FoxO1-dependent induction of acute myeloid leukemia by osteoblasts in mice.

Osteoblasts, the bone forming cells, affect self-renewal and expansion of hematopoietic stem cells (HSCs), as well as homing of healthy hematopoietic cells and tumor cells into the bone marrow. Constitutive activation of ß-catenin in osteoblasts is sufficient to alter the differentiation potential of myeloid and lymphoid progenitors and to initiate the development of acute myeloid leukemia (AML) in mice. We show here that Notch1 is the receptor mediating the leukemogenic properties of osteoblast-activated ß-catenin in HSCs. Moreover, using cell-specific gene inactivation mouse models, we show that FoxO1 expression in osteoblasts is required for and mediates the leukemogenic properties of ß-catenin. At the molecular level, FoxO1 interacts with ß-catenin in osteoblasts to induce expression of the Notch ligand, Jagged-1. Subsequent activation of Notch signaling in long-term repopulating HSC progenitors induces the leukemogenic transformation of HSCs and ultimately leads to the development of AML. These findings identify FoxO1 expressed in osteoblasts as a factor affecting hematopoiesis and provide a molecular mechanism whereby the FoxO1/activated ß-catenin interaction results in AML. These observations support the notion that the bone marrow niche is an instigator of leukemia and raise the prospect that FoxO1 oncogenic properties may occur in other tissues.

Integrating animal health and foodborne disease surveillance.

The control of foodborne diseases from an animal source has become an important part of public health policy. Since the agents that cause these diseases originate in animals, Veterinary Services, as well as Public Health Services, must be involved in their control. Control programmes should be established either through cooperation between the two Services or by the consolidation of all those involved into a single food control agency. Surveillance is an important part of these control programmes. The following questions must be addressed when planning an effective surveillance programme. What is the relative incidence, morbidity, mortality and economic cost of the foodborne disease in humans? Is the animal population the exclusive or a significant source of the human foodborne infection? What kind of surveillance is needed to identify the disease-causing agent in the animal population? Are we interested in identifying all cases of a disease in order to eradicate it or is our aim to reduce its incidence in the animal population? Do we have the ability to control the disease in the animal population? What disease detection tests are available? What are the sensitivity, specificity and cost of these diagnostic tests? Finally, does the country, region or agency involved have the legal, financial and educational resources to carry out this surveillance and follow it up with appropriate action? After these questions have been resolved,the veterinary and public health sectors must jointly decide if surveillance and control are feasible. If so, they can then begin to develop an appropriate programme.

Clinical presentation of inhalational anthrax following bioterrorism exposure: report of 2 surviving patients.

The use of anthrax as a weapon of biological terrorism has moved from theory to reality in recent weeks. Following processing of a letter containing anthrax spores that had been mailed to a US senator, 5 cases of inhalational anthrax have occurred among postal workers employed at a major postal facility in Washington, DC. This report details the clinical presentation, diagnostic workup, and initial therapy of 2 of these patients. The clinical course is in some ways different from what has been described as the classic pattern for inhalational anthrax. One patient developed low-grade fever, chills, cough, and malaise 3 days prior to admission, and then progressive dyspnea and cough productive of blood-tinged sputum on the day of admission. The other patient developed progressively worsening headache of 3 days' duration, along with nausea, chills, and night sweats, but no respiratory symptoms, on the day of admission. Both patients had abnormal findings on chest radiographs. Non-contrast-enhanced computed tomography of the chest showing mediastinal adenopathy led to a presumptive diagnosis of inhalational anthrax in both cases. The diagnoses were confirmed by blood cultures and polymerase chain reaction testing. Treatment with antibiotics, including intravenous ciprofloxacin, rifampin, and clindamycin, and supportive therapy appears to have slowed the progression of inhalational anthrax and has resulted to date in survival.

Levels of phospholipid metabolites in breast cancer cells treated with antimitotic drugs: a 31P-magnetic resonance spectroscopy study.

Magnetic resonance spectroscopy (MRS) methods have provided valuable information on cancer cell metabolism. In this study, we characterized the 31P-MR spectra of breast cancer cell lines exhibiting differences in hormonal response, estrogen receptors (positive/negative), and metastatic potential. A correlation was made between the cytotoxic effect of antimitotic drugs and changes in cell metabolism pattern. Because most anticancer drugs are more effective on proliferating cells, our study attempted to elucidate the metabolic profile and specific metabolic changes associated with the effect of anticancer drugs on proliferating breast cancer cell lines. Accordingly, for the 31P-MRS experiments, cells were embedded in Matrigel to preserve their proliferation profile and ability to absorb drugs. The MRS studies of untreated cells indicated that the levels of phosphodiesters and uridine diphosphosugar metabolites were significantly higher in estrogen receptor-positive and low metastatic potential cell lines. 31P-MRS observations revealed a correlation between the mode of action of anticancer drugs and the observed changes in cell metabolic profiles. When cells were treated with antimicrotubule drugs (paclitaxel, vincristine, colchicine, nocodazole), but not with methotrexate and doxorubicin, a profound elevation of intracellular glycerophosphorylcholine (GPC) was recorded that was not associated with changes in phospholipid composition of cell membrane. Remarkably, the rate of elevation of intracellular GPC was much faster in cell population synchronized at G2-M compared with the unsynchronized cells. The steady-state level of GPC for paclitaxel-treated cells was reached after approximately 4 h for synchronized cells and after approximately 24 h (approximate duration of one cell cycle) for the unsynchronized ones. These observations may indicate a correlation between microtubule status and cellular phospholipid metabolism. This study demonstrates that 31P-MRS may have diagnostic value for treatment decisions of breast cancer and reveals new aspects of the mechanism of action of antimicrotubule drugs.

Recent advances in the treatment of acute leukemia: 1999.

This review briefly summarizes literature noteworthy in the field of adult acute leukemia published during 1999. The relationship between specific cytogenetic abnormalities and response to treatment was explored within a clinical framework. In particular, detailed analyses of the abnormalities seen in acute promyelocytic leukemia were examined. Two case reports of special interest were published: one shed light on the role of histone deacetylase inhibitors in combination with all-trans retinoic acid, and the other, on the role of granulocyte colony-stimulating factor in this disease. The clinical activity of arsenic was also reported and its mechanism of action explored. In acute lymphoblastic leukemia, attention was focused on occult translocations, and the importance of minimal residual disease was again emphasized. Lastly, results of early clinical trials using an anti-CD19 antibody were reported, with provocative results.

Enhancement of 5-fluorouracil anabolism by methotrexate and trimetrexate in two rat solid tumor models, Walker 256 carcinosarcoma and Novikoff hepatoma, as evaluated by 19F-magnetic resonance spectroscopy.

Although 5-fluorouracil (5-FU) is one of the most effective single agents in treating solid tumors, its low effectiveness as a single agent has led to development of a number of modulators intended to enhance its therapeutic effectiveness. Of these, methotrexate (MTX) and trimetrexate (TMTX) have been shown to have synergistic anticancer activity with 5-FU. The effect of these two drugs on the uptake and the intratumoral metabolism of 5-FU was studied in two rat tumor models using 19F-nuclear magnetic resonance spectroscopy: on excised samples of Walker 256 carcinosarcoma and noninvasively (in vivo) in Novikoff hepatoma. In the rats bearing the Walker 256 tumor, a 4-hr pretreatment with MTX showed the maximal increase in the rate of conversion from 5-FU to its fluorinated nucleotides/nucleosides. In the rats bearing the Novikoff hepatoma, both modulators increased the amounts of cyctotoxic anabolites of 5-FU, but at the doses administered, the cumulative amounts of 5-FU anabolites formed after MTX were significantly higher than those formed after TMTX or after saline control. On the other hand, the increase in the levels of the fluorinated nucleotides/nucleosides after TMTX peaked at a later time. The possible significance of these findings is that timing of administration of a modulator is important because it affects both transport and metabolism of 5-FU. The two modulators studied, both antifolates, act differently on transport and on metabolism: MTX affects both, whereas TMTX, at the level studied, appears to affect predominantly the metabolic process. In addition, significant differences exist between tumor models. These data suggest possible mechanisms and processes that should be studied further in humans, using these noninvasive pharmacokinetic imaging methods for monitoring 5-FU targeting and metabolism.

Characterization of two novel sublines established from a human megakaryoblastic leukemia cell line transfected with p210(BCR-ABL).

Disease progression in chronic myelogenous leukemia (CML) is usually accompanied by chromosomal abnormalities such as an additional Ph chromosome, trisomies of chromosome 8 or 19, or i(17) in addition to the standard translocation t(9;22) (q34;q11). However, detailed studies of the various steps involved during this evolution are difficult to perform, thereby making the study of cell lines that contain the transposed genes BCR-ABL, especially those of human origin, an important focus. In this analysis we investigated the human megakaryoblastic cell line MO7e and its subline transfected with BCR-ABL, MO7e/p210. Initial studies demonstrated that the phenotype of the MO7e line was consistent with a megakaryocytic lineage as originally described and was growth factor dependent in liquid culture. The MO7e/p210 subline, however, was growth factor independent and could be further separated into two distinct sublines based on expression of glycophorin A using the monoclonal antibody R10. The subline R10 negative (R10-) was similar to the parent line MO7e but R10 positive (R10+) cells had a distinct erythroid phenotype. In addition, the R10- and R10+ sublines demonstrated strikingly different colony morphology when cultured in semisolid medium. Furthermore, R10+ cells had additional chromosomal abnormalities not detected in the R10- population. These results demonstrate that the insertion of the BCR-ABL in this human leukemia cell line resulted in two distinct subpopulations of cells, each now growth factor independent, but one with a phenotype and karyotype identical to the parent cell line and the other with a different phenotype and additional chromosomal abnormalities. These two subpopulations derived from the MO7e/p210 transfected cell line may prove useful in further understanding the multistep events that occur in the progression of this disease.

Acute myelogenous leukemia relapsing as granulocytic sarcoma of the cervix. A case report.

BACKGROUND: Granulocytic sarcoma of the uterine cervix is an unusual manifestation of acute myeloid leukemia, representing soft tissue masses of leukemic myeloblasts. An often misdiagnosed entity, it is often confused with other inflammatory or neoplastic conditions, including large cell lymphoma. CASE: A 67-year-old female presented with acute myelogenous leukemia and a normal karyotype. After eight years in complete remission, abdominal pain and an ulcerated mass in the uterine cervix developed, with a normal peripheral blood smear. Vaginal cytology examination revealed myeloid blasts, which, on subsequent cervical biopsy, stained positive for leukocyte common antigen, Kp-1 (CD68), antimyeloperoxidase, lysozyme and chloroacetate esterase, confirming the cytologic diagnosis. K-ras was not mutated at codon 12 or 13. Chemotherapy induced a complete remission, followed nine months later by central nervous system and then systemic relapse. The patient died 13 months after being diagnosed with granulocytic sarcoma of the cervix. CONCLUSION: This case illustrates the value of vaginal cytology and histologic biopsy evaluation in patients with acute myelogenous leukemia, including those without evidence of systemic disease. The characteristic cytologic features of granulocytic sarcoma led to the correct diagnosis. Histologic biopsy evaluation, including immunohistochemistry for myeloid markers, proved of value in confirming the diagnosis.

Fibrin microbeads (FMB) as biodegradable carriers for culturing cells and for accelerating wound healing.

We have developed biodegradable fibrin-derived microbeads as potent cell carriers. The fibrin-derived microbeads, 50-200 microm in diameter, were tested for their attachment to a wide range of cell types. Fibrin-derived microbeads were shown to be greatly haptotactic to cells (such as endothelial cells, smooth muscle cells and fibroblasts), which respond to fibrinogen in contrast to keratinocytes and different cell lines derived from leukocytic lineage. The cells on fibrin-derived microbeads could be maintained for more than 10 d and achieved a high density. 31P-nuclear magnetic resonance was employed to monitor phosphate metabolism in cells, with densities on the order of 100 million cells per g of fibrin-derived microbeads. The 31P-nuclear magnetic resonance adenosine triphosphate and phosphocreatine signals, equivalent to the signal obtained with perfused normal skin, indicated that metabolism of cells on fibrin-derived microbeads was responsive to oxygenation and nutrients. Light, fluorescent, and confocal laser microscopy revealed that the porous fibrin-derived microbeads accommodate up to 200-300 cells due to their high surface area which minimized contact inhibition. Cells could degrade the fibrin-derived microbeads and be transferred to seed culture flasks without trypsinization. In a pig skin wound healing model, fibrin-derived microbeads + fibroblasts were transplanted into full thickness punch wounds. This procedure was compared with other treatment modalities, such as the addition of human platelet-derived growth factor BB or fibrin-derived microbeads alone. By the third day after wounding, only the wounds in which fibroblasts on fibrin-derived microbeads were added showed significant formation of granulation tissue. Based on the above, we project many uses of our novel fibrin-derived microbead technology for cell culturing, wound healing and tissue engineering.

Ehlers-Danlos syndrome type IV with Charcot Marie tooth disease: an unusual combination of diseases.

Ehlers-Danlos Syndrome (EDS) type IV is a rare genetic disorder of connective tissue. Most patients with EDS type IV are frequently unaware of this disorder until the catastrophic rupture of an artery or bowel occurs. We are reporting an association between this and another uncommon autosomal dominant disorder, Charcot Marie Tooth disease. The neurologic problem led to painful foot deformities, requiring surgery, which was complicated by difficulty controlling bleeding in the friable tissues. Other reported associations of heritable disorders of connective tissue and neuropathies are described.

Enteropathy-associated T cell lymphoma with brain involvement.

In a patient with enteropathy-associated T cell lymphoma. there was dissemination to the brain manifesting as an inflammatory lesion. the intestinal and brain lesions were studied using routine histology, immunohistochemistry, and polymerase chain reaction. The jejunum was involved by a multifocal large cell lymphoma associated with multiple inflammatory ulcers and villous atrophy with crypt hyperplasia of the intervening mucosa. The lesion in the brain consisted of necrotic tissue associated with an infiltrate of histiocytes and a relatively scant infiltrate of primarily small lymphocytes. The appearance was that of an inflammatory rather than a neoplastic process. The intestinal lymphoma cells were positive for T cell markers and contained cytotoxic granules detected with the TIA-1 monoclonal antibody. The small lymphocytes and occasional large cells in the cerebral lesion showed the same immunophenotype. DNA extracted from the intestinal lymphoma and the cerebral lesion showed identical monoclonal rearrangement of the TCR-gamma gene. Dissemination from enteropathy-associated T cell lymphoma may masquerade as an inflammatory lesion. Molecular analysis is useful in confirming the diagnosis.

Expression of human herpesvirus-8 oncogene and cytokine homologues in an HIV-seronegative patient with multicentric Castleman's disease and primary effusion lymphoma.

Human herpesvirus-8 (HHV-8) has been described in association with two lymphoproliferative disorders: one benign, multicentric Castleman's disease (MCD), and one malignant, primary effusion lymphoma (PEL). The factors that lead to malignant transformation of lymphoid cells are unknown, although most cases of PEL also are positive for EBV, suggesting a role for EBV as a cofactor in malignant transformation. We encountered a rare case of an HHV-8-associated MCD, followed by the development of an HHV-8-positive pleural PEL and a gastric large cell lymphoma in an HIV-seronegative male patient. The lesions were negative for Epstein-Barr virus (EBV). The combination of these diverse HHV-8-associated lymphoproliferative disorders in a single patient afforded us the ability to study potential differences in gene expression in these conditions. HHV-8 DNA was demonstrated by PCR in lymphoid tissues involved by MCD and PEL. By reverse transcriptase-PCR, HHV-8-related transcripts, including vG-coupled protein receptor, vbcl2, vcyclin D, vIL-6, vMIPI, and vMIPII, were detected in the PEL from the pleural cavity and the gastric lymphoma, whereas these transcripts, except for vIL-6, were not detected in a lymph node biopsy with MCD. Expression of hIL-10 was weak in the PEL from the pleural cavity, and expression of hIL-6 was undetectable in all three lesions. These data suggest that vIL-6 may be integral to the pathogenesis of MCD, whereas other viral transcripts that encode oncogene and chemokine homologues are important for HHV-8 tumorigenicity.

Long-term follow-up of three randomized trials comparing idarubicin and daunorubicin as induction therapies for patients with untreated acute myeloid leukemia.

BACKGROUND: Most clinical trials for acute leukemia have reported results after 2-3 years of follow-up. Comparisons between the original data and longer-term follow-up data may be of interest, particularly with regard to promising new therapies. METHODS: In 1996, survival data were updated from three prospective, randomized comparisons of idarubicin and daunorubicin that began in 1984 and 1985. These were trials of the Memorial Sloan-Kettering Cancer Center (MSKCC), the U.S. Multicenter Study Group, and the Southeastern Cancer Study Group (SEG). The original results of these trials were reported in 1991 and 1992. RESULTS: The original results of the SEG trial demonstrated no significant difference between idarubicin and daunorubicin. The updated survival analysis showed similar results. The MSKCC trial revealed a significant advantage of idarubicin compared with daunorubicin in both the original and the updated analyses. The U.S. Multicenter trial found a significant difference favoring idarubicin in the original analysis, but the difference was not significant in the updated analysis. CONCLUSIONS: It is essential that the median length of follow-up be clearly stated in any clinical trial. When the results obtained with a particularly promising new drug or procedure are presented early in the course of study (within 1-2 years), the investigators should strongly consider a repeat evaluation after an additional 3-5 years of follow-up.

In vivo cyclic AMP responses in rat brain are not modified by chronic electroconvulsive shock.

In vivo microdialysis was used to determine the effects of chronic electroconvulsive shock (ECS), given daily for 10 days, on the cyclic AMP (cAMP) responses to noradrenaline (NA) and to forskolin in the cortex of freely-moving conscious rats. Microdialysis probes were inserted on the final day of ECS administration, and cAMP responses measured the following day. Chronic ECS did not modify the responses to either NA or forskolin. These results differ markedly from those previously obtained with incubated slices of rat brain. It is concluded that care is needed in interpreting results obtained by either ex vivo or in vitro methods.

Recent advances in the treatment of acute leukemia.

This review briefly summarizes literature considered noteworthy in the field of adult acute leukemia published during 1996. Does intensity remains a controversial issue in both acute myelogenous and lymphoblastic leukemia. The most convincing data showing efficacy of high dose fractionated chemotherapy was presented in patients with Burkitt's lymphoma/leukemia; the remainder of clinical studies failed to show a definitive advantage to high-dose therapy. Numerous studies addressed the role of the multidrug resistant phenotype and, at least in adult disease, demonstrated that the presence of this particular phenotype was a poor prognostic indicator. In the pediatric population, the significance of multidrug resistance expression appeared less clear. Discrepancies between protein expression and function were also evaluated in clinical samples and outcomes reported in large clinical series. Among the most interesting scientific investigations were those focused on the molecular mechanisms involved in the specific translocations t(15;17) and t(8;21) in acute myelogenous leukemia and t(12;21) in acute lymphoblastic leukemia. The genes PML and AML1, and ETO were examined in normal hematopoietic progenitors and their fusions proteins, PML/RAR alpha and AML1/ETO, measured in patients in clinical remission, and important data were presented concerning these proteins and measurement of minimal residual disease. Provocative data were also presented suggesting that retinoic acid may induce synthesis of a protein that selectively degrades PML/RAR alpha, and that interferons may regulate PML/RAR alpha expression.