IDA对白血病骨髓基质培养体系中HL-60细胞杀伤效应的观察

目的 :研究细胞毒药物对体外残留白血病模型中HL 6 0细胞的杀伤效应。方法 :采用Dexter型骨髓培养体系形成白血病骨髓基质细胞贴壁层 ,接种HL 6 0细胞共培养 ,用去甲氧基柔红霉素 (IDA)处理后 ,动态观察HL 6 0细胞的活性变化。结果 :随着IDA剂量的增加及培养时间的延长 ,HL 6 0细胞活力逐渐减弱 ,去甲氧基柔红霉素 (IDA)与骨髓基质细胞层或单纯的培养基体外孵育对HL 6 0细胞杀伤能力减弱。结论 :急性白血病骨髓基质有助于HL 6 0细胞逃避化疗药物杀伤 ,对残留白血病的形成具有重要作用。     

Conditions controlling long-term proliferation of Brown Norway rat promyelocytic leukemia in vitro: primary growth stimulation by microenvironment and establishment of an autonomous Brown Norway 'leukemic stem cell line'

Conditions for in vitro long-term maintenance and proliferation of the Brown Norway (BN) rat myelocytic leukemia cell (BNML) are described. During a primary culture of leukemic rat marrow, a few leukemic cells proliferated and were initially dependent on an adherent cell population but later acquired the capability of independent growth. A wild BN leukemic stem cell line has been maintained in vitro for several months, without noticeable phenotypic alterations. The doubling time of the cultured cells was 40 h. The cells were promyelocytes. The cytochemical markers of the original BN leukemia cells were preserved. The cultured cell line transferred leukemia exclusively to BN rats. Wistar and BDIX rats were resistant. The virulence of cultured leukemic cell was measured by shortened survival times after transplantation in animals of a fixed number of leukemic cells. The role of bone marrow microenvironment in the initiation of long-term growth is discussed.     

Cellular control of in vitro progression of murine myeloid leukemia: progression accompanies acquisition of independence from growth factor and stromal cells

The ability of bone marrow stroma cells of normal WCB6F1 (+/+) mice versus their congenic Sl/Sld stromal-defective littermates to support sustained proliferation and leukemic transformation of the growth factor-dependent myeloid cell line FDC-P1 was studied. Extensive proliferation of factor-dependent cells occurred on (+/+) normal long-term marrow culture stroma without the addition of growth factor, whereas factor-dependent cells dissipated from Sl/Sld stromal cultures after addition. The sustained proliferation that occurred on +/+ stromal layers later resulted in the appearance of factor-independent cell lines that were no longer dependent upon stroma. Factor-independent cell lines were cloned by limiting dilution and analyzed for expression of cell surface antigens to prove their origin from FDC-P1. Factor-independent cells, but not factor-dependent cells, formed tumors in syngeneic mice. These studies demonstrate a critical role for marrow stroma in the stepwise development of murine leukemia and are concordant with the previous data obtained in in vivo studies by McCool et al. that the splenic stroma of irradiated Sl/Sld mice do not support growth of Friend virus-induced preleukemic cell colonies. The present data demonstrate in a preleukemia model not induced by Friend virus complex that normal (+/+) stromal cells promote the in vitro proliferation of factor-dependent preleukemic cells and their subsequent transition to factor-independent leukemia cells, but Sl/Sld defective stroma do not efficiently promote this transition.     

永生化人骨髓基质干细胞系MSCxj的转化特征

目的明确永生化人骨髓基质干细胞系MSCxj是否具有转化特征。方法复苏已建立的永生化人骨髓基质干细胞系MSCxj，扩大培养，从致瘤性、血清依赖性、悬浮生长能力和接触抑制性等方面观察细胞的转化特征。结果细胞无裸鼠致瘤性，在软琼脂内不能生长，血清依赖性无显著降低，仍具有接触抑制性。结论MSCxj基本上为正常细胞而无明显转化特征。     

Bone marrow stromal cells regulate caspase 3 activity in leukemic cells during chemotherapy

The interaction between leukemic cells and stromal cells of the bone marrow microenvironment has been shown to enhance leukemic cell survival during exposure to chemotherapeutic agents. In the current study we investigated whether association of B lineage acute lymphoblastic leukemic cells with human bone marrow stromal cells altered caspase activation during chemotherapy treatment. Following treatment with Ara-C or VP-16 in vitro, caspase 3 activity in leukemic cells was consistently reduced by co-culture of leukemic cells with human bone marrow stromal cell layers. These observations suggest that the protective effect of the bone marrow microenvironment on leukemic cells may be due, in part, to regulation of caspase 3 activity.     

Growth Requirements of Normal and Leukemic Human B Cell Progenitors

Leukemic lymphoblasts in B-lineage acute lymphoblastic leukemia (ALL) express morphologic, phenotypic and genotypic features which resemble those of B lymphocyte progenitors in normal bone marrow. Normal immature B cells and cells from most cases of B-lineage ALL rapidly die in vitro unless they are supported by bone marrow-derived stromal feeder layers. Techniques suitable for maintaining normal and leukemic immature B cells in culture have been developed. Thus, the stromal cell types and growth factors that generate a milieu suitable for immature B-cell development can now be elucidated. In addition, the similarities and discrepancies in survival requirements of normal and leukemic B cell precursors can be studied. We postulate that leukemic B cell precursors can survive and expand in microen-vironments incapable of supporting their normal counterparts, and that the study of the survival requirements of ALL cells will provide indications about the aggressivity of the disease in vivo. In this review, we discuss the culture conditions that support in vitro survival of human immature B cells, some of the factors that influence their expansion, and the putative molecular basis for the prolonged life-span of leukemic lymphoblasts.     

Multiple steps in the immortalization of cells of the B lineage.

The ability of A-MuLV to transform bone marrow cells on in vitro culture in agarose is enhanced by inclusion of conditioned media during infection and culture. The conditioned medium of a non-virus producing A-MuLV transformed fibroblast cell line was synergistic with medium from Whitlock-Witte long-term bone marrow cultures, while conditioned medium from modified Dexter-type cultures was not active. These media all contained growth promoting activity for bone marrow cells. There are two types of transformed colonies produced, and transformation of only one type was enhanced by inclusion of conditioned media. Analysis of this type of transformed cell showed them to be pre-B cells. Limiting dilution analysis suggests the transformation process to be dependent on two types of cells, one presumably the target and the second an "accessory cell". Models are presented to account for the factor-dependent in vitro transformation of pre-B cells.     

Stimulatory effects of neopterin on hematopoiesis in vitro are mediated by activation of stromal cell function

The pteridine neopterin (NP) was shown to be produced by monocytes and is known to be a useful marker of immunological activation, although, its biological activity is still unclear. Recently, we found that intravenous administration of NP increased the numbers of blood leukocytes, and granulocyte-macrophage progenitor cells (CFU-GM) in the bone marrow and spleens of mice. In order to elucidate the mechanism whereby NP stimulates hematopoiesis, the effects of NP on hematopoietic stem cell proliferation and differentiation in vitro were studied using a long-term bone marrow culture (LTMC) system with cloned stromal cell line, MS-5. Adding NP to the LTMC increased the numbers of cells in total, CFU-GM and colony-forming unit in spleen (CFU-S). NP also increased the number of CFU-GM in a soft agar culture system, but it did not enhance CFU-GM colony formation when target bone marrow cells were semi-purified (T, B and adherent cell-depleted bone marrow cells) and cultured in this system, suggesting that NP did not directly affect the proliferation of hematopoietic progenitors. Conditioned medium obtained from NP-treated stromal cells had much greater colony-stimulating activity than that obtained from untreated stromal cells. Furthermore, NP treatment stimulated the production of IL-6 and GM-CSF by stromal cells. All these findings suggest that NP stimulates hematopoietic cell proliferation and differentiation in vitro by activating stromal cell function.     

Factors affecting the in vitro evolution of a myeloma cell line.

A continuously growing plasma cell line has been established from the bone marrow of a multiple myeloma patient. Initial growth of the cells was dependent on the presence of bone marrow stromal cells. Following initial outgrowth the cells were maintained by transfer onto non-autocthonous bone marrow stromal cultures. Following approximately one year of continuous growth, a subline was derived which could be grown independently of feeder cells. These stromal-cell-independent myeloma cells nevertheless retained dependence for a growth factor present in stromal-cell-conditioned media. The relevant factor in the conditioned media was determined to be interleukin-6 (IL-6). The cells also ultimately became independent of the conditioned media. These latter cells were shown to contain mRNA for IL-6 and eventually began to secrete IL-6. This cell line has thus progressed from complete dependence on stromal cells to IL-6-dependent growth in the absence of stromal cells to complete self sufficient growth. This in vitro progression may reflect an in vivo pattern of myeloma development.     

Unique lymphoid cell subset target to infection and proliferation induced in vitro by a murine leukemia virus.

The mechanisms by which non-oncogene bearing, slowly transforming T-cell-tropic retroviruses induce leukemia is not well understood. Viruses such as the murine radiation leukemia virus (RadLV) induce oncogenic transformation of T-cells in the thymus only in vivo and after a long latency. The capacity of RadLV to induce proliferation of lymphoid cells in vitro has been analysed here as a first attempt at mapping oncogenic transformation. Autonomously replicating cell lines have been isolated following exposure of splenic lymphocytes to two different isolates of RadLV, following in vitro culture in the presence of T-cell growth factors. Cells of similar precursor lymphoid morphology and phenotype have been isolated and cloned from cultures established from different animals. These cell lines all grow independently of exogenous growth factors in vitro, but are not tumorigenic in mice. Exposure to RadLV under the culture conditions provided has allowed integration of a new retroviral genome into each cell line, but no active replication of virus has been detected in any of the cell lines analysed. A common cell type resembling a lymphoid precursor has been induced to proliferate. These cell lines express cell surface markers attesting to their bone marrow origin, such as CD44 (Pgp-1), Gr-1, B220 and NK1.1, but they do not show the characteristics of T cells which have undergone differentiation within the thymus. They do not express the Thy-1 marker, nor show rearrangement involving any of the T-cell receptor (TCR) alpha, beta gamma or sigma genes. These cells bind several antibodies specific for the CD3-epsilon and TCR-alpha beta structures, and there appears to be aberrant expression of TCR proteins in cells bearing fully rearranged TCR genes. Precursor lymphoid cells and not mature T-cells in spleen, appear to be appropriate targets for RadLV-induced proliferation/immortalisation in vitro. Oncogenic transformation induced by RadLV in vivo may occur within precursor lymphoid cells and must be a complex process dependent on both the differentiation events which occur within the thymus, as well as the thymic environment of stromal cells.     

The AFT024 stromal cell line supports long-term ex vivo maintenance of engrafting multipotent human hematopoietic progenitors.

The immortalized murine stromal cell line AFT024 has been reported to maintain human hematopoietic progenitors in an undifferentiated state in vitro. In the current studies the beige/nude/xid (bnx) mouse in vivo xenograft model was used to examine the engraftment and multilineage generative potential of human hematopoietic progenitors after 2-3 weeks growth on AFT024 stroma, in comparison to primary stromal monolayers derived from post-natal human bone marrow. Eight to 12 months after transplantation of human CD34+CD38- cells from umbilical cord blood, cultured on AFT024 vs human stroma for 2-3 weeks, the murine bone marrow was harvested and analyzed for the presence of human myeloid and lymphoid cells. The mean percent engraftment of total human hematopoietic cells in the murine marrow was significantly higher after co-cultivation on AFT024 than on human stroma. Human myeloid and lymphoid lineage cells were detected in all mice. However, engraftment of myeloid lineage cells (CD33+), B lymphoid (CD19+), and T lymphoid cells (CD4+and CD8+) were significantly higher after co-cultivation of the human cells on AFT024 than on human stroma, prior to transplantation. Interestingly, the length of time in culture did not significantly affect the engraftment of the myeloid and T lymphoid lineage progenitors, but the percentage of B lymphoid lineage engraftment decreased significantly between 2 and 3 weeks of co-cultivation on both types of stroma. Cells with a primitive phenotype (CD45+/CD34-/CD38- and CD45+/CD34-/lin-) and cells with the capacity to generate secondary human CFU after recovery from the bnx bone marrow were maintained at significantly higher levels during culture on AFT024 stroma than on human stroma. The current studies demonstrate that the AFT024 murine stromal cell line supports the ex vivo survival and maintenance of human hematopoietic progenitors that are capable of long-term multilineage reconstitution for 2-3 weeks ex vivo, to levels superior to those that can be obtained using human stromal cells.     

Long-term bone marrow cultures: their use in autologous marrow transplantation

When cultured together, hemopoietic cells and marrow stromal cells can support hemopoiesis in vitro in the absence of added growth factors. The continued production of stem cells, progenitor cells, and mature cells within these "long-term bone marrow cultures" (LTBMC) requires their physical association with the stromal cells. For reasons that are not well understood, leukemic cells often fail to survive in such cultures. We and others have undertaken studies to examine whether LTBMC can be exploited as a way of purging the bone marrow of leukemia patients prior to autologous marrow transplantation.     

甲异靛对白血病骨髓基质细胞调节白血病细胞增殖的影响

 【摘要】　目的　探讨甲异靛对白血病骨髓基质细胞干预白血病细胞增殖的影响。方法 　利用白血病骨髓单个核细胞培养骨髓基质细胞,并建立白血病细胞和骨髓基质的共培养体系。用锥虫蓝拒染实验测定甲异靛对共培养体系中白血病细胞增殖的影响;流式细胞术检测白血病细胞膜上CXCR4的表达。结果　白血病骨髓基质细胞可抑制白血病细胞的增殖。低浓度的甲异靛（5 μmol／L）可促进白血病和骨髓基质细胞共培养体系中白血病细胞的增殖。白血病细胞膜异常高表达CXCR4,甲异靛可明显抑制HL-60细胞和原代白血病细胞膜上CXCR4的表达,骨髓基质细胞可以促进白血病细胞膜上CXCR4的表达。结论　甲异靛可能通过下调白血病细胞膜上CXCR4的表达起抗白血病作用。     

In vitro growth of human multiple myeloma: implications for biology and therapy.

In vitro data allow presentation of a plausible scenario for the in vivo growth, progression, and dissemination of human multiple myeloma (MM) that involves the interactions between the monoclonal B-cell clone and the bone marrow (BM) microenvironment. A large series of adhesion and extracellular matrix molecules allow trapping of circulating plasma cell precursors within the BM, and a battery of locally released cytokines promote their growth and final differentiation. Malignant B cells establish close contacts with BM stromal cells and release a host of cytokines that recruit and activate BM stromal cells and also T lymphocytes to produce other cytokines. All these cytokines might conceivably act in concert in a self-perpetuating mechanism of mutual help between malignant plasma cells and BM stromal cells to favor the progressive expansion of the malignant clone through a sort of an "avalanche effect." Also, most cytokines produced by malignant B cells, stromal cells, and activated T lymphocytes, including IL-1 beta, TNF-beta, M-CSF, IL-3, and IL-6, have osteoclast-activating properties, thus explaining why the expansion of the B-cell clone is matched by the activation and numeric increase of osteoclasts.     

Effects of the chemokine stromal cell-derived factor-1 on the migration and localization of precursor-B acute lymphoblastic leukemia cells within bone marrow stromal layers.

Acute lymphoblastic leukemia (ALL) blasts undergo migration into layers of bone marrow fibroblasts (BMF) in vitro, utilizing the beta1 integrins VLA-4 and VL-5 as adhesion molecules. However, it has been unclear as to whether this is a selective process mediated by specific chemoattractant molecules, or simply a reflection of the highly motile nature of early B cell precursors. We further characterized this process using a transwell culture system, in which the two chambers were separated by an 8 microm diameter microporous membrane, through which leukemic cells could move. When a BMF layer was grown on the upper surface of the membrane there was an 84.1% reduction in transmigration of the human pre-B ALL cell line NALM-6 into the lower chamber, compared to control membrane with no BMF layer. Localization of leukemic cells under the BMF layer was confirmed ultrastructurally, suggesting the possibility that the migration of leukemic cells was directed by a chemotactic agent secreted by BMF. The involvement of the chemokine stromal cell-derived factor-1 (SDF-1) in this process was next investigated. BMF were shown to express m-RNA for SDF-1. Addition of SDF-1 at 100 ng/ml into the lower chamber increased transmigration of NALM-6 across the membrane by 2.2-fold, and also induced a 1.4- to 6.1-fold increase in movement of NALM-6 through a BMF layer into the lower chamber. The receptor for SDF-1, CXCR4, was demonstrated by flow cytometry on all 10 cases of precursor-B ALL analyzed, as well as on NALM-6, KM-3 and REH lines. An inhibitory antibody to CXCR4 was able to block the migration of NALM-6 cells into BMF monolayers grown on plastic by 51%, and in nine cases of ALL by 8-40%, as well as partially inhibit transmigration of leukemic cells through BMF layers along an SDF-1 concentration gradient. These results confirm that precursor-B ALL cells selectively localize within bone marrow stroma in vitro, and that this process is partially due to the stromal chemokine SDF-1 binding to its receptor CXCR4 on leukemic cells. SDF-1 may be important in influencing the localization of precursor-B ALL cells in marrow microenvironmental inches which regulate their survival and proliferation.     

VLA-4 mediated adhesion to bone marrow stromal cells confers chemoresistance to adherent lymphoma cells.

The mechanisms of maintenance of residual lymphoma in bone marrow during chemotherapy are currently not well understood. Previous studies have shown that primary lymphoma cells obtained from histologically negative bone marrow of non-Hodgkin's lymphoma (NHL) patients grew in long-term bone marrow cultures primarily in association with bone marrow stromal cells. Furthermore, the interaction of NHL patient cells with bone marrow stromal cells inhibited their spontaneous apoptosis. The current studies were designed to characterize the components of the heterotypic interaction between lymphoma cells and bone marrow stromal cells as well as to probe the consequences of this interaction as it pertains to the potential survival of minimal numbers of lymphoma cells during chemotherapy. Cellular adhesion assays performed in the presence of either neutralizing antibodies to VCAM- or the alpha and beta subunit of VLA-4 resulted in >95%, 82% and 35% inhibition of lymphoma cell line adhesion to the bone marrow stromal line MS-5, respectively. Modulation of VLA-4 affinity by the 8A2 antibody resulted in enhanced secondary adhesion at 24 and 72 hours to either cellular fibronectin (65% and 65%) or MS-5 cells (60% and 55%), superceding levels obtained using untreated lymphoma cells (<20%). The bone marrow stromal cells induced a chemoprotective effect for adherent lymphoma cells over a 3-log dose range of vincristine, resulting in a 2-log increase in the ED50 at day 6 of culture. The failure of glutaraldehyde fixed stromal cells to induce a chemoprotective effect demonstrated that viable bone marrow stromal cells were necessary. Similarly, lymphoma/stromal cell conditioned medium also failed to provide a survival advantage. These data demonstrated that viable bone marrow stromal cells possessed the ability to actively inhibit the apoptotic pathways of intimately adherent lymphoma cells and this potentially contributes to their survival during chemotherapy.     

Regulation of lymphoid and myeloid leukemic cell survival: role of stromal cell adhesion molecules

Several laboratories have documented the necessity for direct contact of lymphoid and myeloid leukemic cells with bone marrow stromal cells for optimal survival. Subsequent studies have identified various stromal cell adhesion molecules and soluble factors that facilitate survival through leukemic cell anti-apoptotic signal transduction pathways. This report provides an overview of enhanced leukemic cell survival through adhesive interactions with bone marrow expressed molecules. In addition, we describe the establishment of cloned murine stromal cell lines engineered to constitutively express human VCAM-1 protein on their surface. These stromal cell lines will be useful in studies aimed at better understanding the specific contribution of VCAM-1 : VLA-4 signaling in maintenance of residual leukemic disease.     

Effect of direct cell-to-cell interaction between the KM-102 clonal human marrow stromal cell line and the HL-60 myeloid leukemic cell line on the differentiation and proliferation of the HL-60 line

Hematopoietic cellular interaction was investigated in a coculture of the human clonal marrow stromal line, KM-102, and the myeloid leukemia cell line, HL-60. In the coculture, a large number of HL-60 cells remained in the supernatant but some of them became firmly attached to KM-102 cells. The attached HL-60 cells showed little positive reaction in the NBT test when the culture was supplemented with 10(-9) to 10(-7) M 1 alpha, 25-dihydroxyvitamin D3. In contrast, differentiation in the supernatant HL-60 cells was strikingly responsive to the agent in a dose-dependent way. Furthermore, the complete inhibition was observed in the incorporation of [3H]thymidine into the attached HL-60 cells with autoradiography, but 23.6% of the supernatant cells moderately incorporated [3H] thymidine into their nuclei. There was no attachment between HL-60 cells and stromal cells from human thymus and lymph node, or between lymphocytic leukemia cells and marrow stromal cells. These results indicate that there is direct cellular interaction between myeloid leukemic cells and marrow stromal cells which modulates the proliferation and differentiation of the myeloid leukemic cells. This modulation by marrow stromal cells is more strongly affected by this interaction than by exogenously added differentiation-inducing agents. Apparently marrow stromal cells produce a definitive milieu for the proliferation and differentiation of myeloid leukemic cells.