formerly CGM2). Between November 2002 and December 2003, 45 stage III-IV, 39 stage I-II colorectal cancer patients, 32 non-colorectal cancer patients and 41 healthy individuals were included. Positive selection using HEA-125 immunobeads was applied to blood samples before mRNA extraction, cDNA synthesis and a multiplex CEACAM5/CEACAM7 RT-PCR assay. For both CEACAM5 and CEACAM7, the limit of detection was found to be as low as 1 expressing cell in 10(6) nucleated blood cells. The multiplex RT-PCR assay was negative for the 41 healthy individuals and the 32 non-colorectal cancer patients. The test was positive in 53/84 (63%) of the colorectal cancer patients for CEACAM5 and/or CEACAM7, whereas 32/84 (38%) were positive for both markers. Colorectal cancer patients were positive for one of the two markers in 80% of cases (36/45) for stage III-IV patients (CEACAM5 73%, CEACAM7 51%) and in 44% of cases (17/39) for stage I-II patients. This multiplex RT-PCR assay with two markers proved to be more sensitive than use of a single marker in detecting circulating tumour cells. The discrepant expression of CEACAM5 and CEACAM7 may label circulating tumour cells that have different levels of differentiation and subsequent aggressive behaviour.
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PMID:Immunobead multiplex RT-PCR detection of carcinoembryonic genes expressing cells in the blood of colorectal cancer patients. 1584 4

This study was designed to perform methylation-specific polymerase chain reaction (MS-PCR) assay for p16, E-cadherin, and retinoic acid receptor beta genes on peripheral blood samples from patients with esophageal squamous cell cancers, and compare the results of MS PCR with conventional serum tumor markers and the CEA-specific reverse transcriptase polymerase chain reaction (RT-PCR) assay. Preoperative blood samples were obtained from 30 patients with esophageal cancer, and were subjected to MS PCR and RT-PCR assays. Eleven patients (37%) showed aberrant methylation of the promoter region of at least one gene. On the other hand, circulating tumor cells were detected in 11 patients (37%). There was no correlation between both results and conventional tumor markers. The MS-PCR and RT-PCR assays can serve as complementary diagnostic markers for screening and monitoring patients with esophageal cancers.
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PMID:[Plasma methylation-specific polymerase chain reaction as a diagnostic tool for esophageal cancer patients]. 1721 85

Several molecular approaches, using peripheral blood of patients with cancers, have been assessed recently for ability to detect various primary and recurrent cancers at an early stage. One is the reverse transcriptase polymerase chain reaction (RT-PCR) analysis, which can detect a small number of circulating cancer cells. Another is the methylation-specific polymerase chain reaction (MSP), which detects tumor-specific alterations of cell-free serum DNA released from tumor into the circulation by necrosis and/or apoptosis. In the present study, we set out to assess the diagnostic value of the RT-PCR assay and the MSP assay for an early detection of recurrent diseases in patients after curative gastrectomy. Two of the 25 patients (8%) exhibited a CEA specific signal in their peripheral blood. On the other hand, seven patients (28%) showed aberrant methylation of the promoter region of at least one gene (3 patients for p16, 3 for E-cadherin, 3 for RARbeta genes, and 1 for CDH4 respectively). No abnormal signal was detected in sera from volunteers who served as controls. Of 10 patients who developed recurrences, a CEA-specific signal and aberrant methylation was demonstrated in plasma samples of 1 and 4 patients, respectively. One patient, without definite findings of recurrence at the time of analysis, developed recurrences 6 months later. Both assays can serve as markers that allow selection of those cases requiring more intensive screening and aggressive postoperative treatment.
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PMID:[An early detection of recurrence using reverse transcriptase-polymerase chain reaction (RT-PCR) and methylation-specific polymerase chain reaction (MSP) from peripheral blood in patients after gastrectomy]. 1721 86

Bone marrow (BM) biopsy has been suggested as an independent prognostic tool to improve staging in patients with breast cancer. Two hundred and ten consecutive patients operated for breast cancer from June 2000 to June 2005 who signed an informed consent were enrolled in this protocol. Patients underwent SLN biopsy, and lymph nodes were analysed with serial sections and stained with hematossilin-eosin and immunohistochemistry. At the end of the procedure a BM aspirate from the iliac crest was obtained and 5-10 cc of blood collected. A CEA specific nested reverse transcriptase (RT) polymerase chain reaction (PCR) assay was used to examine BM samples. Results were blinded to both patients and clinicians. The median age of the patients was 56 years (range 34-80), and the median tumor diameter 1,5 cm (range 0.2-4.5). BM aspirates were unsuccessful in ten patients, and RT-PCR was not technically feasible in seventeen women, leaving 183 patients available for analysis of results and follow up. SLN biopsy allowed diagnoses of occult metastases (micrometastases and isolated tumor cells) in 16% of patients (29/183). 25% of T1N0 patients (23/92), 35% of T2N0 patients (6/17), and 44% of N1-2 patients (32/72) were BM+ (p = 0.03). At a median follow up of 35 months 5/122 in the BM- group and 6/61 in the BM+ group have relapsed (p = 0.2), while 1/122 and 4/61 have died of disease (p = 0.04) In conclusion, ultrastaging of breast cancer patients may identify a substantial subgroup of patients N-/BM- who may not require adjuvant chemotherapy, as well as a subgroup N-/BM+ with a decreased survival who may need more aggressive therapies. Further follow-up is needed to confirm this hypothesis, and several studies are under way.
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PMID:Bone marrow and sentinel lymph node biopsy in patients with breast cancer: from staging to ultrastaging? 1731 Aug 38

Early detection of colorectal cancer (CRC) is desired for reducing its mortality rate. Recently, the feasibility of a new method for isolating colonocytes from feces was demonstrated, followed by direct sequencing analysis for detecting colorectal cancer. In the present study, gene expression analysis was conducted using quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR). One hundred and sixty-six patients with CRC and 134 healthy volunteers were enrolled. Messenger RNA expressions of CEA, MMP7, MYBL2, PTGS2 and TP53 in the colonocytes isolated from feces were analyzed by quantitative real-time RT-PCR. Beta-2-microglobulin, used for internal control, could not be detected in approximately 25% each of the CRC patients (39/166) and healthy volunteers (33/134). CEA expression did not differ significantly between CRC patients and healthy volunteers (P = 0.21). MMP7, MYBL2, PTGS2 and TP53 gene expressions were significantly higher in CRC patients than in healthy volunteers (P < 0.001). The overall sensitivity and specificity using these gene expressions were 58.3% (74/127, 95% CI; 49.2-67.0) and 88.1% (89/101, 95% CI; 80.2-93.7), respectively. The sensitivity was dependent on the tumor location (P = 0.01) and tumor size (P = 0.02), but not the tumor depth (P = 0.06) or cancer stage (P = 0.37). Gene expression analysis of colonocytes isolated from feces may be a useful method for CRC screening, if the number of isolated colonocytes is sufficiently high for analysis by quantitative real-time PCR. Therefore, improvement of the colonocyte retrieval system from feces may be necessary for the technique to be developed for clinical use.
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PMID:Detection of colorectal cancer cells from feces using quantitative real-time RT-PCR for colorectal cancer diagnosis. 1901 57


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