Infectious complications in adults undergoing intensive chemotherapy for acute myeloid leukemia in 2001-2005 using the Japan Adult Leukemia Study Group AML201 protocols.

PURPOSE: The Japan Adult Leukemia Study Group (JALSG) AML201 protocols are regimens for remission induction and consolidation chemotherapy of acute myeloid leukemia (AML) and have been widely accepted in Japan since 2001. Management of infectious complications during chemotherapy has a key role in the supportive care of AML patients. METHODS: By using case report forms collected in December 2001 and December 2005, we retrospectively analyzed the infectious complications in adult patients treated by using the JALSG AML201 protocols against AML (excluding promyelocytic leukemia). RESULTS: Of 980 patients, 80.2% experienced febrile neutropenia (FN), 8.3% bacteremia/fungemia, and 10.3% pulmonary infection at least once during remission-induction chemotherapy. Gram-positive bacteremia accounted for 65.1% of bacteremia/fungemia in 2001-2005, compared with 38.2% in 1987-1991 and 45.9% in 1992-1995. Of 750 patients, 81.9% experienced FN, 21.9% bacteremia/fungemia, and 9.1% pulmonary infection at least once during consolidation chemotherapy. During consolidation chemotherapy, bacteremia/fungemia and pulmonary infection were significantly more frequent in the high-dose cytarabine (HDAC) arm than in the conventional multiagent arm (25.9 vs. 17.9% and 12.7 vs. 7.7%, respectively). Invasive pulmonary aspergillosis accounted for 15.8% of pulmonary infections during remission induction and 19.7% during consolidation chemotherapy. CONCLUSIONS: Our data suggest that patterns of infectious complications have changed between 1987 and 2005, possibly because of chemoprophylaxis with oral fluoroquinolones and improved diagnosis of invasive pulmonary aspergillosis by serum antigen analysis.

Management of infection during chemotherapy for acute leukemia in Japan: a nationwide questionnaire-based survey by the Japan Adult Leukemia Study Group.

PURPOSE: We performed a nationwide questionnaire-based survey to evaluate the current clinical practices of infectious complications during chemotherapy for acute leukemia in Japan. METHODS: We e-mailed a questionnaire to member institutions of the Japan Adult Leukemia Study Group in September, 2013. The questionnaire consisted of 50 multiple-choice questions covering therapeutic environment, antimicrobial prophylaxis, screening test during neutropenia, empirical therapy for febrile neutropenia, and the use of granulocyte-colony stimulating factor. The results were compared to those of previous surveys conducted in 2001 and 2007, and also to the recommendations described in the guidelines. RESULTS: Usable responses were received from 141 out of 222 (63.5%) institutions. Chemotherapy for acute myeloid leukemia was performed in protective environment in 90% of the institutions, which increased compared to previous survey (76%). Fluoroquinolones and fluconazole were the most commonly used antimicrobial agents for antibacterial and antifungal prophylaxis, followed by sulfamethoxazole-trimethoprim and itraconazole, respectively. In empirical therapy for febrile neutropenia, monotherapy with ß-lactum antibiotics was the first-line therapy in most of the institutions. While empirical antifungal therapy was adopted for persistent fever in more than half of the institutions, preemptive/presumptive therapy was also used in approximately 40% of the institutions. Most of the clinicians were reluctant to use granulocyte-colony stimulating factor routinely in chemotherapy for acute myeloid leukemia. CONCLUSIONS: This study clarified the current clinical practices of infectious complications during chemotherapy for acute leukemia and would provide important information for the development of a suitable guideline in Japan.

Outcome after first relapse in adult patients with Philadelphia chromosome-negative acute lymphoblastic leukaemia.

To analyse the outcome of adult patients who developed a first relapse of acute lymphoblastic leukaemia (ALL), we collected the clinical data of 332 patients with Philadelphia-chromosome (Ph) negative ALL, aged 16-65 years, who relapsed after first complete remission (CR1) between 1998 and 2008 in 69 institutions all over Japan, including 58 patients who relapsed after allogeneic haematopoietic stem cell transplantation (Allo-HSCT) in CR1. The overall survival (OS) was 43·4% at 1 year, and 16·3% at 5 years from relapse in patients who received chemotherapy alone in CR1. Among patients who relapsed after chemotherapy alone in CR1, 123 (52·5%) achieved a second remission (CR2) following salvage chemotherapy, of whom 62 subsequently underwent Allo-HSCT during CR2. Allo-HSCT in CR2 was significantly associated with better OS. Moreover, the type of salvage chemotherapy influenced OS from relapse. A doxorubicin, vincristine, and predonisone-based (AdVP-type) regimen was related to better OS in patients with longer CR1 (more than 1 year), but was related to worse OS in patients with shorter CR1. In conclusion, the prognosis of patients with relapsed Ph-negative ALL is poor. Allo-HSCT after a first relapse could improve the prognosis. Selection of the optimal salvage chemotherapy might depend on the duration of CR1.

Recovery of kidney function by rituximab-based therapy in a patient with Waldenström's macroglobulinemia-related nephropathy presenting cast nephropathy and interstitial lymphocytic infiltration.

A 60-year-old man with Waldenström's macroglobulinemia (WM) was admitted to our hospital for evaluation of rapid progressive renal deterioration despite 3 cycles of oral melphalan and prednisolone (MP) therapy. Renal biopsy just before introducing hemodialysis revealed cast nephropathy and severe tubulo-interstitial infiltration of B lymphocytes. After 6 cycles of rituximab, cyclophosphamide, vincristine and prednisolone (R-COP) therapy, his renal function improved enough to discontinue hemodialysis. This is a rare case of WM-related renal involvement caused by both monoclonal protein and tumor infiltration and, to our knowledge, the second report on improved renal function by rituximab-based therapy.

Down-regulation of Thanatos-associated protein 11 by BCR-ABL promotes CML cell proliferation through c-Myc expression.

Bcr-Abl activates various signaling pathways in chronic myelogenous leukemia (CML) cells. The proliferation of Bcr-Abl transformed cells is promoted by c-Myc through the activation of Akt, JAK2 and NF-κB. However, the mechanism by which c-Myc regulates CML cell proliferation is unclear. In our study, we investigated the role of Thanatos-associated protein 11 (THAP11), which inhibits c-Myc transcription, in CML cell lines and in hematopoietic progenitor cells derived from CML patients. The induction of THAP11 expression by Abl kinase inhibitors in CML cell lines and in CML-derived hematopoietic progenitor cells resulted in the suppression of c-Myc. In addition, over-expression of THAP11 inhibited CML cell proliferation. In colony forming cells derived from CML-aldehyde dehydrogenase (ALDH)(hi) /CD34(+) cells, treatment with Abl kinase inhibitors and siRNA depletion of Bcr-Abl induced THAP11 expression and reduced c-Myc expression, resulting in inhibited colony formation. Moreover, overexpression of THAP11 significantly decreased the colony numbers, and also inhibited the expression of c-myc target genes such as Cyclin D1, ODC and induced the expression of p21(Cip1) . The depletion of THAP11 inhibited JAK2 or STAT5 inactivation-mediated c-Myc reduction in ALDH(hi) /CD34(+) CML cells. Thus, the induced THAP11 might be one of transcriptional regulators of c-Myc expression in CML cell. Therefore, the induction of THAP11 has a potential possibility as a target for the inhibition of CML cell proliferation.

Small GTPase RAB45-mediated p38 activation in apoptosis of chronic myeloid leukemia progenitor cells.

Chronic myelogenous leukemia (CML) is characterized by a reciprocal chromosomal translocation (9;22) that generates the Bcr-Abl fusion gene. BCR-ABL transforming activity is mediated by critical downstream signaling pathways that are aberrantly activated by tyrosine kinases. However, the mechanisms of BCR-ABL anti-apoptotic effects and the signaling pathways by which BCR-ABL influences apoptosis in BCR-ABL-expressing cells are poorly defined. In this study, we found that treatment with ABL kinase inhibitors or depletion of BCR-ABL induced the expression of RAB45 messenger RNA and protein and induced apoptosis via reduction of mitochondrial membrane potential and p38 activation in CML cell lines and BCR-ABL(+) progenitor cells from CML patients. Overexpressed RAB45 induced the activation of caspases-3 and -9 and reduced the expression of Survivin, XIAP, c-IAP1 and c-IAP2 in CML cells. Moreover, in colony-forming cells derived from CML-aldehyde dehydrogenase(hi)/CD34(+) cells, treatment with ABL kinase inhibitors induced RAB45 expression and reduced mitochondrial membrane potential, resulting in inhibited colony formation of Bcr-Abl(+) progenitor cells. The overexpression of RAB45 significantly decreased colony numbers and induced apoptosis through the activation of caspases-3 and -9. Furthermore, the overexpression of RAB45 increased the phosphorylation levels of p38, resulting in the induction of apoptosis and inhibition of proliferation of CML progenitor cells. Our results identify a new signaling molecule involved in BCR-ABL modulation of apoptosis and suggest that RAB45 induction strategies may have therapeutic utility in patients with CML.

Phase I trial of gemtuzumab ozogamicin in intensive combination chemotherapy for relapsed or refractory adult acute myeloid leukemia (AML): Japan Adult Leukemia Study Group (JALSG)-AML206 study.

In order to investigate better molecular-target therapy for acute myeloid leukemia (AML), we conducted a phase I trial of a combination of gemtuzumab ozogamicin (GO) with conventional chemotherapy. Between January 2007 and December 2009, a total of 19 adult Japanese patients with relapsed or refractory CD33-positive AML (excluding acute promyelocytic leukemia) were enrolled. All registered patients received a standard dose of cytarabine (Ara-C) (100 mg/m(2) × 7 days), combined with either idarubicin (IDR) (10-12 mg/m(2) × 3 days) or daunorubicin (DNR) (50 mg/m(2) × 3-5 days), and then GO (3-5 mg/m(2) ), which was administered 1 day after the last infusion of IDR (IAG regimen) or DNR (DAG regimen). While doses of both GO and IDR and the administration period of only DNR were increased, the dose-limiting toxicity (DLT) was assessed. Among 19 patients (nine in the IAG regimen, 10 in the DAG regimen), the median age was 59 years (range 33-64), and the relapsed/refractory ratio was 13/6. In the therapy using 3 mg/m(2) GO in the IAG or DAG regimen, grade 3/4 leukopenia and neutropenia were observed in all patients, but none had grade 3/4 non-hematological toxicities, except febrile neutropenia. Three patients in the IAG regimen who were administered 5 mg/m(2) GO showed DLT. No patients had veno-occlusive disease or sinusoidal obstructive syndrome. In conclusion, 3 mg/m(2) GO combined with Ara-C and IDR or DNR can be safely administered, and phase II trials should be conducted to investigate the clinical efficacy of the combination therapy.

Analysis of bacteremia/fungemia and pneumonia accompanying acute myelogenous leukemia from 1987 to 2001 in the Japan Adult Leukemia Study Group.

We analyzed the incidence and prognosis of bacteremia/fungemia and pneumonia during remission induction therapy of a newly diagnosed acute myelogenous leukemia (AML) in the Japan Adult Leukemia Study Group treated with individual protocols of AML-87/-89 (1987-1991), AML-92 (1992-1995), AML-95 (1995-1997), and AML-97 (1997-2001). Bacteremia/fungemia was present in 251 of 2585 cases (9.7%); the causative microorganism was gram-positive bacteria (GPB) in 122 cases (49%), gram-negative bacteria (GNB) in 90 cases (36%), fungi (F) in 31 cases (12%), and polymicrobes (P) in 8 cases (3%). Particularly prevalent were Pseudomonas aeruginosa in 49 cases (20%), Staphylococcus epidermidis in 29 cases (12%), and Staphylococcus aureus in 25 cases (10%). With AML-87/-89, incidence of bacteremia/fungemia was 11.8% while it was 9.4% with AML-92, 8.7% with AML-95, and 9.2% with AML-97. The proportion of GPB, GNB, F, and P was 40, 41, 16, and 3% in AML-87/-89, 46, 40, 11, and 3% in AML-92, 48, 39, 11, and 2% in AML-95, and 59, 26, 11, and 4% in AML-97. The mortality rate by period was 26.5, 16.4, 14.0, and 6.8%, respectively. Pneumonia was found in 433 cases (16.8%); microbiological research covered 359 cases of AML-87/-89, AML-92, AML-97 and excluded AML-95 as there was no listing for the causative microorganism on questionnaires. Microbiologically documented pneumonia was found in 123 cases (34.3%), with GPB in 33 cases (27%), GNB in 28 cases (23%), F in 44 cases (36%), and P in 18 cases (15%); particularly prevalent were Aspergillus in 23 cases (19%), Staphylococcus aureus in 16 cases (13%), and Pseudomonas aeruginosa in 15 cases (12%). The incidence of pneumonia overall was 24.6% with AML-87/-89, 16.9% with AML-92, 13.9% with AML-95, and 12.9% with AML-97, with a mortality rate of 28.9, 33.3, 16.7, and 16.7%, respectively. Incidence of bacteremia/fungemia and pneumonia complicating AML has tended to decline in recent years, and mortality has also tended to improve.

The FOXM1 transcriptional factor promotes the proliferation of leukemia cells through modulation of cell cycle progression in acute myeloid leukemia.

FOXM1 is an important cell cycle regulator and regulates cell proliferation. In addition, FOXM1 has been reported to contribute to oncogenesis in various cancers. However, it is not clearly understood how FOXM1 contributes to acute myeloid leukemia (AML) cell proliferation. In this study, we investigated the cellular and molecular function of FOXM1 in AML cells. The FOXM1 messenger RNA (mRNA) expressed in AML cell lines was predominantly the FOXM1B isoform, and its levels were significantly higher than in normal high aldehyde dehydrogenase activity (ALDH(hi)) cells. Reduction of FOXM1 expression in AML cells inhibited cell proliferation compared with control cells, through induction of G(2)/M cell cycle arrest, a decrease in the protein expression of Aurora kinase B, Survivin, Cyclin B1, S-phase kinase-associated protein 2 and Cdc25B and an increase in the protein expression of p21(Cip1) and p27(Kip1). FOXM1 messenger RNA (mRNA) was overexpressed in all 127 AML clinical specimens tested (n = 21, 56, 32 and 18 for M1, M2, M4 and M5 subtypes, respectively). Compared with normal ALDH(hi) cells, FOXM1 gene expression was 1.65- to 2.26-fold higher in AML cells. Moreover, the FOXM1 protein was more strongly expressed in AML-derived ALDH(hi) cells compared with normal ALDH(hi) cells. In addition, depletion of FOXM1 reduced colony formation of AML-derived ALDH(hi) cells due to inhibition of Cdc25B and Cyclin B1 expression. In summary, we found that FOXM1B mRNA is predominantly expressed in AML cells and that aberrant expression of FOXM1 induces AML cell proliferation through modulation of cell cycle progression. Thus, inhibition of FOXM1 expression represents an attractive target for AML therapy.

Reduction of Raf kinase inhibitor protein expression by Bcr-Abl contributes to chronic myelogenous leukemia proliferation.

Chronic myelogenous leukemia (CML) is characterized by a reciprocal chromosomal translocation (9;22) that generates the Bcr-Abl fusion gene. The Ras/Raf-1/MEK/ERK pathway is constitutively activated in Bcr-Abl-transformed cells, and Ras activity enhances the oncogenic ability of Bcr-Abl. However, the mechanism by which Bcr-Abl activates the Ras pathway is not completely understood. Raf kinase inhibitor protein (RKIP) inhibits activation of MEK by Raf-1 and its downstream signal transduction, resulting in blocking the MAP kinase pathway. In the present study, we found that RKIP was depleted in CML cells. We investigated the interaction between RKIP and Bcr-Abl in CML cell lines and Bcr-Abl(+) progenitor cells from CML patients. The Abl kinase inhibitors and depletion of Bcr-Abl induced the expression of RKIP and reduced the pERK1/2 status, resulting in inhibited proliferation of CML cells. Moreover, RKIP up-regulated cell cycle regulator FoxM1 expression, resulting in G(1) arrest via p27(Kip1) and p21(Cip1) accumulation. In colony-forming unit granulocyte, erythroid, macrophage, megakaryocyte, colony-forming unit-granulocyte macrophage, and burst-forming unit erythroid, treatment with the Abl kinase inhibitors and depletion of Bcr-Abl induced RKIP and reduced FoxM1 expressions, and inhibited colony formation of Bcr-Abl(+) progenitor cells, whereas depletion of RKIP weakened the inhibition of colony formation activity by the Abl kinase inhibitors in Bcr-Abl(+) progenitor cells. Thus, Bcr-Abl represses the expression of RKIP, continuously activates pERK1/2, and suppresses FoxM1 expression, resulting in proliferation of CML cells.

Management of infection in patients with acute leukemia during chemotherapy in Japan: questionnaire analysis by the Japan Adult Leukemia Study Group.

Guidelines for the management of febrile neutropenia (FN), deep fungal infection or use of granulocyte colony-stimulating factor (G-CSF) published in the US and Europe cannot be directly applied in other countries. In this study, we undertook a questionnaire survey of member institutions of the Japan Adult Leukemia Study Group to investigate the status of, and problems with, the management of infectious complications in patients with acute leukemia. The questionnaire consisted of 52 multiple-choice questions covering therapeutic environment, antibacterial, and antifungal prophylaxis, empirical therapy (ET) for FN, and use of G-CSF. The results were compared to a previous survey performed in 2001. Usable responses were received from 134 of 184 (71.7%) institutions. With regard to antibacterial prophylaxis, fluoroquinolones and sulfamethoxazole-trimethoprim were most commonly used. Regarding antifungal prophylaxis, the most frequently used agent was fluconazole, followed by itraconazole. In ET for FN, monotherapy with cephems or carbapenems accounted for almost all of the responses. Most respondents indicated that they used micafungin (MCFG) in ET. Prophylactic use of G-CSF during remission induction therapy in acute myeloid leukemia was reported by only 4% of respondents. Strategies for antibacterial and antifungal prophylaxis or treatment of FN should be reviewed and updated as needed.

CMC-544 (inotuzumab ozogamicin) shows less effect on multidrug resistant cells: analyses in cell lines and cells from patients with B-cell chronic lymphocytic leukaemia and lymphoma.

The effect of CMC-544, a calicheamicin-conjugated anti-CD22 monoclonal antibody, was analysed in relation to CD22 and P-glycoprotein (P-gp) in B-cell chronic lymphocytic leukaemia (CLL) and non-Hodgkin lymphoma (NHL) in vitro. The cell lines used were CD22-positive parental Daudi and Raji, and their P-gp positive sublines, Daudi/MDR and Raji/MDR. Cells obtained from 19 patients with B-cell CLL or NHL were also used. The effect of CMC-544 was analysed by viable cell count, morphology, annexin-V staining, and cell cycle distribution. A dose-dependent, selective cytotoxic effect of CMC-544 was observed in cell lines that expressed CD22. CMC-544 was not effective on Daudi/MDR and Raji/MDR cells compared with their parental cells. The MDR modifiers, PSC833 and MS209, restored the cytotoxic effect of CMC-544 in P-gp-expressing sublines. In clinical samples, the cytotoxic effect of CMC-544 was inversely related to the amount of P-gp (P = 0.003), and to intracellular rhodamine-123 accumulation (P < 0.001). On the other hand, the effect positively correlated with the amount of CD22 (P = 0.010). The effect of CMC-544 depends on the levels of CD22 and P-gp. Our findings will help to predict the clinical effectiveness of this drug on these B-cell malignancies, suggesting a beneficial effect with combined use of CMC-544 and MDR modifiers.

Depletion of Pleckstrin homology domain leucine-rich repeat protein phosphatases 1 and 2 by Bcr-Abl promotes chronic myelogenous leukemia cell proliferation through continuous phosphorylation of Akt isoforms.

The constitutive activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway commonly occurs in cancers and is a crucial event in tumorigenesis. Chronic myelogenous leukemia (CML) is characterized by a reciprocal chromosomal translocation (9;22) that generates the Bcr-Abl fusion gene. The PI3K/Akt pathway is activated by Bcr-Abl chimera protein and mediates the leukemogenesis in CML. However, the mechanism by which Bcr-Abl activates the PI3K/Akt pathway is not completely understood. In the present study, we found that pleckstrin homology domain leucine-rich repeat protein phosphatases 1 and 2 (PHLPP1 and PHLPP2) were depleted in CML cells. We investigated the interaction between PHLPPs and Bcr-Abl in CML cell lines and Bcr-Abl+ progenitor cells from CML patients. The Abl kinase inhibitors and depletion of Bcr-Abl induced the expression of PHLPP1 and PHLPP2, which dephosphorylated Ser-473 on Akt1, -2, and -3, resulting in inhibited proliferation of CML cells. The reduction of PHLPP1 and PHLPP2 expression by short interfering RNA in CML cells weakened the Abl kinase inhibitor-mediated inhibition of proliferation. In colony-forming unit-granulocyte, erythroid, macrophage, megakaryocyte; colony-forming unit-granulocyte, macrophage; and burst-forming unit-erythroid, treatment with the Abl kinase inhibitors and depletion of Bcr-Abl induced PHLPP1 and PHLPP2 expression and inhibited colony formation of Bcr-Abl+ progenitor cells, whereas depletion of PHLPP1 and PHLPP2 weakened the inhibition of colony formation activity by the Abl kinase inhibitors in Bcr-Abl+ progenitor cells. Thus, Bcr-Abl represses the expression of PHLPP1 and PHLPP2 and continuously activates Akt1, -2, and -3 via phosphorylation on Ser-473, resulting in the proliferation of CML cells.

KIS induces proliferation and the cell cycle progression through the phosphorylation of p27Kip1 in leukemia cells.

CEM, MOLT4 and SUP-B15 cells were transduced with lentivirus-mediated siRNA KIS gene. The mRNA expressions of KIS were successfully reduced in all cell lines. On the other hand, the mRNA expressions of p27(Kip1) in CEM, MOLT4 and SUP-B15 cells were not affected by the transduction with siRNA KIS gene. We showed that KIS protein directly interacted with p27(Kip1) protein, and reduction of KIS inhibited the S10 phosphorylation of p27(Kip1) in leukemia cells. On these cells transfected with siRNA KIS, the inhibition of S10 phosphorylation of p27(Kip1) was strongly suppressed cell proliferation in a time-dependent manner. Moreover, the inhibition of S10 phosphorylation of p27(Kip1) increased a significant population in G0/G1 fraction. These data demonstrated that the KIS activity was induced during G0/G1, and it promotes cell cycle progression by phosphorylation of S10 on p27(Kip1). We showed that KIS mRNA expression was increased in primary leukemia specimens (acute myelogenous leukemia (AML); 37, myelodysplastic syndrome (MDS); 72, acute lymphoblastic leukemia (ALL); 23), and the mean ratios of KIS to G3PDH in AML, MDS and ALL specimens were 3.62+/-0.68, 3.27+/-0.73 and 3.17+/-0.58, respectively. Moreover, we found that KIS protein was overexpressed in all 132 adults cases of various leukemias, including 37 AML (8 M1, 12 M2, 2 M3, 7 M4, 8 M5), 72 MDS (42 RAEB-I, 30 REAB-II) and 23 ALL (23 L2). This study demonstrates that the elevated levels of KIS protein in leukemia cells promote the cell cycle progression in leukemia cells.

HOXA10 expression induced by Abl kinase inhibitors enhanced apoptosis through PI3K pathway in CML cells.

Chronic myelogenous leukemia is characterized by the reciprocal chromosomal translocation (9;22), which generates a novel fusion gene, BCR-ABL. Bcr-Abl-expressing leukemia cells are highly resistant to apoptosis. Imatinib an Abl kinase inhibitor, is a highly effective agent for patients with CML. However, a small percentage of these patients and most advanced-phase patients relapse on imatinib therapy. It is poorly understood whether the Abl kinase inhibitors are able to eradicate CML progenitor or stem cells. In this study, we investigated the role of HOXA10 in CML cell lines and the hematopoietic progenitor cells derived from CML patients, and whether the regulation of HOXA10 eradicates Bcr-Abl(+) hematopoietic stem/progenitor cells. The Abl kinase inhibitors and PI3K inhibitor, LY294002, induced the expression of HOXA10, and it enhanced apoptosis in CML cells. Moreover, the reduction of HOXA10 expression by siRNA in CML cells inhibited apoptosis by treatment with the Abl kinase inhibitors and LY294002. These results revealed that HOXA10 had an important role in induction of apoptosis by the Abl kinase inhibitors in CML cells. Finally, we showed that the inhibition of HOXA10 expression by siRNA increased the numbers of CFU-GEMM, BFU-E, and CFU-GM when the cells were treated with the combination of BMS354825 and LY294002 compared to control cells, and HOXA10 played a critical role in the committed colony-formation in CML. This study shows for the first time that the Abl kinase inhibitor and LY294002 induced HOXA10, and HOXA10 had an important role in apoptosis or cell growth inhibition in CML cells in vitro.

Pharmacokinetics of arsenic species in Japanese patients with relapsed or refractory acute promyelocytic leukemia treated with arsenic trioxide.

PURPOSE: To investigate the pharmacokinetics of arsenic species in Japanese patients with relapsed or refractory acute promyelocytic leukemia (APL) treated with arsenic trioxide (ATO) at a daily dose of 0.15 mg/kg. METHODS: Inorganic arsenic (AsIII and AsV) and the major metabolites monomethylarsonic acid (MAA(V)) and dimethylarsinic acid (DMAA(V)) in plasma and urine collected from 12 Japanese patients were quantified by HPLC/ICP-MS. RESULTS: The plasma concentrations of AsIII and AsV on day 1 reached the similar Cmax (12.4 +/- 8.4 and 10.2 +/- 3.9 ng/ml) immediately after completion of administration followed by a biphasic elimination. The AUC(0-infinity) of AsV was about twice that of AsIII. The appearance of methylated metabolites in the blood was delayed. During the repeated administration, the plasma concentrations of inorganic arsenic reached the steady state. In contrast, the MAA(V) and DMAA(V) concentrations increased in relation to increased administration frequency. The mean total arsenic excretion rate including inorganic arsenic and methylated arsenic was about 20% of daily dose on day 1 and remained at about 60% of daily dose during week 1-4. CONCLUSIONS: This study demonstrates that ATO is metabolized when administered intravenously to APL patients and methylated metabolites are promptly eliminated from the blood and excreted into urine after completion of administration, indicating no measurable accumulation of ATO in the blood.

Clinicopathological and prognostic characteristics of CD33-positive multiple myeloma.

There have been few reports about the CD33 expression on multiple myeloma (MM) cells so far, showing that only a few patients expressed CD33 homogenously on their MM cells. However, in these reports, neither detailed clinical information nor its prognostic significance was described. Therefore, we analyzed the CD33 expression on MM cells from 63 newly diagnosed patients by flow cytometry and the correlation with other clinical parameters to determine the clinicopathological significance of this molecule. Fourteen (22%) patients were positive for CD33. Of the 14 patients with CD33+ MM, >80% of MM cells were positive in six (9.5%). The CD33+ patients had higher beta 2 microglobulin and lactate dehydrogenase levels and higher incidence of anemia and thrombocytopenia than did CD33- patients. The estimated 3-yr overall survival in CD33+ patients was significantly lower than in the CD33- ones (31% and 50%, respectively, P = 0.042). Especially, mortality within a year from diagnosis in the CD33+patients was higher than that in CD33- patients (43% and 10%, respectively, P = 0.005). Serial evaluation of CD33 expression showed that the amount of CD33 significantly increased after a variety of treatment including melphalan and steroid in individual patients. These results suggest that the CD33 expression might be associated with drug resistance to these conventional agents, and CD33 might be a useful target for the development of new therapeutic agents in MM.

Two cases of acute promyelocytic leukemia complicated by torsade de pointes during arsenic trioxide therapy.

We describe 2 patients with acute promyelocytic leukemia (APL) in whom torsade de pointes (TdP) developed during treatment with arsenic trioxide. Patient 1 was a 23-year-old woman with second-relapse APL. Ventricular premature beat bigeminy developed on day 27 of treatment, and episodes of TdP developed on day 28. Patient 2 was a 51-year-old woman with second-relapse APL who had cardiomyopathy due to prior anthracycline treatment. TdP developed on day 17 of treatment. Arsenic trioxide is known to cause electrocardiographic abnormalities, such as ventricular tachycardia and prolongation of QT interval. Patient 1 was given fluconazole as a concomitant drug. Patient 2 had cardiomyopathy and hypokalemia. Careful management is needed during arsenic trioxide therapy because this treatment prolongs the QT interval, possibly inducing episodes of TdP.

Role for interleukin-6 and insulin-like growth factor-I via PI3-K/Akt pathway in the proliferation of CD56- and CD56+ multiple myeloma cells.

OBJECTIVES: Several studies including ours have suggested that lack of CD56 in multiple myeloma (MM) defines a unique patient subset with poorer prognosis. However, the mechanism underlying this aggressive behavior of CD56(-) MM has not been well elucidated. Interleukin-6 (IL-6) or insulin-like growth factor I (IGF-I) induce proliferation of MM cells. In this study, we report about the relationship between CD56 expression and responsiveness to these cytokines. METHODS: We sorted out both CD56(-) and CD56(+) fractions from MM cell lines such as KMS-21-BM and U-266, and investigated their different responsiveness to IL-6 or IGF-I. Furthermore, we compared the effects of these cytokines on the regulation of cell-cycle distribution between CD56(-) and CD56(+) cells. RESULTS: Although CD56(-) cells in both KMS-21-BM and U-266 cells responded significantly to IL-6, CD56(+) cells did not. Ki-67(+) cells in the CD56(-) cells were significantly increased by IL-6. Western blotting showed that IL-6 phosphorylated Akt, and upregulated and downregulated the level of cyclin D1 and p27 protein in the CD56(-) KMS-21-BM cells, respectively. LY-294002 completely blocked these effects of IL-6. On the other hand, Ki-67(+) cells in the CD56(+) cells did not respond to IL-6. Anti-IGF-I mAb significantly reduced Ki-67(+) cells only in the CD56(+) cells. IGF-I phosphorylated Akt and upregulated cyclin D1 in the CD56(+) KMS-21-BM cells, which was completely blocked by LY294002. CONCLUSIONS: These results suggest that CD56(-) and CD56(+) MM cells could be stimulated by IL-6 and IGF-I, respectively, via PI3-K/Akt pathway, and provide useful information for anticytokine therapies.