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

The in vivo combination effect of navelbine (NVB, KW-2307) plus cisplatin was compared with that of vindesine (VDS) plus cisplatin in terms of antitumor activity and side effects. The antitumor activity of NVB or cisplatin against i.p. inoculated P388 leukemia was augmented by their combination on various schedules when the interval of administrations was within 24 h. Against i.v. inoculated P388 leukemia, the most significant combination effect was observed when cisplatin was administered 4 h after NVB injection (ILS(%) > 451) and three long-term survivors were observed. On this schedule, the combination of LD10 of each drug was achieved, indicating the lack of addition of toxicity. This was further proved by examination of body weight change, white blood cell count and platelet count. Interestingly, significant elevation of blood urea nitrogen concentration by cisplatin was prevented by the combination with NVB. The combination of maximum tolerated dose of NVB and cisplatin was also tolerable in nude mice, and their combination effect was observed against human lung large cell carcinoma Lu-65 and adenocarcinoma PC-12. The number of toxic death mice was more in VDS plus cisplatin-treated groups than in NVB plus cisplatin-treated groups, indicating that the combination chemotherapy of NVB plus cisplatin is a better regimen than that of VDS plus cisplatin in experimental tumor systems.
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PMID:Combination effect of navelbine (vinorelbine ditartrate) with cisplatin against murine P388 leukemia and human lung carcinoma xenografts in mice. 829 16

We investigated the possibility that chlorpromazine (CPZ), an antiemetic frequently used to control nausea and vomiting in cancer patients receiving chemotherapy, might modify the progression of the renal toxicity and lethality of cisplatin (CDDP). In mice the preadministration of CPZ (i.p.) 1 h prior to CDDP (i.p.) injection efficiently reduced not only the lethal toxicity, but also the renal (indicated by increased blood urea nitrogen values) and intestinal toxicity (indicated by the incidence of diarrhea) which are usually observed in mice treated with CDDP alone. To further study the apparent protective activity of CPZ against CDDP nephrotoxicity we chose rats a species more commonly used as a model for nephrotoxicity. In F344 rats, CPZ ameliorated CDDP-induced increases in blood urea nitrogen (BUN), urine glucose, protein and lactate dehydrogenase (LDH). The preadministration of CPZ had no observed effect on the antitumor activity of CDDP in mice inoculated i.p. with Sarcoma 180, EL-4 lymphoma, or P-388 leukemia cells. The present study suggest that CPZ may be of therapeutic benefit when used with CDDP. This study also provides a rational basis for the selection of antiemetic therapy.
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PMID:Drug interaction effects on antitumor drugs. XIII. Amelioration of cisplatin lethality and renal toxicity by chlorpromazine in mice. 831 64

The protective effect of 4-hydroxy-2-methyl-N-[2-(tetrazol-5-yl)-phenyl]-2H-1, 2-benzothiazine-3-carboxamide-1, 1-dioxide monosodium salt (HX-1920) on the nephrotoxicity of cisplatin was studied in rats. Effects of HX-1920 on antitumor activity and emesis induced by cisplatin were also examined using mice and ferrets, respectively. All 10 rats injected with both HX-1920 and LD50 of cisplatin survived for 14 days. After 24 hr, co-administration of HX-1920 significantly increased the urinary excretion of cisplatin in rats. HX-1920 also significantly inhibited the cisplatin-induced elevation of urinary N-acetyl-beta-D-glucosaminidase, blood urea nitrogen and plasma creatinine concentrations in rats. HX-1920 had no effect on the number of white blood cell. HX-1920 tended to reduce the emesis induced by cisplatin in ferrets. Furthermore, there was no difference in the survival curve between the cisplatin group and the HX-1920 plus cisplatin group in mice inoculated with P 388 leukemia cells. Thus, HX-1920 did not modify the antitumor activity of cisplatin. These results suggest that HX-1920 has a protective effect on the nephrotoxicity of cisplatin without inhibiting its antitumor activity.
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PMID:The protective effect of 4-hydroxy-2-methyl-N-[2-(tetrazol-5-yl)- phenyl]-2H-1, 2-benzothiazine-3-carboxamide-1, 1-dioxide monosodium salt (HX-1920) on cisplatin-induced toxicity in rats. 847 48

The novel cisplatin analogue D-17872 was studied for its anticancer activity using in vivo and in vitro preclinical models. The compound at the sublethal dose of 215 mg/kg (ca. 50% of the approximate LD50) induced no nephrotoxic effect strong enough to increase the blood urea level in rats. It had good in vivo antitumor efficacy against murine P388 (max. ILS: D-17872 132%, cisplatin 55%) and L1210 leukemia (max. ILS: D-17872 43%, cisplatin 38%), L5222 leukemia of the rat (max. ILS: D-17872 163%, cisplatin 163%) and murine B16 melanoma. Activity against P388 leukemia substantially exceeded that of cisplatin. Moreover, the M5076 reticulum cell sarcoma implanted into the subrenal capsule and the DMBA-induced mammary tumor of the rat were inhibited by D-17872 to a greater extent than by cisplatin (min. T/C: D-17872 -3%, cisplatin 11%). Using clonogenic microassays, D-17872 was active in vitro against a variety of human and rodent tumor cell lines, albeit at higher concentrations than cisplatin (IC50 values: D-17872 2.6-12.7 mumol/l, cisplatin 0.13-0.42 mumol/l). Apart from its cytotoxic action it was able to induce in vitro differentiation of the human HL-60 and K562 and of the murine M1-T22 cell lines, while cisplatin induced differentiation only in the HL-60 cell line. Thus D-17872 exhibited a pharmacological and toxicological profile different from that of the parent compound. The results suggest that induction of differentiation contributes to the antineoplastic efficacy of this novel cisplatin derivative.
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PMID:The antitumor activity of the platinum complex D-17872 is associated with tumor cell differentiation. 848 6

The occurrence and NMR solution structure of a class of biloop hairpins containing the sequence 5'-CGXYAG are presented. These hairpins, which are variations on a sequence found in the reverse transcript of the human T-cell leukemia virus 2 (HLV2), show elevated melting points and high chemical stability toward denaturation by urea. Hairpins with the 5'-CGXYAG configuration have melting points 18-20 degrees higher than hairpins with 5'-CAXYGG or 5'-GGXYAC configurations. The identities of the looping bases, X and Y above, play a negligible role in determining the stability of this DNA hairpin stability. This is very different from G-A based loops in RNA, where the third base must be a purine for high stability [the GNRA loops; V.P. Antao, S.Y. Lai and I. Tinoco, Jr (1991) Nucleic Acids Res., 19, 5901-5905]. We show that these properties are associated with a four base helix unit that contains both a sheared GA base pair and a Watson-Crick CG base pair upon which it is stacked. As an understanding of the significance of AG base pairs has become increasingly important in the structural biology of nucleic acids, we compute an 0.7-0.9 A precision ensemble of NMR solution structures using iterative relaxation matrix methods. Calculations performed on NMR-derived structures indicate that neither base-base electrostatic interactions, nor base-solvent dispersive interactions, are significant factors in determining the observed differences in hairpin stability. Thus the stability of the 5'-CGXYAG configuration would appear to derive from favorable base-base London/van der Waals interactions.
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PMID:Occurrence, solution structure and stability of DNA hairpins stabilized by a GA/CG helix unit. 852 66

We examined mechanisms that protect host defense cells from their cytotoxic effector molecules. Human neutrophil peptides (HNP) 1-3 are microbicidal and cytotoxic defensins, initially synthesized as 94-amino acid preproHNP(1-94), cotranslationally proteolyzed to proHNP(20-94), then converted by removal of the anionic propiece to mature HNP(65-94)(HNP-1 and -3) and HNP(66-94) (HNP-2). We hypothesized that during synthesis and subcellular sorting the anionic propiece inhibits the cytotoxicity of the cationic defensin. We expressed preproHNP-1 cDNA in recombinant baculovirus-infected insect cells that secreted the normally transient proHNP-1(20-94) into the medium. Cyanogen bromide cleaved proHNP-1(20-94) at the fortuitously located Met64 to yield mature recombinant HNP-1(65-94) and unlinked propiece. Recombinant and native HNP-1 purified from PMN were identical as judged by mass spectrometry, retention time in reverse-phase high performance liquid chromatography, migration on acid-urea polyacrylamide gels, and reaction with a conformation-specific antibody. Recombinant and native HNP-1 had comparable microbicidal activity towards Listeria monocytogenes and were similarly potent in permeabilizing K562 leukemia cells, but proHNP-1(20-94) was virtually inactive in both assays. Addition of unlinked propiece (proHNP-1(20-64) with Met64-->homoserine) inhibited the bactericidal and cell-permeabilizing activity of mature HNP-1 in a dose-dependent manner. Linked, and to a lesser extent unlinked, propiece interfered with the binding of HNP-1 to target cells. The propiece thus acts as an efficient intramolecular inhibitor of defensin HNP-1 cytotoxicity.
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PMID:Intramolecular inhibition of human defensin HNP-1 by its propiece. 860 27

O6-Methylguanine-DNA methyltransferase (MGMT) is an important DNA repair protein that plays a key role in cancer chemotherapy by alkylating agents such as carmustine (BCNU) and Dacarbazine (DTIC). Therapy by BCNU and DTIC is reduced by dose-limiting hematological toxicity as a result of low MGMT repair activity in bone marrow cells. In this study, we have constructed a Moloney murine leukemia virus retroviral vector containing the human mgmt gene. High-titer retrovirus producer cells lines have been generated. Retroviral-mediated transfer of the human mgmt gene into murine multi-potent hematopoietic stem cells, FDCP-1, resulted in the expression of a high level of MGMT activity. In comparison with the control cells that were transduced with the parent vector, the MGMT-expressing clones were considerably more resistant to the cytotoxicity of the methylating agents, such as N-methyl-N'-nitro-N-nitrosoguanidine, N-nitroso-N-methyl-urea, and temozolomide, as well as the chloroethylating agents 1-(2-chloroethyl)-1-nitrosourea and BCNU. The protection provided by MGMT could be eliminated by the MGMT inactivator O6-benzylguanine. Thus, the principal lethal lesions produced by these alkylating agents in the murine hematopoietic stem cells and the MGMT deficiency in these cells can be complemented by retroviral-mediated gene transduction.
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PMID:Retrovirus-mediated transfer of the human O6-methylguanine-DNA methyltransferase gene into a murine hematopoietic stem cell line and resistance to the toxic effects of certain alkylating agents. 864 46

It has been reported that the activation of dihydrofolate reductase (DHFR) from L1210 mouse leukaemia cells by KCl or thiol modifiers is accompanied by increased digestibility by proteinases [Duffy, Beckman, Peterson, Vitols and Huennekens (1987) J. Biol. Chem. 262, 7028-7033], suggesting a loosening up of the general compact structure of the enzyme. In the present study, the peptide fragments liberated from the chicken liver enzyme by digestion with trypsin in dilute solutions of urea or guanidine hydrochloride (GuHCl) have been separated by FPLC and sequenced. The sequences obtained are unique when compared with the known sequence of DHFR and thus allow the points of proteolytic cleavage identified for the urea- and GuHCl-activated enzyme to be at or near the active site. It was also indicated by the enhanced fluorescence of 2-p-toluidinylnaphthalene 6-sulfonate that conformational changes at the active site in dilute GuHCl parallel GuHCl activation. The above results indicate that the activation of DHFR in dilute denaturants is accompanied by a loosening up of its compact structure especially at or near the active site, suggesting that the flexibility at its active site is essential for the full expression of its catalytic activity.
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PMID:Activation of chicken liver dihydrofolate reductase by urea and guanidine hydrochloride is accompanied by conformational change at the active site. 867 Jan 38

The relationship between chromatin structure and endonuclease sensitivity was investigated. The cells used in this study were a) human myelogenous leukemic cell lines (HL-60, ML-I, U-937, THP-I) (Group I), which produced internucleosomal DNA cleavage, and b) human T-cell leukemia (MOLT-4), erythroleukemia (K562), glioblastoma (T98G, U87MG) and glioma (KG-1-C) cell lines (Group II), which produced no internucleosomal DNA cleavage, upon treatment with various apoptosis-inducing agents. When the nuclei, isolated from these cells were digested with micrococcal nuclease, chromatin DNA was cleaved into oligonucleosomal units. Although sensitivity to micrococcal nuclease considerably differed from cell to cell, Group I cells were generally more sensitive to micrococcal nuclease digestion than Group II cells. Similar sensitivity to DNase I was observed in both groups of cells. Acid-urea polyacrylamide gel electrophoresis of histone fractions from control and apoptosing HL-60 cells (induced either by hydrogen peroxide or UV irradiation) revealed no significant change in the relative composition of five major histones, indicating the absence of selective degradation of histone HI, but rather the nonspecific degradation of many nuclear proteins. These data suggest a difference in a chromatin structure between Group I and II cells, which might result in the selective production of internucleosomal DNA cleavage only in Group I cells.
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PMID:Chromatin structure and endonuclease sensitivity in human leukemic cell lines. 870 41

Alkaline encrusted cystitis is a rare inflammatory condition of the bladder which has been reported sporadically over the past 80 years. It is caused by infection with urea splitting organisms leading to the deposition of inorganic salts on to the surface of the bladder. We present three cases of alkaline encrusted cystitis. In two cases the encrusted area was associated with foci of malakoplakia. The third case occurred in a patient who had received chemotherapy for acute lymphoblastic leukaemia. To our knowledge, these are the first cases of malakoplakia associated with alkaline encrusted cystitis. These two conditions have a number of clinical and aetiological similarities, and may have more in common than has been previously thought.
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PMID:Alkaline encrusted cystitis associated with malakoplakia. 872 45


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