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)

Current anti-leukemic chemotherapy in patients with myelodysplastic syndromes (MDS) and MDS evolving to acute myeloid leukemia (AML) is associated with low response rates and high treatment-related toxicity. Homoharringtonine (HHT) is a novel cephalotaxime alkaloid with reported efficacy in relapsed and de novo AML and more recently, chronic myeloid leukemia. Although its mechanism(s) of action is not completely understood, in vitro studies have demonstrated both cytotoxic and differentiating activity in leukemic cells, as well as intra-cellular changes suggestive of apoptotic cell death. In a phase II trial, HHT was administered at a dose od 5 mg/m2 by 24-h continuous infusion daily for 9 days to patients with MDS and MDS evolving to AML (MDS/AML). Twenty-eight patients (MDS 16, MDS/AML 12) with a median age of 67 years (range 23-83) were entered. A complete remission was achieved in seven patients, a partial remission was achieved in one patient for an overall response rate of 28% (8/28). There were four of 13 responders in MDS/AML patients and four of 15 in patients with MDS. The median duration of complete response was 7 months (range 2-10). Significant myelosuppression was universal and resulted in a high incidence of induction deaths (13/28) due to neutropenic-related infections. Extramedullary toxicity was mild and consisted of hypo-tension, fluid retention, hypoglycemia, diarrhea, nausea and vomiting. HHT given in this dose and schedule demonstrated limited activity in MDS and MDS/AML and was associated with prolonged pancytopenia and marrow hypoplasia in many patients. Administration of HHT at a lower dose or in combination with hematopoietic growth factors may lead to better results, but treatment with HHT as single agent at this dose and schedule is not currently recommended for these patients.
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PMID:Homoharringtonine in patients with myelodysplastic syndrome (MDS) and MDS evolving to acute myeloid leukemia. 855 35

Homoharringtonine (HHT) is a cytotoxic alkaloid isolated from the evergreen tree cephalotaxus harringtonia native to the southern provinces of China. The principal mechanism of action of HHT is the inhibition of protein synthesis in a dose- and time-dependent manner by acting on the ribosomes of cancer cells. It blocks the progression of cells from G1 phase into S phase and from G2 phase into M phase. It is synergestic or additive in vitro with AraC, amsacrine, actinomycin D and dexamethasone. Clinical studies have indicated that HHT is effective in treating acute myeloid leukemia (AML), chronic myeloid leukemia (CML) and myelodysplastic syndrome (MDS), but not acute lymphoblastic leukemia (ALL) and solid tumors. The dose limiting toxicities are hypotention and myelosuppression. Homoharringtonine has relatively mild extramedullary toxicities and no anthracycline-like cardiac toxicity, which make it a suitable candidate for the treatment of aged patients. Pharmacological studies indicate that HHT belongs to the category of multidrug resistance (MDR)-related drugs. The cells resistant to HHT are cross-resistant to anthracycline, vinca alkaloids, mitoxantrone, but not cis-platine and AraC. Multiple mechanisms, including the sequential emergence of overexpression of multidrug resistance-associated protein (MRP) and MDR1 genes, are involved in the cross-resistance of tumor cells to HHT.
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PMID:Homoharringtonine: an effective new natural product in cancer chemotherapy. 874 64

Homoharringtonine (HHT) is a plant alkaloid with antileukemia activity that is currently being used for treatment of acute, chronic leukemias and MDS. In this study, we show that HHT can induce apoptosis in a variety of human myeloid leukemia cell lines (U937, HL-60, HEL, THP, and K562). U937 and HL60 cells undergo rapid apoptosis on treatment with HHT, as indicated by increased annexin V binding capacity, caspase-3 activation, and cleavage of poly(ADP-ribose) polymerase (PARP). In addition, the expression of bax is upregulated during HHT-induced cell death, whereas the expression of bcl-2 is only slightly decreased. Importantly, treatment of primary leukemic cells, obtained from acute myeloid leukemia patients, resulted in rapid apoptosis. Thus, our data provide the mechanism of HHT and justify the use of HHT in the treatment of human myeloid leukemia.
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PMID:Homoharringtonine mediates myeloid cell apoptosis via upregulation of pro-apoptotic bax and inducing caspase-3-mediated cleavage of poly(ADP-ribose) polymerase (PARP). 1522 52

Homoharringtonine (HHT), a natural alkaloid extracted from various Cephalotaxus species, exerts its antitumoral and anti-angiogenic activity through an inhibition of protein synthesis and the promotion of apoptosis. ChemGenex Pharmaceuticals Ltd, in collaboration with Stragen Group, is developing omacetaxine mepesuccinate, a semisynthetic formulation of HHT, as a potential treatment for chronic myelocytic leukemia (CML), myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML). In preclinical studies, omacetaxine mepesuccinate induced apoptosis in leukemia cell lines. Results from phase II clinical trials revealed omacetaxine mepesuccinate to be active in patients with CML that was resistant to tyrosine kinase inhibitor (TKI) therapy, including those patients who carry the BCR-ABL1T315I mutation, which is highly insensitive to the TKIs imatinib, nilotinib and dasatinib; the therapeutic was also generally well tolerated. Phase II and III clinical trials are underway to assess the activity of omacetaxine mepesuccinate, either alone or in combination with TKIs or other cytotoxic drugs, in patients with CML that is resistant to TKI therapy. Phase I and II clinical trials for omacetaxine mepesuccinate in the treatment of AML and MDS are also ongoing; intravenous, subcutaneous and oral formulations of the drug are being developed. Omacetaxine mepesuccinate appears to hold potential for the treatment of CML and, in particular, imatinib-resistant CML; the development of alternative formulations of the therapeutic further expands the potential for success in drug development.
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PMID:Omacetaxine mepesuccinate--a semisynthetic formulation of the natural antitumoral alkaloid homoharringtonine, for chronic myelocytic leukemia and other myeloid malignancies. 1846 78

This study was aimed to investigate the efficacy of moderate intensity regimen, CHG (homoharringtonine, cytarabine and granulocyte colony-stimulating factor (G-CSF)) on the patients with high-risk MDS or MDS-transformed acute myeloid leukemia. 30 newly diagnosed adult patients with high-risk MDS or MDS-transformed AML were enrolled in this clinical trial to evaluate the efficacy of sequential low-dose homoharringtonine/cytarabine chemotherapy combined with G-CSF priming. Homoharringtonine and Ara-C were injected intravenously at doses of 1 mg and 25 mg daily for 14 consecutive days respectively, G-CSF was injected subcutaneously once daily at a dose of 300 microg on 12 hours prior to chemotherapy and continued given until the end of chemotherapy or when the peripheral WBC count reached > 20 x 10(9)/L. This regimen was given only for one course, and followed by conventional chemotherapy as maintenance or consolidation therapy when CR achieved. 33 patients with high- risk MDS and MDS-transformed AML were injected aclarubicin/Ara-C intravenously at doses of 10 mg and 25 mg for 8 and 14 consecutive days respectively, G-CSF was used at the same dose and the same way as the CHG regimen. 33 patients with high-risk MDS and MDS-transformed AML were treated with HHT/Ara-C intravenously at doses of 2 - 3 mg and 100 - 150 mg daily for 7 consecutive days respectively, G-CSF was injected when WBC count was below 4 x 10(9)/L, and it was stopped to be used when WBC count was > 4 x 10(9)/L. The results showed that (1) 14 patients achieved complete remission (CR) (46.67 %) and 7 patients achieved partial remission (PR) (23.33 %) with one course of CHG regimen, total effective rate was 70%; 14 patient achieved CR (42.4%) and 9 patients achieved PR (27.3%) with one course of CAG regimen, total effective rate was 69.7%; 7 patient achieved CR (33.3%) and 3 patients achieved PR (9.1%) with one course of HA regimen, total effective rate was 42.4%. There was no statistical difference between the effective rate of CHG and CAG, but difference was significant between CHG and HA. (2) Agranulocytosis (neutrophil < 0.5 x 10(9)/L) occurred in 12 cases (40%) of CHG-treated patients with a mean 8 days of agranulocytic period, so the infectious complications were less serious and tolerable without treatment-related death. (3) Among 14 out of 30 patients with CR, 9 relapsed, the mean duration from CR to replace was 8.2 months. All relapsed patients reusing CHG regimen did not achieved CR again. (4) Among 13 cases with CR, 6 patients just received HA or DA regimens as consolidatory and intensive chemotherapy after CR have relapsed, the mean CR time was only 6.1 months. Otherwise, the mean CR time of 7 CR patients received alternative succeeded chemotherapy containing mitoxantrone/idarubicin/THP/homoharringtonine/daunorubicin/aclarubicin after CR was 10.6 months; and among them 4 are still in continuous CR. It is concluded that the CHG chemotherapy regimen has a similar effect with CAG but better than HA, and in a saft chemotherapy regimen with slight myelosuppression in clinical application, strong and alternative succeeded chemotherapy is necessary for CR patients to keep longer CR and survival.
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PMID:[Efficacy of induction chemotherapy for patients with high-risk myelodysplastic syndrome (MDS) or MDS-transformed acute myeloid leukemia with CHG regimen and its comparison with regimen GAG and HA]. 1937 88

Homoharringtonine is an alkaloid inhibitor of protein synthesis with activity in myeloid malignancies. We report a phase II pilot study of homoharringtonine in myelodysplastic syndrome (MDS). Induction consisted of homoharringtonine at 2.5 mg/m(2) via continuous infusion for 7 days. Maintenance was given every 4 weeks. Nine patients were enrolled: five with refractory anaemia with excess blasts, two with refractory anaemia with excess blasts in transformation, one each with refractory anaemia and chronic myelomonocytic leukaemia respectively. Median age was 70 years (55-84) and 6 (66%) were male. Per International Prognostic Scoring System (IPSS) two patients were intermediate-1, five intermediate-2 and two high-risk. Median chemotherapy courses were one (1-3). One patient (11%) responded with complete haematological and cytogenetic remission after one course. Eight patients did not respond (four had stable disease, two progressed to acute leukaemia and two died during induction - from aspergillus pneumonia and intracerebral haemorrhage respectively). Grade 3/4 myelosuppression seen in 56% (5/9). Serious non-haematological toxicities included one case of grade 4 left bundle branch heart block and one grade 3 nephrotoxicity. Median time between courses was 42 days (35-72 days). In conclusion homoharringtonine might have clinical activity in some patients with MDS.
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PMID:A phase II open-label study of the intravenous administration of homoharringtonine in the treatment of myelodysplastic syndrome. 2370 Dec 51

Homoharringtonine (HHT), a plant alkaloid with antitumor properties originally identified nearly 40 years ago, has a unique mechanism of action by preventing the initial elongation step of protein synthesis. HHT has been used widely in China for the treatment of chronic myeloid leukemia (CML), acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Omacetaxine, a semisynthetic form of HHT, with excellent bioavailability by the subcutaneous route, has recently been approved by FDA of the United States for the treatment of CML refractory to tyrosine kinase inhibitors. This review summarized preclinical and clinical development of HHT and omacetaxine for myeloid hematological malignancies.
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PMID:Homoharringtonine and omacetaxine for myeloid hematological malignancies. 2438 17

The methylation inhibitor decitabine (DAC) has great therapeutic value for myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). However, DAC monotherapy is associated with relatively low rates of overall response and complete remission. Previous studies have shown promising results for combination treatment regimens including DAC. Homoharringtonine (HHT), an alkaloid from Chinese natural plants and Cephalotaxus, has demonstrated potential for leukemia treatment. Our studies have suggested that the combination of DAC and HHT has synergistic effects for inhibiting the viability of SKM-1 and Kg-1a cells. This combination leads to enhanced inhibition of colony formation and apoptosis induction compared with DAC alone in SKM-1 but not Kg-1a cells. Only high-dose DAC and HHT significantly up-regulate caspase-3 and caspase-9 and inhibit BCL-XL in the SKM-1 cell line. The combined effects of DAC plus HHT on apoptosis may not only depend on regulation of the apoptosis-related genes we examined but others as well. HHT had no demethylation effects, and HHT in combination with DAC had no enhanced effects on hypomethylation and DNMT1, DNMT3A and DNMT3B mRNA expression in SKM-1 cells. Overall, these results suggest that DAC used in combination with HHT may have clinical potential for MDS treatment.
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PMID:Effects of the combination of decitabine and homoharringtonine in SKM-1 and Kg-1a cells. 2699 10