Bcl10 and MALT1, independent targets of chromosomal translocation in malt lymphoma, cooperate in a novel NF-kappa B signaling pathway

At least two distinct recurrent chromosomal translocations have been implicated in the pathogenesis of MALT lymphoma. The first, t(1;14), results in the transfer of the entire Bcl10 gene to chromosome 14 wherein Bcl10 expression is inappropriately stimulated by the neighboring Ig enhancer. The second, t(11;18), results in the synthesis of a novel fusion protein, API2-MALT1. Until now, no common mechanism of action has been proposed to explain how the products of these seemingly unrelated translocations may contribute to the same malignant process. We show here that Bcl10 and MALT1 form a strong and specific complex within the cell, and that these proteins synergize in the activation of NF-kappaB. The data support a mechanism of action whereby Bcl10 mediates the oligomerization and activation of the MALT1 caspase-like domain. This subsequently activates the IKK complex through an unknown mechanism, setting in motion a cascade of events leading to NF-kappaB induction. Furthermore, the API2-MALT1 fusion protein also strongly activates NF-kappaB and shows dependence upon the same downstream signaling factors. We propose a model whereby both the Bcl10.MALT1 complex and the API2-MALT1 fusion protein activate a common downstream signaling pathway that originates with the oligomerization-dependent activation of the MALT1 caspase-like domain.

No substantial difference in genotype frequencies of interleukin and myeloperoxidase polymorphisms between malignant lymphoma patients and non-cancer controls

BACKGROUND AND OBJECTIVES

The functional polymorphisms regulating immunologic responses may influence the proliferation or suppression of malignant lymphoma. We examined the association between malignant lymphoma risk and the polymorphisms of the IL-1 gene family [IL-1B -31 C/T, IL-1A -889 C/T, and IL-1RN 86-bp variable number of terminal repeat (VNTR)] and myeloperoxidase (MPO -463 G/A).

DESIGN AND METHODS

The hospital-based case-control study was conducted in Japan. Genotypes were examined in a total of 372 lymphoma cases and 241 non-cancer control subjects. The relative risks were estimated by unconditional logistic regression analysis.

RESULTS

The overall allele distribution of these polymorphisms did not differ substantially between patients and controls; the odds ratios were 0.73 (95% confidence interval, 0.48-1.11) for the T allele carriers of IL-1B relative to the non-carriers, 1.01 (0.56-1.82) for the 2-repeat allele (allele 2) carriers of IL-1RN, 0.96 (0.62-1.48) for the T allele carriers of IL-1A, and 1.04 (0.70-1.57) for the A allele carriers of MPO. Subgroup analyses according to histology [diffuse large B-cell lymphoma (DLBL), follicular lymphoma, low-grade lymphoma of mucosa associated lymphoid tissue, and others] failed to illustrate differences except for DLBL which showed a possible association with IL-1A and IL-1B polymorphisms.

INTERPRETATION AND CONCLUSIONS

Our data show a limited association between these polymorphisms and malignant lymphoma risk in total. The possible association of the IL-1A and IL-1B polymorphisms with DLB-needs further clarification.

Association between polymorphisms of folate- and methionine-metabolizing enzymes and susceptibility to malignant lymphoma

Genetic alteration is considered a probable cause of malignant lymphoma. Folate and methionine metabolism play essential roles in DNA synthesis and DNA methylation, and their metabolic pathways might thus affect disease susceptibility. In the present study, 2 polymorphisms were evaluated for a folate metabolic enzyme, methylenetetrahydrofolate reductase (MTHFR), and one was evaluated for methionine synthase (MS). The 2 polymorphisms, MTHFR677 C-->T and MTHFR1298 A-->C, are reported to reduce the enzyme activity, which causes intracellular accumulation of 5,10-methylenetetrahydrofolate and results in a reduced incidence of DNA double-strand breakage. The MS2756 A-->G polymorphism also reduces the enzyme activity and results in the hypomethylation of DNA. To evaluate the association between malignant lymphoma susceptibility and these polymorphisms, hospital-based case-control study was conducted in Aichi Cancer Center. Ninety-eight patients with histologically confirmed lymphoma and 243 control subjects without cancer were evaluated. Unconditional logistic regression analyses revealed a higher susceptibility with the MTHFR677 CC and the MTHFR1298 AA genotypes (odds ratio, 2.26; 95% confidence interval, 1.26-4.02) when those harboring at least one variant allele in either polymorphism of MTHFR were defined as the reference. For the MS polymorphism, the MS2756 GG genotype also showed a higher susceptibility (odds ratio, 3.83; 95% CI, 1.21-12.1) than those with MS2756 AA or AG types. The significance was not altered when these 3 polymorphisms were evaluated in combination, and the results suggest that folate and methionine metabolism play important roles in the occurrence of malignant lymphomas. Further studies to confirm the association and detailed biologic mechanisms are now required.

Century of Jackson-Weiss syndrome: further definition of clinical and radiographic findings in "lost" descendants of the original kindred

Jackson-Weiss syndrome (JWS) is a condition consisting of craniosynostosis characterized by premature fusion of the cranial sutures and/or characteristic radiographic anomalies of the feet. The condition is inherited as an autosomal dominant trait with high penetrance and variable expressivity. Six different mutations in the fibroblast growth factor receptor 2 have been identified in patients with the clinical diagnosis of JWS. Jabs et al. [1994: Nat Genet 8:275-279] identified an Ala344Gly substitution in two branches of the family in which the clinical syndrome was originally described. This is the only publication to document this mutation in a family with the clinical diagnosis of JWS. In this study, we have identified a previously unrecognized branch of the original family with individuals that meet the clinical criteria for the diagnosis of JWS. We demonstrate that a mutation that produces the Ala344Gly substitution is present in affected members. This family illustrates the widely variable expression of the mutation, including a novel phenotype in the proband with a leg-length discrepancy and unilateral absence of the fifth digital ray in her right foot. We identify the clinical and detailed radiographic features of each affected individual and offer considerations when making the diagnosis of JWS.

Target genes downregulated by the BCL-6/LAZ3 oncoprotein in mouse Ba/F3 cells

The BCL-6/LAZ3 gene encodes a zinc-finger transcriptional repressor and is located at the breakpoint of the 3q27-associated translocations that occur most frequently in non-Hodgkin's lymphomas (NHLs). A number of chromosomal translocations involving BCL-6 have been analyzed, but the biological functions of this protein remain obscure. To examine cell responses and target genes related to the BCL-6 signaling pathway, we established Ba/F3 pro-B cells carrying a human BCL-6 transgene that is inducible under control of the lactose operon. Using a cDNA array hybridization technique, we found that the induced BCL-6 protein can downregulate the expressions of the genes, cyclin A2, chemokine receptor CXCR4, and insulin-like growth factor binding protein-4 (IGFBP-4) in the Ba/F3 cells. Northern blot analysis established that the expressions of these genes were indeed downregulated by the induced BCL-6 protein but in a somewhat different manner. The induced BCL-6 protein also inhibited cell proliferation of Ba/F3 cells. These findings strongly suggest that three key genes, namely cyclin A2, CXCR4, and IGFBP-4 may play a role in the downstream of the BCL-6 signaling pathway during B-lymphoid differentiation.

Spontaneous intracranial hypotension during pregnancy

BACKGROUND

Spontaneous intracranial hypotension is characterized by postural headache associated with low cerebrospinal fluid pressure.

CASE

A 37-year-old Japanese woman, gravida 3, para 2, had sudden onset of severe postural headache at 8 weeks' gestation, accompanied by nausea and vomiting. Results of medical and neurologic examinations were normal, and there was no measurable cerebrospinal fluid pressure on lumbar puncture. Brain magnetic resonance imaging showed diffuse subdural fluid collection and a narrowing of the ambient cistern, confirming the diagnosis of spontaneous intracranial hypotension. After a month of bed rest and intravenous fluid infusion, all symptoms subsided gradually and did not recur.

CONCLUSION

Obstetricians should be aware that spontaneous intracranial hypotension can occur in pregnancy.

Myosin light chain kinase regulates capacitative ca(2+) entry in human monocytes/macrophages

Monocytes/macrophages are present in all stages of atherosclerosis. Although many of their activities depend to various extents on changes in intracellular Ca(2+) concentration ([Ca(2+)](i)), mechanisms regulating [Ca(2+)](i) in these cells remain unclear. We aimed to explore the role of myosin light chain kinase (MLCK) in Ca(2+) signaling in freshly isolated human monocytes/macrophages. Large capacitative Ca(2+) entry (CCE) was observed under fura 2 fluoroscopy in human monocytes/macrophages treated with thapsigargin and cyclopiazonic acid. ML-9 and wortmannin, 2 structurally different inhibitors of MLCK, dose-dependently (1 to 100 micromol/L) prevented CCE and completely did so at 100 micromol/L, whereas inhibitors of tyrosine kinase and protein kinase C had only partial effects. Western blotting showed that thapsigargin significantly caused myosin light chain phosphorylation, which was almost completely blocked by ML-9 (100 micromol/L) and wortmannin (100 micromol/L). ML-9 also dose-dependently (1 to 100 micromol/L) inhibited this phosphorylation, which was well correlated with its inhibition of CCE. Transfection with MLCK antisense completely prevented CCE in response to thapsigargin and cyclopiazonic acid, whereas MLCK sense had no effect. These data strongly indicate that MLCK regulates CCE in human monocytes/macrophages. The study suggests a possible involvement of MLCK in many Ca(2+)-dependent activities of monocytes/macrophages.

Molecular diagnosis and gene therapy in musculoskeletal tumors

Significant progress has occurred in the molecular analyses of bone and soft-tissue tumors, and genetic studies have led to the development of important new diagnostic tools for the clinical management of patients with sarcomas. The detection of fusion genes induced by tumor-specific translocations, such as EWS-FLI1 in Ewing's sarcoma, SYT-SSX in synovial sarcoma, and CHOP-FUS in myxoid liposarcoma, is becoming significant for clinical diagnosis, because these sarcomas are often indistinguishable from other bone and soft-tissue tumors. Gene therapies with several gene transfer systems have been employed for some incurable cancers. It has been demonstrated that a Herpes simplex virus thymidine kinase (HSV-tk) gene can convert certain nucleoside analogs, such as ganciclovir, which disrupt DNA synthesis and are toxic to nucleosides. Human chondrosarcoma cells transduced with the HSV-tk gene were more sensitive to the cytotoxity of ganciclovir than non-transduced cells. Coculture of chondrosarcoma cells with and without the HSV-tk gene showed a bystander effect. The local injection of gene transduced cells into the chondrosarcoma implanted in nude mice markedly reduced tumor size after the administration of ganciclovir. These results suggested the possibility of gene therapy for chondrosarcoma.

Different susceptibilities of postmitotic checkpoint-proficient and -deficient Balb / 3T3 cells to ICRF-193, a catalytic inhibitor of DNA topoisomerase II

Two distinct types of Balb / 3T3 cells were isolated which exhibit either 4 N DNA or both 4 N and 8 N DNA after exposure to colcemid for 48 h. They were found to differ with respect to the postmitotic checkpoint, but not the mitotic checkpoint. Firstly, the checkpoint-proficient and -deficient cells exhibited the same accumulation and subsequent decrease in the number of mitotic cells following exposure to microtubule inhibitors. Secondly, after exit from abnormal mitosis in the presence of ICRF (Imperial Cancer Research Fund)-193, the checkpoint-proficient cells were arrested in the next cycle G1, while the checkpoint-deficient cells progressed into S and G2 phase. When either mitotic or asynchronous cells were exposed to ICRF-193, the checkpoint-proficient cells proved more sensitive to the cytotoxic effect of this agent than the checkpoint-deficient cells. The different susceptibilities of the two types of cells to ICRF-193 were not caused by variation in topoisomerase (topo) II function since both the biochemical activity of this enzyme and chromosome segregation were inhibited by similar concentrations of ICRF-193 in both checkpoint-proficient and -deficient cells. We propose that the inhibition of chromosome segregation by ICRF-193 is monitored by the next G1 checkpoint, resulting in an irreversible G1 block in the case of postmitotic checkpoint-proficient cells. As the checkpoint-deficient cells can escape this G1 block, these cells have an increased survival capacity. In summary, ICRF-193 may prove to be a very useful drug for examination of the postmitotic checkpoint.

Myosin light-chain kinase regulates endothelial calcium entry and endothelium-dependent vasodilation

Activation of smooth muscle myosin light-chain kinase (MLCK) causes contraction. Here we have proven that MLCK controls Ca2+ entry (CE) in endothelial cells (ECs): MLCK antisense oligonucleotides strongly prevented bradykinin (BK)- and thapsigargin (TG)-induced endothelial Ca2+ response, while MLCK sense did not. We also show that the relevant mechanism is not phosphorylation of myosin light-chain (MLC): MLC phosphorylation by BK required CE, but MLC phosphorylation caused by the phosphatase inhibitor calyculin A did not trigger Ca2+ response. Most important, we provide for the first time strong evidence that, in contrast to its role in smooth muscle cells, activation of MLCK in ECs stimulates the production of important endothelium-derived vascular relaxing factors: MLCK antisense and MLCK inhibitors abolished BK- and TG-induced nitric oxide production, and MLCK inhibitors substantially inhibited acetylcholine-stimulated hyperpolarization of smooth muscle cell membrane in rat mesenteric artery. These results indicate that MLCK controls endothelial CE, but not through MLC phosphorylation, and unveils a hitherto unknown physiological function of the enzyme: vasodilation through its action in endothelial cells. The study discovers a counter-balancing role of MLCK in the regulation of vascular tone.

API2-MALT1 fusion transcripts involved in mucosa-associated lymphoid tissue lymphoma: multiplex RT-PCR detection using formalin-fixed paraffin-embedded specimens

Malignant lymphoma of mucosa-associated lymphoid tissue (MALT) type is a distinct clinicopathological disease entity in the category of extranodal marginal zone B-cell lymphoma. Recently, we and others have shown that the API2 gene on chromosome 11 and the MALT1 gene on chromosome 18 are fused as a result of t(11;18)(q21;q21) in MALT lymphomas. Here we report a detection assay that can be used for formalin-fixed, paraffin-embedded specimens. It consists of a multiplex one-tube reverse transcriptase-polymerase chain reaction (RT-PCR) followed by three parallel multiplex nested polymerase chain reactions. Eight variants of the fusion transcripts have been reported to date. When these variants were used as positive controls, all were successfully detected. The subsequent direct sequencing confirmed the results. Using this rapid and simple method, we could detect API2-MALT1 fusion transcripts in 5 of 15 (33%) archival cases of MALT lymphoma for a frequency comparable with those of RT-PCR assays using frozen materials. The lung was the preferential anatomical site of origin of MALT lymphomas harboring API2-MALT1 fusion. No fusion transcript was detected in any of 20 high-grade B-cell lymphomas. Our multiplex RT-PCR assay, which can be used for routinely-processed paraffin samples, should serve as a useful molecular tool for clarifying the clinicopathological significance of API2-MALT1 fusion in MALT lymphoma.

Establishment of a follicular lymphoma cell line (FLK-1) dependent on follicular dendritic cell-like cell line HK

A novel cell line, FLK-1, was established from bone marrow cells of a patient with follicular lymphoma by means of co-culture with follicular dendritic cell (FDC)-like cell line HK. Immunophenotypic analysis showed that FLK-1 expressed CD10, CD19, CD20, CD38, IgG and HLA-DR, which is a typical feature of germinal center B cells. Cytogenetic analysis of FLK-1 demonstrated t(14;18)(q32;q21) translocation involving BCL2 and immunoglobulin heavy chain genes. Especially noteworthy is that the growth of FLK-1 was found to be dependent on a FDC line, HK. When HK cells were removed from the culture, FLK-1 cells stopped growing and eventually died. An apoptotic mechanism appeared to be involved as indicated by the presence of chromosome condensation and DNA ladder formation. The culture experiment using micropore membranes showed that soluble factor(s) of HK cells supported the growth, while direct cell-to-cell contact appeared to be necessary for longterm cell proliferation. These findings suggest the importance of the micro-environment for follicular lymphoma cells to grow. The FLK-1 cell line may thus prove to be useful for studying the growth mechanism of follicular lymphoma and provide new insights into the pathogenesis of follicular lymphoma.

The involvement of protein kinase C in myosin phosphorylation and force development in rat tail arterial smooth muscle

Myosin light-chain phosphorylation is the primary mechanism for activating smooth-muscle contraction and occurs principally at Ser-19 of the 20 kDa light chains of myosin (LC(20)). In some circumstances, Thr-18 phosphorylation may also occur. Protein kinase C (PKC) can regulate LC(20) phosphorylation indirectly via signalling pathways leading to inhibition of myosin light-chain phosphatase. The goal of this study was to determine the relative importance of myosin light-chain kinase (MLCK) and PKC in basal and stimulated LC(20) phosphorylation in rat tail arterial smooth-muscle strips (RTA). Two MLCK inhibitors (ML-9 and wortmannin) and two PKC inhibitors (chelerythrine and calphostin C) that have different mechanisms of action were used. Results showed the following: (i) basal LC(20) phosphorylation in intact RTA is mediated by MLCK; (ii) alpha(1)-adrenoceptor stimulation increases LC(20) phosphorylation via MLCK and PKC; (iii) Ca(2+)-induced LC(20) phosphorylation in Triton X-100-demembranated RTA is catalysed exclusively by MLCK, consistent with the quantitative loss of PKCs alpha and beta following detergent treatment; (iv) very little LC(20) diphosphorylation (i.e. Thr-18 phosphorylation) occurs in intact or demembranated RTA at rest or in response to contractile stimuli; and (v) the level of LC(20) phosphorylation correlates with contraction in intact and demembranated RTA, although the steady-state tension-LC(20) phosphorylation relationship is markedly different between the two preparations such that the basal level of LC(20) phosphorylation in intact muscles is sufficient to generate maximal force in demembranated preparations. This may be due, in part, to differences in the phosphatase/kinase activity ratio, resulting from disruption of a signalling pathway leading to myosin light-chain phosphatase inhibition following detergent treatment.

Overexpression of cyclin D1 occurs frequently in human pancreatic endocrine tumors

The molecular pathogenesis of human pancreatic endocrine tumors (PETs) is poorly understood. Three independent animal models have pointed to the pivotal role of the G1/S cell cycle transition in pancreatic endocrine cell proliferation. We thus hypothesized that the cell cycle regulator cyclin D1 may contribute to the pathogenesis of human PETs. Overexpression of cyclin D1 was identified in 43% of cases, and no correlation was observed with clinical phenotype. The novel observation of frequent overexpression of cyclin D1 suggests that this established oncogene may be implicated in the pathogenesis of human PETs. The absence of detectable alterations in cyclin D1 genomic structure suggests that the mechanism for its oncogenic activation in PETs may be transcriptional or posttranscriptional.

Prognostic significance of CD56 expression for ALK-positive and ALK-negative anaplastic large-cell lymphoma of T/null cell phenotype

Anaplastic large cell lymphoma (ALCL) is a distinct entity of non-Hodgkin lymphoma, characterized by a proliferation of pleomorphic large lymphoid cells that express CD30. Recent studies have found that a subset of ALCL aberrantly expresses a chimeric anaplastic lymphoma kinase (ALK) protein as a result of t(2;5)(p23;q35) or variant translocations. ALK-positive ALCLs feature good prognosis, but some of them lead to poor outcomes. Since CD56 is expressed in some ALCLs, its clinical significance was examined in a series of T/null cell type ALCLs. Of 143 patients, 83 (58%) showed ALK-positive staining, and of 140 patients, 25 (18%) expressed CD56. The ALK-positive subgroup was characterized by a younger age of onset (P <.0001), lower serum lactate dehydrogenase level (P =.01), better performance status (P =.03), less frequent extranodal involvement (P =.01), lower international prognostic index (IPI) categories (P =.002), and superior survival (P =.0009) in comparison with the ALK-negative group, suggesting that ALK is a specific marker defining a distinct subtype. CD56(+) cases showed a significantly poor prognosis overall (P =.002) as well as in both ALK-positive and ALK-negative subgroups (P =.02 and P =.04, respectively). Multivariate analysis confirmed that CD56 is independent of other prognostic factors, including IPI. Although CD56(+) cases showed a higher incidence of bone involvement, no other differences in clinicopathologic parameters were found between the CD56(+) and CD56(-) groups. These findings suggest that CD56 is not a marker to identify a distinct subtype of ALCL, but a strong clinical prognostic factor. Effective therapeutic approaches should be explored for high-risk ALCL patients, who can be identified by means of a prognostic model, including CD56.

Identification and characterization of a molecule, BAM11, that associates with the pleckstrin homology domain of mouse Btk

Bruton's tyrosine kinase (Btk) is required for normal B cell development and signal transduction through cell surface molecules, and its defects lead to X-linked immune deficiency in mice and X-linked agammaglobulinemia in humans. In this report, we will describe the identification and characterization of a molecule, BAM11, which binds to the pleckstrin homology domain of Btk. A sequence homology search revealed that BAM11 has 89% homology, at the amino acid level, to human LTG19/ENL, that was originally identified as one of the fusion partners involved in chromosomal translocations of 11q23, MLL/ALL-1/HRX, in leukemia cells. Deletion mutants demonstrated that the region of BAM11 required for binding to Btk was localized between amino acid residues 240 and 256. Forced expression of a truncated form of BAM11 (amino acids 246-368) inhibited IL-5-induced proliferation by 50%, whereas forced expression of full-length BAM11 in Y16 cells did not affect the IL-5 responsiveness. We have also shown that BAM11 (amino acids 246-368) inhibited the kinase activity of Btk. These results suggest that the binding of BAM11 to Btk plays a regulatory role in the Btk signal transduction pathway. A cell fractionation study and analysis using EGFP-fused Btk protein demonstrated that a proportion of Btk is present within the nucleus.

Increased migration in late G(1) phase in cultured smooth muscle cells

Migration and proliferation of smooth muscle cells (SMC) contribute to neointimal formation after arterial injury. However, the relation between migration and proliferation in these cells is obscure. To discriminate between migration and proliferation, we employed a migration assay of SMC at different phases of the cell cycle. Serum-deprived SMC were synchronized in different phases of the cell cycle by addition of serum for various periods of time. Migration induced by platelet-derived growth factor B-chain homodimer was maximal in SMC that were predominantly in the late G(1) (G(1b)) phase. In addition, in nonsynchronized SMC, 65-75% of SMC that had migrated were in the G(1b) phase. Phosphorylated myosin light chain was enriched around the cell periphery in SMC in the G(1b) phase compared with SMC in the other cell cycle phases. Interestingly, the Triton X-100-insoluble fraction of myosin was remarkably decreased in G(1b)-enriched SMC. These findings suggest that migratory activity of SMC may be coupled with the G(1b) phase. The phosphorylation and retention of myosin might explain some of the properties responsible for increased migration.

Analysis of genetic polymorphism in NQO1, GST-M1, GST-T1, and CYP3A4 in 469 Japanese patients with therapy-related leukemia/ myelodysplastic syndrome and de novo acute myeloid leukemia

Several genetic polymorphisms in metabolic activation or detoxification enzymes have been associated with susceptibility to therapy-related leukemia and myelodysplastic leukemia (TRLIMDS). We analyzed gene polymorphisms of NAD(P)H:quinone oxidoreductase (NQOl), glutathione S-tranferase (GST)-MI and -TI, and CYP3A4, the enzymes of which are capable of metabolizing anticancer drugs, in 58 patients with TRL/MDS and in 411 patients with de novo acute myeloid leukemia (AML). Homozygous Ser/Ser genotype of NQOl at codon 187, causing loss of function, was more frequent in the patients with TRLIMDS (14 of 58, 24.1%; OR = 2.62) than in those with de novo AML (64 of 411, 15.6%), and control (16 of 150, 10.6%; P = 0.002). Allelic frequencies of NQOJ were different between TRL/ MDS and de novo AML (P = 0.01). In GST-MJ and -Ti, the incidence of homologous deletion was similar among the three groups. The polymorphism of the 5' promoter region of CYP3A4 was not found in persons of Japanese ethnicity. These results suggest that the NQOJ polymorphism is significantly associated with the genetic risk of TRLIMDS.

Observation of nuclear excitation by electron transition in 197Au with synchrotron X rays and an avalanche photodiode

We have succeeded in observing nuclear excitation by electron transition (NEET) in 197Au by a new method. Monochromatic x-rays of synchrotron radiation were used to ionize the K shell of gold atoms in a target foil. The internal-conversion electrons emitted from excited nuclei were detected with a silicon avalanche photodiode. At a photon energy of 80.989 keV, the NEET probability in 197Au was determined to be (5.0+/-0.6)x10(-8) from a comparison of the event number per photon between NEET and the nuclear resonance at 77.351 keV.

Effects of biopsy on lung metastasis

In order to clarify whether biopsy promotes lung metastasis, open or needle aspiration biopsy was performed 10 or 21 days after S-SLM osteosarcoma cells were transplanted subcutaneously in Fischer rats. The lungs were excised after six weeks and the lung weight and the number of metastatic nodules were measured. The mean weight was more in open than needle biopsy, and the number of nodules was significantly higher in open biopsy after 10 days, compared to the control. From these results we concluded that open is more likely to promote lung metastases compared to needle biopsy under the specific experimental conditions of this study.

Discovery of novel, potent, and selective small-molecule CCR5 antagonists as anti-HIV-1 agents: synthesis and biological evaluation of anilide derivatives with a quaternary ammonium moiety

The search for new small-molecule CCR5 antagonists by high-throughput screening (HTS) of the Takeda chemical library using [(125)I]RANTES and CHO/CCR5 cells led to the discovery of lead compounds (A, B) with a quaternary ammonium or phosphonium moiety, which were synthesized to investigate new MCP-1 receptor antagonists. A series of novel anilide derivatives 1 with a quaternary ammonium moiety were designed, synthesized, and tested for their CCR5 antagonistic activity. Through the optimization of lead compounds, we have found N,N-dimethyl-N-[4-[[[2-(4-methylphenyl)-6, 7-dihydro-5H-benzocyclohepten-8-yl]carbonyl]amino]benzyl]tetrahydr o-2 H-pyran-4-aminium chloride (1r, TAK-779) as a highly potent and selective nonpeptide CCR5 antagonist with a IC(50) value of 1.4 nM in the binding assay. Compound 1r also inhibited the replication of macrophage (M)-tropic HIV-1 (Ba-L strain) in both MAGI-CCR5 cells and PBMCs with EC(50) values of 1.2 and 3.7 nM, respectively. The synthesis and structure-activity relationships of 1r and its related compounds are detailed.

Cyclin D1 expression is useful as a prognostic indicator for advanced esophageal carcinomas, but not for superficial tumors

The purpose of the present study was to define the overexpression of cyclin D1 in superficial and advanced esophageal carcinomas and to investigate whether the expression of this molecule indicates a poor prognosis. This study included 41 patients with superficial esophageal carcinomas (Tis and T1) and 48 patients with advanced esophageal carcinomas (T2, T3, and T4). The expression of cyclin D1 in surgically resected specimens was evaluated immunohistochemically with a monoclonal antibody. Positive immunoreactivity was found in 31 of 89 cases (35%). Overexpression of cyclin D1 did not correlate with TNM classification or histologic type. Of the 48 patients with advanced esophageal carcinomas, 32 patients with cyclin D1-negative tumors survived longer than did 16 patients with cyclin D1-positive tumors (P = 0.0017). In contrast, we observed no survival difference between patients with cyclin D1-positive and -negative superficial esophageal carcinoma. These results suggest that cyclin D1 indicates a poor prognosis in cases of advanced esophageal carcinoma but not in cases of superficial esophageal carcinoma.

The Ikaros gene, a central regulator of lymphoid differentiation, fuses to the BCL6 gene as a result of t(3;7)(q27;p12) translocation in a patient with diffuse large B-cell lymphoma

The BCL6 gene, isolated from the breakpoints of 3q27-associated chromosomal translocations, has been implicated in diffuse large B-cell lymphomas (DLBL). Here we describe the molecular characterization of novel t(3;7)(q27;p12) translocations in 2 patients with DLBL. Molecular genetic analysis of the breakpoint area involving BCL6 revealed the presence of the Ikaros gene, a central regulator of lymphoid differentiation that had been mapped to human chromosome 7 band p13-p11.1. As a molecular consequence of the translocation, the 5' regulatory region of the BCL6 gene was replaced by the putative 5' regulatory region of the Ikaros gene, probably leading to deregulated expression of the BCL6 gene throughout B-cell differentiation. Reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH) analyses of a patient sample established that the t(3;7)(q27;p12) results in fusion of the Ikaros and BCL6 genes. This study provides the first evidence that the Ikaros gene is rearranged in human hematopoietic malignant disorders. (Blood. 2000;95:2719-2721)