Induction of hematopoietic microenvironment by the extracellular matrix from long-term bone marrow cultures

Summary Extracellular matrix (ECM) plays an important role in the regulation of hematopoiesis. The ECM obtained from murine long-term bone marrow cultures (LTBMCs) induces hematopoietic foci formation within 3 months after implantation under the murine renal capsule. The foci consist of approximately 3×10⁶ hematopoietic cells and function for at least 11 months. The induced stroma contains transplantable precursors capable of transferring a hematopoietic microenvironment to secondary recipients, and is insensitive to the stroma-stimulating factor produced in recipient mice after irradiation. The ECM induces hematopoietic foci formation in chimeras irradiated by a dose which is lethal for most of the stromal precursors. These facts point to the differences observed between bone marrow stromal precursors and mesenchymal cells induced under the renal capsule. The foci contain bone, but its appearance is limited to early stages of foci growth, and depends on the dose of implanted ECM. Bone is not formed when the xenogeneic ECM from nonhematopoietic tissue is used as an inducer. In this case, the foci develop slowly and are observed only to the tenth month after implantation. The data obtained demonstrate a novel function of the ECM in the induction of a hematopoietic microenvironment.     

急性髓系白血病患者预后分组方式的探讨

目的 评价原发、初治急性髓系白血病(AML)患者诱导治疗后不同时间骨髓幼稚细胞比例对预后的影响.将细胞遗传学与诱导治疗后不同时间骨髓幼稚细胞比例相结合,提出新的AML患者预后分组方法.方法 回顾性分析1999年1月1日至2008年2月1日于我院住院的原发、初治AML患者(非M3型)105例,所有患者在诱导化疗结束时(T1)和(或)骨髓抑制期(T2)进行骨髓穿刺检查.有细胞遗传学资料的患者97例.结果 (1)T1或T2时间点105例行骨髓穿刺检查的患者,骨髓幼稚细胞<0.05者和≥0.05者相比,T1时间点完全缓解(CR)率分别为86.0%、47.4%,3年无复发生存(RFS)率分别为46.2%、21.6%,3年总生存率分别为49.7%、25.6%.T2时间点二者CR率分别为86.3%、41.4%,3年RFS率分别为52.4%、18.9%,3年总生存率分别为61.1%、35.2%,差异均有统计学意义.且T1和,12时间点骨髓幼稚细胞比例具有相关性.(2)将染色体核型预后中等组患者根据T1或T2时间点骨髓幼稚细胞比例分为二组:骨髓幼稚细胞<0.05者和≥0.05者.前者预后与良好组相近,后者预后与不良组相近.(3)多因素分析表明T1或12时间点骨髓幼稚细胞比例是AML患者的独立预后因素.T1时间点骨髓幼稚细胞比例可能较T2时间点骨髓幼稚细胞比例意义更大.结论 以0.05为界,T1或T2时间点骨髓幼稚细胞比例是原发、初治AML患者(非M3型)CR率、RFS、总生存的独立预后因素.将染色体核型与T1和(或)T2时间点骨髓幼稚细胞比例相结合分组,可进一步区分中等组患者,有助于评估预后和选择治疗方案.     

Adjuvant therapy with rhGM-CSF for the treatment of Blastoschizomyces capitatus systemic infection in a patient with acute myeloid leukemia

 We report a patient with acute myeloid leukemia and Blastoschizomyces capitatus sepsis who developed multiple abscesses when neutrophils recoved. The patient did not respond to antifungal therapy and her clinical condition showed an improvement only after rhGM-CSF was added to the treatment. Received: 30 November 1995 / Accepted: 4 April 1996     

GM-CSF stimulates proliferation of clonal leukemic bone marrow cells in acute myeloid leukemia (AML) in vitro

 Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known to stimulate granulocytes, monocytes, and macrophages. We studied the effect of GM-CSF on (clonal) bone marrow (BM) cells obtained from AML patients after 7 days of culture in vitro: BM samples were obtained from 19 AML patients at diagnosis (DIA), from two patients with persisting disease (PERS), from eight patients in complete remission (CR), and from 12 healthy donors. Flow-cytometric comparison of differentiated, CD 15-positive cells or of CD34-positive blast cells before and after cultivation showed that the proportion of CD15-positive cells was increased in nine of 12 healthy BM samples, in 14 of 19 cases at DIA, in one of three cases during PERS, and in five of six cases in CR of AML. The proportion of CD34-positive cells was increased in one of 12 healthy BM samples, in seven of 19 cases at DIA, in one of two cases during PERS, and in three of seven cases in CR of AML. Southern blot analysis (SBA) performed in six cases during the course of AML, before and after cell culture, showed that clonal DNA increased after GM-CSF treatment in three of five cases studied at DIA, in six of nine cases studied in CR, in the one case studied at PERS, and in the one studied at relapse (REL). In one case of trisomy 8 at DIA a normal karyotype was demonstrated in CR. However, after 7 days of cultivation of the cells in GM-CSF the trisomy 8 was detected in two of 17 metaphases isolated from colony-cells from methylcellulose cultures. Our data show that a 7-day treatment of BM cells with GM-CSF induced a differentiation of healthy and leukemic BM cells in the great majority of cases. An enrichment of CD34-positive cells was not achieved in healthy BM samples. However, in 70% of the cases in CR and in 30% of the cases at DIA of AML, clonal CD34-positive cells were enriched. This means that GM-CSF stimulates ('primes') leukemic cell growth in vitro. Received: August 17, 1998 / Accepted: April 28, 1999     

Cellular aggregates in bone marrow cultures of patients with acute myeloid leukemia

Summary We describe the incidence and morphology of cellular aggregates which may develop in 8 day bone marrow (BM) cultures of patients with acute myeloid leukemia (AML). Aggregates formed in at least one BM culture from 50% (20/39) of the AML group. They developed irrespective of the patient's status (i.e. stages M1–M4), FAB type, and presence of colony stimulating factor (CSF). All aggregates were composed of macrophages, plasma cells, and cells of the myelocyte series surrounding a core of adipocytes and collagen fibrils. The percentage of blasts and promyelocytes in the plated BM aspirate governed the final composition of the aggregate. Patients in Stages M3 or M4 with FAB types M1 or M2 formed aggregates with a high proportion of myelocytic cells; aggregates of all other AML patients were composed predominantly of macrophages and plasmacytes. Aggregates appeared to form as a result of attraction of cells in the medium toward the stroma cell core. Furthermore, the development of aggregates in the absence of exogenous CSF, suggested that stromal cells excreted a factor with CSF-like activity. The results indicate that cellular aggregates in AML-BM cultures reflect the important role of BM stroma in creating microenvironments which enhance the development of hemopoietic stem cells.Supported by grants from the Swiss Cancer League     

Allogenic bone marrow transplantation of chemotherapy for patients with acute myeloid leukemia in first complete remission: a decision analysis approach

 The methodology of decision analysis was originally developed to improve clinical decisions of physicians for individual patients. However, it is also well suited to support consensus procedures. We have used this methodology to analyse the question whether allogeneic bone marrow transplantation (BMT) or consolidation chemotherapy (CCT) should be used as first line postremission treatment in patients with acute myeloid leukemia. Main risk factors relevant for the outcome after BMT and CCT are therapy-related mortality and leukemic relapse, respectively. If the possibility of salvage BMT for patients relapsing after CCT is included, the outcomes of the two strategies come rather close. However, they are clearly different in subtypes of leukemia with high or low risk of relapse, and in patients at high risk for BMT-related mortality. Sensitivity analysis considering the variation of more than one risk factor provides valuable information for decision making for both individual patients and particular subgroups of patients with acute myeloid leukemia. Received: 22 January 1996 / Accepted: 25 January 1996     

The radiation response and recovery of bone marrow stroma with particular reference to long-term bone marrow cultures

There is evidence for long-term haematopoietic dysfunction in some patients treated with radiotherapy. Although the underlying mechanisms are unclear, both stem cell and environmental defects have been implicated. In the present article we review the evidence concerning the role of stromal cells. According to the endpoints used, a wide range of radiosensitivities for the stroma have been reported. Long-term bone marrow cultures provide a system in which both functional and regenerative aspects of the stroma can be studied. A dose of 5 Gy applied prior to the establishment of long-term bone marrow cultures decreases both the formation of a confluent adherent stromal layer and its capacity to support haematopoiesis. In contrast, in its fully established phase, the adherent layer displays a high radioresistance due to the low proliferative stress applied to its stromal populations. A dose of 10 Gy given to a fully established adherent layer does not prevent haematopoietic engraftment and sustained haematopoiesis. At doses above 100 Gy a macrophage-like and epithelioid cell-type become dominant, which preserve their ability of producing growth regulatory molecules at doses as high as 500 Gy. These data suggest that the main effect on the stroma is a delayed expression of irradiation damage due to the slow rate of turnover of stromal cells. So far, there is little evidence for persistent deficiencies in the functional roles of stromal cell populations.     

Pre CFU-F in bone marrow cultures from children with hematopoietic disease including acute leukemia

Summary Stromal precursor cells from bone marrow aspirates of children have been studied in culture. In 7 day liquid cultures normal individuals and patients with acute leukemia in remission grew 110±50 CFU-F and 100±40 CFU-F (colony forming unit — fibroblasts) respectively, per 6×10⁵ buffy coat mononuclear cells. Staining with monoclonal antibodies suggests that stromal cells from CFU-F colonies are fibroblasts. CFU-F colony growth from the bone marrow of patients with active leukemia was low. After cultivation periods of more than 21 days, we observed, in addition, still more immature, clonogenic fibroblast precursor cells, pre CFU-F, and round cells attached to stromal cells from pre CFU-F colonies. From the round cells, we have passaged pre CFU-F and CFU-GM (colony forming unit — granulocytic, monocytic) in secondary cultures. Our observations are in agreement with the concept that the bone marrow stromal cell matrix serves as a sanctuary for reversibly attached clonogenic cells of both the hematopoietic and fibroblast lineages.     

MTS1 expression and prognosis in acute myeloid leukemia

 MTS1, a tumor supressor gene located on chromosome 9p21, has been shown to be altered in a number of human tumor cell lines, primary solid tumors, and leukemias. In this study we found low expression of MTS1 in lymphocytes from seven of nine healthy donors, but in none of eight granulocyte samples from the same controls, suggesting a physiological role of MTS1 in peripheral blood cells capable of proliferation, but not in end-stage differentiated cells. We detected MTS1 mRNA expression in 38 of 57 patients (66%) with acute myelogenous leukemia (AML) treated in a standardized clinical protocol. No deletion of the MTS1 gene was found in any of the AML samples tested. There was no significant association between expression of MTS1 and response to therapy, progression-free, or overall survival. Except for a negative correlation between MTS1 level and leukocyte count at diagnosis (p=0.03), there was also no association with any of the known prognostic parameters in AML. We conclude that MTS1 shows a significantly higher expression in leukemic than in normal peripheral blood cells, that deletion of MTS1 is not a frequent event in AML, and that its expression is not significantly correlated with outcome of the disease. Received: 7 April 1997 / Accepted: 18 August 1997     

Granulopoietic differentiation in long-term bone marrow cultures from children with congenital neutropenia

The capacity of granulopoietic precursor cells (CFU-GM) to differentiate in vitro was evaluated in five children with congenital neutropenia using short-term colony assays and long-term marrow cultures. In all five children, methylcellulose assays revealed normal numbers of CFU-GM, which displayed an appropriate response to various sources of GM-CSF and differentiated up to the polymorphonuclear leukocyte state (PMN). In contrast, neutrophil PMN were not observed in long-term bone marrow cultures from three patients, despite a normal production of CFU-GM, myeloblasts, and promyelocytes during the 5-6 week culture period. Thus, in these patients, the characteristic "block" in granulocytic maturation observed in vivo was reproduced in vitro in long-term cultures. Granulocytic differentiation proceeded normally in long-term cultures from the two other patients, thus indicating heterogeneity in the expression of the defect. These results might indicate abnormal interactions between stromal and hematopoietic cells in long-term marrow cultures from some patients with congenital neutropenia. Furthermore, our results showed some correlation between the granulocytic defect in vitro and the clinical outcome in vivo.     

Bulky lymphadenopathy in acute myeloid leukemia

 Two cases of acute myeloid leukemia (AML) presenting with bulky adenopathy are reported. Both patients were febrile at admission and showed massive and diffuse lymph node involvement, hepatomegaly, and splenomegaly. Erythematopapular leukemic skin lesions were present in one case at the onset and developed in the other at the time of relapse. Anemia, thrombocytopenia, and moderate leukocytosis were present in both. The presence of immature cells in peripheral blood and bone marrow allowed a rapid diagnosis of AML, FAB M1, in one patient. In the other case, owing to the paucity of immature cells in peripheral blood and bone marrow, lymph node biopsy with histology, imprint cytology, and immunocytochemistry were essential for the diagnosis (AML, FAB M2, with trilineage dysplasia and basophilic involvement). Both patients achieved complete remission (CR), followed by an early relapse 3 months later. They underwent allogeneic bone marrow transplantation (BMT) from HLA identical siblings. One patient is actually alive and in CR at 6 months after BMT; the other patient showed a leukemic regrowth after transplantation and died 4 months later. Received: December 8, 1997 / Accepted: April 29, 1998     

急性白血病缓解期骨髓造血干/祖细胞体外增殖特征的研究

目的：探讨急性白血病缓解期骨髓造血干／祖细胞增殖特性及对其对不同细胞因子的反应。方法：分离骨髓的单个核细胞（MNC），在含有重组人FLT3配基（rhFL)、干细胞因子（rhSCF)、白细胞介素-3(rhIL-3)、粒－巨噬细胞刺激因子（rhGM-CSF)及促红细胞生成素（EPO）的不同组合下，选用甲基纤维素法半固体培养体系培养7－14d，观察其CFU－GM及BFU－E的集落产率。结果：急性白血病缓期患者骨髓造血干细胞对各种细胞因子增殖反应有所不同（以SCF、FL的作用尤为显著）。与对照组比较，差异有显著性（P＜0．05）。结论：急性白血病缓解期患者的造血干／祖细胞活性比对照组减低。     

Blood-derived macrophage layers in the presence of hydrocortisone support myeloid progenitors in long-term cultures of CD34+ cord blood and bone marrow cells

 Monocytes/macrophages secrete various cytokines that induce proliferation of colony-forming unit granulocyte-macrophage (CFU-GM) in short-term assays. To determine whether macrophages also support proliferation of more primitive progenitors, i.e., cells that give rise to colony forming cells in a 5-week long-term culture (LTC), we established plastic-adherent macrophage layers from human peripheral blood (PB) and filgrastim (G-CSF)-mobilized progenitor cell collections in the presence of hydrocortisone, and compared these layers with bone marrow (BM) stroma regarding their suitability to support proliferation and differentiation of CD34⁺ BM and cord blood (CB) cells in 5-week LTCs. CD34⁺ cells were seeded onto irradiated macrophage and BM stromal layers, as well as without any preformed layer. After 5 weeks, colony formation (CFU-GM, BFU-E/CFU-E) and cell expansion were determined. CD34⁺ cells from BM and CB yielded more CFU-GM and total nucleated cells at 5 weeks in the presence of both types of adherent layer compared with cultures without a layer (p<0.05). For CD34⁺ BM cells, macrophage layers were superior to BM stroma in enhancing CFU-GM and CFU-E/BFU-E output (p<0.05). In contrast, BM stroma was favorable compared with macrophages concerning nucleated cell expansion from CD34⁺ CB cells (p=0.027). The macrophage nature of PB-derived adherent cells was confirmed immunocytochemically by positive staining for CD68, Ki-M1p, CD31, CD54, inconstant staining for CD14, and negative staining for CD1a, CD3, CD15, CD34, and CD62E. Cytochemical reactions were positive for α-naphthyl acetate esterase and negative for peroxidase and periodic acid-Schiff, consistent with the immunophenotype. In conclusion, the results show that blood-derived macrophages support CFU-GM generation from CD34⁺ CB and BM progenitors for 5 weeks in vitro. Differential effects on proliferation and maturation of BM versus CB progenitors are discussed. Received: February 16, 1999 / Accepted: June 21, 1999     

急性白血病骨髓中的血管生成的研究

目的 研究血管生成在急性白血病发病，预后中的作用。方法 应用免疫组化法检测30例初治急性白血病患者的骨髓活检组织治疗前后微血管密度（MVD）及血管内皮生长因子（VEGF）的变化。结果 初治急性白血病患者骨髓病理组织中的MVD和VEGF阳性率明显高于正常对照组；骨髓完全缓解后其MVD及VEGF阳性率明显下降，与正常对照组无显著性差异；治疗后未完全缓解组的MVD及VEGF阳性率较治疗前无显著性下降。结论 急性白血病骨髓中存在血管生成，可能与急性白血病的预后有关。     

Chromosomal aberrations in bone marrow mesenchymal stroma cells from patients with myelodysplastic syndrome and acute myeloblastic leukemia

OBJECTIVE: Bone marrow mesenchymal stroma cells (BMSC) are key components of the hematopoietic microenvironment. The question of whether BMSC from patients with hematological disorders have cytogenetic abnormalities is discussed controversially, some studies indicating that they are cytogenetically normal and others providing evidence of their aberrations. PATIENTS AND METHODS: We performed standard and molecular cytogenetic analyses of both hematopoietic cells and BMSC from 31 patients with myelodysplastic syndrome (MDS, n = 18) and acute myeloid leukemia (AML, n = 13) and 7 healthy individuals. Mononuclear cells were isolated from fresh bone marrow aspirates at the time of initial diagnosis for cytogenetic analysis of hematopoietic cells (HC) and selection of BMSC. RESULTS: Clonal cytogenetic aberrations were observed in HC from 8 (44%) MDS and 8 (61%) AML patients. Cytogenetic analyses of BMSC were successfully performed in 27 of the 31 cases. Structural chromosomal aberrations, including t(1;7), t(4;7), t(7;9), t(7;10), t(7;19), t(15;17), and others, were detectable in BMSC from 7 of 16 (44%) MDS and 6 of 11 (54%) AML patients. The breakpoints of chromosomes in BMSC were typical for leukemia aberrations. Two patients showed clonal chromosomal markers. CONCLUSIONS: BMSC from MDS and AML patients show chromosomal abnormalities. Although the majority of cytogenetic aberrations in BMSC were not clonal and differed from chromosomal markers in HC from the same individual, detection of typical chromosomal changes in BMSC suggests enhanced genetic susceptibility of these cells in MDS/AML. This may indicate potential involvement of BMSC in the pathophysiology of MDS/AML.     

Aspergillus osteoarthritis in acute lymphoblastic leukemia

 We report an unusual case of arthritis of the right wrist due to Aspergillus fumigatus without evidence for a generalized infection, following chemotherapy for acute lymphoblastic leukemia. The diagnosis was made by surgical biopsy. Amphotericin-B (Am-B) was not tolerated by the patient. Liposomal preparations of Am-B penetrate poorly into bone and cartilage. Therefore, oral itraconazole was given; the arthritis improved and chemotherapy was continued without infectious complications. Two weeks after complete hematopoietic recovery, an intracranial hemorrhage from a mycotic aneurysm of a brain vessel occurred, although the patient was still receiving itraconazole. We emphasize the importance of prompt and thorough efforts to identify the causative agent in immunocompromised patients with a joint infection. Itraconazole is effective in Aspergillus osteoarthritis but, due to its poor penetration into the brain, the combination with a liposomal formulation of Am-B is recommended. Received: January 4, 1999 / Accepted: June 21, 1999     

Kinetics of hematopoiesis in bone marrow cultures from patients with chronic myeloid leukemia: effect of recombinant cytokines in dexter-type long-term cultures

Chronic myeloid leukemia (CML) is a hematological neoplasia that results from the transformation of a hematopoietic stem cell. It is characterized by the expansion of the myeloid lineage, which results in the accumulation of mature and immature granulocytes in peripheral blood and bone marrow. However, when CML marrow cells are cultured in Dexter-type long-term cultures (LTMC) hematopoiesis is defective and can be sustained for only a few weeks. One possible explanation for the deficient growth of hematopoietic cells in CML LTMC is that some factors that act as key regulators of hematopoiesis are absent in this experimental system. Thus, we tested this hypothesis by adding recombinant cytokines to these cultures. As a first approach, we added recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF), rhGranulocyte-CSF (rhG-CSF) and rhErythropoietin (rhEPO); each factor was added individually once a week. Addition of rhGM-CSF and rhG-CSF resulted in a significant increase in the levels of nucleated cells and myeloid progenitors; the highest effects were seen in the presence of rhGM-CSF. Interestingly, such a cytokine also induced a significant decrease in the levels of erythroid progenitors. Recombinant hEPO had no significant effects on nucleated cells or myeloid progenitors, however, it induced a significant, although transient, increase in the levels of erythroid cells. The above results indicate that the hematopoietic regulators used here (rhGM-CSF, rhG-CSF and rhEPO) are capable of stimulating the growth of hematopoietic cells in LTMC from CML patients. Thus, this study demonstrates that it is, indeed, possible to manipulate CML LTMC by the addition of recombinant cytokines; this observation may be of particular relevance, since this in vitro experimental system has already been used as a method for purging of leukemic cells in autologous transplant settings. By using specific recombinant hematopoietic modulators it might be possible to make LTMC a more efficient system for such a clinical purpose.     

Persistence of murine myeloid leukaemic cells in long-term bone marrow cultures

Patterns of growth in long-term bone marrow culture were compared for a number of murine myeloid leukaemias. A leukaemic pattern of haematopoiesis was maintained in culture for a period of at least 15 weeks for one of the lines. However in the other five murine myeloid leukaemic lines studies, the leukaemic cells appeared not to survive in culture and normal haematopoiesis was established. Transplantation of cells from these established cultures at weeks 7 or 11 into syngeneic recipients revealed that leukaemic cells were present. Thus leukaemic cells seem to persist in long-term bone marrow cultures even in morphologically normal cultures.     

Stimulation of proliferation and differentiation of acute myeloid leukemia cells on a bone marrow stroma in culture

Purified acute myeloid leukemia (AML) blasts were placed in Dexter cultures with and without a preestablished normal bone marrow stroma to investigate whether their proliferation was dependent on a stroma, as is the case with normal marrow cells. It was also studied whether AML cells were induced to differentiate under a stromal influence. Ten patients with untreated AML were included in the study. In most cases, AML cells were maintained at higher levels when a normal stroma was present. Cell recoveries varied widely between patients. Net cell production was apparent in nine of ten stroma cultures. In most paired cultures without a preestablished stroma, cell numbers decreased. Leukemic colony-forming cells (L-CFU) (clonogenic cells) were also recovered in higher numbers from stroma cultures, but decreased rapidly. The peak of L-CFU preceded that of AML nucleated cells. Cytogenetic analysis (three cases) confirmed the AML karyotype of cultured cells. AML blasts were tested weekly with a number of monoclonal antibodies. During culture, the percentage of cells expressing mature monocytic and granulocytic surface antigens increased markedly, suggesting progressive maturation. Morphologic maturation at the same time was incomplete. Thus, AML cells proliferate and differentiate in vitro under the influence of a normal bone marrow stroma, a property which these cells share with normal bone marrow cells.     

Fatal pulmonary hemorrhage in patients with acute leukemia and fulminant pneumonia caused by Stenotrophomonas maltophilia

 Pulmonary hemorrhage is a rare cause of death in patients with acute leukemia. Within a 3-month period we observed three such cases, all of which were associated with the gram-negative opportunistic pathogen Stenotrophomonas maltophilia. Since fatal lung bleeding had previously not been observed in conjunction with this organism, we collected the data from all patients with documented S. maltophilia infections or colonizations of the past year and analyzed the risk factors for a lethal outcome. A total of eight patients were identified. In the three patients with fatal hemorrhage, the interval between first complaints (chest pain, cough, fever) and death from lung bleeding was 36–72 h. A fourth patient with acute leukemia died of nonhemorrhagic respiratory failure 9 days after developing S. maltophilia-associated pneumonia. All four patients had received intensive chemotherapy and were severely neutropenic and thrombocytopenic. Such a combination of predisposing factors was not observed in the four patients with nonfatal infections or colonizations. Pulsed-field gel electrophoresis demonstrated that the infections were unrelated. S. maltophilia was also isolated from a faucet in a patient's room, but the strain isolated was genetically different from the strain causing the patient's pneumonia. Our data suggest that severe bone marrow aplasia and a recent history of intensive chemotherapy are predisposing factors for the development of fulminant hemorrhagic S. maltophilia pneumonia. Since some of the infections and colonizations developed despite prophylactic administration of antibacterial agents with documented in vitro activity against the pathogen and none was controlled by such agents, it is clear an efficient treatment strategy needs to be developed. Received: 23 January 1997 / Accepted: 24 February 1997