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)

Receptors for granulocyte colony-stimulating factor (G-CSFRs) have been confirmed on the cell surfaces of several non-haematopoietic cell types, including bladder cancer cells. This observation has naturally led to the hypothesis that the expression of G-CSFR on these cells may enhance their growth by G-CSF. In this study, the expression of G-CSFR was determined in both established human bladder cancer cell lines and primary bladder cancers. We studied five different human bladder cancer cell lines (KU-1, KU-7, T-24, NBT-2 and KK) and 26 newly diagnosed bladder tumours. G-CSFR mRNA expressions on cultured cell lines were determined using the reverse transcriptase polymerase chain reaction (RT-PCR) method. Furthermore, the G-CSFR binding experiments on the cultured cell lines were conducted using the Na(125)I-labelled G-CSF ligand-binding assay method. Moreover, the G-CSFR mRNA expressions on primary bladder tumour specimens were assessed using the in situ RT-PCR method. Three out of the five cultured cell lines (KU-1, NBT-2 and KK) exhibited G-CSFR mRNA signals when the RT-PCR method was used. The G-CSFR binding experiments showed an equilibrium dissociation constant (K[d]) of 490 pM for KU-1, 340 pM for NBT-2 and 103 pM for KK cells. With in situ RT-PCR, the tumour cells of 6 out of 26 primary bladder tumour specimens (23.1%) presented positive G-CSFR mRNA signals. Thus, in this study, G-CSFR expression was frequently observed on bladder cancer cells. Therefore, the clinical use of G-CSF for patients with bladder cancer should be selected with great care.
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PMID:Granulocyte colony-stimulating factor receptor expression on human transitional cell carcinoma of the bladder. 916 42

The gene AML1/PEBP2 alphaB encodes the alpha subunit of transcription factor PEBP2/CBF and is essential for the establishment of fetal liver hematopoiesis. Rearrangements of AML1 are frequently associated with several types of human leukemia. Three types of AML1 cDNA isoforms have been described to date; they have been designated AML1a, AML1b, and AML1c. All of these isoforms encode the conserved-Runt domain, which harbors the DNA binding and heterodimerization activities. We have identified a new isoform of the AML1 transcript, termed AML1 deltaN, in which exon 1 is directly connected to exon 4 by alternative splicing. The AML1 deltaN transcript was detected in various hematopoietic cell lines of lymphoid to myeloid cell origin, as revealed by RNase protection and reverse transcriptase PCR analyses. The protein product of AML1 deltaN lacks the N-terminal region of AML1, including half of the Runt domain, and neither binds to DNA nor heterodimerizes with the beta subunit. However, AML1 deltaN was found to interfere with the transactivation activity of PEBP2, and the molecular region responsible for this activity was identified. Stable expression of AML1 deltaN in 32Dcl3 myeloid cells blocked granulocytic differentiation in response to granulocyte colony-stimulating factor. These results suggest that AML1 deltaN acts as a modulator of AML1 function and serves as a useful tool to dissect the functional domains in the C-terminal region of AML1.
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PMID:A novel transcript encoding an N-terminally truncated AML1/PEBP2 alphaB protein interferes with transactivation and blocks granulocytic differentiation of 32Dcl3 myeloid cells. 919 49

Hemorrhagic shock (HS) initiates a series of inflammatory processes that includes the activation of polymorphonuclear granulocytic neutrophils (PMN). We tested the hypothesis that HS induces granulocyte colony-stimulating factor (G-CSF), a cytokine that augments PMN effector functions, in the lungs of rats. Sprague-Dawley rats were subjected to compensated or decompensated HS followed by resuscitation and death at 4 or 8 h. Animals subjected to HS demonstrated acute lung injury with PMN infiltration, edema, and hypoxia. Using semiquantitative reverse transcriptase-polymerase chain reaction, we detected a 1.9- to 7.1-fold increase in G-CSF mRNA levels in the lung of animals subjected to HS compared with sham controls. Levels of G-CSF mRNA increased with increased duration of the ischemic phase of resuscitated shock. In situ hybridization revealed that bronchoepithelial cells were the major cellular site of G-CSF mRNA. Thus production of G-CSF mRNA by bronchoepithelial cells is dramatically increased in a rat model of HS that also demonstrated lung injury. Increased local G-CSF levels may contribute to PMN recruitment and activation and resultant lung injury in HS.
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PMID:Hemorrhagic shock induces G-CSF expression in bronchial epithelium. 937 35

Polymorphonuclear neutrophils (PMNs) are essential effector cells in host defense and tissue inflammatory responses. These responses may be initiated after cross-linking of cell surface Fc receptors that bind the constant portion of IgG (FcgammaR). We evaluated the effect of cross-linking FcgammaRI or FcgammaRII on interleukin-6 (IL-6) production by purified PMNs from normal donors or from patients being treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF). In PMNs from normal donors, IL-6 mRNA was detected by reverse transcriptase-polymerase chain reaction only after FcgammaRI or FcgammaRII cross-linking. We also found that IL-6 mRNA could be detected in PMNs after either in vitro or in vivo rhG-CSF treatment in the absence of FcgammaR cross-linking. IL-6 protein was found to be produced intracellularly and secreted by PMNs after cross-linking FcgammaRI or FcgammaRII or after rhG-CSF stimulation. Cross-linking FcgammaRI or FcgammaRII on PMNs from patients treated with rhG-CSF resulted in a synergistic increase in IL-6 secretion. Upregulation of IL-6 production by PMNs after rhG-CSF treatment may contribute to a clinical engraftment syndrome that occurs during periods of rapid increase in PMN numbers in patients receiving rhG-CSF.
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PMID:Interleukin-6 production by human neutrophils after Fc-receptor cross-linking or exposure to granulocyte colony-stimulating factor. 949 Jun 96

During human development, the liver and marrow both function as hematopoietic organs, but little is known about differences in the production of macrophages and neutrophils by these two organs. We used immunohistochemical stains to quantify the ratio of neutrophils to macrophages within the liver and the marrow of 16 fetuses from 5 to 16 wk postconception. At 5 wk the liver had a ratio of one granulocyte [myeloperoxidase (MPO)-positive cell] to every 9 +/- 5 (X +/- SD) macrophages (KP-1-positive cells). Between 5 and 16 wk, the granulocyte to macrophage ratio in the liver was constant, whereas it changed markedly in the marrow. Before 8 wk no MPO-positive or KP-1-positive cells were observed in bones. At 10 wk, bones still had no MPO-positive cells, but KP-1-positive cells were abundant. At 11-12 wk the granulocyte to macrophage ratio was 1 to 1 +/- 1, but by 13-16 wk it had increased to 8 +/- 3 MPO-positive cells to one KP-1-positive cell. We hypothesized that at 13-16 wk the abundance of MPO-positive cells in the marrow and their scarcity in the liver was the result of production of granulocyte colony-stimulating factor (G-CSF) and its receptor (G-CSF-R) in the marrow and their absence in the liver. However, by reverse transcriptase-PCR mRNAs for G-CSF and G-CSF-R were positive in both organs at all gestations, and G-CSF and G-CSF-R proteins (by immunohistochemistry) were also abundant in all liver and marrow specimens. We then hypothesized that progenitors in the fetal liver were intrinsically different from those in the marrow, and were unable to generate clones of neutrophils. However, progenitors from the liver produced neutrophils abundantly in culture. Thus, the explanation is likely related to as yet undescribed environmental differences between the fetal liver and marrow.
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PMID:Hematopoiesis in the liver and marrow of human fetuses at 5 to 16 weeks postconception: quantitative assessment of macrophage and neutrophil populations. 962 87

Previous reports showed that granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cells (G-PBMC) are hyporesponsive to alloantigen compared with control PBMC. In the current study, neutralizing antibodies to interleukin-10 (IL-10) increased the proliferative response of G-PBMC to alloantigen by 50. 14% (+/- 12.79%; n = 8), whereas the proliferative response of control PBMC was not affected. The inhibition of OKT3-stimulated CD4 cell proliferation by G-PBMC-derived CD14(+) cells could also be abrogated by the addition of IL-10 neutralizing antibodies. Further, IL-10 levels correlated with the number of CD14 cells in these cultures. Constitutive IL-10 mRNA levels detected by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) were 10-fold higher in G-PBMC compared with control PBMC. This translated into significantly higher IL-10 levels after 24-hour lipopolysaccharide (LPS) stimulation of G-PBMC compared with control PBMC (P = .036). IL-10 mRNA levels were also fivefold higher in isolated G-PBMC-derived CD14 cells compared with control CD14 cells. This corresponded to increased constitutive production of IL-10 by isolated G-PBMC-derived CD14 cells compared with control CD14 cells (357.2 +/- 104.5 v 51.7 +/- 30.5, P = .051). In conclusion, these data suggest that monocytes contained within G-PBMC, which, in comparison to marrow, are increased in absolute number and relative proportion to T cells, may suppress T-cell responsiveness by secretion of IL-10.
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PMID:Production of interleukin-10 by granulocyte colony-stimulating factor-mobilized blood products: a mechanism for monocyte-mediated suppression of T-cell proliferation. 963 19

It is well-known that low dose cytosine arabinoside (LDAC) has activity in elderly patients with acute myeloid leukemia (AML). Several studies have shown that AML patients with t(8;21) in long term complete remission (CR) following intensive chemotherapy or allogeneic bone marrow transplantation (BMT) still have persistence of AML1-MTG8 transcripts by reverse transcriptase polymerase chain reaction (RT-PCR) method. We report here a patient who has no evidence of residual disease detectable by RT-PCR after LDAC. A 69-year-old patient did not obtain CR after two courses of intensive chemotherapy with behenoyl-ara-C, daunorubicin, 6-mercaptopurine and prednisolone. He received subcutaneous LDAC 10 mg every 12 h and granulocyte colony-stimulating factor (G-CSF) for 29 days and achieved CR. He continued on a 21 to 28-day course of LDAC without G-CSF every 2 or 3 months and has remained well and in CR for 5 years without chimeric AMLI-MTG8 transcript by RT-PCR. LDAC therapy seems to be effective in eradicating the leukemic clone as post-induction or maintenance therapy in this patient. This is the first case report of the disappearance of AML1-MTG8 transcript by RT-PCR in a patient with t(8;21) in long-term remission after LDAC.
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PMID:Disappearance of AML1-MTG8 transcript by reverse transcriptase polymerase chain reaction in a patient in remission of acute myeloid leukemia (M2) after low-dose cytosine arabinoside. 971 19

In multiple myeloma (MM), the VDJ rearrangement of the immunoglobulin heavy chain expressed by MM plasma cells provides a unique clonotypic marker. Although clonotypic MM cells have been found in the circulation, their number has been controversial. Our objective was to provide direct evidence, using single-cell assays, for the frequency of clonotypic cells in blood of 18 MM patients, and to confirm their identity as B cells. The clonotypic Ig heavy-chain (IgH) VDJ was determined from single plasma cells using consensus reverse transcriptase-polymerase chain reaction (RT-PCR), subcloning, and sequencing. For all patients, using patient-specific primers, clonotypic transcripts were amplified from 10 or more individual plasma cells. Using in situ RT-PCR, for all patients greater than 80% of plasma cells were found to be clonotypic. Three separate methods, RT-PCR, single-cell RT-PCR, and in situ RT-PCR, were used to analyze clonotypic cells in peripheral blood mononuclear cells (PBMC) from MM patients. Sequencing of the IgH transcripts expressed by individual cells obtained by limiting dilution of freshly isolated PBMC from a MM patient showed that all B cells expressed an identical CDR3. This intraclonal homogeneity indicates an escape from antigenic-selection, characteristic of malignant B cells. For this patient, the frequency of clonotypic PBMC, about 25%, was comparable to the number of PBMC B cells (34%). Because the PBMC included less than 1% plasma cells, virtually all clonotypic PBMC must be B cells. Using single-cell RT-PCR, clonotypic IgH transcripts were identified in individual sorted B cells from blood. To accurately quantify the number of clonotypic B cells, sorted B cells derived from 18 MM patients (36 samples) and 18 healthy donors (53 samples) were analyzed using in situ RT-PCR with patient-specific primers. Clonotypic transcripts were not detectable among normal B cells. For the 18 MM patients, a mean of 66% +/- 4% (SE) of blood B cells were clonotypic (range, 9% to 95%), with mean absolute number of 0.15 +/- .02 x 10(9)/L blood. Over time in individual patients, conventional chemotherapy transiently decreased circulating clonotypic B cells. Their numbers were increased in granulocyte colony-stimulating factor (G-CSF)- mobilized blood of one patient. However, clonotypic B cells of a one patient became undetectable after allogeneic transplant, correlating with complete remission. Although contributions to MM spread and progression is likely, their malignant status and impact has yet to be clarified. Their high frequency in the blood, and their resistence to conventional chemotherapy suggests that the number of circulating clonotypic cells should be clinically monitored, and that therapeutic targeting of these B cells may benefit myeloma patients.
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PMID:A high frequency of circulating B cells share clonotypic Ig heavy-chain VDJ rearrangements with autologous bone marrow plasma cells in multiple myeloma, as measured by single-cell and in situ reverse transcriptase-polymerase chain reaction. 976 69

Several reverse transcriptase polymerase chain reaction (RT-PCR) assays have been described for the detection of circulating tumour cells in blood and bone marrow. Target mRNA sequences for this purpose are the cytokeratins (CK) 19 and 20, the carcinoembryonic antigen (CEA), and the prostate-specific antigen messages. In this study, we investigated biological factors influencing the specificity of the CK19 and CEA RT-PCR assays. Bone marrow, granulocyte colony-stimulating factor (G-CSF)-mobilized blood stem cells and peripheral blood samples obtained from healthy volunteers (n = 15; CEA n = 7), from patients with epithelial (n = 29) and haematological (n = 23) cancer and from patients with chronic inflammatory diseases (n = 16) were examined. Neither CEA nor cytokeratin 19 messages could be amplified from bone marrow samples from healthy subjects and from patients with haematological malignancies. In contrast, specimens from patients with inflammatory diseases scored positive up to 60%. To investigate the influence of inflammation on target mRNA expression, haemopoietic cells were cultured with and without cytokine stimulation in vitro. CK19 messages could be easily detected in cultured marrow cells without further stimulation, CEA messages only after gamma-interferon (gamma-INF) stimulation. In contrast, G-CSF-mobilized peripheral blood stem cells were positive for CK19 messages only after stem cell factor (SCF) or interleukin stimulation. We conclude that transcription of so-called tissue-specific genes is inductible in haemopoietic tissues under certain conditions. These factors have to be considered in future applications of RT-PCR for the detection of minimal residual disease.
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PMID:Specificity of reverse transcriptase polymerase chain reaction assays designed for the detection of circulating cancer cells is influenced by cytokines in vivo and in vitro. 982 Jan 79

We compared the cell cycle status and expression of mRNA for the amphotropic retroviral receptor in hematopoietic stem cells isolated from bone marrow and cytokine mobilized peripheral blood. CD34+ cells from six normal volunteers were enriched by immune selection from steady-state bone marrow and granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood (10 microg/kg/day for 5 days). Cell cycle status of the phenotypically primitive CD34+CD38- hematopoietic stem cell population was analyzed using a four-color flow cytometry technique that distinguished the G0, G1, and S/IG2/M phases of the cell cycle. Semiquantitative reverse transcriptase-polymerase chain reaction was performed to measure mRNA expression of the amphotropic retroviral receptor. Peripheral blood hematopoietic stem cells had 2.6-fold more cells in the G1 phase of the cell cycle compared to steady-state bone marrow. Furthermore, lineage CD34+CD38- cells from G-CSF mobilized peripheral blood had a fourfold higher level of amphotropic retrovirus receptor mRNA. In conclusion, we found that CD34+ CD38- hematopoietic stem cells isolated from G-CSF mobilized peripheral blood differ from those isolated from steady-state bone marrow in that a significant proportion have entered the G1 phase of the cell cycle and express higher levels of amphotropic receptor mRNA. These biologic properties are consistent with the reported rapid recovery of hematopoietic function following transplantation with peripheral blood hematopoietic stem cells and make these cells a preferred target for retroviral-based gene transfer.
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PMID:Granulocyte colony-stimulating factor mobilized peripheral blood stem cells enter into G1 of the cell cycle and express higher levels of amphotropic retrovirus receptor mRNA. 1039 Jan 91


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