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)

HO-221, N-[4-(5-bromo-2-pyrimidinyloxy)-3-chlorophenyl]-N'-(2- nitrobenzoyl) urea is a new benzoylphenylurea derivative. The compound exhibits significant antitumor effects against various animal tumors, and was especially effective against the solid tumors implanted subcutaneously. HO-221 inhibits DNA polymerase alpha activity strongly in vitro. In this study, we examined the cross-resistance of HO-221 to various antitumor agents using sublines of mouse leukemia. HO-221 showed antitumor effects in mice bearing L 1210 or P 388 leukemia resistant to 10 antitumor agents, DM (daunomycin), MMC (mitomycin C), CDDP (cisplatin), 5-FU (5-fluorouracil), Ara-C (cytosine arabinoside), MTX (methotrexate), CPA (cyclophosphamide), CQ (carboquone), ADM (adriamycin) and VCR (vincristine), respectively. These antitumor agents were also effective in P 388 leukemia resistant to HO-221 (P 388/HO-221). Furthermore, CDDP- and MMC-resistant sublines showed a collateral sensitivity to HO-221 in vivo. The grow the inhibitory effects were also noted in vitro in ADM-, CDDP- and MMC-resistant cells by HO-221. However, the in vitro experiments didn't show such collateral sensitivity on the resistant sublines. These results suggest that there is no cross-resistance between HO-221 and other known antitumor agents, and that HO-221 seemed to be worth for evaluating clinical usefulness.
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PMID:[Cross-resistance of HO-221 and various antitumor agents in sublines of mouse leukemia]. 189 47

N-(o-methoxyphenyl)-maleimide (I), an intermediate obtained during the synthesis of pyrrolidinedione-N-mustards, did not exhibit antitumor activity against Ehrlich (ascites) carcinoma. The effect of co-administration of (I), with established anticancer drugs was studied against P388 leukemia, S180 (ascites) and Ehrlich (ascites) carcinoma. A significant potentiation in the activity of 5-Fluorouracil (5-FU) against Ehrlich (ascites) carcinoma by (I) was observed. The possible mechanisms responsible for potentiation of the activity of 5-FU are presented.
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PMID:Influence of N-(o-methoxyphenyl)-maleimide on 5-fluorouracil cytotoxicity in Ehrlich (ascites) carcinoma. 190 58

Myelo-cytotoxicity of extended nitrous oxide (N2O) inhalation was described almost forty years ago and then incidentally applied already with temporary success for suppressing leukemia. In 1948 the accompanying megaloblastic maturation arrest was explained by inactivation of the methylcobalamin coenzyme and subsequent folate deficiency. We studied the anti-leukemic effect of N2O on a transplantable acute leukemia in B(rown) N(orway) rats. Progression of this B,N,M(yelocytic)L(eukemia) was measured as spleen and liver weights, and leukemic blood cell counts. The deoxyuridine (dU)-suppression test provided in vitro indication of the functional folate activity of leukemic cells. Breathing of N2O-oxygen considerably reduced but did not eradicate, BNML-proliferation. Addition of anti-metabolites, interfering with some enzyme in the folate metabolism beyond the methylcobalamin co-enzyme dependent methionine synthase step, acted at least synergistically. The anti-leukemic effect of cycloleucine, which reduces S-adenosyl-methionine synthesis by inactivation of methionine adenosyltransferase, was moderate but became much stronger with N2O inhalation. Methotrexate, a potent anti-leukemic agent by inhibiting tetrahydrofolate (THF) generation through inactivation of di-HF reductase, became highly anti-BNML, even in low dosage when combined with or preceded by N2O. 5-Fluorouracil, which inhibits methylene-THF dependent thymidilate synthase, itself was surprisingly anti-BNML, but also became much more potent with previous or concomitant N2O exposure. Preliminary dU-suppression test results with human acute leukemia cells, exposed to N2O and/or folate antagonists in vitro, correlated well with the in vivo BNML-experiments. Combining the anticobalamin activity of N2O with an anti-folate therefore seems to be a promising chemotherapeutic approach.
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PMID:Anti-leukemic potential of methyl-cobalamin inactivation by nitrous oxide. 218 35

A study was made of the in vivo effects of equitoxic doses of AT-125 and 5-FU combination, being administered either simultaneously (% ILS 152) or with a 6-h pretreatment with AT-125 (% ILS 184). To examine the biochemical basis for the scheduled synergism, measurements were made of the concentration of PRPP, the specific activities of CPS II, cytidine, thymidine, uridine, deoxyuridine kinases, and fluorinated nucleotide formation in P388 tumors and the small intestine. Two hours after in vivo simultaneous treatment of mice bearing tumors the concentration of PRPP increased 9- and 6-fold above baseline in the tumor and the small intestine, respectively. In the AT-125 pretreatment arm the concentration of PRPP increased 18- and 7-fold above baseline in the tumor and the small intestine, respectively. CPS II activity was reduced to 28%-18% of control in the tumors in the simultaneous and pretreatment groups, respectively, whereas it remained unchanged in the small intestine. Specific activities of cytidine kinase (5.5 +/- 1), thymidine kinase (4.0 +/- 1.6), uridine kinase (35.6 +/- 6.5), and deoxyuridine kinase (2.4 +/- 1.1) nmol/mg protein/h remained unchanged with treatment. In concert with the increased intratumor concentration of PRPP, fluorinated nucleotide formation was proportionally increased in the treatment arms. These results indicate the importance of drug scheduling of the above two agents in treating P388 leukemia.
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PMID:Biochemical mechanisms for the scheduled synergism of (alpha S, 5S)-2 amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid and 5-fluorouracil in P388 leukemia. 240 73

The effects of extracellular folate concentration on intracellular folate and phosphoribosylpyrophosphate (PRPP) levels and the cytotoxicity of methotrexate and 5-fluorouracil were studied in human KB cells grown in fetal bovine serum-supplemented Eagle's minimum essential medium, which contained standard high folic acid levels (2.3 microM) (standard or S medium), or folic acid-free serum-supplemented medium containing approximately 4 nM 5-methyltetrahydrofolate (physiological or P medium), a folate level and form more comparable to that in normal human serum. Macrocytosis and prolongation of the doubling time by 150% were observed after 5-10 serial passes in P medium, but after 10-15 serial passes, KB cells became "adapted" to P medium with return of size and doubling time to values indistinguishable from cells maintained in S medium. Cellular folate levels fell, and marked elevations in PRPP levels from 68 +/- 43 to 642 +/- 287 pmol/mg cell protein (mean +/- SD) were observed as KB cells were serially passed through P medium. Human leukemia HL-60 and K562 cells and MJY-alpha mouse mammary tumor cells serially passed in P medium also exhibited 10- to 20-fold elevations in PRPP levels. Glucose consumption, glucose decarboxylation, thymidine and adenosine specific uptake, thymidine incorporation into DNA, and 5-fluorouracil uptake were studied in KB cells with elevated and control PRPP levels. As determined by clonal assay, despite elevated PRPP levels, KB cells cultured in P medium were less sensitive to 5-fluorouracil than cells cultured in S medium unless exogenous folate was added. These data support the concept that endogenous folate levels may be inadequate for optimal 5-FU pharmacological action in KB cells with a modulated increase in PRPP levels.
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PMID:Effect of intracellular folate concentration on the modulation of 5-fluorouracil cytotoxicity by the elevation of phosphoribosylpyrophosphate in cultured human KB cells. 244 72

To investigate the characteristics in antitumor effects of 2-trimethylsilylethylthioethylamine(KAS-010) and its conjugate with 5-FU (KAS-011), the antitumor and immunomodulating activities of these silicon compounds were examined with various systems. Both KAS-010 and KAS-011 administered orally was found to be effective to B 16 melanoma, Meth A sarcoma and MM 46 mammary carcinoma in vivo. On the other hand, KAS-011 administered orally exhibited a marked antitumor activity against L 1210 leukemia bearing mice. Furthermore, these silicon compounds inhibited significantly metastases to the lymph nodes and lung of Lewis lung carcinoma implanted id into the right ear of BDF1 mice. Especially, KAS-011 in combination with tumor amputation resulted in a remarkable prolongation of the survival time (% ILS: 93.8%) in this antimetastatic model. The cell killing effect was mainly dependent on the exposure time of these silicon compounds in cultured KB and human lung cancer (OAT) cells. Moreover, a significant increase of delayed type hypersensitivity reaction (DTHR) to sheep red blood cell (SRBC) induced by KAS-010 was seen in old aged mice. The DTHR in B 16 melanoma and Ehrlich carcinoma bearing mice treated with KAS-010 was significantly higher than those of non-treated tumor bearing mice, indicating an enhanced cellular immunity to KAS-010 possibly resulting in a remarked antitumor effect. We also found that tumor free mice treated these silicon compounds were acquired specific tumor immunity to Meth A sarcoma and MM 46 mammary carcinoma.
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PMID:[Characteristics in antitumor effects of organic silicon related compounds]. 254 47

New reactions of methyl 2,2-difluoro glycosides are described that were utilized for synthesis of some novel nucleoside derivatives. Thus, treatment of methyl 2-deoxy-2,2-difluoro-3,4-O-isopropylidene-alpha (beta)-D-erythro-pyranoside (2) with anhydrous HCl resulted in selective displacement of one fluorine atom with chlorine to give a 2-deoxy-2-chloro-2-fluoro glycoside 3. Reaction of 3 with silylated uracil in the presence of SnCl4 provided a 2-deoxy-2-fluoro-2-uracil-substituted glycoside 4. 2-Fluoro-2-deoxy glycosides substituted with other pyrimidines at C-2 were prepared similarly by the reaction of acylated 2,2-difluoro or 2-fluoro-2-bromo derivatives (5 and 6, respectively) with silylated pyrimidines. The resulting 2'-fluorinated isonucleosides were evaluated for their antitumor and antiviral activities. Compounds 7a,b, 8a,b, and 10a,b demonstrated 50% tumor cell growth inhibition in vitro (IC50) at 10(-4)-10(-5) M. At similar concentrations no antiviral activity was observed in vitro. Therapeutic activity was obtained with 7a,b and 8a,b in DBA/2 mice with L1210 leukemia. Administration of 7a,b at 500 mg/kg, ip daily, for 5 consecutive days, resulted in a 55% increase in life span (% ILS) while administration of 8a,b in the same manner at 200 mg/kg caused a 29% ILS. Treatment with 7a,b to mice with drug-resistant L1210 sublines (5-FU and araC) resulted in 22 and 57% increases in life span, respectively. Lewis lung carcinoma and M5076 sarcoma in mice also responded to the administration of 7a,b with reductions in tumor growth for both tumors and significant increases in life span in mice with Lewis lung carcinoma. Although the mechanism of action of 7a,b is not known, it has been found to be a relatively fast-acting, cell-cycle nonspecific cytotoxic agent that decreases [3H]deoxyuridine incorporation, blocks L1210 cells at the G2 phase of the cell cycle, and is not reversed by exogenous thymidine. These 2'-fluorinated isonucleosides have demonstrated biological activity and may have potential as antitumor drugs.
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PMID:2'-Fluorinated isonucleosides. 1. Synthesis and biological activity of some methyl 2'-deoxy-2'-fluoro-2'-pyrimidinyl-D-arabinopyranosides. 270 26

The combined effect of cisplatin (CDDP) with various types of antitumor drugs was examined in P 388 leukemia in vivo. Three representative drugs were chosen from every group of alkylating agents, antitumor antibiotics, antimetabolites, and plant originated drugs. According to their dependency on administration schedules, the dose-dependent and time-dependent drugs were administered once, and daily 5 times, respectively, before and after the single administration of CDDP. In addition to these sequential combinations, simultaneous treatment with CDDP was examined for the drugs which were singly administered. The combined effect was assessed by comparing ILS (increase in life span) in a combined group with the sum of ILS's of each of the 2 single-treatment groups. Synergistic effect was observed in the combination of CDDP with all drugs except MMC. Among them CYC, CQ, ACNU, ADR, PEP, ET, VCR, and VDS produced synergistic effect in any treatment schedules, irrespective of the combination sequences. In the cases of the combination with antimetabolites, the combined effect was depended on the treatment sequences; prior treatment of 5-FU, and posterior treatment of Ara-C and MTX to CDDP administration exhibited a synergistic effect, but the combination in reverse sequence remained almost additive.
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PMID:[Combined effect of CDDP with various types of antitumor drugs against P 388 leukemia]. 273 70

Methylene blue can inhibit the growth of Ehrlich ascitic tumor, L1210 leukemia and P388 leukemia in mice. The average life span of the treated animals was obviously longer than that of the controls. Methylene blue was superior to 5-Fu in the treatment of L1210 leukemia of mice and two thirds of the mice with P388 leukemia were healthy and survived for more than 60 days after administrated different doses of methylene blue. When adriamycin was given simultaneously with methylene blue to mice, the acute toxic effect of adriamycin was decreased and the survival time prolonged. Methylene blue is a highly ionized and a rapidly eliminated drug which can combine well with tissues at higher concentration maintained for several hours and can easily pass through the blood-brain barrier.
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PMID:[Antitumor effect of methylene blue in vivo]. 280 52

A cell line (SCC-25) derived from a human squamous cell carcinoma was found to have a higher level of in situ thymidylate synthase activity when compared to a faster-growing cell line, L1210 leukemia, and approximately 5 times the level of activity of a cell line with the same growth rate, S91-A melanoma. These results led to an examination of the effects of both direct and indirect inhibitors of this enzyme using intact SCC-25 cells. It was found that drugs that have an indirect effect on this enzyme--methotrexate (MTX), hydroxyurea (HU), and 3,4-dihydroxybenzylamine (3,4-DHBA)--acted as noncompetitive inhibitors and the inhibition of thymidylate synthase by these drugs did not result in the accumulation of its substrate, dUMP. This suggested that these drugs are also inhibiting steps leading to the formation of dUMP by a mechanism that is coordinated with the inhibition of thymidylate synthase. 5-Fluorodeoxyuridine (FUDR), a competitive inhibitor of thymidylate synthase, did cause an increase in the dUMP pool size indicating that this drug did not affect the synthesis of this substrate. There was a good correlation for the inhibition of growth, DNA synthesis, and thymidylate synthase with HU, 3,4-DHBA, and FUDR. However, the results suggested fundamentally different mechanistic reasons for the close relationship among these three inhibitory effects. Finally the inhibition of growth by MTX did not appear to correlate with the inhibition of DNA synthesis. The implication of these results for the therapy of epidermally derived proliferative disorders, especially with combinations such as MTX and 5-FU, is discussed.
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PMID:Comparison of the inhibitory effects of hydroxyurea, 5-fluorodeoxyuridine, 3,4-dihydroxybenzylamine, and methotrexate on human squamous cell carcinoma. 294 54


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