thioguanine-anhydrous and Leukemia--Promyelocytic--Acute

Until recently, the standard of care in the treatment of APL has involved the combination of all-trans retinoic acid with anthracycline-based chemotherapy during both induction and consolidation. Additionally, the intensity of consolidation chemotherapy has evolved according to a universally accepted relapse-risk stratification algorithm based on the white cell and platelet counts at presentation. That standard of care is being challenged by the increasing incorporation of arsenic trioxide into front-line treatment protocols, based on two complementary observations. The first is the undoubted anti-leukaemic activity of arsenic trioxide as shown in the relapsed and refractory setting, and in the initial management of low- and intermediate-risk patients. The second is an improved understanding of the action of both all-trans retinoic acid and arsenic trioxide in mediating APL cell eradication, with increasing recognition that PML-RARA fusion protein degradation rather than direct induction of terminal differentiation is the primary mechanism for their ability to eliminate leukaemia initiating cells. As a result, we believe the standard of care for initial therapy in APL is shifting towards an all-trans retinoic acid plus arsenic trioxide-based approach, with additional chemotherapy reserved for patients with high-risk disease.

Topics: Adult; Age Factors; Aged; Anthracyclines; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Arsenic Trioxide; Arsenicals; Blood Coagulation Factors; Clinical Trials as Topic; Combined Modality Therapy; Cytarabine; Etoposide; Humans; Hydroxyurea; Idarubicin; Leukemia, Promyelocytic, Acute; Maintenance Chemotherapy; Middle Aged; Mitoxantrone; Multicenter Studies as Topic; Oxides; Platelet Transfusion; Practice Guidelines as Topic; Remission Induction; Risk Assessment; Thioguanine; Treatment Outcome; Tretinoin

The first multicenter treatment study for AML in childhood in Germany was performed from 1978 onwards. The therapy plan was designed similar to that for the acute lymphoblastic leukaemia (ALL). The drugs with the highest efficacy in AML, cytarabine cutting catara-bine and anthracyclines, were combined during induction and consolidation, followed by preventive cranial irradiation and maintenance therapy similar to that in ALL. The remission rate of the initial study was 80%, and the 5-year survival rate increased from less than 10% before 1970 to 40%. 5 subsequent trials have further increased the 5-year survival to now 70% and even 90% in the subgroup of core-binding factor leukaemias by using an intensified and optimised treatment schedule.The AML-BFM studies were the only prospective study sequence testing the benefit of cranial irradiation. Results from study -87 including the non-randomized patients showed an increased risk of CNS and/or bone marrow relapses in non-irradiated patients. Later on there was evidence that 12 Gy resulted in the same relapse rate as 18 Gy. The AML-BFM studies always used the experience from the previous study to optimize the next study. This approach was essential together with improved supportive treatment and experience of the medical staff for the step-wise and considerable increase of longterm survival within the 6 subsequent AML-BFM studies.

Topics: Antineoplastic Combined Chemotherapy Protocols; Child; Combined Modality Therapy; Cranial Irradiation; Cyclophosphamide; Cytarabine; Daunorubicin; Doxorubicin; Etoposide; Germany; Humans; Idarubicin; Leukemia, Erythroblastic, Acute; Leukemia, Myeloid, Acute; Leukemia, Promyelocytic, Acute; Methotrexate; Multicenter Studies as Topic; Prednisone; Randomized Controlled Trials as Topic; Survival Rate; Thioguanine; Vincristine

We investigated the benefit of adding all-trans retinoic acid (ATRA) to chemotherapy for younger patients with nonacute promyelocytic acute myeloid leukemia and high-risk myelodysplastic syndrome, and considered interactions between treatment and molecular markers. Overall, 1075 patients less than 60 years of age were randomized to receive or not receive ATRA in addition to daunorubicin/Ara-C/thioguanine chemotherapy with Ara-C at standard or double standard dose. There were data on FLT3 internal tandem duplications and NPM1 mutations (n = 592), CEBPA mutations (n = 423), and MN1 expression (n = 195). The complete remission rate was 68% with complete remission with incomplete count recovery in an additional 16%; 8-year overall survival was 32%. There was no significant treatment effect for any outcome, with no significant interactions between treatment and demographics, or cytarabine randomization. Importantly, there were no interactions by FLT3/internal tandem duplications, NPM1, or CEBPA mutation. There was a suggestion that ATRA reduced relapse in patients with lower MN1 levels, but no significant effect on overall survival. Results were consistent when restricted to patients with normal karyotype. ATRA has no overall effect on treatment outcomes in this group of patients. The study did not identify any subgroup of patients likely to derive a significant survival benefit from the addition of ATRA to chemotherapy.

Topics: Adolescent; Adult; Antineoplastic Combined Chemotherapy Protocols; CCAAT-Enhancer-Binding Proteins; Child; Child, Preschool; Cytarabine; Daunorubicin; Female; fms-Like Tyrosine Kinase 3; Gene Expression Regulation, Leukemic; Genotype; Humans; Infant; Infant, Newborn; Leukemia, Promyelocytic, Acute; Male; Middle Aged; Mutation; Nuclear Proteins; Nucleophosmin; Reverse Transcriptase Polymerase Chain Reaction; Thioguanine; Treatment Outcome; Tretinoin; Young Adult

Preliminary independent reports of the Italian GIMEMA and the Spanish PETHEMA trials for newly diagnosed acute promyelocytic leukemia (APL) indicated a similarly high antileukemic efficacy in terms of complete remission and disease-free survival rates. To better investigate these studies and the prognostic factors influencing relapse risk, this study analyzed the updated results of 217 patients with PML/RAR alpha-positive APL enrolled in GIMEMA (n = 108) and PETHEMA (n = 109). All patients received identical induction (AIDA schedule) and maintenance. For consolidation, GIMEMA patients received 3 courses including idarubicin/cytarabine, mitoxantrone/etoposide, and idarubicin/cytarabine/thioguanine, whereas PETHEMA patients received the same drugs and dose schedule of idarubicin and mitoxantrone with the omission of nonintercalating agents. Depending on whether molecular relapses were classified as censored or uncensored events, the 3-year Kaplan-Meier estimates of relapse-free survival (RFS) for the combined series were 90 +/- 2% and 86 +/- 2%, respectively. Minor differences observed between the 2 patient cohorts were negligible. Multivariate regression analysis of RFS showed that initial leukocyte (WBC) and platelet counts were the only variables with independent prognostic value. The resulting predictive model for RFS demonstrated its capability of segregating patients into low-risk (WBC count 40 x 10(9)/L), intermediate-risk (WBC count 10 x 10(9)/L) groups, with distinctive RFS curves (P <.0001). The conclusions are that omission of nonanthracycline drugs from the AIDA regimen is not associated with reduced antileukemic efficacy and a simple predictive model may be used for risk-adapted therapy in this disease. (Blood. 2000;96:1247-1253)

Topics: Adolescent; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Cohort Studies; Cytarabine; Etoposide; Female; Humans; Idarubicin; Leukemia, Promyelocytic, Acute; Male; Middle Aged; Mitoxantrone; Multivariate Analysis; Predictive Value of Tests; Recurrence; Risk; Thioguanine; Tretinoin

A high hemorrhagic risk and a complete response to the differentiative agent all-trans-retinoic acid (ATRA) are the main clinical features of acute promyelocytic leukemia (APL), two distinct subtypes of which have been recognized, the common hypergranular leukopenic form (M3) and a microgranular hyperleukocytic variant (M3v). We analyzed, with emphasis on both disease- and therapy-related prognostic factors, the results from a 9-year trial in 65 adults with M3 and M3v APL, treated homogenously with a short-term therapy (STT) program excluding maintenance. STT comprised a maximum of six courses with doxorubicin, cytosine arabinoside (ara-C), and 6-thioguanine. Sixty-five APL patients formed the study group, M3v accounting for 25% of cases. In M3v, the absolute blast cell count was significantly higher (p < 0.0001) and early hemorrhagic deaths were more frequent (p = 0.05). The blast count correlated inversely with the probability of remission (p = 0.005), poor-risk patients being those with > 10 x 10(9)/l blast cells. During the study, the median survival improved from 0.1 to 2.7 years (p = < 0.005). In first place, response to chemotherapy increased from 42 to 84% (p = 0.006), by giving daily prophylactic platelet transfusions (to > 30 x 10(9)/l) and no heparin (course I), and by avoiding too toxic high-dose ara-C and deferring treatment in infected/neutropenic patients showing the atypical differentiative bone marrow pattern (course II). Secondly, the probability of first unmaintained remission differed significantly between patients given intentionally more than four total chemotherapy courses or intermediate/high-dose ara-C consolidation (0.59 at 5 years) and those treated less intensively (0.21) (p < 0.005). Intensive STT was very effective for the management of adult APL patients at standard hemorrhagic risk and receiving optimal supportive care. In high-risk patients with hyperleukocytosis and M3v, induction results could be improved by the concomitant use of ATRA. M3v in adults must be recognized promptly because of the very high early hemorrhagic risk.

Topics: Adolescent; Adult; Age Factors; Antineoplastic Combined Chemotherapy Protocols; Bone Marrow Transplantation; Combined Modality Therapy; Cytarabine; Cytoplasmic Granules; Disease-Free Survival; Disseminated Intravascular Coagulation; Doxorubicin; Female; Hemorrhage; Humans; Leukemia, Promyelocytic, Acute; Life Tables; Male; Middle Aged; Prospective Studies; Remission Induction; Survival Analysis; Thioguanine; Treatment Outcome

Acute promyelocytic leukemia (AML FAB M3, APL) and acute myelomonocytic leukemia with abnormal eosinophils (AML M4Eo) are considered distinct entities with characteristic clinical, morphological, cytogenetic, and prognostic features. Promyelocytic leukemia is characterized by abnormal promyelocytes replacing normal hematopoiesis associated with a translocation between the long arms of chromosomes 15 and 17 t (15; 17), severe coagulopathy, and responsiveness to all-trans retinoic acid (tretinoin). Characteristic features of AML M4Eo are a myelomonocytic marrow infiltration, eosinophils with abnormal immature granules positive for chloroacetate esterase, an inversion or translocation of chromosome 16, and an increased risk of meningeal relapses. Prognosis of both types of AML has been reported to be better than prognosis of the other entities combined. Since most of the published data were collected from heterogeneous patient populations treated with various chemotherapeutic regimens, we have analyzed treatment outcome of AML M3 and M4Eo in the AMLCG-85 study for patients younger than 60 years. For the total population of 594 patients of this study, CR rate was 68.89%, early death rate 11.60%, and no or partial remission was achieved in 19.51% of the cases. Of 40 patients with AML M3 or M3 v complete remission was attained in 62.5%. Nine patients died within 42 days after the start of antileukemic therapy (22.5%). Of these nine, four died because of infection, five because of bleeding. Relapse-free survival rate was 59% after 3 years, significantly better than the respective curve of the other FAB types combined (35% after 3 years). In AML M4Eo, 91.7% of the 24 patients reached complete remission. The early death rate was 8.3%. No case of nonresponse was seen. Relapse-free survival rate was 49% after 3 years compared with 35% for the other types combined.

Topics: Antineoplastic Combined Chemotherapy Protocols; Cause of Death; Cytarabine; Daunorubicin; Humans; Leukemia, Myelomonocytic, Acute; Leukemia, Promyelocytic, Acute; Middle Aged; Mitoxantrone; Recurrence; Remission Induction; Thioguanine

Fifty-seven adult patients with acute promyelocytic leukemia (APL) were treated between 1974 and 1984 with daunorubicin (DNR) or 4-(9-acridinylamino)methanesulfan-m-anisidide (AMSA) in combination with arabinosylcytosine (Ara-C) and 6-thioguanine (TG); they also received prophylactic heparin. Forty-one patients (72%) achieved complete remission (CR), including 11 of 12 patients who received the AMSA-containing regimen. The incidence of early fatal hemorrhage was 14%, lower than that of earlier studies or other published reports. Elevated WBC and serum lactate dehydrogenase levels at diagnosis were associated with an increased incidence of life-threatening hemorrhage and shorter remission duration. Advanced age was an unfavorable prognostic factor for male patients. Both DNR and AMSA in combination protocols are effective treatments for APL. The incidence of CR is similar to that achieved in other types of acute nonlymphoblastic leukemia (ANLL) with the same protocols, but the median duration of remission is significantly longer in APL (24 v 9 months) and the percentage of remissions longer than 60 months is also higher in APL (35% v 5%).

Topics: Adolescent; Adult; Aged; Amsacrine; Antineoplastic Combined Chemotherapy Protocols; Cytarabine; Daunorubicin; Female; Hemorrhage; Heparin; Humans; Leukemia, Promyelocytic, Acute; Male; Middle Aged; Nervous System Neoplasms; Prognosis; Remission Induction; Thioguanine

Topics: Antineoplastic Combined Chemotherapy Protocols; Cytarabine; Daunorubicin; Diagnosis, Differential; Dyspnea; Female; Follow-Up Studies; Humans; Induction Chemotherapy; Leukemia, Promyelocytic, Acute; Middle Aged; Mitoxantrone; Pleural Effusion; Pulmonary Edema; Thioguanine; Tomography, X-Ray Computed; Tretinoin

Despite improvement of prognosis, older age remains a negative prognostic factor in acute promyelocytic leukemia (APL). Reports on disease characteristics and outcome of older patients are conflicting. We therefore analyzed 91 newly diagnosed APL patients aged 60 years or older (30 % of 305 adults with APL) registered by the German AML Cooperative Group (AMLCG) since 1994; 68 patients (75 %) were treated in studies, 23 (25 %) were non-eligible, and 31 % had high-risk APL. Fifty-six patients received induction therapy with all-trans retinoic acid and TAD (6-thioguanine, cytarabine, daunorubicin), and consolidation and maintenance therapy. Treatment intensification with a second induction cycle (high dose cytarabine, mitoxantrone; HAM) was optional (n = 14). Twelve patients were randomized to another therapy not considered in this report. The early death rate was 48 % in non-eligible and 19 % in study patients. With the AMLCG regimen, 7-year overall, event-free and relapse-free survival (RFS) and cumulative incidence of relapse were 45 %, 40 %, 48 %, and 24 %, respectively. In patients treated with TAD-HAM induction, 7-year RFS was superior (83 %; p = 0.006) compared to TAD only, and no relapse was observed. In our registered elderly patients, we see a high rate of non-eligibility for treatment in studies and of high-risk APL. In patients who can undergo a curative approach, intensified chemotherapy is highly effective, but is restricted to a selection of patients. Therefore, new less toxic treatment approaches with broader applicability are needed. Elderly patients might be a particular target group for concepts with arsenic trioxide.

Topics: Age Factors; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Arsenic Trioxide; Arsenicals; Bone Marrow; Cytarabine; Daunorubicin; Disease-Free Survival; Female; Follow-Up Studies; Germany; Humans; Kaplan-Meier Estimate; Leukemia, Promyelocytic, Acute; Leukocyte Count; Maintenance Chemotherapy; Male; Middle Aged; Mitoxantrone; Multicenter Studies as Topic; Oxides; Prognosis; Randomized Controlled Trials as Topic; Remission Induction; Risk; Thioguanine; Treatment Outcome; Tretinoin

Localized large vessel thrombosis in acute leukaemia is rare, haemorrhagic complications being more common.. We present a patient with acute promyelocytic leukaemia (APL) presenting with an acutely ischaemic lower limb. Large vessel thrombosis is a rare presentation of APL. We reviewed the literature on the coagulopathy of APL and discuss the pathology and current treatment options.. Disordered haemostasis is typical of acute promyelocytic leukaemia (FAB M3) and relates to the intrinsic properties of the blast cells as well as thrombocytopenia from bone marrow involvement. Expression of procoagulants, stimulation of cytokines and alterations in endothelial cell anticoagulant properties initiate a disseminated intravascular coagulation (DIC) resulting in the typical clinical and laboratory findings in APL. The promyelocytes are characterized by the balanced reciprocal translocation between chromosomes 15 and 17. All-trans-retinoic acid (ATRA) induces differentiation in these cells, revolutionizing the treatment of APL.. Unexpected limb ischaemia in a young, apparently healthy patient might be the presenting symptom of an underlying haematological disorder such as APL. A thorough haematological investigation should be performed prior to contemplating surgery. New treatment strategies based on knowledge of the molecular biology of APL has improved the prognosis of patients suffering from APL.

Topics: Amputation, Surgical; Antineoplastic Combined Chemotherapy Protocols; Arterial Occlusive Diseases; Cysteine Endopeptidases; Cytarabine; Daunorubicin; Female; Gangrene; Humans; Intermittent Claudication; Ischemia; Leg; Leukemia, Promyelocytic, Acute; Middle Aged; Neoplasm Proteins; Neoplastic Stem Cells; Popliteal Artery; Remission Induction; Smoking; Thioguanine; Thrombophilia; Thromboplastin; Thrombosis; Toes; Tretinoin

Topics: Amputation, Surgical; Anticoagulants; Antineoplastic Combined Chemotherapy Protocols; Arterial Occlusive Diseases; Cytarabine; Daunorubicin; Female; Foot Diseases; Heparin; Humans; Leukemia, Promyelocytic, Acute; Middle Aged; Necrosis; Popliteal Artery; Thioguanine; Tretinoin

Numerous children have been treated successfully for cancer and are surviving into adulthood. As this population has aged, an increasing number of secondary malignancies has emerged. Renal cell carcinoma (RCC) is a rare tumor in childhood and has not been documented previously to occur after treatment of acute promyelocytic leukemia (APL). This report describes the clinical course of APL treated in a child in whom RCC subsequently developed during adolescence approximately 5 years after therapy.

Topics: Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Renal Cell; Cerebral Infarction; Child; Chromosomes, Human, Pair 17; Combined Modality Therapy; Cranial Irradiation; Cytarabine; Daunorubicin; Dexamethasone; Etoposide; Humans; Hypertension; Kidney Failure, Chronic; Leukemia, Promyelocytic, Acute; Male; Neoplasms, Second Primary; Obesity; Remission Induction; Thioguanine

The use of all-trans retinoic acid (ATRA) has changed the natural course of acute promyelocytic leukemia (APL), increasing the percentage of lasting complete remissions. However, management of the few relapses remains undefined. The purpose of the present study was to evaluate the different behavior of APL patients relapsed after induction chemotherapy which had or had not included ATRA.. We retrospectively studied 8 patients (3 male and 5 female) who had relapsed after a clinical and molecular complete remission (CR). Five patients relapsed after conventional chemotherapy including anthracyclines, without ATRA which was not available at the onset (group A), 3 relapsed after induction treatment according to AIDA protocol (Idarubicin + ATRA) (group B). Seven patients had both molecular and clinical relapses, 1 (group B) had only a molecular relapse. The median first CR duration was 33 months (range 8-63). To induce a second CR all patients were treated with ATRA 45 mg/m2/day given orally until CR, combined with mitoxantrone 6 mg/m2/day for 6 days and cytarabine 1 g/m2/day for 6 days.. Seven out of 8 patients (87.5%) achieved second CR, 1 (group A) did not respond and died within two months. Second CR duration was 21, 43+, 56+, 62+ months in group A and 5, 10, 12+ (with molecular relapse) months in group B. Therefore, only one patient relapsed in group A, while all the group B patients relapsed.. ATRA combined with chemotherapy is an effective approach to treating APL relapse. It produces a high incidence of second CR with an acceptable toxicity. The duration of the second CR seems, however, to be longer in patients never treated with ATRA before than in patients who relapsed after the AIDA protocol. Therefore, it might be appropriate to adopt more aggressive protocols in this latter subset of patients.

Topics: Adolescent; Adult; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Bone Marrow Transplantation; Combined Modality Therapy; Cytarabine; Daunorubicin; Etoposide; Female; Humans; Idarubicin; Leukemia, Promyelocytic, Acute; Male; Middle Aged; Mitoxantrone; Recurrence; Remission Induction; Salvage Therapy; Thioguanine; Treatment Outcome; Tretinoin

Eleven cases of acute leukemia patients were treated with autologous bone marrow transplantation (ABMT) following intensive chemotherapy with TACC protocol. Among them, eight were in first remission, three in second remission. The median age was 38 years (24-45 years). Bone marrow was purged in vitro before transplantation with procaine and hyperthermia in three cases with acute promyelocytic leukemia. In all patients, ABMT was successful. The results of treatment are as follows: as of May, 1994, the median remission and disease-free survival period was 31 months (6-57), seven cases have been in complete remission for 6-57 months (median 42 months) after treatment and are still alive. In four cases, ABMT was complicated by infection but it was controlled by antibiotics.

Topics: Adult; Antineoplastic Combined Chemotherapy Protocols; Bone Marrow Purging; Bone Marrow Transplantation; Cyclophosphamide; Cytarabine; Disease-Free Survival; Female; Humans; Leukemia, Promyelocytic, Acute; Lomustine; Male; Middle Aged; Thioguanine

We report a case of therapy-related acute myeloid leukemia (t-AML), M4 FAB subtype, with t(10;11)(p14;q21) chromosome abnormality developed in a patient treated for acute promyelocytic leukemia (APL) after 4 years of continuous complete remission (CCR). Two distinct forms of t-AML have been described: the classical type and the second type. Our case has many characteristics in common with the second type of t-AML such as: exposure to topoisomerase II active agents (idarubicin (IDA), mitoxantrone (MITOX), etoposide (VP16)), M4 FAB subtype, a latency period of 39 months and absence of a preleukemic phase. However, it differs in the chromosome 11 breakpoint (band q21 instead of q23) and absence of ALL-1 (Hrx, MLL, Htrx) gene involvement. This can represent the second observation of t-AML occurring after treatment for APL.

Topics: Adolescent; Antineoplastic Combined Chemotherapy Protocols; Chromosomes, Human, Pair 10; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 15; Chromosomes, Human, Pair 17; Cytarabine; Etoposide; Female; Humans; Idarubicin; Karyotyping; Leukemia, Myelomonocytic, Acute; Leukemia, Promyelocytic, Acute; Mercaptopurine; Methotrexate; Mitoxantrone; Neoplasms, Second Primary; Remission Induction; Thioguanine; Translocation, Genetic

The coexistence of leukemia and pregnancy is extremely rare. This paper describes two cases of acute promyelocytic leukemia diagnosed during the second trimester of pregnancy and the most suitable approach to the management of this situation is analyzed. Possible teratogenic effects of mono- or polychemotherapy during pregnancy, depending upon the gestational age at which chemotherapy is given, are discussed.

Topics: Abnormalities, Drug-Induced; Adult; Antineoplastic Combined Chemotherapy Protocols; Bone Marrow Transplantation; Cytarabine; Daunorubicin; Etoposide; Fatal Outcome; Female; Humans; Leukemia, Promyelocytic, Acute; Mitoxantrone; Pregnancy; Pregnancy Complications, Neoplastic; Pregnancy Outcome; Recurrence; Thioguanine

The thiopurines 6-thioguanine (6TG) and 6-mercaptopurine (6MP) are cytotoxic to proliferating cells by a mechanism involving incorporation into DNA via the purine salvage pathway, and resistance to these agents can be conferred by lack of the salvage pathway enzyme hypoxanthine-guanine phosphoribosyltransferase. However, human and murine hypoxanthine-guanine phosphoribosyltransferase-deficient leukemia cell lines have been shown to respond to 6TG by growth arrest and differentiation by a mechanism apparently not involving incorporation of 6TG into DNA. If so, leukemia cells resistant to 6MP should still respond to 6TG by growth arrest via an undescribed epigenetic mechanism. To test this, polyclonal 6MP-resistant variants were produced from three human leukemia cell lines, HL-60, U937, and CCRF-CEM. Treatment of both sensitive and resistant cells with 6TG induced growth arrest. The effect of 6TG in the 6MP-sensitive HL-60 and U937 cells was associated with significant loss of viability and DNA fragmentation. In contrast, the 6TG-treated 6MP-resistant cells exhibited a slower decline in viability and no DNA fragmentation. To identify the mechanism by which 6TG may induce growth arrest, tRNA was isolated from 6MP-resistant cells cultured for 48 h with 6TG. 6TG was found to be incorporated into tRNAs normally containing queuine in the anticodon wobble position. These studies may provide a basis for the development of new therapeutic regimens for the treatment of leukemia.

Topics: Apoptosis; Cell Differentiation; Cell Division; Drug Screening Assays, Antitumor; Humans; Hypoxanthine Phosphoribosyltransferase; Leukemia, Promyelocytic, Acute; Lymphoma, Large B-Cell, Diffuse; Mercaptopurine; Precursor Cell Lymphoblastic Leukemia-Lymphoma; RNA, Transfer; Thioguanine; Tumor Cells, Cultured

Acute promyelocytic leukemia (APML) almost always involves a chromosomal translocation t(15:17) that results in the fusion of the retinoic acid receptor alpha (RAR alpha) gene with a transcription factor gene called PML. Several cases of APML with t(11;17) have recently been described, involving fusion of the RAR alpha gene with a new zinc finger gene named PLZF. We report here a second non-classical translocation, t(5;17), with a rearranged RAR alpha gene in a child with APML. Based on restriction endonuclease analysis, the rearrangement of RAR alpha occurred within the second intron, the common breakpoint site for t(15;17). The leukemic cells in the bone marrow aspirate were a mixture of hypergranular and hypogranular bilobed promyelocytes. Although less than 1% abnormal promyelocytes were identified after induction therapy, cytogenetics revealed persistent t(5;17). Therefore, the child was treated with all-trans-retinoic acid (ATRA). There was no disease progression, and one marrow was interpreted as remission, with confirmation by cytogenetics which failed to reveal the translocation. However, disease reoccurred shortly after completion of ATRA. This poor response to ATRA may be an additional characteristic associated with non-classical translocations in APML. The identification of a second variant translocation involving the RAR alpha gene in APML suggests yet another RAR alpha rearrangement related to neoplastic myelopoiesis.

Topics: Antineoplastic Combined Chemotherapy Protocols; Bone Marrow; Child, Preschool; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 15; Chromosomes, Human, Pair 17; Cytarabine; Daunorubicin; Etoposide; Female; Humans; Karyotyping; Leukemia, Promyelocytic, Acute; Receptors, Retinoic Acid; Retinoic Acid Receptor alpha; Thioguanine; Translocation, Genetic

18 patients with acute promyelocytic leukemia (APL) were treated with HATP (Harringtonine, Adriamycin, Thioguanine, Prednisone) chemotherapy combined with chinese traditional medications. These medications are known to strengthen vital energy, promote blood circulation, remove stasis and clear toxic materials. 16 patients had complete remission (88.8%) and one partial remission with a total effective rate of 94.4%. Complete remission (CR) was achieved after 3 to 4 courses of treatment in most of the cases. 14 patients were still in CR at the completion of this study and the average duration of survival was 40.5 months. With the various therapeutic actions mentioned above, the traditional medications might decrease the toxicity of chemotherapy, reduce its side effects and prevent the occurrence of DIC. The combined use of traditional medications with chemotherapy may increase the rate and duration of CR as well as prolong the survival.

Topics: Adolescent; Adult; Antineoplastic Combined Chemotherapy Protocols; Doxorubicin; Drugs, Chinese Herbal; Female; Harringtonines; Humans; Leukemia, Promyelocytic, Acute; Male; Middle Aged; Prednisone; Thioguanine

Promyelocytic leukemia HL-60 cells can be induced to differentiate into granulocytic cells by various agents including retinoic acid (RA), dimethyl sulfoxide, and 6-thioguanine (6-TG). Although the induced cells are no longer capable of proliferation, a few cells continue to divide in the presence of inducers, and these cells are resistant to terminal differentiation by these inducers (R. E. Gallagher, D. A. Giangiulio, C-S. Chang, C. J. Glover, and R. L. Felsted, Blood, 68: 1402-1406, 1986). The present study examined the structures of O-glycans attached to leukosialin, a major sialoglycoprotein in HL-60 cells, and the activities of glycosyltransferases involved in O-glycan synthesis. Leukosialin from RA-resistant and 6-TG-resistant HL-60 sublines migrated much more slowly than those from wild-type HL-60 cells when applied to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The dimethyl sulfoxide-resistant HL-60 subline, on the other hand, expressed leukosialin with a molecular weight similar to wild-type HL-60 cells. RA-resistant and 6-TG-resistant HL-60 cells were found to express a significant amount of tetrasaccharides that contain no sialic acid residue, while wild-type HL-60 cells expressed mainly disialosyl hexasaccharides and contained no detectable amount of asialo-oligosaccharides. Furthermore, wild-type HL-60 cells treated with the inducers for 4 days were found to express the same saccharides present in untreated wild-type HL-60 cells, indicating that the altered O-glycans present in RA and 6-TG sublines were not caused by a direct effect of these agents but rather are intrinsically unique to these sublines. To better understand the mechanisms underlying the differences in O-glycans, the activities of four sialyltransferases were measured: Gal beta 1----3GalNAc alpha 2----3sialyltransferase, Gal beta 1----4(3) GlcNAc alpha 2----3sialyltransferase, Gal beta 1----4GlcNAc alpha 2----6sialyltransferase, and GalNAc alpha 2----6sialyltransferase. Among them, Gal beta 1----3GalNAc alpha 2----3sialyltransferase and Gal beta 1----4(3)GlcNAc alpha 2----3sialyltransferase were much lower in the RA- or 6-TG-resistant HL-60 subline than in wild-type HL-60 cells. These findings indicate that the differences in O-glycans are due to the differences in alpha 2----3sialyltransferase activities. These results strongly suggest that O-glycans associated with leukosialin may play some role in HL-60 cell differentiation.

Topics: Antigens, CD; Cell Differentiation; Drug Resistance; Electrophoresis, Polyacrylamide Gel; Humans; Leukemia, Promyelocytic, Acute; Leukosialin; Polysaccharides; Sialoglycoproteins; Sialyltransferases; Thioguanine; Tretinoin; Tumor Cells, Cultured

6-Thioguanine (6-TG)-induced differentiation of hypoxanthine phosphoribosyltransferase (IMP: pyrophosphate phosphoribosyltransferase, EC 2.4.2.8)-deficient HL-60 cells is characterized by 2 days of growth, after which morphological differentiation proceeds. Addition of the tRNA wobble base queuine, in the presence of 6-TG, maintains the proliferative capability of the cells. The ability of 6-TG to induce differentiation correlates with c-myc mRNA down-regulation, but queuine has no effect on this parameter. Treatment with 6-TG for 2-3 days commits HL-60 cells to granulocytic differentiation, and, once committed, these cells do not respond to the monocytic inducer phorbol 12-myristate 13-acetate. Nonetheless, when cells are treated with queuine and 6-TG, they maintain the promyelocytic morphology and are capable of being induced down the monocytic pathway by phorbol 12-myristate 13-acetate as indicated by stabilization of c-fms mRNA and cell adherence. In the absence of queuine, phorbol 12-myristate 13-acetate is incapable of inducing monocytic markers in the 6-TG-treated cells. The data presented indicate that 6-TG-induced differentiation of HL-60 cells is a tRNA-facilitated event and that the tRNA wobble base queuine is capable of maintaining both the proliferative and pluripotent potential of the cells.

Topics: Anticodon; Blotting, Northern; Cell Differentiation; Cell Division; Cell Line; Gene Expression; Genes, myc; Guanine; Humans; Hypoxanthine Phosphoribosyltransferase; Kinetics; Leukemia, Promyelocytic, Acute; RNA, Messenger; RNA, Neoplasm; Thioguanine

A rapid decrease in expression of the oncogene c-myc has been associated with the induction of differentiation of HL-60 human leukemia cells. In this manner, the treatment of a hypoxanthine phosphoribosyltransferase (HPRT)-deficient HL-60 variant (HL-60/var) with 6-thioguanine (TG) was accompanied by lower c-myc mRNA levels. This occurred in the absence of 6-thioguanosine 5'-monophosphate (TGMP) synthesis and without alterations in cellular nucleotide pool sizes. Paradoxically, inhibition of c-myc expression in the wild type HL-60 (HL-60/wt) cell, which is only weakly induced to differentiate by TG, was 5-fold more sensitive to the thiopurine (IC50 = 35 microM). Furthermore, inosine, which blocks the formation of TGMP and enhances the extent of differentiation of HL-60/wt cells, decreased the sensitivity of c-myc expression in the HL-60/wt to TG. These actions of TG and inosine on c-myc were also observed in the human colon carcinoma cell line COLO 320, further dissociating some of the effects of TG on c-myc expression from granylocytic differentiation. The hematopoietic granulocyte-macrophage colony stimulating factor (GM-CSF) elevated c-myc expression and antagonized the actions of TG on c-myc in the HL-60 cells. GM-CSF more readily antagonized the inhibitory action of TG in the HL-60/var cell line when compared to the HL-60/wt cells, restoring c-myc levels to that of the untreated controls. Hence, TG inhibited c-myc expression by two distinct mechanisms in cells which express high levels of the oncogene: a TGMP-dependent, differentiation-independent process with an IC50 of 35 microM, and a TGMP-independent action with an IC50 of 175 microM that was associated with induction of differentiation and was reversed more readily by GM-CSF.

Topics: Adenocarcinoma; Cell Division; Colonic Neoplasms; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Leukemia, Promyelocytic, Acute; Proto-Oncogene Proteins c-myc; Proto-Oncogenes; Ribonucleotides; RNA; Thioguanine; Tumor Cells, Cultured

Co-incubation of human leukemia cell lines with naturally occurring nucleobases (hypoxanthine or adenine) significantly prevented the cytotoxic activity of 6-thiopurines. Extracellular hypoxanthine decreased the transport of 6-mercaptopurine into cells, but adenine had no significant effect. However, intracellular thioinosine monophosphate accumulation in the presence of 10 microM, 6-mercaptopurine was reduced to below 1% or 10% of that of the controls when 50 microM hypoxanthine or adenine was added, respectively. Finally, in adenine phosphoribosyl transferase deficient mutants, adenine provided no protective effect against 6-thiopurines, whereas hypoxanthine retained its modulating activity. These data suggest that the nucleobases compete with 6-thiopurines for the ribose-phosphate donor, 5'-phosphoribosyl-1-pyrophosphate, thus preventing the formation of active metabolites of 6-thiopurines.

Topics: 2-Aminopurine; Adenine; Adenine Phosphoribosyltransferase; Antineoplastic Agents; Biological Transport; Humans; Hypoxanthine; Hypoxanthine Phosphoribosyltransferase; Hypoxanthines; Inosine Monophosphate; Leukemia-Lymphoma, Adult T-Cell; Leukemia, Promyelocytic, Acute; Mercaptopurine; Thioguanine; Thionucleotides; Tumor Cells, Cultured

A variety of purine analogs inhibit the growth and induce the differentiation of human promyelocytic leukemia (HL-60) cells that lack the purine salvage enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). Mechanisms by which purine analogs induce differentiation offer unique potential for cancer chemotherapy. The guanine analogs, 6-thioguanine and 8-azaguanine, induce granulocytic differentiation of HGPRT-deficient HL-60 promyelocytes. Although these compounds are useful as model purine analogs that induce differentiation in HGPRT-deficient HL-60 cells, they suffer the disadvantage that they are highly cytotoxic to wild-type cells. We studied the effect of the hypoxanthine analog 6-ethylmercaptopurine on wild-type and HGPRT-deficient HL-60 cells. 6-Ethylmercaptopurine inhibits growth and produces a specific terminal end-cell in both types of HL-60 cells. The mechanism appears to be independent of the normal modes of cytotoxic activation through HGPRT or adenine phosphoribosyltransferase (APRT), since no new peaks were seen in HPLC chromatograms of the nucleotide pools. Furthermore, hypoxanthine and adenine failed to prevent growth inhibition by 6-ethylmercaptopurine, and inhibition of IMP dehydrogenase and the consequential alteration of the guanine nucleotide pools does not appear to be involved. The mechanism differs from that of guanine analog-induced differentiation in HGPRT-deficient HL-60 cells.

Topics: Antimetabolites, Antineoplastic; Cell Transformation, Neoplastic; Depression, Chemical; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Hypoxanthine Phosphoribosyltransferase; Hypoxanthines; Leukemia, Promyelocytic, Acute; Mercaptopurine; Thioguanine; Tumor Cells, Cultured

Eight patients with acute non-lymphocytic leukemia in adults refractory to Daunomycin (DM)-based conventional regimens were treated with AMSA-based regimens. Complete remission (CR) was obtained in 4 (50%) and partial remission (PR) in 2 (25%). The median time to CR was 26.5 days and 3 cases achieved CR in the first cycle. The median duration of CR was 8.3 months. Hematologic toxicity was severe and the nadir (median) of leukocytes and platelets was 0.15 x 10(3)/microliters and 15.5 x 10(3)/microliters, respectively. Other adverse effects were mucositis, nausea.vomiting and hepatotoxicity which occurred over 50%, while cardiac toxicity was not observed. This study indicates that AMSA is clinically non-cross-resistant to DM and considered to be an active drug for salvage therapy.

Topics: Adolescent; Adult; Aged; Amsacrine; Antineoplastic Combined Chemotherapy Protocols; Cytarabine; Daunorubicin; Drug Evaluation; Drug Resistance; Female; Humans; Leukemia, Myeloid, Acute; Leukemia, Promyelocytic, Acute; Leukopenia; Male; Middle Aged; Prednisolone; Remission Induction; Thioguanine; Thrombocytopenia

The effect of 6-thioguanine (6-TG) and alpha-interferon (IFN-alpha) was evaluated in vitro to determine their effectiveness in combination on the therapeutically relevant events of: HL-60 cell cytotoxicity, HL-60 cell differentiation, and natural killer (NK)-cell mediated cytotoxicity. 6-TG was toxic to HL-60 cells (ID50 = 0.6 microM; 24-h exposure) while IFN-alpha (up to 1000 IU/ml) had minimal cytotoxic activity. Sequence-dependent activity was observed, inasmuch as the IFN-alpha pretreatment sequence was antagonistic, while the other schedules were additive or, possibly, synergistic. The combination of 0.5 microM 6-TG and 100 IU/ml IFN-alpha produced the same level of HL-60 cell differentiation as each agent alone, suggesting no benefit from the combination on this process. The effect of 6-TG and IFN-alpha on NK cell-mediated cytotoxicity was found to be sequence dependent. NK cell activity was markedly stimulated by IFN-alpha, whereas 6-TG alone seemed to have no direct effect. However, when the NK cells were pretreated with 100 IU/ml IFN-alpha followed by 10 microM 6-TG, the IFN-alpha-enhanced activity of NK cells was ablated. These results suggest that the immunosuppressive activity of 6-TG may be related to the acute inhibition of cytokine activation. Our results suggest that 6-TG and IFN-alpha have considerable interactions, which are sequence dependent. The optimal sequence for potential therapeutic application of these anticancer agents appears to be 6-TG pretreatment followed by IFN-alpha.

Topics: Antineoplastic Combined Chemotherapy Protocols; Cell Differentiation; Humans; Interferon Type I; Killer Cells, Natural; Leukemia, Promyelocytic, Acute; Thioguanine; Tumor Cells, Cultured

We have measured the forward mutation rate at the hypoxanthine phosphoribosyltransferase (HPRT) gene of the human promyelocytic leukemia cell line HL-60 and have determined the molecular spectrum of spontaneous HPRT mutations in 45 independent 6-thioguanine-resistant HL-60 sublines. Four fluctuation tests using a total of 132 replicate HL-60 cultures revealed a mean forward mutation rate of HL-60 cells to thioguanine resistance of 1.7-6 x 10(-7)/cell/generation. Blot hybridization analysis of the X-linked HPRT gene using a human HPRT complementary DNA probe revealed abnormalities in HPRT gene structure and/or HPRT mRNA expression in 24 of 45 (53%) independent thioguanine-resistant HL-60 sublines. Six different classes of mutation were identified. The most prevalent (47%; 21 of 45 mutations) consists of mutations that are not detected by blot hybridization analyses and that do not disrupt HPRT mRNA production. These results suggest that a comparatively low forward mutation rate may be found in malignant human cells that exhibit both karyotypic and molecular evidence of genomic instability and that several different molecular classes of mutation may contribute to thioguanine resistance in HL-60, and perhaps in other, malignant human cells. The forward mutation assay system we have developed using the X-linked HPRT gene of HL-60 cells may be useful for analyses of the mutagenic potential and molecular spectrum of mutations produced by chemotherapeutic agents, suspected human mutagens and carcinogens, and phagocyte respiratory burst oxidants in human cells.

Topics: Humans; Hypoxanthine Phosphoribosyltransferase; Leukemia, Promyelocytic, Acute; Mutation; Neoplasm Metastasis; Oxygen Consumption; Phagocytes; RNA, Messenger; Thioguanine; Tumor Cells, Cultured; X Chromosome