Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Retinoic acids (RAs) exert pleiotropic effects on cellular growth and differentiation. All-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA), a stereoisomer of ATRA, induce differentiation of leukemic cell lines and cells from patients with acute myelogenous leukemia (AML) in vitro. Despite information on the effects of RAs on hematopoietic cells, little is known about how RAs act on the hematopoietic microenvironment, especially on bone marrow stromal cells. Based on recent observations that various cytokines produced mainly by bone marrow stromal cells regulate hematopoiesis, we analyzed the effects of RAs on cytokine production by these cells. ATRA or 9-cis RA treatment of human bone marrow stromal cell line KM101, which produces macrophage colony-stimulating factor (M-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) constitutively, enhanced mRNA levels of both cytokines in a dose-dependent manner. Both RAs also stimulated M-CSF production from primary cultures of human bone marrow stromal cells. Both retinoic acid receptor (RAR)-alpha and retinoid X receptor (RXR)-alpha were expressed constitutively in KM101 cells. ATRA did not affect the expression of either receptor, whereas 9-cis RA increased RXR-alpha mRNA expression in a dose-dependent manner, but did not affect levels of RAR-alpha mRNA. These findings may have important biologic implications for both the role of RAs in hematopoiesis and the therapeutic effects of ATRA on the hematopoietic microenvironment in patients with acute promyelocytic leukemia (APL).
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PMID:Retinoids (all-trans and 9-cis retinoic acid) stimulate production of macrophage colony-stimulating factor and granulocyte-macrophage colony-stimulating factor by human bone marrow stromal cells. 799 28

Acute promyelocytic leukemia (APL) is a homogeneous subgroup of acute myeloid leukemias (AMLs) characterized by the presence of the t(15,17) translocation and the resulting promyelocytic myeloid leukemia/retinoic acid receptor alpha (PML/RAR alpha) fusion proteins. To date APL is the only AML that is sufficiently sensitive to all-trans retinoic acid's (ATRA) differentiating effect. In vivo ATRA alone achieves complete remission in most APL patients. However, failure or partial responses are observed and the molecular basis of the absence of ATRA response in these patients has not been determined. To gain insights in the cell growth and differentiation of APL cells, expression of hematopoietic growth factors (HGF) shown to be produced by leukemic cells (interleukin-1 beta [IL-1 beta], IL-6, tumor necrosis factor alpha (TNF alpha), granulocyte colony-stimulating factor [G-CSF], granulocyte-macrophage colony-stimulating factor [GM-CSF], and IL-3) was studied in 16 APL samples. Twelve APL cases expressed IL-1 beta, IL-6, and TNF alpha, but not G-CSF, GM-CSF, and IL-3. These cases achieved complete remission with ATRA therapy. The four remaining patients (either TNF alpha negative or G-CSF, GM-CSF or IL-3 positive) did not achieve complete remission with ATRA. In all cases, in vivo response to ATRA therapy was correlated to the in vitro differentiation effect of all-trans retinoic acid 10(-6) mol/L. Thus, ATRA differentiation induction was strongly correlated to the HGF expression (P < .0001). These results suggest that the presence or absence of HGF's expression by APL cells may contribute to the therapeutic effect of ATRA in this disease.
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PMID:Hematopoietic growth factor expression and ATRA sensitivity in acute promyelocytic blast cells. 819 61

In previous studies, it was shown that the fusion region of the pml/RAR-alpha protein, expressed by acute promyelocytic leukemia (APL) cells, can be specifically recognized in vitro by donor (D. E. ) CD4 T cells in a HLA class II DR11-restricted fashion. We present here the results on the recognition of several pml/RAR-alpha peptides by APL patients expressing HLA DR11. The in vitro immunization of peripheral blood lymphocytes from four patients in remission (S. R., F. R., M. M., P. G.) with BCR1/25, a 25-mer pml/RAR-alpha, did not elicit either a polyclonal or a clonal immune response specific to the peptide. We then generated new donor anti-pml/RAR-alpha CD4(+) T-cell clones. These clones were tested for their recognition of BCR1/25. One clone (C3/5, CD3(+), CD4(+), CD8(-)) was selected for further analysis. Clone C3/5 showed specific proliferation, cytotoxicity, and cytokine (tumor necrosis factor alpha, granulocyte-macrophage colony-stimulating factor) production when challenged with autologous lymphoblastic cell lines pulsed with peptide BCR1/25. C3/5 cells developed specific proliferation and cytotoxicity when challenged with peptide-pulsed lymphoblastic cell lines and peripheral blood lymphocytes from the four DR11(+) APL patients. APL blasts, available only from patients F. R. and P. G., were not lysed by C3/5 and were unable to present peptide BCR1/25. Incubation of APL cells with IFN-gamma failed to induce HLA class II molecules and recognition by the C3/5 clone. Since APL cells do not express HLA class II molecules, we tested in two donors (D. E. and C. H. R.) and in patients S. R. and P. G. whether the use of 9-mer peptides (BCR1/9) would generate a CD8/HLA class I-restricted response. No peptide-specific T-cell line or clone could be generated from both donors and patients. These findings are discussed in relation to possible therapeutic approaches to the immunotherapy of APL.
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PMID:Lack of T-cell-mediated recognition of the fusion region of the pml/RAR-alpha hybrid protein by lymphocytes of acute promyelocytic leukemia patients. 981 8

Several lines of investigation suggest that granulocyte colony-stimulating factor (G-CSF) augments all-trans retinoic acid (ATRA)-induced neutrophil differentiation in acute promyelocytic leukemia (APL). We sought to characterize the relationship between G-CSF- and ATRA-mediated neutrophil differentiation. We established a G-CSF receptor-transduced promyelocytic cell line, EPRO-Gr, derived from the granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent EPRO cell line harboring a dominant-negative retinoic acid receptor alpha (RARalpha). In EPRO-Gr, neutrophil differentiation occurs either in GM-CSF upon addition of ATRA or upon induction with G-CSF alone. Transient transfection of EPRO-Gr cells with a RARE-containing reporter plasmid demonstrates increased activity in the presence of ATRA, but not G-CSF, while STAT3 phosphorylation occurs only in response to G-CSF. This suggests that ATRA-mediated differentiation of EPRO-Gr cells occurs via a RARE-dependent, STAT3-independent pathway, while G-CSF-mediated differentiation occurs via a RARE-independent, STAT3-dependent pathway. ATRA and G-CSF thus regulate differentiation by divergent pathways. We characterized these pathways in the APL cell line, NB4. ATRA induction of NB4 cells resulted in morphologic differentiation and up-regulation of C/EBPepsilon and G-CSFR, but not in STAT3 phosphorylation. The addition of G-CSF with ATRA during NB4 induction resulted in STAT3 phosphorylation but did not enhance differentiation. These results may elucidate how G-CSF and ATRA affect the differentiation of primary and ATRA-resistant APL cells.
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PMID:G-CSF signaling can differentiate promyelocytes expressing a defective retinoic acid receptor: evidence for divergent pathways regulating neutrophil differentiation. 1460 78