Remote Mesoscopic Signatures of Induced Magnetic Texture in Graphene.

Mesoscopic conductance fluctuations are a ubiquitous signature of phase-coherent transport in small conductors, exhibiting universal character independent of system details. In this Letter, however, we demonstrate a pronounced breakdown of this universality, due to the interplay of local and remote phenomena in transport. Our experiments are performed in a graphene-based interaction-detection geometry, in which an artificial magnetic texture is induced in the graphene layer by covering a portion of it with a micromagnet. When probing conduction at some distance from this region, the strong influence of remote factors is manifested through the appearance of giant conductance fluctuations, with amplitude much larger than e^{2}/h. This violation of one of the fundamental tenets of mesoscopic physics dramatically demonstrates how local considerations can be overwhelmed by remote signatures in phase-coherent conductors.

Incidentally Detected Gastric Gastrointestinal Stromal Tumor during Living Donor Liver Transplant Surgery for Hepatocellular Carcinoma: The First Two Cases.

Coexistence of hepatocellular carcinoma and gastrointestinal stromal tumor is rare. In this case series, we aimed to present an unusual coincidence of a gastrointestinal stromal tumor and hepatocellular carcinoma in patients who underwent living donor liver transplantation for hepatocellular carcinoma who had an incidental gastric gastrointestinal tumor which was detected intraoperatively.

Universal scaling of weak localization in graphene due to bias-induced dispersion decoherence.

The differential conductance of graphene is shown to exhibit a zero-bias anomaly at low temperatures, arising from a suppression of the quantum corrections due to weak localization and electron interactions. A simple rescaling of these data, free of any adjustable parameters, shows that this anomaly exhibits a universal, temperature- (T) independent form. According to this, the differential conductance is approximately constant at small voltages (V < kBT/e), while at larger voltages it increases logarithmically with the applied bias. For theoretical insight into the origins of this behaviour, which is inconsistent with electron heating, we formulate a model for weak-localization in the presence of nonequilibrium transport. According to this model, the applied voltage causes unavoidable dispersion decoherence, which arises as diffusing electron partial waves, with a spread of energies defined by the value of the applied voltage, gradually decohere with one another as they diffuse through the system. The decoherence yields a universal scaling of the conductance as a function of eV/kBT, with a logarithmic variation for eV/kBT > 1, variations in accordance with the results of experiment. Our theoretical description of nonequilibrium transport in the presence of this source of decoherence exhibits strong similarities with the results of experiment, including the aforementioned rescaling of the conductance and its logarithmic variation as a function of the applied voltage.

Pregnancy After Liver Transplantation: Risks and Outcomes.

OBJECTIVE: The aim of this study was to evaluate the outcomes of liver transplant recipients who became pregnant after transplantation. METHODS: The clinical data of all patients who underwent liver transplantation between January 2007 and December 2016 in our liver transplantation institute were reviewed. The following data were analyzed: indications for transplantation, recipient age at the beginning of pregnancy, the interval between transplantation and pregnancy, maternal and fetal complications, type of delivery, the health condition of neonates, and modifications in immunosuppressive therapy. RESULTS: During the study period, 1890 patients underwent liver transplantation. There were 185 women (9.8%) in childbearing age (15-45 years old), and 18 (9.7%) of them became pregnant during the study period. There were a total of 26 pregnancies. The mean age of patients at the time of operation was 25.3 ± 5.2 years, and the mean interval between operation and conception was 32.7 ± 15.3 months. Seventeen pregnancies (65.4%) ended in a live birth in the study. Six pregnancies (23%) resulted with no maternal or fetal complications. The most frequent maternal complication during pregnancy was pregnancy-induced hypertension (n = 3; 16.6%). CONCLUSIONS: Despite advances in immunosuppressive therapy and increasing experience in the management of these patients, pregnancies in liver transplant recipients are still more risky than in the general population for both the mother and the fetus. Thus, the issues related to fertility should be comprehensively discussed with the patients and their partners, preferably before transplantation, and pregnancies in liver transplant recipients should be followed up more carefully by a multidisciplinary team.

Living related donor liver transplantation with atrio-caval anastomosis of inferior vena cava graft stored in deep-freeze for budd-Chiari syndrome.

We have previously reported our experience in inferior vena cava resection and reconstruction techniques during liver transplantation for Budd-Chiari syndrome. Herein, we present on a case that demonstrates the importance of experience in complex vascular reconstruction techniques for living donor liver transplantation. A 15-year-old boy was scheduled for living donor liver transplantation for Budd-Chiari syndrome. Venous occlusion was extended up to the right atrial orifice of the supra-hepatic vena cava. Retro- and supra-hepatic segments of the vena cava was resected. Inferior vena cava graft stored in deep-freeze was available. Venous reconstruction was performed with end-to-end atrio-caval anastomosis. Surgical treatment was completed with the implantation of the right liver lobe donated by the patient's mother. Post-surgical course was uneventful.

Realizing the potential of zebrafish as a model for human disease.

The value of the zebrafish (Danio rerio) as a model for human disease has been substantiated by a number of recently published papers. Several zebrafish mutants with "human" diseases have been found, spanning a variety of human pathologies. These successful studies utilizing the zebrafish have been made possible by the development of key reagents such as YAC, PAC, and BAC libraries, as well as radiation hybrid panels. With the further establishment of new tools and access to the newly generated resources, the zebrafish is poised to serve as a novel model for human disease.

Positional cloning of zebrafish ferroportin1 identifies a conserved vertebrate iron exporter.

Defects in iron absorption and utilization lead to iron deficiency and overload disorders. Adult mammals absorb iron through the duodenum, whereas embryos obtain iron through placental transport. Iron uptake from the intestinal lumen through the apical surface of polarized duodenal enterocytes is mediated by the divalent metal transporter, DMTi. A second transporter has been postulated to export iron across the basolateral surface to the circulation. Here we have used positional cloning to identify the gene responsible for the hypochromic anaemia of the zebrafish mutant weissherbst. The gene, ferroportin1, encodes a multiple-transmembrane domain protein, expressed in the yolk sac, that is a candidate for the elusive iron exporter. Zebrafish ferroportin1 is required for the transport of iron from maternally derived yolk stores to the circulation and functions as an iron exporter when expressed in Xenopus oocytes. Human Ferroportin1 is found at the basal surface of placental syncytiotrophoblasts, suggesting that it also transports iron from mother to embryo. Mammalian Ferroportin1 is expressed at the basolateral surface of duodenal enterocytes and could export cellular iron into the circulation. We propose that Ferroportin1 function may be perturbed in mammalian disorders of iron deficiency or overload.

A novel endothelial cell-based gene therapy platform for the in vivo delivery of apolipoprotein E.

A major focus in gene therapy has been the use of recombinant viruses to deliver genes in vivo. Although this approach shows much promise, there are many safety concerns associated with the use of viral materials in the treatment of human diseases. Our alternative cell-based gene therapy approach utilizes endothelial cells (Pro 175) isolated from the murine embryonic yolk sac. These endothelial cells were evaluated for their potential use in gene therapy as a gene delivery platform. As a test model, we used these cells to deliver apolipoprotein E (apoE) in the murine apoE knockout atherosclerosis model. The lack of apoE protein in these animals results in high levels of serum cholesterol and formation of severe aortic plaques and lesions at a young age. After transplantation of the apoE secreting Pro 175 endothelial cells into apoE-deficient mice, serum cholesterol levels were measured at 2 week intervals. During the 3 months after the initiation of these experiments, levels of cholesterol in the animals having received the apoE secreting endothelial cells were statistically lower compared with the levels of age-matched controls having received non-secreting endothelial cells. Concomitant with cholesterol reduction, atherosclerotic aortic plaques were noticeably reduced in the experimental apoE+ animals. These results highlight the potential of these unique endothelial cells as an efficient delivery platform for somatic gene therapy.

Leptin stimulates fetal and adult erythroid and myeloid development.

The ob gene product, leptin, has been shown in several studies to be involved in weight control and recombinant leptin recently has entered clinical trials to treat obesity. The leptin receptor (OB-R/B219) is expressed in a variety of protein isoforms not only in the central nervous system, but also in reproductive, and hematopoietic tissues. We reported recently that the OB-R/B219 was associated with a variety of hematopoietic lineages as well as the small fraction of cells containing the long-term reconstituting hematopoietic stem cells. Herein we report that leptin significantly stimulates the proliferation and differentiation of yolk sac cells and fetal liver cells and stimulates directly hematopoietic precursors. Leptin alone can increase the number of macrophage and granulocyte colonies, and leptin plus erythropoietin act synergistically to increase erythroid development. These data show that leptin has a significant, direct effect on early hematopoietic development and can stimulate the differentiation of lineage-restricted precursors of the erythrocytic and myelopoietic lineages. These observations along with a recent report strongly support our previous hypothesis that leptin has an unanticipated important role in hematopoietic and immune system development.

Adhesion of human myeloma-derived cell lines to bone marrow stromal cells stimulates interleukin-6 secretion.

Previous studies show that human myeloma-derived cell lines specifically adhere to fibronectin (FN) through very late antigen-4 (VLA-4; alpha 4 beta 1 integrin complex) and RGD-peptide mechanisms, which may contribute to the localization of tumor cells in bone marrow (BM). In these studies, we characterized the adhesion of myeloma-derived cell lines to both normal and myeloma BM stromal cells (BMSCs) and the effect of adhesion on DNA synthesis. Because interleukin-6 (IL-6) plays an important role in the pathogenesis of multiple myeloma, we also examined the effects of tumor cell adhesion on IL-6 secretion by BMSCs. In 51chromium binding assays, the U266, ARH-77, and IM-9 cell lines showed 52% +/- 12%, 55% +/- 6%, and 47% +/- 7% specific adherence, respectively, to normal BMSCs and 74% +/- 4%, 60% +/- 3%, and 61% +/- 6% specific adherence, respectively, to myeloma BMSCs. In contrast, only 12% to 13% specific binding of HS-Sultan cells to BMSCs was noted. The binding of myeloma cells to BMSCs was partially blocked with anti-beta 1 monoclonal antibody (MoAb), anti-beta 2 integrin MoAb, and excess RGD peptide, suggesting multiple mechanisms for the adhesion of myeloma cell lines to BMSCs. Binding of cell lines to FN or myeloma BMSCs did not affect cell line proliferation; however, adhesion of myeloma cell lines to normal BMSCs decreased DNA synthesis, ie, stimulation indices are 0.1 +/- 0.04, 0.2 +/- 0.1, 0.2 +/- 0.07, and 0.1 +/- 0.06 for the adherent non-IL-6-dependent U266, ARH-77, HS-Sultan, and IM-9 cells, respectively (n = 5, P < .01). In contrast, adherence of IL-6-dependent B9 cells increased their proliferation (stimulation index, 3.2 +/- 0.7). Significant (twofold to eightfold) increases in IL-6 secretion were evident in cell line-adherent (> or = 12 hours) normal and myeloma BMSC cultures. Paraformaldehyde fixation of BMSCs before adhesion completely abrogated IL-6 secretion, suggesting that IL-6 secretion was triggered in BMSCs rather than in cell lines. Partial blocking of cell line adhesion to BMSCs, using anti-beta 1 integrin and anti-beta 2 integrin MoAbs and RGD peptide, also partially blocked the triggering of IL-6 secretion by BMSCs. When cell lines were placed in Transwell inserts and then cultured with either normal or myeloma BMSCs, permitting juxtaposition without cell to cell contact between myeloma cell lines and BMSCs, no increase in IL-6 secretion was observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Interleukin-6 functions as an intracellular growth factor in hairy cell leukemia in vitro.

The role of interleukin-6 (IL-6) in the growth of B cell derived hairy cell leukemia (HCL) was characterized. Purified hairy cells (HCs) did not increase DNA synthesis in vitro in response to exogenous IL-6; however, they expressed IL-6 receptor (IL-6R) mRNA and bound directly fluorochrome labeled IL-6. IL-6 mRNA was not detectable in tumor cells by Northern blotting, but was evident using PCR amplification. Although intracytoplasmic IL-6 protein was not demonstrable, HCs did secrete low levels of IL-6. Neutralizing antibody to IL-6 did not inhibit HC DNA synthesis. Since tumor necrosis factor (TNF) is a growth factor for HCL, we determined whether the TNF effect could be IL-6-mediated. TNF markedly augmented in vitro DNA synthesis by HCs. TNF did not alter IL-6R expression or IL-6 binding; however, IL-6 mRNA and IL-6 protein were detectable after 3-d culture of HCs with TNF. In addition, IL-6 secretion by HCs was markedly augmented by TNF. Finally, although neither IL-6 nor anti-IL-6 antibody altered TNF-induced DNA synthesis by HCs, IL-6 antisense oligonucleotide inhibited TNF-induced DNA synthesis and IL-6 secretion by HCs. Therefore, IL-6 does not directly affect the growth of HCL, but rather mediates TNF-induced DNA synthesis via an intracytoplasmic mechanism.

Regulation of c-jun gene expression in human T lymphocytes.

The present studies have examined the effects of mitogens on induction of early response gene expression in normal peripheral blood T and Jurkat cells. Pokeweed mitogen (PWM) or anti-CD3 significantly increases c-jun messenger RNA (mRNA) levels in T cells. This transient PWM-related increase in c-jun transcripts is maximal after 15 to 30 minutes of exposure of T cells to PWM. PWM induces c-jun gene expression in a concentration-dependent manner. Moreover, PWM similarly induces expression of other genes coding for leucine zipper transcription factors, ie, jun-B and c-fos. Nuclear run on assays demonstrate that PWM treatment is associated with an increased rate of c-jun gene transcription. Transient expression assays with c-jun promoter fragments linked to the chloramphenicol acetyltransferase gene suggest that the PWM-induced increase in transcription is mediated by the AP-1 transcription factor complex. Moreover, treatment of T cells with actinomycin D to block further transcription before their culture with PWM suggests that the increase in c-jun gene expression by PWM is also regulated at least in part by a posttranscriptional mechanism. Cycloheximide does not alter c-jun mRNA induction by PWM. Finally, given that PWM induces B-cell differentiation in an interleukin-6 (IL-6)-mediated, T-cell-dependent manner, the relationship of c-jun and IL-6 gene expression in PWM-stimulated T cells was examined. The induction of IL-6 mRNA in T cells stimulated by PWM occurs after maximal induction of c-jun mRNA, at a time when the latter is no longer detectable. These findings suggest that PWM induces c-jun gene expression in T cells by a transcriptional and posttranscriptional mechanism and that AP-1 confers PWM inducibility of this gene. Because the IL-6 promoter has several potential transcriptional control elements, one of which is an AP-1-binding site, future experiments will evaluate the role of c-jun in the regulation of PWM-induced IL-6 synthesis by T cells.

Interleukin-11 promotes accessory cell-dependent B-cell differentiation in humans.

Interleukin-11 (IL-11) is a recently described stromal-derived cytokine that supports the growth of an IL-6-dependent murine plasmacytoma line in the presence of antibody to IL-6 and appears to act in a manner similar to IL-6 on hematopoietic stem cells. Because IL-6 is known to promote differentiation of normal human B cells, the role of IL-11 on B-cell differentiation in vitro was characterized. IL-11 does not result in significantly increased DNA synthesis or Ig secretion by purified B cells alone or B cells cultured with Staphylococcus Cowan I, a T-cell-independent B-cell mitogen. In contrast, purified B cells cultured in the presence of pokeweed mitogen (PWM), irradiated T cells, and monocytes show increased DNA synthesis at day 3 and increased IgG and IgM secretion at day 7 of culture; addition of IL-11 further augments Ig secretion without change in DNA synthesis, an effect that can only be partially blocked by monoclonal antibody to IL-6. Similar experiments confirmed that increased IgG secretion was demonstrable when either IL-11 or IL-6 was added to B cells + CD4+/45RA- T cells + monocytes + PWM; in contrast, Ig secretion was low and equivalent when CD4+/45RA+ T cells were cultured with B cells+monocytes+PWM with or without IL-6 or IL-11. Neither IL-6 nor IL-11 could significantly increase phytohemagglutinin (PHA)-induced DNA synthesis by CD4+/45RA- or CD4+/45RA+ T cells. Although PWM or IL-11 induced IL-6 mRNA expression in both CD4+/45RA- T cells and monocytes, in neither cell did IL-11 increase IL-6 mRNA expression over that noted to PWM alone. These observations support the view that IL-11 promotes differentiation of human B lymphocytes only in the presence of accessory T cells and monocytes and that a minor component of this effect may be through stimulation of IL-6 production by CD4+/45RA- T cells and monocytes.

Characterization of adhesion molecules on human myeloma cell lines.

In multiple myeloma, malignant plasma cells are localized in marrow and rarely circulate in peripheral blood. To investigate the role of adhesion proteins in this process, we determined the expression and function of adhesion molecules on cell lines derived from patients with myeloma. The U266, ARH-77, IM-9, and HS-Sultan cell lines strongly expressed beta 1 and alpha 4 integrins (89% to 98% positive), confirming that VLA-4 is the principal integrin on these cell lines. The U266 and IM-9 cell lines also expressed alpha 3 integrin on 15% to 20% cells. In contrast, all lines lacked cell surface alpha 2, alpha 5, and alpha 6 integrin expression (< 5% positive). These cell lines adhered to fibronectin (20% to 40% specific binding), without significant binding to either collagen or laminin. Adhesion of these cell lines to fibronectin was partially blocked with either anti-beta 1 integrin monoclonal antibody (MoAb) (75% inhibition), anti-alpha 4 integrin MoAb (75% inhibition), or RGD peptide (50% inhibition), but was unaffected by anti-alpha v beta 3 or anti-alpha IIb beta 3 MoAbs. Moreover, the combination of anti-beta 1 plus RGD peptide or anti-alpha 4 plus RGD peptide inhibited binding to fibronectin by 80% and 95%, respectively. Finally, pretreatment and coculture of the IM-9 cell line with interleukin-6 (IL-6) resulted in a 52% decrease in specific binding to fibronectin (30% +/- 6% to 15% +/- 6%; P = .001), associated with a decrease in the number of cells expressing VLA-4 and a decrease in intensity of VLA-4 expression. These data suggest that myeloma cells adhere to fibronectin through VLA-4 as well as through RGD-dependent mechanisms, and that this binding can be downregulated by IL-6. Future studies of binding of both myeloma cell lines and freshly isolated tumor cells to extracellular matrix proteins and to marrow stroma may enhance our understanding of localization and trafficking of cells within the bone marrow microenvironment.

Role of interleukin 6 in the growth of myeloma-derived cell lines.

The role of interleukin 6 (IL-6) in the growth of five multiple myeloma-derived cell lines was characterized. The U266 and RPMI 8226 cell lines demonstrated increased DNA synthesis when cultured with exogenous IL-6, expressed IL-6 cell surface receptors (IL-6Rs) and expressed mRNA for IL-6R. However, these cells did not secrete detectable IL-6 protein, and a neutralizing antibody to IL-6 did not inhibit their growth. Three other myeloma-derived cell lines ARH-77, IM-9 and HS-Sultan did not respond to exogenous IL-6, secrete IL-6 or express cell surface IL-6Rs. The IL-6 responsive cell lines bore late B-cell surface antigens (Ags), CD38 and PCA-1, whereas those lines which were non-IL-6 responsive strongly expressed B1 (CD20) and B4 (CD19) Ags, representing earlier stages in B-cell differentiation. Finally, the two IL-6 responsive cell lines did not express Epstein-Barr virus (EBV) proteins; in contrast, EBV encoded proteins typically expressed during latency could be detected in the three non-IL-6 responsive lines, confirming infection with virus. These studies clarify the heterogeneity observed in the myeloma cell line phenotype and biology and suggest that the U266 and RPMI 8226 cell lines, which express IL-6 cell surface receptors and are IL-6 responsive, may be useful for further study of IL-6 signal transduction in and related IL-6 mediated growth of myeloma in vivo. In contrast, those cell lines which are IL-6-independent provide a model for further study of EBV transformation and IL-6-dependent growth mechanisms in malignancy.

Lack of a role of interleukin 11 in the growth of multiple myeloma.

Interleukin (IL) 11 is a recently described lymphokine which, like IL-6, stimulates normal hematopoietic murine and human hematopoietic progenitor cells and therefore has potential value for either enhancing hematopoiesis in disease states or augmenting hematopoietic recovery after myeloablative therapies. Since IL-6 is known to promote the growth of human myeloma, either in an autocrine or paracrine fashion, we examined the effect of IL-11 on the growth of a murine plasmacytoma cell line, human myeloma-derived cell lines, and freshly isolated human myeloma cells. Interleukin 11 does increase DNA synthesis by the murine plasmacytoma line T10 in the presence of neutralizing antibody to IL-6. However, neither human myeloma cells nor derived cell lines express IL-11 mRNA; secrete IL-11; express IL-11 cell surface receptors; or augment either DNA synthesis or Ig secretion in response to exogenous IL-11. These findings strongly suggest that IL-11 does support the growth of a murine plasmacytoma cell line but does not play a role in the growth of either freshly isolated human myeloma cells or derived cell lines.

Monoclonal antibody-purged autologous bone marrow transplantation therapy for multiple myeloma.

Eleven patients with plasma cell dyscrasias underwent high-dose chemoradiotherapy and anti-B-cell monoclonal antibody (MoAb)-treated autologous bone marrow transplantation (ABMT). The majority of patients had advanced Durie-Salmon stage myeloma at diagnosis, all were pretreated with chemotherapy, and six had received prior radiotherapy. At the time of ABMT, all patients demonstrated good performance status with Karnofsky score of 80% or greater and had less than 10% marrow tumor cells. Eight patients had residual monoclonal marrow plasma cells and 10 patients had paraprotein. Following high-dose melphalan and total body irradiation (TBI) there were seven complete responses, three partial responses, and one toxic death. Granulocytes greater than 500/mm3 were noted at a median of 21 (range 12 to 46) days posttransplant (PT) and untransfused platelets greater than 20,000/mm3 were noted at a median of 23 (12 to 53) days PT in 10 of the 11 patients. Natural killer cells and cytotoxic/suppressor T cells predominated early PT, with return of B cells at 3 months PT and normalization of T4:T8 ratio at 1 year PT. Less than 5% polyclonal marrow plasma cells were noted in all patients after transplant. Three of the seven complete responders have had return of paraprotein, two with myeloma, and have subsequently responded to alpha 2 interferon therapy. Eight patients are alive at 18.9 (8.9 to 43.1) months PT and four remain disease-free at 12.3, 17.5, 18.9, and 29 months PT. This preliminary study confirms that high-dose melphalan and TBI can achieve high response rates without unexpected toxicity in patients who have sensitive disease, and that MoAb-based purging techniques do not inhibit engraftment. Although the follow-up is short- and long-term outcome to be determined, relapses post-ABMT in these heavily pretreated patients suggest that ABMT or alternative treatment strategies should be evaluated earlier in the disease course.

Response patterns of hairy cell leukemia to B-cell mitogens and growth factors.

The effect of mitogens and/or recombinant B-cell growth factors (M/GFs) on the in vitro growth of hairy cells was examined. Tumor cells were isolated from the spleens of four patients with hairy cell leukemia (HCL) by Ficoll-Hypaque sedimentation and E-rosetting. Enrichment for tumor cells was confirmed with intracytoplasmic immunoglobulin (Ig) staining, tartrate resistant acid phosphatase (TRAP) staining, and staining using monoclonal antibodies (MoAbs) directed at B, T, myeloid, and monocytoid antigens (Ags) in indirect immunofluorescence assays. Tumor cells were B1(CD20)+ B2(CD21)- B4(CD19)+ IL-2R(CD25)+ PCA-1 +/- TRAP+. HCLs neither synthesized DNA nor secreted Ig in response to culture with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-2, IL-3, IL-4, IL-5, or IL-6. However, a proliferative response (stimulation index greater than or equal to 3.0) without Ig secretion was triggered in HCLs by mitogens or combinations of GFs. Specifically, DNA synthesis was induced at 3 days in three of four HCL samples cultured with Staphylococcus aureus Cowan A (SAC) or the combination of phorbol ester (TPA) and the calcium ionophore A 23187 (Ca2+); DNA synthesis was triggered later (day 7) by tumor necrosis factor (TNF) or by IL-4 and IL-5. In contrast, the fourth patient, a nonresponder to SAC or TPA/Ca2+, demonstrated increased DNA synthesis at day 3 when cocultured with IL-4 and IL-5. Both autoradiography and staining with antibromodeoxyuridine (BrdU) MoAb conjugated to fluorescein confirmed DNA synthesis by only a minority (5% to 23%) of tumor cells within each patient. Dual staining confirmed that responsive cells were both BrdU+ and TRAP+. DNA synthesis induced by TPA/Ca2+ was blocked specifically by anti-IL-6 Ab; in contrast, the HCL proliferative response to SAC, TNF, or IL-4 and IL-5 was not inhibited by anti-IL-6 Ab. alpha-Interferon inhibited the response to TPA/Ca2+, TNF, or IL-4 and IL-5 without any effect on response to SAC. Finally, peroxidase-antiperoxidase staining demonstrated that HCLs are induced by TPA/Ca2+, but not by SAC, to produce intracytoplasmic IL-6. These data demonstrate IL-4, IL-5, and IL-6 mediated DNA synthesis by HCLs in vitro and suggest a possible in vivo role for these growth factors in the pathophysiology of HCL.

Response patterns of purified myeloma cells to hematopoietic growth factors.

Tumor cells were isolated from the bone marrow of seven patients with multiple myeloma and from the peripheral blood of three patients with plasma cell leukemia using Ficoll-Hypaque (FH) density sedimentation followed by immune rosette depletion of T, myeloid, monocytoid, and natural killer (NK) cells. Enrichment to greater than or equal to 93% plasma cells was confirmed with Wright's-Giemsa staining, with intracytoplasmic immunoglobulin staining, and with staining using monoclonal antibodies (MoAbs) directed at B, T, myeloid, monocytoid, and myeloma antigens in indirect immunofluorescence assays. Myeloma cells neither proliferated nor secreted Ig in response to G/M-CSF, G-CSF, M-CSF, interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-2 (IL-2), or interleukin-4 (IL-4). Significant proliferation (SI greater than or equal to 3.0) was induced by interleukin-6 (IL-6) in six of ten patients (SI of 31 and 43 in two cases); and to interleukin-3 (IL-3) and interleukin-5 (IL-5), independently, in two patients each. Peak proliferation to IL-5 or IL-6 and to IL-3 occurred in cells pulsed with 3[H] thymidine at 24 and 48 hours, respectively; and proliferation to combinations of factors did not exceed that noted to IL-6 alone; Ig secretion was not documented under any culture conditions. Three myeloma-derived cell lines similarly studied demonstrated variable responses. The heterogeneity in the in vitro responses of myeloma cells and derived cell lines to exogenous growth factors enhances our understanding of abnormal plasma cell growth and may yield insight into the pathophysiology of plasma cell dyscrasias.