transforming-growth-factor-beta and Lymphoma

Transforming growth factor-beta (TGF-beta) is an important physiologic regulator of cell growth and differentiation. TGF-beta has been shown to inhibit the proliferation of quiescent hematopoietic stem cells and stimulate the differentiation of late progenitors to erythroid and myeloid cells. Insensitivity to TGF-beta is implicated in the pathogenesis of many myeloid and lymphoid neoplasms. Loss of extracellular TGF receptors and disruption of intracellular TGF-beta signaling by oncogenes is seen in a variety of malignant and premalignant states. TGF-beta can also affect tumor growth and survival by influencing the secretion of other growth factors and manipulation of the tumor microenvironment. Recent development of small molecule inhibitors of TGF-beta receptors and other signaling intermediaries may allow us to modulate TGF signaling for future therapeutic interventions in cancer.

Topics: Animals; Apoptosis; Hematopoiesis; Humans; Leukemia; Lymphoma; Multiple Myeloma; Myelodysplastic Syndromes; Receptors, Transforming Growth Factor beta; Signal Transduction; Transforming Growth Factor beta

The polypeptide cytokines, IL-1 and TGF-beta affect nearly every tissue and cell type in the body. IL-1 is the prototype of the proinflammatory molecule while TGF-beta is essentially anti-inflammatory. IL-1 is part of the cascade of cytokines that are produced during microbial invasion or bodily injury and enhance a variety of host responses, particularly in the immunological and haemopoietic systems, while TGF-beta acts as an inhibitor of these responses. At several levels, IL-1 and TGF-beta act in opposition to one another. IL-1 stimulates the expression of many genes in lymphoid and marrow stromal cells that stimulate haemopoietic cell growth and differentiation, while TGF-beta inhibits these IL-1 mediated effects. Also, TGF-beta stimulates secretion of the IL-1Ra. In addition, IL-1 induces the cell surface expression of cytokine receptors on lymphoid and haemopoietic cells, while TGF-beta dramatically inhibits the cell surface expression of these receptors, including the IL-1 receptor. Finally, IL-1 augments lymphoid and haemopoietic cell growth and TGF-beta potently inhibits this proliferation. The interactions of these cytokines serve to illustrate that the net balance of stimulatory and inhibitory signals determines the fate of a given cell which may be responsible for regulating homeostatic cell growth (Figure 1). Thus, the regulation of cytokine production and/or antagonism of their effects continues to be a therapeutic goal in the treatment of many diseases.

Topics: Animals; Bone Marrow Cells; Cell Cycle; Cell Differentiation; Cell Division; Colony-Forming Units Assay; Cytokines; Gene Expression Regulation; Hematopoiesis; Hematopoietic Cell Growth Factors; Hematopoietic Stem Cells; Humans; Interleukin-1; Leukemia; Lymphocyte Activation; Lymphoma; Mice; Models, Biological; Organ Culture Techniques; Receptors, Cell Surface; T-Lymphocytes; Transforming Growth Factor beta

It is now apparent that the transforming growth factor beta (TGF-beta) family of proteins has potent immunoregulatory properties ranging from effects on the growth and differentiation of primitive stem cells to the differentiated functions of immune effector cells. Although most reports have described the immunosuppressive activities of TGF-beta, recent evidence supports the concept that TGF-beta can have both inhibitory and stimulatory actions on these systems. Recently, it has been found that TGF-beta can have autocrine as well as paracrine effects on the immune system, indicating that immune cells can activate the inactive secreted form of TGF-beta. Furthermore, TGF-beta has differential intracellular effects on cell surface receptor modulation, tyrosine phosphorylation, and cytokine gene transcription as well as cell-mediated cytotoxicity. Importantly, the administration of TGF-beta has proven beneficial in several animal disease models such as septic shock, allograft rejection, and autoimmunity. Moreover, the increased levels of TGF-beta found in several disease states associated with immunosuppression such as different forms of malignancy, chronic degenerative diseases, and AIDS implicate the involvement of TGF-beta in the pathogenesis of some diseases. Ultimately, well designed clinical trials will determine whether the exciting potential of TGF-beta can be used to treat or prevent disease.

Topics: Animals; Autoimmunity; Humans; Immune Tolerance; Immunity; Inflammation; Lymphoma; Neoplasms; Receptors, Cell Surface; Receptors, Transforming Growth Factor beta; Retroviridae Infections; Transforming Growth Factor beta

Patients undergoing hematopoietic stem cell transplantation (HSCT) are submitted to a conditioning regimen of high-dose chemotherapy, with or without radiation therapy, which usually results in oral ulcerations and mucosal barrier breakdown. Oral mucositis (OM) is a common and debilitating toxicity side effect of autologous and allogeneic HSCT. The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on the severity of OM and inflammatory mediator (TNF-α, IL-6, IL-1β, IL-10, TGF-β, metalloproteinases, and growth factors) levels in saliva and blood of HSCT patients. Thirty patients were randomly assigned to two groups: control (n = 15) and laser (n = 15). LLLT was applied from the first day of the conditioning regimen until day 7 post-HSCT (D + 7). Saliva and blood were collected from patients on admission (AD), D-1, D + 3, D + 7, and on marrow engraftment day (ME). Clinical results showed less severe OM in the laser group (p < 0.05). The LLLT group showed increased matrix metalloproteinase 2 (MMP-2) levels in saliva on D + 7 (p = 0.04). Significant differences were also observed for IL-10 on D + 7 and on ME in blood plasma, when compared to the control group (p < 0.05). No significant differences were seen in saliva or blood for the other inflammatory mediators investigated. LLLT was clinically effective in reducing the severity of chemotherapy-induced OM in HSCT patients, and its mechanism of action does not seem to be completely linked to the modulation of pro- or anti-inflammatory cytokines, growth factors or matrix metalloproteinases.

Topics: Adult; Female; Hematopoietic Stem Cell Transplantation; Humans; Inflammation Mediators; Interleukin-10; Interleukin-6; Lasers, Semiconductor; Leukemia; Low-Level Light Therapy; Lymphoma; Male; Matrix Metalloproteinase 2; Middle Aged; Myeloablative Agonists; Saliva; Stomatitis; Transforming Growth Factor beta; Transplantation Conditioning; Tumor Necrosis Factor-alpha; Young Adult

Topics: Cell Line, Tumor; Humans; Killer Cells, Natural; Lymphoma; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Tumor Microenvironment

In clinical practice, major efforts are underway to identify appropriate drug combinations to boost anticancer activity while suppressing unwanted adverse effects. In this regard, we evaluated the efficacy of combination treatment with the widely used chemotherapeutic drug doxorubicin along with the TGFβRI inhibitor galunisertib (LY2157299) in aggressive B-cell non-Hodgkin lymphoma (B-NHL). The antiproliferative effects of these drugs as single agents or in combination against several B-NHL cell lines and the synergism of the drug combination were evaluated by calculating the combination index. To understand the putative molecular mechanism of drug synergism, the TGF-β and stress signaling pathways were analyzed after combination treatment. An aggressive lymphoma model was used to evaluate the anticancer activity and post-therapeutic immune response of the drug combination in vivo. Galunisertib sensitized various B-NHL cells to doxorubicin and in combination synergistically increased apoptosis. The antitumor activity of the drug combinations involved upregulation of p-P38 MAPK and inhibition of the TGF-β/Smad2/3 and PI3K/AKT signaling pathways. Combined drug treatment significantly reduced tumor growth and enhanced survival, indicating that the synergism between galunisertib and Dox observed in vitro was most likely retained in vivo. Based on the tumor-draining lymph node analysis, combination therapy results in better prognosis, including disappearance of disease-exacerbating regulatory T cells and prevention of CD8

Topics: Apoptosis; Cell Line, Tumor; Doxorubicin; Drug Synergism; Humans; Immune System; Lymphoma; Neoplasms; Phosphatidylinositol 3-Kinases; Transforming Growth Factor beta

The inherent abilities of natural killer (NK) cells to recognize and kill target cells place them among the first cells with the ability to recognize and destroy infected or transformed cells. Cancer cells, however, have mechanisms by which they can inhibit the surveillance and cytotoxic abilities of NK cells with one believed mechanism for this: their ability to release exosomes. Exosomes are vesicles that are found in abundance in the tumor microenvironment that can modulate intercellular communication and thus enhance tumor malignancy. Recently, our lab has found cancer cell exosomes to contain the inhibitor of apoptosis (IAP) protein survivin to be associated with decreased immune response in lymphocytes and cellular death. The purpose of this study was to explore the effect of survivin and lymphoma-derived survivin-containing exosomes on the immune functions of NK cells. NK cells were obtained from the peripheral blood of healthy donors and treated with pure survivin protein or exosomes from two lymphoma cell lines, DLCL2 and FSCCL. RNA was isolated from NK cell samples for measurement by PCR, and intracellular flow cytometry was used to determine protein expression. Degranulation capacity, cytotoxicity, and natural killer group 2D receptor (NKG2D) levels were also assessed. Lymphoma exosomes were examined for size and protein content. This study established that these lymphoma exosomes contained survivin and FasL but were negative for MHC class I-related chains (MIC)/B (MICA/B) and TGF-β. Treatment with exosomes did not significantly alter NK cell functionality, but extracellular survivin was seen to decrease natural killer group 2D receptor (NKG2D) levels and the intracellular protein levels of perforin, granzyme B, TNF-α, and IFN-γ.

Topics: Cell Line, Tumor; Cell Lineage; Cell Proliferation; Exosomes; Fas Ligand Protein; Flow Cytometry; Gene Expression Regulation, Neoplastic; Genes, MHC Class I; Histocompatibility Antigens Class I; Humans; Inhibitor of Apoptosis Proteins; Killer Cells, Natural; Lymphoma; NK Cell Lectin-Like Receptor Subfamily K; Survivin; Transforming Growth Factor beta

Topics: Animals; Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Cadherins; Caspase 3; Caspase 9; Cell Line, Tumor; Cell Proliferation; Cephalotaxus; Curcuma; Curcumin; Drug Therapy, Combination; Homoharringtonine; Lymphoma; Mice, Inbred BALB C; Mice, Nude; Neoplasm Invasiveness; Phytotherapy; Plant Extracts; Signal Transduction; Smad3 Protein; Transforming Growth Factor beta; Xenograft Model Antitumor Assays

An effective host immune system prevents the growth of most cancer cells. However, as intestinal nematodes are able to induce both immunotolerance and immunosuppression in the host, it is possible that their presence could allow co-occurring cancer cells to proliferate and metastasize. Our findings indicate that previous, subsequent or concurrent intestinal nematode infection affects the formation of lung metastatic nodules in mice experimentally infected with Heligmosomoides polygyrus. In addition, pre-infection with nematodes renders mice resistant to metastasis development in lungs, with the inoculated EL4 cancer cells being located mainly in mesenteric lymph nodes. The present paper discusses the nematode-induced mechanisms which may influence the metastatic process.

Topics: Animals; Disease Models, Animal; Helminthiasis; Immunomodulation; Intestinal Diseases, Parasitic; Lung Neoplasms; Lymphoma; Male; Mice; Nematode Infections; Nematospiroides dubius; Neoplasm Metastasis; Transforming Growth Factor beta

There are diverse investigations focused on the therapies of lymphoma. Our research was taken to identify the effects of lentiviral-mediated Smad4 gene silencing on chemosensitivity of human lymphoma cells to adriamycin (ADM) via transforming growth factor β (TGFβ) signaling pathway. Raji/ADM cells were cultured and infected with lentiviral particles Smad4-short hairpin (shRNA) and control-shRNA. Then, the messenger RNA (mRNA) and protein levels of TGFβ signaling pathway-related factors (Smad4, Smad3, cyclinE, cyclinD1, and p21) in Raji/ADM cells were determined. The effect of Smad4-shRNA on cell viability, invasion and migration, and apoptosis were also detected. Compared with the Raji group, increased mRNA and protein levels of Smad4, Smad3, cyclinE, cyclinD1, enhanced cell proliferation, migration and invasion as well as decreased mRNA, and protein levels of p21 and cell apoptosis rate were found in the Raji/ADM and control-shRNA groups. However, Smad4 gene silencing resulted in decreased mRNA and protein levels of Smad4, Smad3, cyclinE, and cyclinD1 along with inhibited cell proliferation, migration and invasion but increased expression of p21 together with cell apoptosis. Collectively, Smad4 gene silencing can inhibit the activation of TGFβ signaling pathway, thereby enhancing the chemosensitivity of human lymphoma cells to ADM.

Topics: Apoptosis; Cell Line, Tumor; Cell Movement; Cell Survival; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Doxorubicin; Gene Expression Regulation, Neoplastic; Gene Silencing; Humans; Lentivirus; Lymphoma; Neoplasm Invasiveness; RNA, Messenger; Signal Transduction; Smad3 Protein; Smad4 Protein; Transforming Growth Factor beta

Although cancer tissue generally shows limited immune responses, some cancers abound with lymphocytes, which generally show favorable prognosis. These cancers, despite their rarity, are important in analyzing immune responses in cancer tissue. Transforming growth factor β1 (TFGβ1) is a multifunctional cytokine, generally having an immunosuppressive function. The present study analyzes the in situ TGFβ1 expression in 23 cases of lymphocyte-rich gastric carcinomas (Ly-rich GCs) using immunohistochemistry and in situ hybridization. Immunohistochemistry revealed that latency-associated peptide (LAP) of TGFβ1 was localized in mainly immune cells in all cases, which was more abundant than in control GCs. Expression of LAP by cancer cells was only focal. In situ hybridization also confirmed abundant TGFβ1 mRNA expression in the lymphoid stroma. Double immunofluorescent microscopy identified LAP

Topics: Aged; Aged, 80 and over; Dendritic Cells; Female; Forkhead Transcription Factors; Humans; Immunohistochemistry; Lymphocytes, Tumor-Infiltrating; Lymphoma; Male; Middle Aged; Stomach Neoplasms; Stromal Cells; T-Lymphocytes, Regulatory; Transforming Growth Factor beta; Transforming Growth Factor beta1

Neoplastic processes, tumor growth, and tumor cell proliferation and survival are often due to the altered activation of different signaling pathways. The increased activity of PI3K/AKT/mTOR signaling has been shown to be an important regulator of tumor growth in several solid tumors and in mantle cell lymphomas. The active form of mTOR kinase (mammalian target of rapamycin) is a key signaling molecule, and it exists in two different complexes, mTORC1 and mTORC2. In the present work, mTOR activity was investigated in different lymphoma types, in parallel with clinical data. We also examined in Hodgkin lymphomas (HL) the role of mTOR activity in survival mechanisms such as antiapoptotic protein expression and alterations in the microenvironment. We determined which lymphoma types display characteristic high mTOR activity in our TMA (tissue microarray) study. We observed that mTOR activity is increased in mitotic lymphoid cells compared to interphasic cells. The number of diffuse large B cell lymphoma (DLBCL) and HL cases was extended in a further set of TMA. We observed significantly higher mTOR activity in the non-centrum germinativum derived subtype of DLBCL than in the centrum germinativum derived subtype, which was a prognostic marker; 63% of mTOR active cases showed Rictor overexpression, indicating mTORC2 activity. High mTOR activity was also established in 92% of HL cases, which was linked to mTORC1. This finding was not a prognostic marker, however, it can be useful in targeted therapy. We observed the overexpression of the antiapoptotic protein BCL-xL and NFκB-p50 in the majority of mTOR active HLs. HLs showed high numbers of regulatory T cells in the microenvironment and high expression of galectin-1 in tumor cells and in the extracellular matrix, when compared to reactive lymph nodes. We confirmed that mTOR inhibition had significant antiproliferative and antiapoptotic effects in lymphoma cell lines and in lymphoma xenografts (HL, DLBCL, Burkitt lymphoma). We also showed that rapamycin was able to augment the effect of chemotherapeutic agents and TGF-β. Taken together, mTOR activity may be a potential therapeutic target in different lymphoma types. However, patient and inhibitor selection criteria must be carefully considered. The combination of mTOR inhibitors with other agents will probably offer the highest efficiency for achieving the best clinical response, and may also allow dose reduction in order to decrease late treatment toxicity in th. A neopláziás folyamatok kialakulása, a daganat növekedése, a daganatsejtek proliferációja és túlélése hátterében gyakran különbözõ jelutak magváltozott aktivitása áll. A PI3K/AKT/mTOR jelút fokozott aktivitása szolid daganatokban és köpenysejtes lymphomákban a daganatkialakulás és -növekedés fontos szabályozója. Az aktív mTOR (mammalian target of rapamycin) kináz két komplex (mTORC1, mTORC2) meghatározó eleme. Az mTOR-aktivitás szerepét vizsgáltuk különbözõ humán lymphomákban, összefüggéseket keresve a betegek klinikai adataival. Hodgkin-lymphomákban (HL) tanulmányoztuk, hogy a magas mTOR-aktivitás milyen, a daganat túlélésében fontos folyamatokban vesz részt (antiapoptotikus mechanizmusok és mikrokörnyezeti változások). Meghatároztuk azokat a humán lymphomatípusokat, amelyekre magas mTOR-aktivitás jellemzõ. Kimutattuk, hogy a mitotikus lymphoid sejtek mTOR-aktivitása magasabb, mint a nem osztódó sejteké. Nagyobb esetszámot tartalmazó TMA-blokkokon (tissue microarray) tovább vizsgáltuk a diffúz nagy B-sejtes lymphoma (DLBCL) és a HL eseteket. Szignifikáns összefüggést mutattunk ki DLBCL-s betegek altípusmegoszlása (csíraközpont-eredetû és nem csíraközpont-eredetû DLBCL-ek) és az mTOR-aktivitás között. DLBCL-ban a fokozott mTOR-aktivitás negatív prognosztikus markernek bizonyult. A HL-ek 92%-a magas mTOR-aktivitást mutatott (mTORC1-hez köthetõ), ami prognosztikus faktorként nem, viszont terápiás célpontként felhasználható. A HL-ek mikrokörnyezetének vizsgálata szerint a regulátor T-sejtek mennyisége a mikrokörnyezetben, valamint a galektin-1-expresszió a tumorsejtekben és az extracelluláris mátrixban emelkedett. A magas mTOR-aktivitás és a galektin-1-expresszió között kapcsolatot találtunk in vitro kísérleteinkben, ahol az mTOR gátlása transzlációs szinten csökkentette a galektin-1-expressziót. Az mTOR-gátlás jelentõségét – proliferációgátló és apoptotikus hatását – humán lymphoma xenograftokban (HL, DLBCL, Burkitt-lymphoma) bizonyítottuk. In vitro kombinációs kezelésekben a rapamycin apoptotikus hatást fokozó szerepét igazoltuk. Munkánkban meghatároztuk azokat a lymphomatípusokat, amelyekben az mTOR-gátlás célzott terápiaként alkalmazható lehet. Eredményeink alapján annak meghatározása, hogy melyik komplexhez köthetõ az mTOR-aktivitás, nagyon fontos a megfelelõ mTOR-gátló (klasszikus vagy kettõs gátlók) kiválasztásában. A jövõben a magas mTOR-aktivitást mutató lymphomákban várhatóan kombinációs kezelésben az mTOR-gátlók használata hozzájárulhatna a jobb t

Topics: Animals; Antineoplastic Agents; Apoptosis; Apoptosis Regulatory Proteins; bcl-X Protein; Burkitt Lymphoma; Cell Line; Drug Synergism; Galectin 1; Gene Expression Regulation, Neoplastic; Hodgkin Disease; Humans; Immunosuppressive Agents; Interphase; Lymphoma; Lymphoma, Large B-Cell, Diffuse; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Mitosis; Multiprotein Complexes; NF-kappa B p50 Subunit; Signal Transduction; Sirolimus; T-Lymphocytes, Regulatory; Tissue Array Analysis; TOR Serine-Threonine Kinases; Transforming Growth Factor beta; Up-Regulation; Xenograft Model Antitumor Assays

c-Myc transformed human Burkitt's lymphoma (BL) cells are highly sensitive to TGF-β-induced apoptosis. Previously we demonstrated that TGF-β-mediated cell death in BL cells is regulated via the mitochondrial intrinsic apoptosis pathway, which is dependent on the activation of BAX and/or BAK. TGF-β directly induces transcription of the BH3-only protein BIK and represses expression of the pro-survival factor BCL-X(L) but has no effect on the direct BAX/BAK "activators" BIM or BID (tBID). Here we show that TGF-β induces the BH3-only activator PUMA to aid induction of the intrinsic cell death pathway. TGF-β also induced PUMA in normal germinal center CD77-positive centroblasts isolated from human tonsil tissue. PUMA was a direct TGF-β target gene in B-cells, and we identify a putative Smad-binding region within the human PUMA promoter that recruits Smad3 and Smad4 in cells in response to TGF-β signaling. Constitutive activity of the isolated Smad-binding region in luciferase reporter assays was dependent on Smad consensus sequences and was partially dependent on endogenous TGF-β signaling and Smad4. Knockdown of PUMA in BL cells using lentiviral shRNA resulted in slower kinetics of the TGF-β-mediated apoptotic response. Analysis of Eμ-Myc cell lines demonstrated that c-myc-driven murine lymphomas are also sensitive to TGF-β-mediated apoptosis. Moreover, Puma(-/-) Eμ-Myc lines demonstrated significantly delayed kinetics of the apoptotic response when compared with wild type lymphomas. TGF-β therefore induces a polygenic response in Myc-driven lymphomas involving transcription of PUMA, which is necessary for the rapid induction of cell death.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Cell Line; Cell Survival; Gene Expression Regulation, Neoplastic; HEK293 Cells; Humans; Kinetics; Lymphoma; Lymphoma, B-Cell; Mice; Promoter Regions, Genetic; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-myc; Signal Transduction; Transcription, Genetic; Transforming Growth Factor beta; Tumor Suppressor Protein p53

By breeding TRAMP mice with S100A9 knock-out (S100A9(-/-)) animals and scoring the appearance of palpable tumors we observed a delayed tumor growth in animals devoid of S100A9 expression. CD11b(+) S100A9 expressing cells were not observed in normal prostate tissue from control C57BL/6 mice but were readily detected in TRAMP prostate tumors. Also, S100A9 expression was observed in association with CD68(+) macrophages in biopsies from human prostate tumors. Delayed growth of TRAMP tumors was also observed in mice lacking the S100A9 ligand TLR4. In the EL-4 lymphoma model tumor growth inhibition was observed in S100A9(-/-) and TLR4(-/-), but not in RAGE(-/-) animals lacking an alternative S100A9 receptor. When expression of immune-regulating genes was analyzed using RT-PCR the only common change observed in mice lacking S100A9 and TLR4 was a down-regulation of TGFβ expression in splenic CD11b(+) cells. Lastly, treatment of mice with a small molecule (ABR-215050) that inhibits S100A9 binding to TLR4 inhibited EL4 tumor growth. Thus, S100A9 and TLR4 appear to be involved in promoting tumor growth in two different tumor models and pharmacological inhibition of S100A9-TLR4 interactions is a novel and promising target for anti-tumor therapies.

Topics: Angiogenesis Inhibitors; Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Calgranulin B; CD11b Antigen; Cell Proliferation; Down-Regulation; Humans; Lymphoma; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogen-Activated Protein Kinases; Prostatic Neoplasms; Protein Binding; Quinolines; Quinolones; Spleen; Toll-Like Receptor 4; Transforming Growth Factor beta

Dysregulation of certain microRNAs (miRNAs) in cancer can promote tumorigenesis, metastasis and invasion. However, the functions and targets of only a few mammalian miRNAs are known. In particular, the miRNAs that participates in radiation induced carcinogenesis and the miRNAs that target the tumor suppressor gene Big-h3 remain undefined. Here in this study, using a radiation induced thymic lymphoma model in BALB/c mice, we found that the tumor suppressor gene Big-h3 is down-regulated and miR-21 is up-regulated in radiation induced thymic lymphoma tissue samples. We also found inverse correlations between Big-h3 protein and miR-21 expression level among different tissue samples. Furthermore, our data indicated that miR-21 could directly target Big-h3 in a 3'UTR dependent manner. Finally, we found that miR-21 could be induced by TGFβ, and miR-21 has both positive and negative effects in regulating TGFβ signaling. We conclude that miR-21 participates in radiation induced carcinogenesis and it regulates TGFβ signaling.

Topics: Animals; Apoptosis; Cell Proliferation; Extracellular Matrix Proteins; Gene Expression Regulation, Neoplastic; Lymphoma; Male; Mice; Mice, Inbred BALB C; MicroRNAs; Neoplasms, Radiation-Induced; Thymus Neoplasms; Transforming Growth Factor beta

Zinc-finger (ZF) transcriptional repressor growth factor independence 1 (Gfi-1) has an important role in hematopoiesis and inner ear development, and also functions as an oncoprotein that cooperates with c-Myc in lymphomagenesis. Gfi-1 represses transcription by directly binding to conserved sequences in the promoters of its target genes. CDKN1A encoding p21(Cip1) has been identified as a Gfi-1 target gene and has been shown to contain Gfi-1 binding sites in the upstream promoter region. We show here that Gfi-1 represses CDKN1A in a manner that is independent of its DNA binding activity. Gfi-1 interacts with POZ-ZF transcription factor Miz-1, originally shown to be a c-Myc-interacting partner, and through Miz-1 binds to the CDKN1A core promoter. Interestingly, Gfi-1 and c-Myc, through Miz-1, form a ternary complex on the CDKN1A promoter, and function in collaboration to repress CDKN1A. Gfi-1 knockdown results in enhanced levels of p21(Cip1) and attenuated cell proliferation. Notably, similar to c-Myc, the expression of Gfi-1 is downregulated by transforming growth factor-beta (TGFbeta) and the level of Gfi-1 influences the response of cells to the cytostatic effect of TGFbeta. Our data reveal an important mechanism by which Gfi-1 regulates cell proliferation and may also have implications for understanding the role of Gfi-1 in lymphomagenesis.

Topics: Animals; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p21; Cytostatic Agents; DNA; DNA-Binding Proteins; Down-Regulation; Hematopoiesis; Humans; Kruppel-Like Transcription Factors; Lymphoma; Mice; Promoter Regions, Genetic; Proto-Oncogene Proteins c-myc; Rats; Transcription Factors; Transcription, Genetic; Transforming Growth Factor beta; Zinc Fingers

Activated RAS/BRAF oncogenes induce cellular senescence as a tumor-suppressive barrier in early cancer development, at least in part, via an oncogene-evoked DNA damage response (DDR). In contrast, Myc activation-although producing a DDR as well-is known to primarily elicit an apoptotic countermeasure. Using the Emu-myc transgenic mouse lymphoma model, we show here in vivo that apoptotic lymphoma cells activate macrophages to secrete transforming growth factor beta (TGF-beta) as a critical non-cell-autonomous inducer of cellular senescence. Accordingly, neutralization of TGF-beta action, like genetic inactivation of the senescence-related histone methyltransferase Suv39h1, significantly accelerates Myc-driven tumor development via cancellation of cellular senescence. These findings, recapitulated in human aggressive B cell lymphomas, demonstrate that tumor-prompted stroma-derived signals may limit tumorigenesis by feedback senescence induction.

Topics: Animals; Apoptosis; Cellular Senescence; Lymphoma; Macrophage Activation; Macrophages; Methyltransferases; Mice; Mice, Transgenic; Proto-Oncogene Proteins c-myc; Repressor Proteins; Transforming Growth Factor beta; Tumor Suppressor Protein p53

Deregulated expression of Myc under the control of an immunoglobulin enhancer induces lymphoma formation in mice. The development of lymphomas is limited by TGFβ-dependent senescence and high levels of Myc expression are continuously required to antagonize senescence. The biological processes underlying senescence are not fully resolved. We report here a comprehensive analysis of TGFβ-dependent alterations in gene expression when the Myc transgene is switched off. Our data show that Myc-induced target genes are downregulated in a TGFβ-independent manner. In contrast, TGFβ is required to upregulate a broad spectrum of genes that are characteristic of different T-cell lineages when Myc is turned off. The analysis reveals a significant overlap between these Myc-repressed genes with genes that are targets of polycomb repressive complexes in embryonic stem cells. Therefore, TGFβ-dependent senescence is associated with gene expression patterns indicative of abortive cellular differentiation along several lineages.

Topics: Animals; Cell Differentiation; Cell Lineage; Cellular Senescence; Down-Regulation; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Lymphoma; Mice; Polycomb-Group Proteins; Proto-Oncogene Proteins c-myc; Repressor Proteins; T-Lymphocytes; Transforming Growth Factor beta; Up-Regulation

Established tumors suppress antitumor immune responses and induce tolerance by incompletely characterized mechanisms, and this phenomenon is an important barrier to tumor immunotherapy. Single vaccination with tumor cells expressing gp96-Ig stimulates robust expansion of tumor-specific CTLs in tumor-naïve mice and this expansion is inhibited by established tumors. Interestingly, frequent vaccinations restore antitumor immune responses in the presence of established tumors. Syngeneic EG7 tumor-bearing mice have heterogeneous responses to frequent vaccination with EG7-gp96-Ig, with 32% complete responders and 68% partial responders. Comparison of responders to nonresponders revealed an inverse correlation between tumor-specific CTL expansion in the peripheral blood and tumor size. To identify immune cells and molecules associated with effective antitumor immune responses, reverse transcription-PCR arrays were performed using cells isolated from the vaccination site. ELISAs, cellular phenotyping, and tumor immunohistochemistry were also performed comparing vaccine responders to nonresponders. These data show that up-regulation of T-bet, RORgammat, IFNgamma, CCL8, CXCL9, and CXCL10 at the vaccination site are associated with vaccine-induced antitumor immunity. These data correlate with increased CTL expansion in the peripheral blood of responders, increased infiltration of responder tumors by CD8+ cells and interleukin-17+ cells, and decreased infiltration of responder tumors by CD11b+Gr-1+ cells and FoxP3+ cells. Furthermore, serum ELISAs revealed a significant elevation of transforming growth factor-beta in nonresponders as compared with responders. Interestingly, CD8+ T cells isolated from responders and nonresponders have equivalent cytotoxic activity in vitro. Taken together, our data suggest that established tumors may escape immunosurveillance by preventing clonal expansion of tumor-specific CTL without inducing anergy.

Topics: Animals; Cancer Vaccines; CD11b Antigen; Cell Line, Tumor; Chemokine CXCL10; Cytotoxicity, Immunologic; Forkhead Transcription Factors; Interleukin-17; Lymphoma; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Recombinant Fusion Proteins; T-Lymphocytes, Cytotoxic; Th1 Cells; Transforming Growth Factor beta; Vaccination

Tranilast (N-[3,4-dimethoxycinnamonyl]-anthranilic acid) is a drug of low toxicity that is orally administered, and has been used clinically in Japan as an antiallergic and antifibrotic agent. Its antifibrotic effect is thought to depend on the inhibition of transforming growth factor-beta (TGF-beta). It has also been shown to exert antitumor effects, but its mode of action is unclear. Here, we explored the antitumor effects of tranilast in vitro and in vivo. Tranilast inhibited the proliferation of several tumor cell lines including mouse mammary carcinoma (4T1), rat mammary carcinoma stem cell (LA7), and human breast carcinoma (MDA-MB-231 and MCF-7). Tranilast blocked cell-cycle progression in vitro. In the highly metastatic 4T1 cell line, tranilast inhibited phospho-Smad2 generation, consistent with a blockade of TGF-beta signaling. It also inhibited the activation of MAP kinases (extracellularly regulated kinase 1 and 2 and JNK), which have been linked to TGF-beta-dependent epithelial-to-mesenchymal transition and, indeed, it blocked epithelial-to-mesenchymal transition. Although tranilast only partially inhibited TGF-beta production by 4T1 tumor cells, it potently inhibited the production of TGF-beta, interferon-gamma, IL-6, IL-10, and IL-17 by lymphoid cells, suggesting a general anti-inflammatory activity. In vivo, female BALB/c mice were inoculated with syngeneic 4T1 cells in mammary fat pads and treated with tranilast by gavage. Tranilast reduced (>50%) the growth of the primary tumor. However, its effects on metastasis were more striking, with more than 90% reduction of metastases in the lungs and no metastasis in the liver. Thus, tranilast has potential activity as an antimetastatic agent in breast cancer.

Topics: Animals; Antineoplastic Agents; Carcinoma; Cell Line, Tumor; Cell Transdifferentiation; Drug Screening Assays, Antitumor; Enzyme Activation; Female; Humans; Liver Neoplasms; Lung Neoplasms; Lymphoma; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mitogen-Activated Protein Kinases; Neoplasm Proteins; Organ Specificity; ortho-Aminobenzoates; Rats; Rats, Sprague-Dawley; Smad2 Protein; Species Specificity; Thymoma; Thymus Neoplasms; Transforming Growth Factor beta

CD4+CD25+ regulatory T cells (Treg) that suppress T cell-mediated immune responses may also regulate other arms of an effective immune response. In particular, in this study we show that Treg directly inhibit NKG2D-mediated NK cell cytotoxicity in vitro and in vivo, effectively suppressing NK cell-mediated tumor rejection. In vitro, Treg were shown to inhibit NKG2D-mediated cytolysis largely by a TGF-beta-dependent mechanism and independently of IL-10. Adoptively transferred Treg suppressed NK cell antimetastatic function in RAG-1-deficient mice. Depletion of Treg before NK cell activation via NKG2D and the activating IL-12 cytokine, dramatically enhanced NK cell-mediated suppression of tumor growth and metastases. Our data illustrate at least one mechanism by which Treg can suppress NK cell antitumor activity and highlight the effectiveness of combining Treg inhibition with subsequent NK cell activation to promote strong innate antitumor immunity.

Topics: Animals; Carcinoma, Lewis Lung; Cell Communication; Cell Line, Tumor; Immunotherapy, Adoptive; Interleukin-12; Killer Cells, Natural; Ligands; Lung Neoplasms; Lymphoma; Melanoma, Experimental; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Neoplasm Transplantation; Neoplasms, Experimental; NK Cell Lectin-Like Receptor Subfamily K; Receptors, Immunologic; Receptors, Natural Killer Cell; Spleen; T-Lymphocytes, Regulatory; Transforming Growth Factor beta

Mlh1-knockout mice have been developed as a useful model of hereditary non-polyposis colorectal cancer (HNPCC). In this study, we analyzed the pathology of gastrointestinal tumours (GIT) in these mice in detail and examined the possible effects of ionizing radiation on the induction of intestinal tumours to evaluate the late response to radiotherapy in HNPCC. Mlh1-/- mice spontaneously developed GIT and thymic lymphomas by 48 weeks. GIT included not only well differentiated adenocarcinomas but also poorly differentiated and mucinous adenocarcinomas, suggesting that this mouse is a good model for HNPCC. In contrast to colon cancers from HNPCC patients, however, carcinomas of Mlh1-/- mice expressed p53 and showed a lack of transforming growth factor (TGF)-betaRII mutation, which resulted in the expression of TGF-betaRII protein. Irradiation of 10-week-old Mlh1-/- mice accelerated GIT development but had little effect at 2 weeks. Mlh1+/- and Mlh1+/+ mice were not susceptible to spontaneous or radiation-induced thymic lymphomas and GIT until 72 weeks after birth. The development and pathology of GIT in Mlh1-/- mice suggest that this mouse is a good model for HNPCC, although tumour-related responsible genes might be different from HNPCC. As X-ray exposure promoted carcinogenesis of GIT in adult Mlh1-/- mice, an increased risk of secondary cancers after radiotherapy for HNPCC patients should be taken into consideration.

Topics: Adaptor Proteins, Signal Transducing; Adenocarcinoma; Animals; Base Pair Mismatch; beta Catenin; Carrier Proteins; Colorectal Neoplasms, Hereditary Nonpolyposis; Disease Models, Animal; Disease Progression; Gastrointestinal Neoplasms; Genes, Neoplasm; Immunohistochemistry; Lymphoma; Mice; Mice, Knockout; Mutation; MutL Protein Homolog 1; Neoplasm Proteins; Nuclear Proteins; Radiotherapy; Receptors, Transforming Growth Factor beta; Thymus Neoplasms; Transforming Growth Factor beta; Transforming Growth Factor beta2; Tumor Suppressor Protein p53

Our previous studies show that growth hormone overexpression (GHo) upregulates the expression of the IGF-1R and IGF-2R resulting in the protection of the EL4 lymphoma cell line from apoptosis. In this study, we report that GHo also increases TGF-beta1 protein expression measured by luciferase promoter assay, Western analysis, and ELISA. Further, the data show that antibody to TGF-betaR2 decreases TGF-beta1 promoter activity to the level of vector alone control cells. GHo cells treated with (125)I-rh-latent TGF-beta1 showed increased activation of latent TGF-beta1 as measured by an increase in the active 24kDa, TGF-beta1 compared to vector alone control cells. The ability of endogenous GH to increase TGF-beta1 expression is blocked in EL4 cells by antisense but not sense oligodeoxynucleotides or in cells cultured with antibody to growth hormone (GH). The data suggest that endogenous GH may protect from apoptosis through the IGF-1R receptor while limiting cellular growth through increased expression and activation of TGF-beta1.

Topics: Animals; Antibodies; Gene Expression; Gene Expression Regulation, Neoplastic; Genetic Vectors; Growth Hormone; Iodine Radioisotopes; Lymphoma; Mice; Promoter Regions, Genetic; RNA, Messenger; Smad2 Protein; Smad3 Protein; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Cells, Cultured

Transforming growth factor beta1 (TGF beta1) has antiproliferative and/or apoptotic effect on lymphoid cells. In certain lymphomas exogenous TGF beta1 is able to induce apoptosis, however many lymphoid malignancies are resistant to the endogenous TGF beta1 production. We studied the expression and the activity of TGF beta1 signalling components in B cell lymphoma cell lines (e.g. HT 58 cells) and in isolated human peripheral mononuclear cells (PBMCs) from healthy individual's and B-CLL patient's blood. We found that all signal transducer Smads (Smad2,-3; Smad4) and at least one of the inhibitory Smads (Smad6,-7) were expressed in non-treated lymphoma cells, but the inhibitory Smads did not in normal/control PBMCs. However, after TGF beta1 treatment Smad6 disappeared, while the expression of Smad7 increased in HT 58 cells. The activity of Smad signals was proved by phosphorylation of Smad2, nuclear translocation of Smad2/3, and the increased expression of Smad-dependent gene, TIEG in TGF beta1 treated lymphoma cells. These results showed that Smad signaling is available in certain different human lymphoma cells, however ISmads expression could inhibit the signal transmission. This findings indicates that the lost sensitivity of lymphoma cells toward a physiological regulatory factor could be reversed.

Topics: Apoptosis; Cell Line, Tumor; DNA-Binding Proteins; Humans; Lymphoma; RNA, Messenger; Signal Transduction; Smad2 Protein; Smad3 Protein; Smad4 Protein; Smad6 Protein; Smad7 Protein; Trans-Activators; Transforming Growth Factor beta; Transforming Growth Factor beta1

Transforming growth factor-beta1 (TGF-beta1) is a pleiotrophic cytokine that mediates differentiation, growth, and apoptosis. As a potent immunosuppressive agent, TGF-beta1 induces apoptosis in primary lymphocytes. However, it has been recognized that TGF-beta1 plays certain roles in development or progression of hematopoietic tumours via inhibition of Fas-mediated apoptotic cell death. Several studies have highlighted the mechanisms of TGF-beta1-induced Fas resistance and its contribution to aggressive tumour behavior. In this study, we have focused on the mechanisms by which TGF-beta1 protected leukaemia/lymphoma cells from Fas-mediated apoptosis. The presented study provides that TGF-beta1 inhibited Fas-mediated apoptosis of leukaemia/lymphoma cells in two distinct pathways. First, TGF-beta1 reduced expression of surface Fas receptors by blockade of trafficking cytoplasmic Fas to the surface, which allowed the leukaemia cells to resist Fas-mediated cell death. However, total Fas levels including both surface and cytoplasmic Fas were not altered, indicating that forced degradation of Fas or transcriptional regulation was not involved. Second, TGF-beta1 up-regulated Fas signaling pathway inhibitor cFLIPL to block the pro-caspase-8 cleavage and thus promoted survival of leukaemia/lymphoma cells. Our findings may partly explain why higher concentration of serum TGF-beta1 in cancer patient was related with poor prognosis.

Topics: Apoptosis; Carrier Proteins; CASP8 and FADD-Like Apoptosis Regulating Protein; fas Receptor; Humans; Intracellular Signaling Peptides and Proteins; Leukemia; Lymphoma; Transforming Growth Factor beta; Transforming Growth Factor beta1

The use of ELISA techniques to measure cytokine levels in clinical samples has chiefly replaced more labour intensive bioassays. ELISA measurements, however, do not reflect the functional activity of a cytokine within a sample; interleukin-1 (IL-1), for example, has two agonist isoforms (IL-1 alpha and IL-1 beta) and a competitive receptor antagonist (IL-1ra), and can be regulated by transforming growth factor beta1 (TGF-beta 1). The net effect of these cytokines, rather than IL-1 levels, are frequently suggested to regulate tissue inflammation, but confirming this has been difficult.. We used the ELA4.NOB-1/CTLL co-culture IL-1 bioassay to investigate whether IL-1 activity was inhibited by IL-1ra and TGF-beta 1 in a predictable manner.. Thymidine incorporation into CTLL cells, induced by IL-1, was reduced dose dependently by IL-1ra and TGF-beta 1. With optimal levels of IL-1 CTLL responsiveness was reduced by 90% by 1 ng/ml TGF-beta 1 and completely abolished by 100 ng/ml IL-1ra. As expected, TGF-beta 1 and IL-1ra had independent mechanisms of action on the bioassay cell lines, and, in combination, they caused an additive, but not synergistic, effect. Importantly, the effect of these cytokines could be completely abolished in the presence of neutralising antibodies.. Bioassay should provide specific functional information on the net IL-1 activity of clinical samples, while the use of specific antibodies could ascertain the contribution of individual cytokines within such samples.

Topics: Animals; Binding, Competitive; Biological Assay; Cell Division; Coculture Techniques; Dose-Response Relationship, Drug; Drug Interactions; Enzyme-Linked Immunosorbent Assay; Humans; Interleukin 1 Receptor Antagonist Protein; Interleukin-1; Lymphoma; Mice; Recombinant Proteins; Sialoglycoproteins; T-Lymphocytes, Cytotoxic; Thymidine; Transforming Growth Factor beta; Transforming Growth Factor beta1; Tumor Cells, Cultured

The early B-cell factor (EBF)-associated zinc-finger protein (EBFAZ) binds to and negatively regulates EBF, a basic helix-loop-helix transcription factor required for B-cell lineage commitment and development of the olfactory epithelium. It also binds to SMA- and MAD-related protein 1 (SMAD1) and SMAD4 in response to bone morphogenic protein 2 (BMP2) signaling. It is highly related to ecotropic viral integration site 3 (EVI3), a protein that, like EBFAZ, contains 30 Krüppel-like zinc-finger repeats. In previous studies, we showed that Evi3 is a frequent target of retroviral integration in AKXD27 B-cell lymphomas. Here, we show that EBFAZ is also a frequent target. Integrations at Ebfaz and Evi3 are mutually exclusive, suggesting that they function in the same tumor pathway. Lymphomas with integrations at Ebfaz or Evi3 express the pre-B-cell-specific marker immunoglobulin lambda chain 5, and contain immunoglobulin heavy-chain rearrangements, suggesting that they are blocked at an early B-cell stage. Unlike Evi3, which is expressed at low levels in normal B cells, or Ebfaz, which is not expressed in B cells, both genes are highly expressed following viral integration. Collectively, our results suggest that ectopic expression of Ebfaz can substitute for the upregulated expression of Evi3 in B-cell disease and highlight the importance of this gene family in hematopoietic cancer.

Topics: Amino Acid Sequence; Animals; Base Sequence; Blotting, Southern; Bone Morphogenetic Protein 2; Bone Morphogenetic Proteins; DNA-Binding Proteins; DNA, Complementary; Exons; Immunoglobulin Heavy Chains; Lymphoma; Lymphoma, B-Cell; Mice; Models, Genetic; Molecular Sequence Data; Protein Binding; Retroviridae; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Smad Proteins; Smad1 Protein; Smad4 Protein; Tissue Distribution; Trans-Activators; Transcription Factors; Transforming Growth Factor beta; Up-Regulation; Virus Integration

We report here on a patient with splenic marginal zone lymphoma presenting diffuse fibrosis of bone marrow and spleen. After splenectomy and chemotherapy, bone marrow biopsy demonstrated an improvement of fibrosis. Plasma concentration of transforming growth factor (TGF)-beta was much higher in this patient than in those of age-matched non-Hodgkin's lymphoma patients ( n=5) at diagnosis, decreasing after resolution of myelofibrosis. Immunostaining with the TGF-beta antibody revealed that the lymphoma cells in bone marrow and spleen were positive for TGF-beta. TGF-beta secreted by tumor cells was thought to stimulate the growth of fibroblasts and synthesize collagen in bone marrow and splenic fibroblasts, and play an important role in the development of marrow and splenic fibrosis in this patient. This is the first report of a patient with splenic marginal zone lymphoma presenting as myelofibrosis associated with bone marrow involvement of lymphoma cells which secrete a large amount of TGF-beta.

Topics: Aged; Bone Marrow Cells; Female; Fibrosis; Humans; Immunohistochemistry; Lymphoma; Primary Myelofibrosis; Spleen; Splenic Neoplasms; Transforming Growth Factor beta

We assessed mRNA for chosen pro- and anti-inflammatory cytokines in T-lymphocytes of peripheral blood in paediatric patients with leukemias and lymphomas. Levels of four different cytokine mRNAs (IFN-gamma, IL-10, IL-4, TGF-beta) were determined by the real-time PCR technique. In the whole examined group, at the time of diagnosis, we noted lower amounts of mRNA for TGF-beta1, comparing to respective values in the control patients. In the ALL group, we observed the following: 1) at the time of diagnosis: lower amounts of mRNA for IL-4 and for TGF-beta1, comparing to respective values in the control group; 2) lower amounts of mRNA for IL-10 after remission induction, comparing to the time of diagnosis. In our opinion, "immunedysregulation" in lymphoproliferative diseases in children is not caused by IFN-gamma deficiency. The deficit of anti-inflammatory cytokines, i.e., IL-4, TGF-beta, with higher amounts of IL-10, suggests their role in cancer development.

Topics: CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cytokines; Hodgkin Disease; Humans; Interleukin-10; Lymphoma; Lymphoma, Non-Hodgkin; Polymerase Chain Reaction; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Remission Induction; RNA, Messenger; T-Lymphocytes; Transforming Growth Factor beta

The Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP-1) is absolutely required for EBV transformation of B cells. LMP-1 mimics a constitutively activated receptor of the tumor necrosis factor receptor family, mediating diverse oncogenic functions that influence growth, differentiation and susceptibility to apoptosis. Given the critical functions of LMP-1 in EBV-associated transformation, it represents a rational therapeutic target for modulation. We used antisense oligodeoxynucleotides targeted to LMP-1 as a strategy to suppress LMP-1 expression and thereby inhibit its functions. In previous studies, we have shown that short-term treatment of EBV-positive lymphoblastoid cell lines (LCLs) with LMP-1 antisense oligodeoxynucleotides can dramatically reduce levels of LMP-1 protein in association with inhibition of proliferation, stimulation of apoptosis, down-regulation of Bcl-2 and Mcl-1 and enhanced sensitivity to the chemotherapeutic agent, etoposide. Here, we provide further evidence of the profound effects of reducing LMP-1 levels using antisense oligodeoxynucleotides in EBV-transformed B cells. We have shown that LMP-1 antisense treatment of LCLs partially restores sensitivity to the anti-proliferative and apoptotic effects of transforming growth factor-beta, a potent negative regulator of normal human B-cell growth, in association with a reduction in cyclin D2 levels. In addition, LMP-1 antisense sensitizes LCLs to chemotherapeutic drugs from diverse classes, including etoposide, vincristine and dexamethasone, by enhancing apoptotic cell death. Finally, the anti-proliferative and apoptotic effects of LMP-1 antisense treatment were observed not only in laboratory-derived LCLs, but also in an EBV-positive cell line derived from an AIDS-related lymphoma. These studies demonstrate that antisense targeting of LMP-1 represents a rational therapeutic strategy for EBV-positive lymphoproliferative disorders.

Topics: Antineoplastic Agents, Hormonal; Antineoplastic Agents, Phytogenic; Apoptosis; B-Lymphocytes; Cell Division; Cell Line, Transformed; Cell Separation; Cyclin D2; Cyclins; Dexamethasone; DNA, Antisense; Down-Regulation; Etoposide; Flow Cytometry; Humans; Immunoblotting; Lymphoma; Myeloid Cell Leukemia Sequence 1 Protein; Neoplasm Proteins; Proto-Oncogene Proteins c-bcl-2; Transforming Growth Factor beta; Tumor Cells, Cultured; Vincristine; Viral Matrix Proteins

Helix-loop-helix (HLH) proteins are essential factors for lymphocyte development and function. One class of HLH proteins, the E-proteins, regulate many aspects of lymphocyte maturation, survival, proliferation, and differentiation. E-proteins are negatively regulated by another class of HLH proteins known as the Id proteins. The Id proteins function as dominant negative inhibitors of E-proteins by inhibiting their ability to bind DNA. Here we discuss the function and regulation of the Id proteins in lymphocyte development.

Topics: Animals; Cell Differentiation; Cell Division; Cell Lineage; Cell Transformation, Neoplastic; Clonal Deletion; DNA; DNA-Binding Proteins; Female; Gene Expression Regulation, Developmental; H-Y Antigen; Helix-Loop-Helix Motifs; Hematopoiesis; Humans; Inhibitor of Differentiation Protein 1; Inhibitor of Differentiation Protein 2; Inhibitor of Differentiation Proteins; Lymphocyte Activation; Lymphocyte Subsets; Lymphoma; Male; MAP Kinase Signaling System; Mice; Mice, Knockout; Mice, Transgenic; Models, Biological; Multigene Family; Neoplasm Proteins; Protein Kinases; Repressor Proteins; TCF Transcription Factors; Transcription Factor 7-Like 1 Protein; Transcription Factors; Transcription, Genetic; Transforming Growth Factor beta

Topics: Gene Expression Regulation, Enzymologic; Humans; Interleukin-1; Interleukin-6; Lipopolysaccharides; Lymphoma; Transforming Growth Factor beta; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha; Urokinase-Type Plasminogen Activator

Transforming growth factor beta 1 (TGF beta 1) has been shown to inhibit growth stimulation in normal human B cells as well as in Epstein Barr virus (EBV)-negative Burkitt's lymphoma (BL) cell lines. The mechanisms for this potent growth inhibition are not completely defined. Here we show that a number of EBV-negative lymphoma B cell lines (BL-41, Ramos and CAPA-2), when exposed in vitro to TGF beta 1, undergo apoptosis. Maximum apoptosis was observed at 48 h following TGF beta 1 treatment, with no apparent effect on the expression of c-myc and bcl-2 proteins. Similar induction of apoptosis was observed when these lymphoma cell lines were treated with aphidicolin, a DNA synthesis inhibitor. In contrast, various preparations (14 out of 17) of normal human tonsilar B cells showed no significant apoptosis, although both TGF beta 1 and aphidicolin inhibited anti-mu/IL-4 induced DNA synthesis in all preparations. Furthermore, another TGF beta 1 sensitive EBV-negative BL cell line, CA46, exhibited no apoptosis in response to TGF beta 1 and aphidicolin, corroborating the findings in normal human B cells. Taken together, these data support the hypothesis that exposure to TGF beta 1, which results in cell cycle arrest and DNA synthesis inhibition, may not be obligatory or sufficient for the induction of apoptosis. Rather, induction of apoptosis or lack of it may be intrinsically determined by an interplay between extracellular and intracellular regulators of cellular growth.

Topics: Aphidicolin; Apoptosis; B-Lymphocytes; Cell Cycle; Cell Division; Chromatin; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Genes, myc; Growth Inhibitors; Humans; Lymphoma; Nucleic Acid Synthesis Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Proto-Oncogene Proteins c-myc; RNA, Messenger; Transforming Growth Factor beta; Tumor Cells, Cultured

Topics: Bone Marrow Transplantation; Combined Modality Therapy; Female; Hepatic Veno-Occlusive Disease; Humans; Leukemia; Lymphoma; Prospective Studies; Transforming Growth Factor beta

Activins, members of a family of the transforming growth factor beta (TGF beta), are involved in the regulation of multiple biological events. We found a novel effect of activin A on hybridoma and myeloma cell lines. Activin A exhibited a cytotoxic effect on interleukin-6 (IL-6)-dependent B9 cells and induced a significant increase in the proportion of fragmented DNA. B9 cells exposed to activin A released high amounts of lactate dehydrogenase (LDH) and exhibited the typical ladder pattern of DNA fragmentation of apoptotic cells. IL-6 did not prevent apoptosis of B9 cells induced by activin A. The cytotoxicity of activin A to B9 cells was suppressed by follistatin. On the other hand, TGF beta showed no cytotoxic effect on B9 cells. These findings indicate that apoptosis induced by activin A could be one of the mechanisms to prevent uncontrolled cell growth.

Topics: Activins; Animals; Apoptosis; Cell Line; Cell Survival; DNA Damage; Dose-Response Relationship, Drug; Follistatin; Glycoproteins; Growth Substances; Humans; Hybridomas; Inhibins; Interleukin-6; Kinetics; Lymphoma; Mice; Multiple Myeloma; Transforming Growth Factor beta; Tumor Cells, Cultured

Activated lymphocytes and malignant lymphoma cells derived from them (Ki-1 positive lymphoma cells) share similar mechanisms of proliferation. To further examine the inhibitory role of endogenous transforming growth factor beta (TGF beta) in Ki-1 positive lymphoma cells, the authors studied anti-TGF beta antibodies and measured their effect on proliferation. A monoclonal antibody (T1A5) prepared against a unique antigenic epitope of high molecular weight Hodgkin's TGF beta and a polyclonal rabbit antibody prepared against highly purified 25,000 D porcine platelet TGF beta 1 were used. Both antibodies are shown here to inhibit the biological activity of Hodgkin's TGF beta and to crossreact with their respective antigens in immunoblotting. DNA synthesis by Ki-1 lymphoma cells was increased 138-fold by anti-TGF beta 1 antibody and 262-fold by anti-Hodgkin's TGF beta. Exogenous TGF beta 1 suppression was completely reversed by anti-TGF beta 1 antibody and IL-2-induced proliferation was markedly potentiated (41 fold). L-428 Reed-Sternberg cells secrete physiologically active TGF beta but have fewer than 500 TGF beta receptor sites per cell; no significant proliferative response was measured for either anti-TGF beta 1 or anti-Hodgkin's TGF beta. These results show the suppressive effect of exogenous TGF beta 1 on indolent Ki-1 lymphoma cells and suggest that the endogenous secretion of high molecular weight physiologically active TGF beta is important in maintaining the indolent nature of this low-grade Ki-1 positive lymphoma.

Topics: Antibodies; Antigens, CD; Antigens, Neoplasm; Cell Division; Hodgkin Disease; Humans; Interleukin-2; Ki-1 Antigen; Lymphoma; Neutralization Tests; Transforming Growth Factor beta; Tumor Cells, Cultured

In this study we have investigated the ability of transforming growth factor-beta 3 (TGF-beta 3, 1000 pM) to protect hematopoietic bone marrow (BM) progenitor cells from the cytotoxic activity of 4-hydroperoxycyclophosphamide (4-HC, 100 microM) in vitro. Hematopoietic progenitors were purified by negative depletion of accessory and maturing cells or enriched by positive (CD 34+ cells) selection. For comparison the same treatment was tested on three different lymphoid cell lines CEM, SK-DHL-2, and LY-16. The experimental protocol was designed to mimic ex vivo purging conditions. Therefore, tumor cells and enriched hematopoietic precursors were mixed with irradiated BM cells. Our results demonstrated that preincubation of enriched progenitor cells with TGF-beta 3 for up to 72 h followed by 4-HC treatment resulted in an increased survival of colonies derived from granulocyte-macrophage (CFU-GM) and erythroid (BFU-E) colony-forming cells, whereas a substantially lower number of colonies was observed in the control group. Similar results were observed when BM cells were first treated with 4-HC followed by TGF-beta 3 incubation for 24 or 48 h. In contrast, TGF-beta 3 provided no protection to the 4-HC cytotoxicity toward the lymphoma and leukemia cell lines. Three to four log of tumor cell killing was induced by 4-HC in the presence or absence of preincubation with TGF-beta 3. These data suggest that TGF-beta 3 is able to protect normal BM progenitors from the cytotoxic activity of an alkylating agent (4-HC) in vitro, whereas it does not offer any protection to lymphoma cell lines. These findings will have important implications for developing better purging conditions for autologous GM transplantation.

Topics: Bone Marrow Cells; Bone Marrow Purging; Cell Survival; Cyclophosphamide; Erythroid Precursor Cells; Granulocytes; Hematopoietic Stem Cells; Humans; Leukemia; Lymphoma; Macrophages; Transforming Growth Factor beta; Tumor Cells, Cultured

Transforming growth factor-beta (TGF-beta) and a glucocorticosteroid, Dexamethasone (DXM), both cause transcriptional induction of Epstein-Barr virus (EBV) early antigens (EA) in Daudi lymphoma cells. The viral induction occurs through the viral promoter DR overlapping an origin of replication which is active during the lytic cycle. Each hormone requires specific regions on the DR promoter. Since these regions also mediate the action of two viral transcription factors, EB1 and R, it may be emphasized that EB1 and/or R are involved in the EA induction process by TGF-beta and by DXM.

Topics: Antigens, Viral; Dexamethasone; Gene Expression Regulation, Viral; Genes, Viral; Herpesvirus 4, Human; Lymphoma; Mifepristone; Promoter Regions, Genetic; Restriction Mapping; Transfection; Transforming Growth Factor beta; Tumor Cells, Cultured

The expression of cytokine genes for tumor necrosis factor alpha (TNF alpha), lymphotoxin and transforming growth factor beta (TGF beta), all of which are known to suppress normal hematopoiesis, was investigated in 32 patients with lymphoid malignancies using Northern blot analysis. Messenger RNA (mRNA) for TNF alpha, lymphotoxin and TGF beta was detected in 9 cases, 2 cases and 7 cases, respectively. When the relationship between cytokine gene expression and surface phenotype was analyzed, the expression of CD19 correlated significantly with expression of the TNF alpha gene (P less than 0.05). This suggests that B cell malignancies are likely to produce TNF alpha. When the hematological parameters of patients expressing and not expressing the gene were compared, the expression of TNF alpha mRNA was found to correlate with more profound anemia in acute lymphoblastic leukemia (P less than 0.05). Both granulocyte and platelet counts were lower in patients expressing TNF alpha mRNA; however, the decreases were not significant. Neither lymphotoxin nor TGF beta gene expression correlated significantly with any hematological parameter.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blotting, Northern; Cytokines; Female; Gene Expression; Hematopoietic Stem Cells; Humans; Leukemia; Lymphoma; Lymphotoxin-alpha; Male; Middle Aged; Multiple Myeloma; Phenotype; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Transforming growth factor-beta (TGF-beta) exerts profound inhibitory effects on a number of cell types, including normal B- and T-lymphocytes. In contrast, we have found a number of lymphoid tumor cell lines to be insensitive to the antiproliferative effects of TGF-beta 1 or TGF-beta 2. Binding and cross-linking with radioiodinated TGF-beta 1 demonstrated either low or absent expression of all three TGF-beta receptor species on three B-cell tumor lines, but T-cell and non-T, non-B tumors expressed large numbers of receptors. Treatment of the B-cell lines with phorbol 12-myristate 13-acetate (PMA) induced the expression of TGF-beta receptors and inhibited proliferation in all three lines in a dose- and time-dependent manner. The cell lines constitutively produced TGF-beta mRNA and released small amounts of latent TGF-beta; however, PMA induced the release of active TGF-beta. A neutralizing antibody to TGF-beta was able to reverse the PMA-induced growth inhibition of the malignant lymphoma cell line, RL, and addition of exogenous TGF-beta reversed the effect of the neutralizing antibody. Thus, TGF-beta can inhibit human lymphoma cell growth in vitro through an autocrine mechanism. Some lymphoma cells appear to have escaped from TGF-beta negative regulation by failing to express functional TGF-beta receptors and/or by failing to secrete active TGF-beta receptors and/or by failing to acts to inhibit lymphoma cell growth is by inducing the expression of TGF-beta receptors and the secretion of active TGF-beta, thereby reestablishing an autocrine growth-inhibitory loop.

Topics: B-Lymphocytes; Cell Division; Humans; Immunologic Techniques; Lymphocyte Activation; Lymphoma; Mitogens; Receptors, Cell Surface; Receptors, Transforming Growth Factor beta; Tetradecanoylphorbol Acetate; Transforming Growth Factor beta; Tumor Cells, Cultured