levoleucovorin and Leukemia

Topics: Humans; Leucovorin; Leukemia; Lymphoma, Non-Hodgkin; Methotrexate

Topics: Antineoplastic Combined Chemotherapy Protocols; Central Nervous System; Clinical Trials as Topic; Combined Modality Therapy; Humans; Injections, Intravenous; Injections, Intraventricular; Injections, Spinal; Leucovorin; Leukemia; Male; Methotrexate; Nervous System Neoplasms; Prognosis; Radiation Injuries; Testicular Neoplasms

The comprehensive use of methotrexate is possible because there is an easy way of reducing the toxic effects of this drug. Effective in the antidotic action are alkalinization of the urine, increasing hydration of the patient, and "rescue" of purine and pyrimidine metabolism in the tissues by use of reduced folates. Only intravenous administration, by means of infusion given over a long period (24 hours or more), results in reliable and reproducible concentrations in the plasma. Oral administration should be abandoned because of the variable resorption and the different concentrations reached in plasma by different individuals. Local administration, such as by intrathecal injection, is useful only when the interval between two succeeding injections is 14 days or more. On the basis of known pharmacokinetic constants, the dose of methotrexate and of citrovorum factor (leucovorin) which will result in the desired concentration in plasma, and possibly also in tissues, can easily be calculated. Use of the principle of concentration X time in dosage calculations will result in the avoidance of giving unnecessarily high doses of methotrexate.

Topics: Administration, Oral; Central Nervous System; Central Nervous System Diseases; Child; DNA; Drug Therapy, Combination; Humans; Infusions, Parenteral; Injections, Spinal; Kinetics; Leucovorin; Leukemia; Methotrexate

Topics: Antibodies, Neoplasm; B-Lymphocytes; Cyclophosphamide; DNA, Neoplasm; Doxorubicin; Drug Therapy, Combination; Humans; Immunotherapy; Leucovorin; Leukemia; Lymphoma; Methotrexate; T-Lymphocytes

Topics: Child; Drug Resistance; Folic Acid Antagonists; Humans; Leucovorin; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Methotrexate

Topics: Antineoplastic Agents; Asparaginase; Daunorubicin; Humans; Leucovorin; Leukemia; Lymphatic Diseases; Mercaptopurine; Methotrexate; Prednisolone; Vincristine

The Cancer and Leukemia Group B (CALGB) conducted sequential Phase II multicenter trials to evaluate the activity of edatrexate alone (E) or with leucovorin rescue (EL) in patients with malignant pleural mesothelioma (CALGB Protocol 9131).. Twenty patients were accrued to the E portion of the study and received edatrexate, 80 mg/m(2), intravenously over 20-30 minutes weekly. After a protocol amendment precipitated by excessive toxic events with E, 40 patients were enrolled in the EL arm and received the same dose of edatrexate with leucovorin, 15 mg orally, every 6 hours for 4 doses beginning 24 hours after edatrexate. Eligibility criteria included a CALGB performance status of 0-2 and no prior chemotherapy. A central pathology review was performed. Of the 58 patients included in this analysis (20 receiving E and 38 receiving EL), 36 had epithelial cell type and 22 had mixed or sarcomatous cell types. There were 31 patients with measurable disease and 27 with evaluable disease.. The overall response rate was 25% for E (95% confidence interval [95% CI], 9-49%) and 16% for EL (95% CI, 6-31%). There was a 5% complete response [CR] rate, a 10% partial response [PR] rate, and a 10% regression [R] rate for E and a 0% CR rate, a 3% PR rate, and a 13% R rate for EL. The median survival duration from study entry was 9.6 months and 6.6 months, respectively, for E and EL; 1-year survival was 50% and 32%, respectively, for E and EL. There were four early deaths with the E regimen (including two from neutropenic sepsis) and one early death with the EL regimen (from progressive disease). Principal toxicities included mu cositis, myelosuppression, and rash, which were less frequent with leucovorin rescue.. Moderate antitumor activity has been observed with both regimens. Leucovorin rescue ameliorated the mucosal, hematologic, and dermatologic toxicities of edatrexate, but also may have reduced its efficacy.

Topics: Aminopterin; Antineoplastic Agents; Dose-Response Relationship, Drug; Female; Humans; Leucovorin; Leukemia; Male; Mesothelioma; Middle Aged; Pleural Neoplasms; Survival Rate; Treatment Failure

Fifty-seven patients undergoing bone marrow transplantation were randomly assigned to receive either cyclosporin A (CsA, n = 26) or methotrexate, followed by rescue with folinic acid (MTX + FA, n = 31) as prophylaxis for graft-versus-host disease (GVHD). All patients but one receiving CsA had evidence of sustained engraftment, and there was no difference between the two groups on the day in which marrow engraftment was documented. Oropharyngeal mucositis was of similar incidence and severity in the two groups. In contrast, patients receiving CsA showed higher renal and hepatic toxicity rates than those treated with MTX + FA. Severe-to-moderate acute GVHD (grades II-IV) was documented in 12 patients receiving CsA and in 12 treated with MTX + FA. The cumulative incidence of this complication was similar in both groups (46.1% and 38.7%). Similarly, there was no difference in the incidence of chronic GVHD. The leukemic relapse rates were also comparable, as well as the estimated probability of survival, which was 55% in patients treated with MTX + FA and 41% in those who were given CsA. We conclude that MTX + FA is as effective as CsA in the prevention of GVHD, with the additional advantage of reduced renal and hepatic toxicities.

Topics: Actuarial Analysis; Acute Disease; Adolescent; Adult; Blood Transfusion; Bone Marrow Transplantation; Cyclosporins; Drug Therapy, Combination; Female; Graft vs Host Disease; Humans; Leucovorin; Leukemia; Male; Methotrexate; Middle Aged; Postoperative Complications; Prospective Studies; Random Allocation; Recurrence

Patients with advanced indolent lymphoma often have long survival (median, 4 to 8 years) in spite of frequent relapses. The inability of combination chemotherapy or radiation therapy (RT) to render patients disease free has led to radically divergent treatment approaches. Initial treatment may vary from aggressive combined modality therapy to no initial treatment. We sought to evaluate these two divergent approaches in a randomized trial of advanced indolent lymphomas (nodular, poorly differentiated lymphocytic; nodular mixed; diffuse, well-differentiated lymphocytic; diffuse, intermediately differentiated lymphocytic; and diffuse, poorly differentiated lymphocytic). A total of 104 patients were entered: 44 were randomly assigned to "watch and wait" in which only carefully defined, limited RT was administered if necessary; 45 were randomly assigned to aggressive combined modality treatment with prednisone, methotrexate, doxorubicin, cyclophosphamide, plus etoposide plus mechlorethamine, vincristine, procarbazine, prednisone (ProMACE-MOPP), followed by total nodal irradiation (TNI); and 15, with symptoms requiring initial therapy, received the identical combined treatment but were not randomly assigned. Of 41 evaluable patients on watch and wait, 23 (56%) have still not required systemic therapy, although 16 (39%) have received limited RT. Median time to crossover was 34 months. Of 18 patients crossed over, seven of the 16 who completed therapy (43%) achieved CR; two (11%) have relapsed. Histologic progression was seen in six (15%) of 41 patients on watch and wait without intervening chemotherapy. Of 45 patients randomly assigned to chemotherapy, 37 (82%) have completed induction therapy, and 29 of the 37 (78%) achieved CR. Twenty-five of those 29 patients (86%) are still in their first remission. Median duration of initial remission has not been reached but will exceed 4 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Antineoplastic Combined Chemotherapy Protocols; Combined Modality Therapy; Cyclophosphamide; Doxorubicin; Etoposide; Evaluation Studies as Topic; Humans; Leucovorin; Leukemia; Leukemia, Radiation-Induced; Lymph Nodes; Lymphoma, Non-Hodgkin; Mechlorethamine; Methotrexate; Neoplasms, Multiple Primary; Neoplasms, Radiation-Induced; Palliative Care; Prednisone; Procarbazine; Random Allocation; Vincristine

Topics: Antineoplastic Combined Chemotherapy Protocols; Central Nervous System; Clinical Trials as Topic; Combined Modality Therapy; Humans; Injections, Intravenous; Injections, Intraventricular; Injections, Spinal; Leucovorin; Leukemia; Male; Methotrexate; Nervous System Neoplasms; Prognosis; Radiation Injuries; Testicular Neoplasms

The cooperative study group, consisting of 11 institutes, conducted a study by the high-dose methotrexate (MTX) with citrovorum factor (CF) rescue therapy on acute leukemia and malignant lymphoma that were resistant to other anti-cancer chemotherapy. In acute leukemia the rates of complete remission (CR) and partial remission (PR) were 16.7% and 26.7%, respectively, and in malignant lymphoma the response rate (excellent plus good response) was 38.9%. This therapy would be safely carried out by alkalinization of urine and adequate hydration under sufficient clinical surveillance. From the results of the present study, high-dose MTX-CF therapy seems to be one of effective regimens for acute leukemia and malignant lymphoma that are resistant to the conventional doses of MTX or other anti--cancer agents. Also, with this therapy, treatment or prophylaxis of symptoms of central nervous system and of other pharmacological sanctuaries can be expected, which may be one of the useful points of H-MTX-CF therapy.

Topics: Acute Disease; Adolescent; Adult; Child; Clinical Trials as Topic; Drug Administration Schedule; Drug Therapy, Combination; Female; Humans; Leucovorin; Leukemia; Lymphoma; Male; Methotrexate

The relationship between changes in the bone marrow labeling index and the patient's subsequent response to cycle-specific agents was studied by the South-eastern Cancer Study Group in adults with acute leukemia. Ninety-eight patients were randomized to one of two treatment regimens. Schedule 1 consisted of a single intravenous (i.v.) push of cytosine arabinoside followed in 48 hours by a large dose of oral methotrexate distributed over 24 hours and i.v. vincristine. Leucovorin rescue was employed to control the toxic effects of the high dose methotrexate and the cycle was repeated every 7 days. Schedule 2 differed only in that there were three daily injections of cytosine arabinoside preceding vincristine and methotrexate injections and each cycle was given every 10 days. Cell kinetic studies were performed in 30 patients and revealed that the majority of patients who had a response to therapy had some increase in the marrow labeling index 48 hours after cytosine arabinoside injection. In general, those patients who had no response to therapy had little change. There was no significant difference between schedules in the ability to induce an increase in labeling index 48 hours after cytosine arabinoside or in the increment achieved by the responders. However, there was a significant difference in the response rate seen with these schedules. Schedule 1 achieved only a 24% remission rate in acute nonlymphocytic leukemia (ANLL) while schedule 2 was associated with a 52% remission rate. In acute lymphoblastic leukemia (ALL) both schedules induced a 60% remission rate while none of the four patients with blast crisis of chronic granulocytic leukemia (CGL) responded. Analysis of the characteristics associated with remission revealed that more females achieved a remission than males and that the presence of pretreatment infection was the greatest contributing cause of early death and thus severely limited the ability to achieve a remission. As opposed to the current regimens used in ANLL, schedule 2 did not require significant bone marrow hypoplasia (as judged by the degree of hematological toxicity) to achieve a remission and there was no decrease in response seen with increasing age. The data suggest that increased efficiency of cycle-specific, antitumor agents may occur by increasing the proportion of human leukemic cells in DNA synthesis.

Topics: Adult; Age Factors; Antineoplastic Agents; Bone Marrow; Bone Marrow Cells; Cell Division; Cytarabine; Female; Humans; Leucovorin; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Male; Methotrexate; Middle Aged; Remission, Spontaneous; Sex Factors; Vincristine

Topics: Bone Marrow; Bone Marrow Cells; Cytarabine; Daunorubicin; DNA, Neoplasm; Drug Therapy, Combination; Humans; Kinetics; Leucovorin; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Methotrexate; Mitotic Index; Thioguanine

Topics: Adenocarcinoma; Camptothecin; Chemotherapy, Adjuvant; Colonic Neoplasms; Disease-Free Survival; Ethics, Medical; Fluorouracil; Humans; Irinotecan; Leucovorin; Leukemia; Randomized Controlled Trials as Topic; Recurrence; Treatment Outcome; Uncertainty

Short, intensive cycles of chemotherapy have resulted in improved survival in BurkittOs lymphoma/leukemia (BL) in adults. The prognosis of patients with immunodeficiency virus (HIV)-associated BL is considered to be poor, but these patients have seldom been treated with BL-specific protocols. However, a study (PETHEMA-LAL3/97) in which patients with BL were treated regardless of their HIV status failed to find differences between HIV-infected and immunocompetent individuals. Furthermore, patients who received highly active antiretroviral therapy (HAART) seemed to have a slightly better disease-free survival than those who did not (p=0.051). We extended the follow-up analysis to elucidate the role of HAART in the survival of HIV-infected patients included in the PETHEMA-LAL3/97 protocol.

Topics: Acquired Immunodeficiency Syndrome; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Antiretroviral Therapy, Highly Active; Cyclophosphamide; Cytarabine; Dexamethasone; Disease-Free Survival; Etoposide; Female; Follow-Up Studies; Humans; Ifosfamide; Leucovorin; Leukemia; Lymphoma, AIDS-Related; Male; Methotrexate; Middle Aged; Prednisone; Treatment Outcome; Vincristine

We have studied the molecular basis for the resistance of human CEM leukemia cells to GW1843, a thymidylate synthase inhibitor. GW1843-resistant cells displayed a approximately 100-fold resistance to GW1843 and methotrexate but were collaterally sensitive to the lipophilic antifolates trimetrexate and AG337, which enter cells by diffusion. These cells exhibited a 12-fold decreased methotrexate influx but surprisingly had a 2-fold decreased folic acid growth requirement. This was associated with a 4-fold increased influx of folic acid, a 3.5-fold increased steady-state level of folic acid, and a 2.3-fold expansion of the cellular folate pool. Characterization of the transport kinetic properties revealed that GW1843-resistant cells had the following alterations: (a) 11-fold decreased transport K(m) for folic acid; (b) 6-fold increased transport K(m) for GW1843; and (c) a slightly increased transport V(max) for folic acid. Sequence analysis showed that GW1843-resistant cells contained the mutations Val-29 --> Leu, Glu-45 --> Lys, and Ser-46 --> Ile in the first transmembrane domain of the reduced folate carrier. Transfection of the mutant-reduced folate carrier cDNA into methotrexate transport null cells conferred resistance to GW1843. This is the first demonstration of multiple mutations in a confined region of the human reduced folate carrier in an antifolate-resistant mutant. We conclude that certain amino acid residues in the first transmembrane domain play a key role in (anti)folate binding and in the conferring of drug resistance.

Topics: Antimetabolites, Antineoplastic; Biological Transport; Blotting, Northern; Blotting, Southern; Blotting, Western; Carrier Proteins; Cell Division; Cell Membrane; Chlorides; DNA Mutational Analysis; DNA, Complementary; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Enzyme Inhibitors; Exons; Folic Acid; Folic Acid Antagonists; Humans; Indoles; Inhibitory Concentration 50; Isoindoles; Kinetics; Leucovorin; Leukemia; Membrane Proteins; Membrane Transport Proteins; Methotrexate; Mutagenesis, Site-Directed; Mutation; Polymorphism, Single-Stranded Conformational; Protein Structure, Secondary; Protein Structure, Tertiary; Quinazolines; Recombinant Proteins; Reduced Folate Carrier Protein; Thymidylate Synthase; Time Factors; Transfection; Trimetrexate; Tumor Cells, Cultured

Effects of lipophilic thymidylate synthase (TS) inhibitor AG337 on human head and neck squamous cell carcinoma (HNSCC) cell lines and CCRF-CEM human leukemia cells and sublines with acquired methotrexate (MTX) resistance were assayed using continuous or intermittent drug exposure. During 120-h continuous exposure, HNSCC cell lines A253 and FaDu are equally MTX sensitive (EC50 equals approximately 15nM); AG337 is less potent (EC50 approximately equals 1 microM). A253 is intrinsically resistant to 24-h intermittent MTX exposure (EC50 equals approximately 17 microM; FaDu, EC50 equals approximately 0.3 microM); both HNSCC cell lines are resistant to 24-h AG337 exposure (EC50 >100 microM). CCRF-CEM shows MTX (EC50 =14 nM) and AG337 (EC50 equals approximately 0.6 microM) sensitivity in continuous exposure similar to HNSCC; however, AG337 retains potency against CCRF-CEM cells in intermittent exposure (24-h, EC50 equals approximately 2 microM; 6-h, EC50 equals approximately 48 microM). The reduced folate leucovorin (LV) at > or = 0.1 microM fully protects from growth inhibition by continuous MTX exposure, but growth inhibition by AG337 is reversed only slightly by < or = 100 microM LV. Thymidine fully protects A253 and FaDu against growth inhibition by AG337, while hypoxanthine alone is without effect, suggesting inhibition is TS-specific. CCRF-CEM sublines with acquired MTX-resistance resulting from DHFR overexpression, defective MTX transport, or defective MTX polyglutamylation retain full sensitivity to AG337 in continuous exposure (all EC50 =0.4 microM). These data indicate that AG337 may be useful in therapy of tumors that have acquired resistance to MTX by most common mechanisms.

Topics: Cell Cycle; Cell Division; Culture Media; Drug Resistance; Enzyme Inhibitors; Fetal Blood; Head and Neck Neoplasms; Humans; Hypoxanthine; Inhibitory Concentration 50; Leucovorin; Leukemia; Methotrexate; Quinazolines; Thymidine; Thymidine Phosphorylase; Thymidylate Synthase; Tumor Cells, Cultured

Thymidylate synthase (TS) inhibitor effects on growth of human head and neck squamous cell carcinoma (HNSCC) cell lines and CCRF-CEM human leukemia cells and sublines with acquired methotrexate (2,4-diamino-10-methylpteroylglutamic acid) (MTX) resistance were studied. During 120-h treatment, HNSCC cell lines A253 and FaDu are equally sensitive to MTX, whereas the polyglutamylatable TS inhibitors ZD1694 and BW1843U89 are 5- to 35-fold more potent than MTX and the lipophilic AG331 is approximately 10(2)-fold less potent than MTX. A253 is intrinsically resistant to intermittent (24 h) MTX and BW1843U89 exposure (higher EC50 values and shallower slopes of concentration-response curves relative to FaDu); AG331 and ZD1694 largely overcome this intrinsic resistance to intermittent exposure. Thymidine (TdR) protects against growth inhibition by these inhibitors, confirming that TS is their target in HNSCC; at high AG331 levels, TdR only partially protects, implying that a second site of action exists. Growth inhibition of HNSCC by ZD1694 and BW1843U89 is protected by leucovorin (LV) at > or = 10(-7) and > 10(-3) M, respectively; 10(-4) M LV cannot protect HNSCC cells against AG331. Results similar to protection studies are obtained if LV addition is delayed < or = 24 h after ZD1694 or BW1843U89 exposure. CCRF-CEM sublines with acquired MTX resistance resulting from dihydrofolate reductase (DHFR) overexpression, defective MTX transport, or defective MTX polyglutamylation retain full sensitivity to AG331. Cells with defective MTX transport are highly cross-resistant to ZD1694 and BW1843U89, implicating the reduced folate/MTX carrier in their transport. Minor cross-resistance of the DHFR overexpressing line to ZD1694 and BW1843U89 is observed. A subline with highly defective MTX polyglutamylation is cross-resistant to 120-h exposure to ZD1694, but not to BW1843U89, suggesting a profound contribution of polyglutamylation to the mechanism of action of ZD1694.

Topics: Antimetabolites, Antineoplastic; Antineoplastic Agents; Cell Division; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Enzyme Inhibitors; Growth Inhibitors; Head and Neck Neoplasms; Humans; Leucovorin; Leukemia; Methotrexate; Thymidylate Synthase; Tumor Cells, Cultured

The types of folates used during the development of resistance to methotrexate have been suggested to play an important role in the mechanisms of established resistance. In this study, effects of reduced and oxidized folates on the development of resistance to a thymidylate synthase (TS) inhibitor, N10-propargyl-5, 8-dideazafolic acid (CB3717), were examined in the human leukemia cell line MOLT-3. MOLT-3 cells were made resistant to CB3717 by soft-agar cloning in RPMI-1640 medium with either pteroylglutamic acid (PGA) or a more physiological folate (10 nM leucovorin). A 40-fold CB3717-resistant subline developed in PGA (MOLT-3/CB3717(40)-PGA) showed amplification of the TS gene with a concomitant increased level in the gene expression. A 200-fold CB3717-resistant subline (MOLT-3/CB3717(200)-PGA), which was derived from MOLT-3/CB3717(40)-PGA, showed further enhancement of amplification of the TS gene. In contrast, even a 200-fold CB3717-resistant subline developed in leucovorin (MOLT-3/CB3717(200)-LV) showed neither amplification nor overexpression of the TS gene. Both MOLT-3/CB3717(200)-PGA and MOLT-3/CB3717(200)-LV cells showed decreased membrane transport of PGA as well as methotrexate. These results suggest that the types of folates used during the development of CB3717 resistance may play a role in resistance, and that impaired transport of PGA, in CB3717-resistant MOLT-3 cells developed in PGA, might have accelerated amplification of the TS gene.

Topics: Biological Transport; Drug Resistance; Enzyme Inhibitors; Folic Acid; Gene Amplification; Genes; Humans; Leucovorin; Leukemia; Methotrexate; Quinazolines; Thymidylate Synthase; Tumor Cells, Cultured

The transport properties and growth-inhibitory potential of 37 classic and novel antifolate compounds have been tested in vitro against human and murine cell lines expressing different levels of the reduced folate carrier (RFC), the membrane-associated folate binding protein (mFBP), or both. The intracellular targets of these drugs were dihydrofolate reductase (DHFR), glycinamide ribonucleotide transformylase (GARTF), folylpolyglutamate synthetase (FPGS), and thymidylate synthase (TS). Parameters that were investigated included the affinity of both folate-transport systems for the antifolate drugs, their growth-inhibitory potential as a function of cellular RFC/mFBP expression, and the protective effect of either FA or leucovorin against growth inhibition. Methotrexate, aminopterin, N10-propargyl-5,8-dideazafolic acid (CB3717), ZD1694, 5,8-dideazaisofolic acid (IAHQ), 5,10-dideazatetrahydrofolic acid (DDATHF), and 5-deazafolic acid (efficient substrate for FPGS) were used as the basic structures in the present study, from which modifications were introduced in the pteridine/quinazoline ring, the C9-N10 bridge, the benzoyl ring, and the glutamate side chain. It was observed that RFC exhibited an efficient substrate affinity for all analogues except CB3717, 2-NH2-ZD1694, and glutamate side-chain-modified FPGS inhibitors. Substitutions at the 2-position (e.g., 2-CH3) improved the RFC substrate affinity for methotrexate and aminopterin. Other good substrates included PT523 (N alpha-(4-amino-4-deoxypteroyl)-N delta-hemiphthaloyl-L-ornithine), 10-ethyl-10-deazaaminopterin, and DDATHF. With respect to mFBP, modifications at the N-3 and 4-oxo positions resulted in a substantial loss of binding affinity. Modifications at other sites of the molecule were well tolerated. Growth-inhibition studies identified a series of drugs that were preferentially transported via RFC (2,4-diamino structures) or mFBP (CB3717, 2-NH-ZD1694, or 5,8-dideazaisofolic acid), whereas other drugs were efficiently transported via both transport pathways (e.g., DDATHF, ZD1694, BW1843U89, or LY231514). Given the fact that for an increasing number of normal and neoplastic cells and tissue, different expression levels of RFC and mFBP are being recognized, this folate antagonist structure-activity relationship can be of value for predicting drug sensitivity and resistance of tumor cells or drug-related toxicity to normal cells and for the rational design and development of novel antifolates.

Topics: Acyltransferases; Animals; Biological Transport, Active; Carrier Proteins; Cell Division; Enzyme Inhibitors; Folate Receptors, GPI-Anchored; Folic Acid; Folic Acid Antagonists; Humans; Hydroxymethyl and Formyl Transferases; Leucovorin; Leukemia; Leukemia L1210; Membrane Proteins; Membrane Transport Proteins; Mice; Peptide Synthases; Phosphoribosylglycinamide Formyltransferase; Receptors, Cell Surface; Reduced Folate Carrier Protein; Structure-Activity Relationship; Substrate Specificity; Thymidylate Synthase; Tumor Cells, Cultured

Urinary N-acetyl-beta-D-glucosaminidase (NAG-ase) activity is a very sensitive parameter of kidney proximal tubular damage. Using urinary NAG-ase activity/urinary creatinine as the NAG index, the serum methotrexate (MTX) level and urinary pH were investigated simultaneously. These parameters were measured in 17 leukaemic children. During MTX treatment, NAG indices were normal in 5 children and only slightly elevated occasionally in 9 patients. Among them, transiently high serum MTX levels (Patient A) or low urinary pH (Patient B) were accompanied by high NAG indices. MTX toxicity has been diagnosed in 3 cases, when permanently high NAG indices were in accordance with other clinical signs.

Topics: Acetylglucosaminidase; Antineoplastic Combined Chemotherapy Protocols; Biomarkers; Burkitt Lymphoma; Child; Creatinine; Diuresis; Humans; Hydrogen-Ion Concentration; Kidney Diseases; Kidney Tubules, Proximal; Leucovorin; Leukemia; Lymphoma, Non-Hodgkin; Methotrexate; Neoplasm Proteins; Precursor Cell Lymphoblastic Leukemia-Lymphoma

A study was performed to determine whether the addition of folinic acid to a combination of methotrexate (MTX) and cyclosporin A (CsA) after allogeneic bone marrow transplantation (BMT) could improve tolerance to the regimen without inhibiting its ability to prevent graft-versus-host disease (GVHD). Sixty-nine adult BMT patients received CsA plus MTX 15 mg/m2 on day 1 and 10 mg/m2 on days +3, +6 and +11. Folinic acid 5 mg was started 24 h after each MTX dose and continued 6 hourly until 12 h before the next dose of MTX. The median age of the group was 37 years and 13 patients (19%) received bone marrow from mismatched and/or unrelated donors. No MTX doses were omitted or modified. Grade II-IV acute GVHD occurred in 18 patients (29%) and chronic GVHD in 35 of 56 (64%) patients at risk. There were no cases of grade > or = III stomatitis. Transplant-related mortality was 7% before 100 days and 20% overall (9% for low risk leukaemia) with a median follow-up of 41 months (range 24-88 months). This regimen of folinic acid rescue may contribute to a well tolerated GVHD prophylaxis protocol with reasonably low BMT-related mortality. Our results suggest that the ability of MTX to prevent acute GVHD is not abrogated by folinic acid given in this way.

Topics: Acute Disease; Administration, Oral; Adolescent; Adult; Bone Marrow Transplantation; Chronic Disease; Cyclosporine; Drug Therapy, Combination; Female; Follow-Up Studies; Graft Rejection; Graft vs Host Disease; Humans; Leucovorin; Leukemia; Male; Methotrexate; Middle Aged; Transplantation, Homologous

The effect of reduced and oxidized folates on the development of methotrexate (MTX) resistance has been examined in human leukemia cell line K562 (K562/S). K562/S cells were made resistant to MTX by soft-agar cloning either in RPMI-1640 medium (K562/MTX-PGA) or in folic-acid-free RPMI-1640 medium containing 10 nM leucovorin (K562/MTX-LV). The optimal concentrations of leucovorin for the growth of K562/S, K562/MTX-PGA and K562/MTX-LV cells were 1 nM, 5 nM and 10 nM respectively. K562/MTX-PGA cells were 24-fold resistant to MTX as noted by impaired MTX transport. In contrast, K562/MTX-LV cells were 26-fold resistant to MTX as noted by gene amplification of dihydrofolate reductase. Furthermore cross-resistance to cytosine arabinoside was only demonstrated in K562/MTX-PGA, while the K562/MTX-LV cells showed no significant cross-resistance to cytosine arabinoside. These results suggest that the type and level of folates used during the development of MTX resistance may play a role in the mechanism for MTX resistance. Leukemia cells that are grown in leucovorin might serve as a model for acquired MTX resistance in vivo.

Topics: Cell Cycle; Drug Resistance; Folic Acid; Humans; Leucovorin; Leukemia; Methotrexate; Tetrahydrofolate Dehydrogenase; Tumor Cells, Cultured

The mechanism of acquired methotrexate-resistance in an estrogen-receptor positive human breast cancer cell line (MTX(R)ZR-75-1) was studied. MTX(R) ZR-75-1 cells are 250-fold resistant to methotrexate when grown in the presence of 1 microM folinic acid and 2,400-fold resistant in the presence of 1 microM folic acid. This drug resistant cell line also showed collateral sensitivity (10-fold) to trimetrexate (TMQ), when grown in the presence of folinic acid. Using fluoresceinated methotrexate (F-MTX), FACS analysis indicated that there is no intracellular accumulation of methotrexate into MTX(R) ZR-75-1 cells, as determined by competition of F-MTX and methotrexate binding to dihydrofolate reductase. These characteristics strongly indicate that the mechanism of resistance involved down regulation of the reduced-folate transporter. To investigate this further, the transport kinetics of parental and MTX(R) ZR-75-1 cells were examined. Although the V(max) for methotrexate transport in wild-type (WT) ZR-75-1 breast cancer cells was 1-2 orders of magnitude lower than that in the well characterized leukemia cell lines, such as L1210 and CCRF-CEM cells, kinetic analysis indicated that transport of methotrexate into WT ZR-75-1 cells involved a mechanism that was similar if not identical to the reduced folate transporter. In contrast, no specific uptake of methotrexate was detected in MTX(R) ZR-75-1cells. Furthermore, neither cell line expressed detectable levels of folate binding protein, a binding protein with high affinity for folic acid as well as for reduced folates and antifolates. These results indicate that the level of expression of the reduced-folate carrier may be an important factor in determining the sensitivity of breast cancer cells as well as leukemia cells to antifolate compounds.

Topics: Animals; Antimetabolites, Antineoplastic; Biological Transport; Breast Neoplasms; Carrier Proteins; Drug Resistance, Neoplasm; Flow Cytometry; Folate Receptors, GPI-Anchored; Folic Acid; Folic Acid Antagonists; Humans; Leucovorin; Leukemia; Methotrexate; Mice; Receptors, Cell Surface; Receptors, Estrogen; Tetrahydrofolate Dehydrogenase; Trimetrexate; Tumor Cells, Cultured; Vitamin B Complex

A human cell culture system is described for biological testing of potent new folate-targeted antileukemic drugs that are poorly transported. Basic amino acid (lysine and ornithine) polymers were employed as carriers for increasing the uptake of folate analogs by human leukemia cell lines. In growth inhibition assays, the lymphocytic CCRF-CEM line displayed sensitivities to covalent methotrexate (MTX) conjugates of poly-L-lysine (Mr = 15,000, 50,000, or 100,000) or poly-L-ornithine (Mr = 35,000) which were identical to the sensitivities of these cells to the unconjugated polymers during continuous (120 hr) and pulse (24 hr) exposures; both polymers and conjugates were 50-fold less toxic than unconjugated MTX. The growth inhibitory effects of the polymers or MTX-conjugates were not reversed by simultaneous inclusion of leucovorin, while those of MTX were reversed. In contrast, the nonlymphocytic K562 line showed toxicity by the MTX-conjugates at nontoxic levels of the polymers during continuous, but not pulse, exposures. During continuous exposure the conjugates were only 10-fold less toxic than unconjugated MTX. Toxicities of the MTX-conjugates for the K562 line under continuous exposure conditions were reversed by the simultaneous presence of leucovorin or the lysosomotropic agent leupeptin and thus appeared to be a true antifolate effect which required uptake and lysosomal degradation. This human cell line is thus a suitable system in which to study the effects of antifolates which can be coupled to basic polymers.

Topics: Blood Physiological Phenomena; Drug Carriers; Folic Acid Antagonists; Humans; Leucovorin; Leukemia; Lysosomes; Methotrexate; Peptide Synthases; Peptides; Polylysine; Tumor Cells, Cultured

The cytotoxic effects of the antifolates methotrexate (MTX) and trimetrexate (TMQ) were investigated for two human leukemic CCRF-CEM cell lines, one expressing the "classical" reduced folate/MTX carrier (CEM-RF), another lacking this carrier but expressing a membrane associated folate binding protein (CEM-FBP). CEM-FBP cells were found to be highly resistant to MTX compared to CEM-RF cells, especially in short exposures. For example, after 4 h incubation, IC50 values for MTX were 251 microM and 0.98 microM for CEM-FBP and CEM-RF cells, respectively. On the other hand, CEM-FBP cells were much more sensitive to the lipophilic antifolate TMQ than CEM-RF cells as shown by IC50 values (after 4 h of exposure) of 0.059 microM and 7.5 microM, respectively. Finally, the reversal of TMQ cytotoxicity by folinic acid was significantly impaired for CEM-FBP cells, in contrast to CEM-RF cells. These results indicate that the nature of the membrane transport system for folates can be a critical determinant in tumor cell sensitivity or resistance to antifolates.

Topics: Biological Transport; Carrier Proteins; Folate Receptors, GPI-Anchored; Folic Acid; Humans; In Vitro Techniques; Leucovorin; Leukemia; Methotrexate; Quinazolines; Receptors, Cell Surface; Trimetrexate; Tumor Cells, Cultured

The effects of the fluoropyrimidines on leukemic cells of mouse and human origin have been studied in the presence of folinic acid. This reduced folate enhanced the cytotoxicity and the growth inhibitory potency of 5-fluorouracil (5-FUra) and of 5-fluoro-2'-deoxyuridine (FUdR) against all cell lines examined. The human leukemic cell lines used (two T- and two B-cells) were affected by these fluoropyrimidines only at substantially higher concentrations than were found to be inhibitory to mouse L1210 cells; however, the enhancement of the activity of the fluoropyrimidines occurred over the same range of folinic acid concentrations in mouse and human cells. Whereas the total intracellular folate pool increased continuously with every increment of folinic acid added to the medium, the enhancement of the potency of the fluoropyrimidines was limited. Augmentation of the effects of FUdR exceeded that of 5-fluorouracil in the human leukemic cells studied. The cytotoxicity of the fluoropyrimidines (as defined by cloning efficiency) was enhanced to a greater extent than was growth inhibition so that an impressive lethal synergism was noted; for instance, exposure of L1210 cells to nontoxic concentrations of 5-fluorouracil or FUdR in the presence of folinic acid resulted in a 98 or 99.9% cell kill, respectively. In contrast to previous predictions, the fluoropyrimidines were more inhibitory to mouse leukemic cells containing folate pools that were suboptimal for growth than for folate-replete cells. Growth rate experiments showed that cells exposed to moderate concentrations of FUdR were initially inhibited but recovered with time, whereas in cells exposed to both FUdR and folinic acid, the initial growth inhibitory effects were sustained. We conclude that folinic acid stabilizes the effects of the fluoropyrimidines on thymidylate synthase of both mouse and human leukemic cell populations and that this enhancement is reflected in both inhibition of the growth of and the lethality to these cells. We suggest that only doses of the fluoropyrimidines that are capable of initially inhibiting thymidylate synthase to a high degree will be synergistic with excess reduced folates.

Topics: Animals; Cell Line; Cell Survival; Dose-Response Relationship, Drug; Drug Synergism; Floxuridine; Fluorouracil; Folic Acid; Humans; Leucovorin; Leukemia; Leukemia L1210; Mice

Normal marrow cell kinetics were studied by flow cytometry with computer analysis in 11 children with malignancies who received high-dose MTX followed by CF rescue. Nine children with hematological tumors in remission each received an infusion of MTX over 24 h, followed by delayed CF rescue. In 8 of the 9, an accumulation of cells in early to mid-S phase and a decrease of cells in G2/M phase were observed at 24-48 h after the beginning of the MTX infusion. At 144 h after MTX infusion this kinetic perturbation disappeared and the DNA histogram returned to the same state as before therapy. Two children who had malignant bone tumors without marrow infiltration each received an infusion of MTX over 6 h with early CF rescue following an initial IV injection of vincristine. They did not have any prominent perturbation of marrow cell kinetics after MTX exposure, except for a transient increase of cells in G2/M phase. These results confirm that with the high-dose MTX therapy described above for hematological malignancies the impairment of marrow cell kinetics was much more severe and was soon followed by complete recovery, whereas with the therapy for solid tumors the impairment was much slighter.

Topics: Adolescent; Age Factors; Bone Marrow; Cell Cycle; Child; Child, Preschool; DNA; Female; Flow Cytometry; Humans; Infant; Leucovorin; Leukemia; Leukocyte Count; Lymphoma; Male; Methotrexate; Mitotic Index; Platelet Count

High dose administration of anticancer drugs was discussed putting an emphasis on methotrexate and cytosine arabinoside. High dose methotrexate in combination with leucovorin rescue was effective on various kinds of cancer which had become resistant to conventional doses of anti-cancer drugs. The administration of high-dose methotrexate, however, should be performed with meticulous precautions to prevent serious side effects. Side effects included gastrointestinal mucositis, hepatic dysfunction, nausea and vomiting. Central nervous system manifestations were sometimes observed. High-dose cytosine arabinoside of 3 g/m2 per 12 hours X 12 was given by 2-hours infusion to patients with acute leukemia who had become resistant to conventional combination chemotherapy, or to relapsed patients. This regimen in combination with L-asparaginase or anthracyclines resulted in a fairly high remission rate among those intractable cases. High-dose cytosine arabinoside in combination with anthracyclines has recently been tried on patients with acute leukemia as an initial treatment for remission induction and consolidation. In this case, no intensification treatment was performed to maintain remission. Patients treated with this regimen as an initial medication showed a high remission induction rate and long remission duration. Forty percent of the patients were still alive after 3 years.

Topics: Acute Disease; Antineoplastic Combined Chemotherapy Protocols; Asparaginase; Cytarabine; Daunorubicin; Doxorubicin; Drug Administration Schedule; Drug Synergism; Drug Therapy, Combination; Humans; Infusions, Parenteral; Leucovorin; Leukemia; Methotrexate; Neoplasms

Topics: Acute Disease; Adolescent; Adult; Drug Evaluation; Drug Therapy, Combination; Female; Humans; Leucovorin; Leukemia; Lymphoma; Male; Methotrexate; Middle Aged

Methotrexate (MTX) was administered by continual intravenous infusion for 24 hours in doses ranging from 200-800 mg/m2 to 16 patients who had metastatic cancers and normal bone marrows and 11 patients with acute leukemia. Citrovorum factor (CF) was administered every 6 hours for 12-15 doses beginning 36 hours after the start of the MTX infusion. Plasma and urine were collected to measure MTX concentration. Daily bone marrow aspirates were obtained for measuring intracellular MTX concentration, labelling index (LI), mitotic index (MI), grain count distribution, cellular DNA distribution by flow cytometry (FCM), and marrow morphology. The plasma MTX concentration proved to be a function of dose and creatinine clearance. There was a positive correlation between the creatinine clearance and MTX clearance. The intracellular MTX concentration correlated highly with the plasma concentration. The LI, grain count, and proportion of cells in S phase increased on days 2 and 3. The magnitude of the changes on days 2 and 3 was dose related. The MI fell on day 2 and recovered by day 4. Transient megaloblastic changes occurred. The cell cycle perturbations in leukemic marrow were less pronounced than those in normal marrows. These observations are consistent with a transient, dose related, S phase delay.

Topics: Acute Disease; Adult; Bone Marrow Examination; Dose-Response Relationship, Drug; Drug Administration Schedule; Humans; Kinetics; Leucovorin; Leukemia; Methotrexate; Radioimmunoassay

In this study, three methods are utilized to analyze toxicity produced by methotrexate and the lipid-soluble antifolate, 2,4-diamino-5-(3',4'-dichlorophenyl)-6-methylpyrimidine, in human lymphoblasts (WIL-2) and leukemic cells. These methods detect increasingly severe metabolic damage; inhibition of deoxyuridine incorporation into DNA, the reversibility of inhibition of deoxyuridine incorporation by supplementation with formyltetrahydrofolate as Ca2+ leucovorin, and the ability of cells to form clones in soft agarose. The critical dose and exposure time for establishing and maintaining the metabolic toxicity of methotrexate is examined in detail. It is shown that, if an initial loading dose of methotrexate is of high enough concentration or is maintained for a sufficient period to achieve greater than 98% inhibition of deoxyuridine incorporation, this inhibition can be sustained by low concentrations of 2,4-diamino-5-(3',4'-dichlorophenyl)-6-methylpyrimidine or methotrexate. Concentrations of methotrexate or 2,4-diamino-5-(3',4'-dichlorophenyl)-6-methylpyrimidine that equal or exceed 0.1 microM are sufficient for maintenance of inhibition by an initial loading dose of methotrexate but escape from inhibition that occurs if lower levels of drug are used. The possible implications of these observations for in vivo protocols are discussed.

Topics: Cell Line; Cell Survival; Deoxyuridine; Dose-Response Relationship, Drug; Folic Acid Antagonists; Humans; Leucovorin; Leukemia; Methotrexate; Pyrimethamine; Time Factors

Topics: Adolescent; Child; Child, Preschool; Drug Administration Schedule; Humans; Infant; Leucovorin; Leukemia; Lymphoma; Methotrexate; Neuroblastoma

Topics: Animals; Asparaginase; Breast Neoplasms; Carboxypeptidases; Child; Drug Administration Schedule; Drug Therapy, Combination; Female; Gastrointestinal Neoplasms; Genital Neoplasms, Female; Head and Neck Neoplasms; Humans; Leucovorin; Leukemia; Lung Neoplasms; Lymphoma; Melanoma; Methotrexate; Neoplasms; Osteosarcoma; Tetrahydrofolates; Thymidine

Topics: Adult; Antimetabolites, Antineoplastic; Blood-Brain Barrier; Brain Neoplasms; Child; History, 20th Century; Humans; Leucovorin; Leukemia; Methotrexate; Spinal Cord Neoplasms

Topics: Amidines; Drug Combinations; Drug Interactions; Humans; Leucovorin; Leukemia; Pentamidine; Pneumonia, Pneumocystis; Pyrimethamine; Remission, Spontaneous; Sulfadiazine

Topics: Half-Life; Humans; Leucovorin; Leukemia; Meningitis; Pyrimethamine; Time Factors

Topics: Arachnoid; Humans; Injections, Spinal; Leucovorin; Leukemia; Meninges; Methotrexate; Radiation Effects; Skull

Topics: Adenine; Allopurinol; Bone Marrow; Bone Marrow Cells; Carbon Radioisotopes; Cell-Free System; Chromatography, Paper; Formates; Guanine Nucleotides; Humans; Hypoxanthines; Kinetics; Leucovorin; Leukemia; Leukemia, Myeloid, Acute; Leukocytes; Ligases; Mercaptopurine; Pentosephosphates; Pentosyltransferases; Spectrophotometry, Ultraviolet; Tetrahydrofolates

Topics: Animals; Antineoplastic Agents; Drug-Related Side Effects and Adverse Reactions; gamma-Glutamyl Hydrolase; Half-Life; Hydrolysis; Leucovorin; Leukemia; Male; Methotrexate; Mice; Pseudomonas; Survival Rate; Time Factors; Weight Loss

Topics: Acute Disease; Drug Synergism; Humans; Injections, Intravenous; Leucovorin; Leukemia; Methotrexate; Neoplasms

Topics: Acute Disease; Cell Division; Child; Female; Humans; Leucovorin; Leukemia

Topics: Adenine; Adolescent; Child; Corrinoids; Hematinics; Humans; Immune Sera; Infant; Leucovorin; Leukemia; Mucins; Pyruvates; Tissue Culture Techniques; Vitamin B 12

Topics: Adolescent; Child; Hematoma; Hematoma, Epidural, Cranial; Hematoma, Subdural; Humans; Hydrocephalus; Leucovorin; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Meninges; Mercaptopurine; Methotrexate; Pathology; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Prednisone; Radiography; Subarachnoid Hemorrhage; Vinblastine

Topics: Aminopterin; Humans; Leucovorin; Leukemia; Leukemia, Lymphoid; Meninges; Methotrexate

Topics: Ethinyl Estradiol; Humans; Leucovorin; Leukemia; Leukemia, Lymphoid; Lymphocytes; Male; Prednisone; Prostatic Neoplasms; Steroids

Topics: Blood Cells; Folic Acid; Humans; Isomerases; Leucovorin; Leukemia; Mercaptopurine; Metabolism; Methotrexate; Oxidoreductases

Topics: Folic Acid; Hematologic Tests; Humans; Leucovorin; Leukemia; Leukocytes

Topics: Animals; Folic Acid; Leucovorin; Leukemia; Neoplasms, Experimental; Peptones; Research Design; Tissue Culture Techniques

Topics: Acute Disease; Aminopterin; Antimetabolites; Folic Acid; Leucovorin; Leukemia

Topics: Folic Acid; Leucovorin; Leukemia; Neoplasms; Recurrence

Topics: Anemia; Folic Acid; Folic Acid Antagonists; Humans; Leucovorin; Leukemia

Topics: Aminopterin; Animals; Combined Modality Therapy; Folic Acid; Leucovorin; Leukemia; Mice; Sarcoma, Myeloid

Topics: Acute Disease; Antimetabolites; Folic Acid; Folic Acid Deficiency; Leucovorin; Leukemia; Leukemia, Myeloid

Topics: Aminopterin; Antimetabolites; Folic Acid; Leucovorin; Leukemia; Leukemia, Lymphoid; Lymphatic Vessels

Topics: Acute Disease; Antimetabolites; Folic Acid; Leucovorin; Leukemia

Topics: Folic Acid; Folic Acid Antagonists; Humans; Leucovorin; Leukemia; Neoplasms

Topics: Antimetabolites; Biochemical Phenomena; Folic Acid; Leucovorin; Leukemia; Neoplasms

Topics: Cell Division; Folic Acid Antagonists; Leuconostoc; Leucovorin; Leukemia

Topics: Autopsy; Folic Acid; Leucovorin; Leukemia

Topics: Amino Acids; Biomedical Research; Folic Acid Antagonists; Leucovorin; Leukemia