Effect of peroxisome proliferator-activated receptor alpha ligand fenofibrate on K(v) channels in the insulin-secreting cell line HIT-T15.

Ligands for peroxisome proliferator-activated receptors alpha (PPARalpha) are clinically used for the treatment of patients with hyperlipidemia. As we have previously shown, a synthetic ligand of PPARalpha, fenofibrate, has a stimulatory effect on insulin secretion in clonal hamster insulinoma beta-cell line HIT-T15 cells. We have also demonstrated that fenofibrate directly inhibits ATP-sensitive potassium (K(ATP)) channels, an effect independent of PPARalpha. In this study, fenofibrate was shown to be able to reduce voltage-dependent K(+) (K(v)) channel currents in voltage-independent manner. Therefore, fenofibrate may modulate insulin secretion not only via inhibition of K(ATP) channels but also via reduction of the K(v) channel current.

Chromosomal imbalances in adult T-cell leukemia revealed by comparative genomic hybridization: gains at 14q32 and 2p16-22 in cell lines.

Comparative genomic hybridization was used to identify chromosomal imbalances in eight cell lines and 12 blood samples from patients with adult T-cell leukemia/lymphoma (ATL). The chromosomes most often over-represented in the cell lines were 2p (6 cases), 7q (4 cases), and 14q (4 cases), with minimal common regions at 2p16-22, 7q21-36, and 14q32, respectively. Distinct imbalances were detected in only 7 of the clinical samples. Chromosomes 14q32 and 2p16-22 harbor TCL1 and a transcription factor, HTLF (human T-cell leukemia virus enhancer factor), respectively. FISH analysis revealed that TCL1 did not juxtapose to TCRA, and we detected no expression of TCL1 in any of the ATL cell lines despite the 14q32 amplifications. Moreover, expression of HTLF was not elevated in the ATL cell lines bearing multiplication of 2p. These results suggest that chromosomal regions 2p16-22 and 14q32 harbor genes other than HTLF and TCL1 that are involved in cellular immortalization or in the pathogenesis of ATL.

Gains, losses, and amplifications of genomic materials in primary gastric cancers analyzed by comparative genomic hybridization.

By means of comparative genomic hybridization (CGH), we screened 58 primary gastric cancers for changes in copy number of DNA sequences. We detected frequent losses on Ip32-33 (21%), 3p21-23 (22%), 5q14-22 (36%), 6q16 (26%), 9p21-24 (22%), 16q (21%), 17p13 (48%), 18q11-21(33%), and 19(40%). Gains were most often noted at I p36 (22%), 8p22-23 (24%), 8q23-24 (29%), 11q12-13 (24%), 16p(21%), 20p (38%), 20q (45%), Xp21-22(38%), and Xq21-23 (43%), with high-level amplifications at 6p21(2%),7q31(10%), 8p22-23(5%), 8q23-24 (7%), 11q13(4%), 12p12-13(4%), 17q21(2%), 19q12-13(2%), and 20q13(2%). High-level amplification at 8p22-23 has never been reported in any other cancer type and its frequency was as high as that reported for the MYC, MET, and KRAS genes. We narrowed down the smallest common amplicon to 8p23.1 by reverse-painting FISH to prophase chromosomes. Southern blot analysis using one EST marker (D38736) clearly demonstrated that amplification of this exon-like sequence had occurred in all three tumors in which amplifications at 8p22-23 had been detected by CGH. Our data provide evidence for several, previously undescribed, genomic aberrations that are characteristic of gastric cancers.

Comparative genomic hybridization of squamous cell carcinoma of the esophagus: the possible involvement of the DPI gene in the 13q34 amplicon.

We investigated copy number aberrations in 29 primary tumors and 12 cell lines of esophageal squamous cell carcinoma (ESC) using comparative genomic hybridization. In the primary tumors, the most common sites of copy number gains were 3q26.3-27 (45%), 8q24 (41%), 5p15 (38%), Xq27-28 (38%), 14q32 (31%), 11q13 (28%), and 20q13.3 (28%). High-level gains (HLGs) indicative of gene amplifications were identified at 11q13 in two cases, and in one case each at 2q33-34, 3q25-29, 5p15.1-15.2, 7q21-22, 11p11.2, 12p11.2-12, and 13q34. Recurrent losses were observed only at 9p13(17.2%). In the 12 ESC cell lines, the most common sites of HLGs were 5p15.1-15.3 (four cases), 11q13 (four cases), 8q24.1-24.2 (three cases), 20q13.2-13.3 (three cases), 3q26.3 (two cases), and 7p15-22 (two cases). Less frequent HLGs (one case each) were observed at 2p16-22, 3q25, 7p12-14, 7q21-22, 9q34, 10q21, 11p11.2, 14q13-14, 14q31-32, 15q22-26, and 17p11.2. Chromosomes and chromosome arms that showed frequent losses in the cultured lines were 18q (58%), 4 (50%), 9p (50%), and 3p (42%). These findings provide evidence for a number of previously unknown genomic aberrations in ESC, suggesting target regions for positional cloning of genes relevant to carcinogenesis in the esophagus. In particular, we identified a significant amplification of the DPI gene (TFDPI), a transcription factor that forms heterodimers with E2FI, in the single primary tumor that exhibited HLG at 13q34.

Identification of a novel gene, MASL1, within an amplicon at 8p23.1 detected in malignant fibrous histiocytomas by comparative genomic hybridization.

We used comparative genomic hybridization to study malignant fibrous histiocytomas (MFHs) from 19 patients to detect changes in the copy number of DNA sequences, along entire chromosomes. Together with losses and gains in various chromosomal regions, distinct high-level amplifications were found at six loci (4q12-21, 8p21-pter, 8q24.1-qter, 9q12-13, 12p11.2-pter, and 15q11.2-15), suggesting that those regions may contain unknown (proto) oncogenes. We focused on the 8p amplicon, where detailed characterization allowed us to determine that the minimal common amplified region lay between markers D8S1819 and D8S550 at 8p23.1. A novel gene designated MASL1 (MFH-amplified sequences with leucine-rich tandem repeats 1) was isolated from within this narrowly defined region. Expression of the MASL1 gene was enhanced significantly in MFH tumors bearing the 8p amplicon. The primary structure of its deduced product revealed an ATP/GTP-binding site, three leucine zipper domains, and a leucine-rich tandem repeat, all of which are important structural or functional elements for interactions among proteins related to the cell cycle. These features suggest that overexpression of MASL1 might well be oncogenic with respect to MFH.

Amplification on double-minute chromosomes and partial-tandem duplication of the MLL gene in leukemic cells of a patient with acute myelogenous leukemia.

Partial-tandem duplication (PTD) of an internal portion of MLL occurs in some cases of acute myelogenous leukemia (AML) with trisomy 11 or a normal karyotype. This type of MLL rearrangement may be transcribed into an mRNA species that is capable of encoding a partially duplicated protein associated with leukemogenesis. However, although several kinds of oncogenes, especially MYC, are often amplified on double-minute chromosomes (dmins) in hematological malignancies, no amplification of MLL has been reported in AML. Here, we report the first documented case of a patient with AML whose leukemic cells exhibited amplification of MLL on dmins. Furthermore, in this patient, MLL was rearranged in a PTD manner, with in-frame fusion of exons 2 and 6.

Identification of amplified DNA sequences on double minute chromosomes in a leukemic cell line KY821 by means of spectral karyotyping and comparative genomic hybridization.

Double minute chromosomes (dmin) are cytogenetic hallmarks of amplified genes. Using spectral karyotyping (SKY) and comparative genomic hybridization (CGH), we identified the origin of amplified DNA in a leukemic cell line, KY821, that harbors numerous dmin. The SKY revealed that the DNA sequences of dmin are derived from materials of chromosome 8, and CGH showed a high degree of overrepresentation only at 8q22-24, indicating that in KY821 only chromosomal material of 8q22-24, containing MYC, is amplified in dmin. An approach combining SKY with CGH should facilitate efforts to identify novel chromosomal regions of gene amplification and contribute information about genetic lesions that underly neoplastic tumors.

Identification of an Efs isoform that lacks the SH3 domain and chromosomal mapping of human Efs.

Efs was originally found by expression cloning of a mouse embryo cDNA library through its Fyn-SH3 binding capacity (Ishino et al., Oncogene 11, 2331-2338, 1995). Efs has characteristic regions important in intracellular signal transduction; these are an SH3 domain, a cluster of putative ligands for SH2 domains and proline-rich sequences with SH3-binding consensus. In this paper, we report cDNA cloning of human Efs and a variant of it from a hippocampal cDNA library. The human Efs gene was mapped to chromosome 14q11.2-q12 by fluorescence in situ hybridization. We identified two forms of human Efs, designated hEfs1 and hEfs2. hEfs1 represents the human counterpart of original mouse embryo Efs (mEfs1). hEfs2, the newly identified form, is identical to hEfs1, except for its lack of the SH3 domain. hEfs1 and mEfs1 are 80% identical in their amino acid sequences and 100% identical within the SH3 domain. Reverse transcription polymerase chain reaction analysis of adult mouse tissue RNA indicated expression of Efs2 and of Efs1 in various tissues. Evidence suggesting the presence of the Efs2 protein in human tissue was obtained by immunoprecipitation followed by immunoblotting with two different anti-Efs antibodies. Possible functions of Efs2 are discussed.

Synergistic effects of stem cell factor and interleukin 6 or interleukin 11 on the expansion of murine hematopoietic progenitors in liquid suspension culture.

The synergistic effects of stem cell factor (SCF) in combination with other growth factors including interleukin (IL)-6, IL-11, IL-3, GM-CSF, G-CSF, IL-1 alpha and interferon-gamma (IFN-gamma) on the expansion of murine hematopoietic progenitors were studied in a short-term liquid suspension culture system. Bone marrow (BM) cells obtained 2 days after 5-fluorouracil (5-FU) injection were cultured for up to 18 days in serum-containing and serum-free cultures in the presence of combinations of various cytokines. The numbers of nucleated cells, total colony-forming cells (CFC), mixed-colony forming units (CFU-Mix) and high-proliferative potential colony-forming cells (HPP-CFC) before and after liquid suspension cultures were measured in the presence of different combinations of cytokines. Combinations of SCF with IL-11, IL-6 or IL-1 alpha markedly increased the numbers of total CFC, CFU-Mix and HPP-CFC. A combination of SCF and IL-3 also expanded the number of total CFC; however, the fold increase was smaller than those of SCF plus IL-11, IL-6 or IL-1 alpha. Three or four factor combinations including SCF with IL-3, IL-6 and IL-11 did not yield increased numbers of total CFC over that supported by SCF plus either IL-6 or IL-11. The addition of IFN-gamma to the culture containing SCF plus IL-11 resulted in a decrease of the expansion efficiency. However, this difference is not statistically significant. In contrast, the addition of IFN-gamma to the cultures containing SCF plus IL-6 did not affect the expansion efficiency. Interestingly, the addition of IL-1 alpha in the culture containing SCF plus IL-3 significantly increased the number of HPP-CFC over that supported by SCF plus IL-3 (p < 0.01). In contrast, IL-1 alpha did not significantly affect the expansion efficiency in the presence of SCF plus IL-6 or IL-11. These results suggest that combinations of SCF plus either IL-6 or IL-11 or a combination of SCF, IL-3 and IL-1 alpha can most effectively expand murine hematopoietic progenitors derived from day-2 post-5-FU BM cells in vitro.

[A combined consecutive therapy with fosfomycin and sulbactam/cefoperazone for bacterial infections associated with hematological diseases].

A combination antibacterial therapy with fosfomycin (FOM) and sulbactam/cefoperazone (SBT/CPZ) was applied to 78 patients with severe infections associated with hematological diseases. In this protocol, FOM was followed by SBT/CPZ and each drug was administered for 1 hour intravenously and consecutively. Among 72 evaluable patients, 43 patients had acute leukemia, myeloblastic or lymphoblastic, 22 had malignant lymphoma, 3 had multiple myeloma, and 4 had other hematological diseases as underlying diseases. Bacterial infections diagnosed were sepsis in 21 patients, suspected sepsis in 47, and other infections in 4. The overall efficacy rate of this treatment was 72.2%, and those for individual infections were 66.7% for sepsis, 74.5% for suspected sepsis, and 75.0% for other infectious diseases. Among 22 bacteria separated from patients with sepsis, 78.6% (11/14 strains) were eradicated by this treatment. This protocol was also effective in 57.1% (8/14) of patients whose granulocyte count was less than 100/mm3 during the course of treatment as well as in 83.3% (15/18) of patients with granulocyte count over 500/mm3. There was no difference in effectiveness between those patients to whom G-CSF was administered and those to whom it was not (17/24, 70.8% vs 35/48, 72.9%). As an adverse reaction, a transient increase of GOT and/or GPT was observed in 2 patients (2.8%). The consecutive administration treatment of FOM and SBT/CPZ is thus an effective and safe regimen for the treatment of patients with hematological diseases complicated by severe infections.

[Peripheral blood stem cell collection with high dose etoposide].

Peripheral blood stem cells (PBSC) were collected from 24 patients who were treated with high dose etoposide. Studied patients included one with acute lymphoblastic leukemia, 4 with acute myeloid leukemia (AML), 1 with myelodysplastic syndrome, 13 with lymphoma, 1 with malignant histiocytosis, 2 with myeloma, and 4 with testicular tumor. Etoposide was infused at a dose of 500 mg/m2 for 4 days, followed by subcutaneous injection of recombinant human granulocyte-colony stimulating factor from the nadir of leukocyte. PBSC were collected by processing 15-20 liters of blood apheresis in the recovery phase of chemotherapy. In all patients, the number of CFU-GM collected per aphereresis ranged from 0.01 to 59.4 x 10(5)/kg, and more than 5 x 10(5)/kg CFU-GM were collected in 19 of the patients (73%). All leukemia patients treated along with our protocols have remained in complete remission, but one patient with AML relapsed within 1 month after the treatment. Ten lymphoma patients were assessable for antitumor effect, and complete response (CR) was observed in 2, partial response (PR) was 7, and no change (NC) in one patient. Two patients with myeloma were classified to be NC. Three of the 4 patients with testicular tumor were PR, and the other one was NC. Eleven patients subsequently underwent PBSCT. The number of days required to achieve an absolute granulocyte count of 0.5 x 10(9)/l was 7 to 11 days, with a mean of 8.6.

Multiple aberrant splicing of the p53 transcript without genomic mutations around exon-intron junctions in a case of chronic myelogenous leukaemia in blast crisis: a possible novel mechanism of p53 inactivation.

We found three truncated p53 transcripts in a patient with chronic myelogenous leukaemia in blast crisis carrying chromosome 17 abnormalities. Sequencing of these transcripts revealed complete absence of the entire exons 7, 8 and 9 in one, exons 8 and 9 in another, and exon 10 in the other. Sequencing analysis of genomic DNA, however, revealed no mutation in exons 6-10 and their flanking introns. These results suggest that the aberrant p53 transcripts in this case might not result from splicing mutations but from an unknown affected splicing process.

[Clinical effects of a combination treatment with fosfomycin and clavulanic acid/ticarcillin for infections in patients complicated with hematological disorders].

We evaluated clinical effects and toxicities of a combination of fosfomycin (FOM) and clavulanic acid/ticarcillin (CVA/TIPC) for treatment of infections complicated with hematological disorders in 61 patients. Fifty-eight patients were evaluable, including 40 with acute leukemia, 13 with malignant lymphoma and 5 with other hematological disorders. Clinical efficacies were excellent in 21 cases, good in 13 cases, fair in 2 cases and poor in 22 cases. The efficacy rate was 58.6% (34 cases/58 cases). This treatment was also effective in 12 of 20 cases in which granulocyte counts were less than 500/microliters through the course of administration. No subjective side effects were observed. Abnormal values in laboratory tests were noted in 1 case. Mild elevations of GOT and GPT were observed. Thus, the combination of FOM and CVA/TIPC is an effective and safe regimen for the treatment of infections in patients complicated with hematological disorders.