Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the long-term in vivo effects of recombinant granulocyte-macrophage colony stimulating factor (rhGM-CSF) on granulocyte functions in nine patients with myelodysplastic syndrome (MDS). The treatment schedule consisted of a 14 d course of rhGM-CSF (250 micrograms/m2/d s.c.) for patients with refractory anaemia (RA) and refractory anaemia with ringed sideroblasts (RARS), while patients with refractory anaemia with excess of blasts (RAEB) and refractory anaemia with excess blasts in transformation (RAEBt) received a 14 d combination course of rhGM-CSF (250 micrograms/m2 s.c.) and low dose cytosine arabinoside (20 mg/m2 s.c.). rhGM-CSF increased the mean neutrophil count from 3.9 x 10(9)/l to 44 x 10(9)/l. Significant increases of myeloperoxidase content in granulocytes occurred during treatment (P = 0.003). Phagocytosis and killing of Staph. aureus by granulocytes was markedly enhanced during treatment. Microbicidal capacity normalized in four out of six patients during GM-CSF therapy. However, chemotaxis in response to zymosan-activated serum (ZAS) and f-Met-Leu-Phe (f-MLP), was further impaired on the last day of treatment, which was associated with a marked increase in the expression of the granulocyte adhesion receptors CD11a (P = 0.01), CD11b (P = 0.002), CD11c (P = 0.00015) and CD18 (P = 0.0014). GM-CSF therapy did not cause significant changes in hexose monophosphate (HMP)-shunt activity, chemiluminescence, nor superoxide production. The present results show that in vivo administration of GM-CSF is able to repair at least in part the neutrophil anomalies in patients with myelodysplastic syndrome (MDS), which might be useful in modulating host response to infections. However, increased adherence and impaired chemotaxis may explain some toxicities observed during treatment with GM-CSF.
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PMID:In vivo administration of granulocyte-macrophage colony stimulating factor enhances neutrophil function in patients with myelodysplastic syndromes. 195 74

f-Met-Leu-Phe-stimulated luminol-enhanced chemiluminescence was found to be repeatedly defective in some MDS patients. This defect was not attributed to myeloperoxidase deficiency, nor to a defect in NADPH oxidase function, because PMA chemiluminescence was found to be normal in these individuals. An arbitrary value of 7 mV (half the mean control value) was chosen to subdivide the group: MDS patients with values < 7 mV had a mean f-Met-Leu-Phe chemiluminescence response of 2.5 +/- 0.5 compared to MDS patients with values > 7 mV who had a mean response of 15.6 +/- 1.6 mV, P < 0.01 (healthy controls 14 +/- 2 mV). The characteristics of the f-Met-Leu-Phe receptor and initial calcium flux results suggested that the receptor itself was normal in number and function in low f-Met-Leu-Phe responders. The rate of superoxide generation, which is calcium-dependent, was also found to be in the normal range in low f-Met-Leu-Phe responders, although total superoxide production was reduced in some of these patients. When MDS neutrophils with a low f-Met-Leu-Phe response were stimulated with PMA, chemiluminescence was normal, suggesting normal activity of the NADPH-oxidase complex. Furthermore, myeloperoxidase activity was reduced in only three out of the 11 low f-Met-Leu-Phe responders. Following priming with GM-CSF, f-Met-Leu-Phe chemiluminescence was 27 +/- 1.6 mV in low f-Met-Leu-Phe responders compared to controls (87.7 +/- 11 mV, P < 0.005). Thus, although responses were improved, they were not as marked as in control neutrophils. These data suggest that a subgroup of MDS patients have a low f-Met-Leu-Phe chemiluminescence response which is not due to a defect in the f-Met-Leu-Phe receptor or oxidase activity, and in the majority of cases MPO activity is normal. Initial patient survival data suggest that these patients may have an increased risk of infective mortality. It is proposed that defective f-Met-Leu-Phe chemiluminescence results from a putative defect in cell-signalling mechanism upstream of PKC, and GM-CSF priming only partially improves responsiveness.
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PMID:Identification of a subgroup of myelodysplastic patients with a neutrophil stimulation-signalling defect. 791 69

The aim of this study was to assess the possible influence of genetic polymorphisms in hOGG1, XRCC1, XRCC3, XPD, XPG and APE1 on the observed DNA damage in a group of Turkish myelodysplastic syndrome (MDS) patients. A total of 39 patients with myelodysplastic syndrome and 78 age-matched healthy control subjects were included in our study. Polymerase chain reaction/restriction fragment length polymorphism analysis was performed for the detection of DNA repair gene variants. No significant differences in DNA repair enzymes APE1, XRCC1 and XPG were found between MDS patients and controls. On the other hand, XRCC3, XPD and hOGG1 were associated with an increased risk of MDS (p=0.004, p=0.000, p=0.017, respectively). Specifically, Thr/Met genotype was more relevant in patients (p=0.026) in XRCC3; in hOGG1, Cys+ genotype was found higher in patients (p=0.017); and in XPD, Gln/Gln genotypes were found higher in the patient (p=0.001). In conclusion, XRCC3, XPD and hOGG1 genotypes are associated with an increased MDS risk, suggesting their possible involvement in the pathogenesis and biology of this disease.
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PMID:Investigation of DNA repair gene variants on myelodysplastic syndromes in a Turkish population. 2515 60

Myelodysplastic syndromes and acute myeloid leukemia with TP53 mutations are characterized by frequent relapses, poor or short responses, and poor survival with the currently available therapies including chemotherapy and 5-azacitidine (AZA). PRIMA-1Met(APR-246,APR) is a methylated derivative of PRIMA-1, which induces apoptosis in human tumor cells through restoration of the transcriptional transactivation function of mutant p53. Here we show that low doses of APR on its own or in combination with AZA reactivate the p53 pathway and induce an apoptosis program. Functionally, we demonstrate that APR exerts these activities on its own and that it synergizes with AZA in TP53-mutated myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML) cell lines and in TP53-mutated primary cells from MDS/AML patients. Low doses of APR on its own or in combination with AZA also show significant efficacy in vivo Lastly, using transcriptomic analysis, we found that the APR + AZA synergy was mediated by downregulation of the FLT3 pathway in drug-treated cells. Activation of the FLT3 pathway by FLT3 ligand reversed the inhibition of cell proliferation by APR + AZA. These data suggest that TP53-mutated MDS/AML may be better targeted by the addition of APR-246 to conventional treatments.
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PMID:Synergistic effects of PRIMA-1Met (APR-246) and 5-azacitidine in TP53-mutated myelodysplastic syndromes and acute myeloid leukemia. 3148 57