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

We have utilized the MTT assay to measure the metabolic activity of cells from the bone marrow of 55 patients with acute myeloid leukaemia (AML), myelodysplastic syndrome (MDS) and non-clonal disease. Doubling dilutions of cells were exposed to MTT for 3-4 h. The mean optical density of the formazan produced by each cell dilution was plotted and the gradient of the line produced was calculated, higher gradients indicating more metabolically active cells. Results showed that the median activity of mononuclear cells from seven patients with non-clonal disease was 0.202 (range 0.175-0.253); blast cells from 27 patients with de novo AML had a median activity of 0.187 (range 0.079-0.345) and 13 patients with MDS a median of 0.155 (range 0.062-0.311). Seven assays on mononuclear cells from five patients in remission had a median activity of 0.203 (range 0.190-0.248), indicating no significant difference between these and normal patients. There was no correlation between the metabolic activity of cells when compared with their proliferative capacity, cell size and expression of P-glycoprotein. Following exposure of the AML patients' blast cells to the anthracyclines, cytosine arabinoside, 6-thioguanine and etoposide, cell survival was measured using the MTT assay. While there was no correlation between the in vitro sensitivity of these cells to the anthracyclines or etoposide, less metabolically active cells showed significantly greater sensitivity to 6-thioguanine. Conversely, the more active cells appeared to be more sensitive to cytosine arabinoside. Patients whose blasts cells showed higher metabolic activity appeared to achieve remission and had a longer mean survival time. Therefore, by using a simple technique we were able to establish that some patients were more likely to respond to certain cytotoxic regimes. Our preliminary study reflected the multifactorial nature of clinical response in AML and MDS, so providing further information on the relationship between cellular metabolic activity and treatment failure.
 ...
PMID:An in vitro study of blast cell metabolism in acute myeloid leukaemia using the MTT assay. 868 80

Bryostatin has shown promise both as a cytotoxic agent and more recently as a modulator of 1-beta-D-arabinofuranosylcytosine (ara-C) resistance. This compound is currently in phase I and II trials as a single agent. We have used the 3-4,5-dimethylthiazol-2,5-diphenyltetrazolium bromide (MTT) assay as a means of investigating the direct effects of bryostatin and the effects of co-incubating this agent with ara-C on fresh blast cells from 53 patients with acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS). Additional studies evaluated the levels of accumulation and retention of 1-beta-D-arabinofuranosylcytosine 5'-triphosphate (ara-CTP) in cells exposed to ara-C with and without bryostatin. Cells were exposed to bryostatin at a range of concentrations (0.1-100 nM) for 48 h and at 1 nM for both modulation studies and assessment of ara-CTP production. We found bryostatin to be cytotoxic in 18/58 (31%) tests whilst potentiation of formazan production in the MTT assay was seen in 21/58 (36%) patients. On co-incubation with bryostatin, 16/58 (27%) tests showed increased cytotoxicity to ara-C. Furthermore, there was a significant increase in the accumulation of ara-CTP on co-incubation with bryostatin (p = 0.0401). We found patients with in vitro resistance were more likely to become sensitised following exposure to bryostatin (p < 0.01). This study has emphasised the need to optimise treatment regimens for individual patients using this approach.
 ...
PMID:Modulation of resistance to ara-C by bryostatin in fresh blast cells from patients with AML. 966 42

We have demonstrated that antisense phosphorothioate oligonucleotides (S-ODNs) inhibit influenza virus A replication in MDCK cells. The liposomally encapsulated and the free antisense phosphorothioate oligonucleotides with four target sites (PB1, PB2, PA, and NP) were tested for their abilities to inhibit virus-induced cytopathogenic effects by a MTT assay using MDCK cells. The liposomally encapsulated S-ODN complementary to the sites of the PB2-AUG initiation codon showed highly inhibitory effects. Therefore, the antiviral effects of S-ODN-PB2-AUG and PA-AUG were examined in a mouse model of influenza virus A infection. PB2-AUG oligomer treated i.v. significantly prolonged the mean survival time in day (MDS) and increased the survival rates with does dependent manner.
 ...
PMID:In vitro and in vivo anti-influenza A virus activity of antisense oligonucleotides. 1047 46

Drug resistant cells often have an increased capacity to repair their DNA after damage by cytotoxic agents. Aphidicolin can inhibit this DNA repair. We describe a study of the effect of aphidicolin to modulate the sensitivity to cytotoxic drugs of blast cells from 13 patients with AML, 11 with de novo disease on presentation and 2 secondary to MDS. Three patients had relapsed following previous therapy and samples were received from 1 patient both on presentation and relapse. Blast cells were exposed to anthracyclines, antimetabolites or etoposide +/- aphidicolin (15 microM) for 48 hours. The MTT assay was used to measure cell survival and the LC50 (concentration of drug required for 50% cell kill) was calculated. Overall, there was a significant increase in sensitivity to ara-C on co-incubation with aphidicolin in 12/14 samples (p = 0.007). The median increase in sensitivity was 3.88-fold (range 1.26- to 80-fold). Interestingly, when patients were grouped according to in vitro sensitivity to ara-C, cells from resistant patients demonstrated the greatest increase in sensitivity (median 14-fold compared to 2-fold for the sensitive group, p = 0.02). Despite the documented evidence for altered DNA repair as a mechanism of resistance to the topoisomerase II inhibitors, we found no significant increase in sensitivity to daunorubicin, doxorubicin or etoposide on co-incubation with aphidicolin. Nevertheless, we believe the unparalleled modulation of ara-C warrants further investigation.
 ...
PMID:Aphidicolin markedly increases the in vitro sensitivity to ara-C of blast cells from patients with AML. 1050 Aug 35

To investigate the effect of 5-aza-2'-deoxycytidine (5-Aza-CdR) on cell of high-risk patients with myelodysplastic syndrome (MDS) in vitro, the growth inhibition of MUTZ-1 cell induced by 5-Aza-CdR was detected by MTT method; apoptosis was detected by morphological observation and translocation of phosphatidylserine (PS) was examined by flow cytometry assay; the expressions of P15INK4B, DNA methyltransferases (DNMT)(1), DNMT(3A) and DNMT(3B) gene on mRNA level were detected by RT-PCR; methylation of p15INK4B gene in MUTZ-1 cells was detected by PCR using methylation specific primer (MSP). The results showed that 5-Aza-CdR inhibited the growth of MUTZ-1 cells. The IC(50) values of 24, 48 and 72 hours were 6.75, 2.82 and 5.45 mmol/L respectively. Characteristic changes of apoptosis emerged in MUTZ-1 cells after being exposed to 5-Aza-CdR in the different concentration from 0.8 mmol/L to 3.2 mmol/L, and the positive cells of annexin V on the membrane of MUTZ-1 cells were analyzed by flow cytometry. 5-Aza-CdR could activate the p15INK4B gene expression in MUTZ-1 cells by demethylation of the p15INK4B gene in a dose-dependent manner after the cells were treated for 48 hours. Furthermore, 5-Aza-CdR could significantly down-regulate the expressions of DNA methyltransferase genes DNMT(3A) at mRNA level in a dose dependent manner. However, it had no effects on DNMT(1) gene and DNMT(3B) gene. It is concluded that 5-Aza-CdR can inhibit the growth of MUTZ-1 cells and induce the apoptosis of these cells within the range of concentration from 0.8 mmol/L to 3.2 mmol/L, which may be one of the mechanisms of antitumor effects of 5-Aza-CdR. The drug can activate the expression of p15INK4B gene in MUTZ-1 cells by demethylation of the p15INK4B gene through inhibiting the expression of DNMT(3A) gene. It may be the mechanism of 5-Aza-CdR in the treatments of MDS.
 ...
PMID:[Effect of 5-aza-2'-deoxycytidine on cell of high-risk patients with myelodysplastic syndrome in vitro]. 1536 33

To investigate the apoptotic effect of triptolide on MDS cell line MUTZ-1 cells and its mechanism, MUTZ-1 cells were incubated with indicated concentrations of triptolide. The growth of MUTZ-1 cells was observed by MTT assay and apoptosis was detected by DNA fragmentation analysis and flow cytometry using Annexin V-FITC/PI staining. The gene and protein expressions were determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. The results showed that MUTZ-1 cell viability in presence of triptolide decreased markedly in a dose- and time-dependent manner. The growth-inhibitory IC50 value for triptolide treatment was 55.06 ng/ml. A DNA ladder pattern of internucleosomal fragmentation was observed. The translocation of phosphatidylserine at the outer surface of the cell plasma membrane could be induced by triptolide and its level increased following the augmentation of the drug concentration. Treatment of MUTZ-1 cells with triptolide for 12 hours resulted in the activation of caspase-3, cleavage of PARP and decrease of c-IAP2 mRNA. The expressions of pro-caspase 3 and c-IAP2 were inversely correlated with the incidence of apoptosis. (r = -0.907, P = 0.000; r = -0.919, P = 0.000 respectively). In conclusion, Triptolide inhibits MUTZ-1 cell growth by inducing apoptosis. The apoptotic effect of triptolide in MUTZ-1 cells is mediated by the caspase-3 activation and PARP cleavage. Moreover, the activation of caspase-3 may be associated with the down-regulation of c-IAP2.
 ...
PMID:[Study of triptolide-induced apoptosis in MUTZ-1 cells and its allied mechanism]. 1597 36

To study the effects and possible mechanism of Vitamin K(2) (VK(2)) in the treatment of MDS-JSN04 cells, the changes of morphologic features of MDS-JSN04 cells were investigated by cytomorphology, the apoptosis of MDS-JSN04 cells was observed by transmission electron microscope; cellular proliferation was determined by the MTT assay; cell apoptosis, cell cycle shift and expression of myeloid-specific differentiation antigen (CD11b, CD13) were analyzed by flow cytometry (FCM). The expression of apoptosis-related genes bcl-2, survivin and bax were detected by retrotranscriptase polymerase chain reaction (RT-PCR); the activity of caspase-3 was determined by chemiluminescence assay. The results showed that the typical apoptotic morphological features appeared in cells treated with VK(2) for 72 hours; VK(2) induced apoptosis of MDS-JSN04 cells and in a dose-and-time-dependent manner, G(0)/G(1) cell arrest and significantly down-regulated the expression of bcl-2 and survivin, but had no effect on the expression of bax; the activity of caspase-3 significantly increased. It is concluded that VK(2) induces apoptosis of MDS-JSN04 cells through activating caspase-3 pathways and the apoptosis-related genes bcl-2, survivin may play an important role in this process.
 ...
PMID:[Inhibition effect of vitamin K2 on human MDS-JSN04 cell line and its possible mechanism]. 1640 73

The aim of this study was to investigate the inhibition effect of arsenic sulfide (As2S2) on the growth of in vitro cultured BMMNC from MDS patients and to explore its possible cellular and molecular mechanisms. The apoptosis of MDS cells induced by As2S2 solution of different concentrations were studied with MTT, flow cytometry, and RT-PCR. The results showed that (1) low concentration of As2S2 (0-0.6 mg/L) had no marked inhibition effect on proliferation of MDS cells; (2) after treatment with 1.5-50 mg/L of As2S2, both low risk MDS cells and high risk MDS cells presented typical features of apoptosis with a dose-dependent manner, the expression of bcl-2 mRNA and the ratio of bcl-2/bax obviously decreased after As2S2 treatment (P < 0.05); (3) BMMNC from MDS patients had higher apoptosis ratio than that of BMMNC from control. It is concluded that BMMNC excessive apoptosis exists in MDS patients; low concentration of As2S2 (0-0.6 mg/L) shows no inhibition effect on proliferation of MDS cells; high concentration of As2S2 (1.5-50 mg/L) induces apoptosis of MDS cells.
 ...
PMID:[Apoptosis of in vitro cultured BMMNC from MDS patients induced by arsenic sulfide]. 1663 96

The study was aimed to investigate the mechanism of proliferation inhibition and apoptosis of MDS-RAEB MUTZ-1 cells induced by 2-methoxyestradiol (2-ME), the cell proliferation was determined by MTT assay, apoptosis rate was determined with annexinV-FITC/PI double staining and cell cycle was analyzed by flow cytometry (FCM) after MUTZ-1 cells were treated with different concentrations of 2-ME; the changes of morphologic features of MUTZ-1 cells were observed with Wright-Giemsa's staining; lactate dehydrogenase was determined by Beckman Counter; and agarose gel electrophoresis was used to verify whether 2-ME can induce apoptosis of MUTZ-1 cells. The results showed that 2-ME inhibited the proliferation of MUTZ-1 cells in a dose-and time-dependent manner and caused a sustained arrest at G(2)/M phase in MUTZ-1 cells; the typical apoptotic morphological features appeared in MUTZ-1 cells; the production of lactate dehydrogenase was up-regulated and the marked DNA ladder pattern of internucleosomal fragmentation was observed. It is concluded that the mechanism of proliferation inhibition and apoptosis of MUTZ-1 cells induced by 2-ME is probably related with the G(2)/M cell cycle arrest; 2-ME may be a potentially adjunctive anticancer drug useful to treat myelodysplastic syndrome.
 ...
PMID:Mechanism of 2-methoxyestradiol-induced apoptosis in myelodysplastic syndrome MUTZ-1 cell line. 1749 35

To study the effects of sodium valproate (VPA) on human myelodysplastic syndrome cell line MUTZ-1. The cell proliferation was determined by MTT assay, apoptotic morphological features were observed by light microscopy and transmission electronmicroscopy, cell apoptosis and cell cycle shift were analyzed by flow cytometry (FCM). The results showed that VPA could inhibit the growth of MUTZ-1 cells in dose-and time-dependent manners. The typical apoptotic morphological features appeared in MUTZ-1 cells treated with 4 mmol/L VPA for 72 hours. Pyknosis of cells and nuclei, disintegration of nuclear chromatin and apoptotic body could be observed by light microscopy. Aggregation and margination of nuclear chromatin, concentration of plasm, increment of density and chromatin mass of irregular size could be observed by transmission electronmicroscope. The flow cytometric analysis indicated that the VPA could induce cell apoptosis, apoptosis rate increased in dose-dependent manner, ratio of cells at G(0)/G(1) phase increased and ratio of cells at S phase decreased in dose-dependent manner, the cells were arrested at G(0)/G(1) phase. It is concluded that the VPA can induce apotosis and inhibite proliferation of MUTZ-1 cells via arresting cells at G(0)/G(1) phase.
 ...
PMID:[Apoptosis of human myelodysplastic syndrome cell Line MUTZ-1 induced by sodium valproate]. 1770 95


1 2 3 Next >>