Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of inhibition of the capacity to form spermidine and spermine on cell growth were investigated using murine leukaemia L1210 cells and 5'-([(Z)-4-amino-2-butenyl]methylamino)-5'-deoxyadenosine (MDL 73811, AbeAdo), an enzyme-activated irreversible inhibitor of S-adenosyl-L-methionine decarboxylase. Putrescine levels were increased 80-fold, and spermidine and spermine levels were greatly reduced after a 3-day exposure to a maximally inhibitory dose of 10 microM-AbeAdo. Addition of AbeAdo to the culture medium inhibited the growth of L1210 cells measured 3 days later in a dose-dependent manner, but, even at a dose of 10 microM, which was maximally effective, exposure to AbeAdo was not immediately cytostatic. However, the growth rate of L1210 cells chronically exposed to 10 microM-AbeAdo declined steadily until day 12, when the cells stopped growing. L1210 cells exposed to AbeAdo for 12 days could not be rescued from cytostasis by removal of the drug from the culture, but could be rescued by exposure to exogenous spermidine or spermine, indicating that the growth-inhibitory effects of AbeAdo were a result of spermidine and/or spermine depletion. It is suggested that elevated intracellular putrescine in AbeAdo-treated cells sustained limited growth in the absence of physiological levels of spermidine and spermine until certain critical and specific physiological role(s) fulfilled by spermidine (and/or spermine) became deficient resulting in cytostasis. N-(3-Aminopropyl)-1,4-diamino-cis-but-2-ene, a spermidine analogue that is a substrate for deoxyhypusine synthase, was able to mimic the effects of spermidine in reversing AbeAdo-induced cytostasis. Spermidine analogues such as 5,5-dimethylspermidine, which are not substrates for deoxyhypusine synthase, were not active in this way. These results provide evidence that the formation of hypusine in the protein-synthesis initiation factor eIF-5A may be a critical role of spermidine essential for cell growth.
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PMID:Cytostasis induced in L1210 murine leukaemia cells by the S-adenosyl-L-methionine decarboxylase inhibitor 5'-([(Z)-4-amino-2-butenyl]methylamino)-5'-deoxyadenosine may be due to hypusine depletion. 144 35

Eukaryotic initiation factor 5A (eIF-5A) contains an unusual amino acid, hypusine, which is formed post-translationally. Although eIF-5A and its hypusine modification are essential for eukaryotic cell viability, the precise physiological function of it has remained elusive. The aim of the study is to investigate how hypusine formation modulate the proliferation, cell cycle and apoptosis in leukaemia cells. The effects of 1,7-diaminoheptane (DAH), a potent inhibitor of deoxyhypusine synthase, on proliferation and cell viability of leukemia cell lines (Mo7e, TF-1 and THP-1) and MCF-7 cells, were investigated. eIF-5A expression level was detected after cell synchronization. The results showed that inhibition of cell proliferation by DAH was in a concentration-dependent manner while apoptosis was also induced at the same time. Upon treatment of the cell lines with DAH, cell growth was inhibited. Cell cycle analysis showed that DAH induced cell growth arrest at the G(1)-S boundary of the cell cycle. In synchronized MCF-7 cells, the expression level of eIF-5A peaked at G(1) phase but very low at S and G(2)/M phases. It is concluded that hypusine formation of eIF-5A exits in the regulation of cell cycle and the results suggest that eIF-5A is involved in the expression of proteins regulating transition of G(1)-S phase of cell cycle.
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PMID:[The effect of eIF-5A on the G1-S in cell cycle regulation]. 1296 55

Effective inhibition of BCR-ABL tyrosine kinase activity with Imatinib represents a breakthrough in the treatment of patients with chronic myeloid leukemia (CML). However, more than 30 % of patients with CML in chronic phase do not respond adequately to Imatinib and the drug seems not to affect the quiescent pool of BCR-ABL positive leukemic stem and progenitor cells. Therefore, despite encouraging clinical results, Imatinib can still not be considered a curative treatment option in CML. We recently reported downregulation of eukaryotic initiation factor 5A (eIF5A) in Imatinib treated K562 cells. Furthermore, the inhibition of eIF5A by siRNA in combination with Imatinib has been shown to exert synergistic cytotoxic effects on BCR-ABL positive cell lines. Based on the structure of known deoxyhypusine synthase (DHS) inhibitors such as CNI-1493, a drug design approach was applied to develop potential compounds targeting DHS. Here we report the biological evaluation of selected novel (DHSI-15) as compared to established (CNI-1493, deoxyspergualin) DHS inhibitors. We show that upon the compounds tested, DHSI-15 and deoxyspergualin exert strongest antiproliferative effects on BCR-ABL cells including Imatinib resistant mutants. However, this effect did not seem to be restricted to BCR-ABL positive cell lines or primary cells. Both compounds are able to induce apoptosis/necrosis during long term incubation of BCR-ABL positive BA/F3 derivates. Pharmacological synergism can be observed for deoxyspergualin and Imatinib, but not for DHSI-15 and Imatinib. Finally we show that deoxyspergualin is able to inhibit proliferation of CD34+ progenitor cells from CML patients. We conclude that inhibition of deoxyhypusine synthase (DHS) can be supportive for the anti-proliferative treatment of leukemia and merits further investigation including other cancers.
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PMID:Evaluation of deoxyhypusine synthase inhibitors targeting BCR-ABL positive leukemias. 2241 96

N1-guanyl-1,7-diaminoheptane (GC7), a deoxyhypusine synthase inhibitor, has been shown to exert antiproliferation effects in many solid tumors by regulating eukaryotic translation initiation factor 5a2 (eif5a-2). However, little is known about the role of GC7 and eif5a-2 in drug resistance in acute lymphoblastic leukemia (ALL). In the present study, we investigated the effect of GC7 on drug-resistant ALL and its potential mechanism. We found that using the CCK-8 assay that combined treatment with GC7 and vincristine (VCR) significantly inhibited the cell viability of two ALL cell lines. Using EdU incorporation assays and flow cytometry, we also showed that GC7 could markedly enhance the VCR sensitivity of ALL cells by suppressing cell proliferation and promoting apoptosis. Furthermore, we showed that GC7 could downregulate eif5a-2 and myeloid cell leukemia-1 (Mcl-1) expression. Knockdown of eif5a-2 inhibited the expression of Mcl-1 and significantly enhanced the VCR sensitivity. Moreover, eif5a-2 knockdown decreased the regulatory role of GC7 in increasing VCR sensitivity. Thus, our findings indicate that combined treatment with GC7 could enhance VCR sensitivity of ALL cells by regulating the eif5a-2/Mcl-1 axis. Together, our results highlight the potential clinical application of GC7 in VCR-based chemotherapy for the treatment of ALL.
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PMID:N1-guanyl-1,7-diaminoheptane enhances the chemosensitivity of acute lymphoblastic leukemia cells to vincristine through inhibition of eif5a-2 activation. 2888 68