TGF-β Receptor I Kinase Inhibitor Downregulates Cytokine Secretion and Multiple Myeloma Cell Growth in the Bone Marrow Microenvironment.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2355-2355
Author(s):  
Toshiaki Hayashi ◽  
Teru Hideshima ◽  
Klaus Podar ◽  
Paul Richardson ◽  
Olivier Munoz ◽  
...  

Abstract Transforming growth factors (TGFs) have pleiotropic biologic effects on tumor cells and their environment. In multiple myeloma (MM), we have reported that bone marrow stromal cells (BMSCs) from MM patients produce more TGF-β1 than BMSCs from healthy donors, which in turn induces interleukin-6 (IL-6) secretion. In this study, we delineate the functional squelae of TGF-β1 in MM, and importantly, show that the TGF-β receptor I kinase inhibitor SD-208 significantly decreases secretion of both IL-6 and vascular endothelial growth factor (VEGF) from BMSCs, as well as tumor cell growth triggered by MM cell adhesion to BMSCs. Cytokine production and MM cell proliferation triggered by TGF-β1 or adhesion to BMSCs were examined in the presence or absence of SD-208 using ELISA and 3H thymidine incorporation assay, respectively. Effects of SD-208 on TGF-β1-induced signaling pathways triggering IL-6 and VEGF transcription in BMSCs were delineated using immunofluorescence staining, immunoblotting and DNA-binding assay. We here show that adhesion of MM cells to BMSCs triggers secretion of TGF-β1, which further upregulates IL-6 and VEGF secretion in BMSCs. These cytokines in turn mediate MM cell growth, survival, drug resistance, and migration. Importantly, SD-208 significantly inhibits not only transcription but also secretion of both IL-6 and VEGF from BMSCs triggered by either TGF-β1 or adhesion of MM cells to BMSCs. Moreover, SD-208 decreased tumor cell growth triggered by MM cell adhesion to BMSCs. SD-208 works, at least in part, by blocking TGF-β1-triggered nuclear accumulation of Smad2/3 and hypoxia-inducible factor 1α, as well as related production of IL-6 and VEGF, respectively. These studies indicate that SD-208 inhibits production of cytokines mediating MM cell growth, survival, drug resistance, and migration in the BM milieu, thereby providing the preclinical rationale for clinical evaluation of SD-208 to improve patient outcome in MM.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 791-791 ◽  
Author(s):  
Diana Cirstea ◽  
Teru Hideshima ◽  
Loredana Santo ◽  
Samantha Pozzi ◽  
Sonia Vallet ◽  
...  

Abstract Abstract 791 Targeting PI3K/Akt/mTOR signaling is among one of the promising therapeutic strategies in multiple myeloma (MM), since it facilitates MM cell survival and development of drug resistance in the context of the bone marrow microenvironment. Specifically, regulation of PI3K activity, which mediates MM cell growth and drug resistance, by mTOR complex 1 (mTORC1) provides the rationale for use of rapamycin analogs for MM treatment. However, rapamycin alone fails to overcome bone marrow-induced proliferation of MM cells, at least in part, because of the mTORC1-dependent feedback loops which activate PI3K/Akt. More recently, extensive studies of the mTOR network have identified mTORC2 as a “rapamycin-insensitive” complex. Sharing mTOR kinase as a common catalytic subunit, mTORC1 and mTORC2 mediate two distinct pathways: mTORC1 controls cell growth by phosphorylating key regulators of protein synthesis S6 kinase 1 (P70S6K) and the eIF-4E-binding protein 1 (4E-BP1); mTORC2 modulates cell survival and drug resistance by phosphorylating target proteins including Akt and serum/glucocorticoid regulated kinase 1(SGK1)/N-myc downstream regulated 1 (NDRG1). Moreover, studies have also revealed overexpression of a novel mTOR-interacting protein DEP domain containing 6 (DEPTOR), which can modulate mTOR activity and promote PI3K/mTORC2 signaling in primary MM tumor cells and in MM cell lines while mTORC1 remains silenced. We therefore hypothesized that targeting mTOR may disrupt DEPTOR/mTOR interaction and silence mTORC1/mTORC2 signaling, thereby overcoming mTOR resistance in MM cells. To confirm this idea, we used AZD8055, an orally bioavailable selective ATP-competitive mTOR kinase inhibitor, in our MM preclinical models. AZD8055- treatment of MM.1S inhibited phosphorylation of both mTORC1 and mTORC2 substrates: P70S6K; 4E-BP1 including the rapamycin-resistant T37/46 – downstream targets of mTORC1; as well as Akt and NDRG1 – effectors of mTORC2 refractory to rapamycin. Interestingly, AZD8055-mediated mTORC1/mTORC2 downregulation was associated with DEPTOR upregulation, which is consistent with the finding that DEPTOR expression is negatively regulated by mTORC1 and mTORC2. Moreover, inhibition of mTORC1 alone by rapamycin resulted in reduction of DEPTOR, associated with Akt activation. Furthermore, we observed that DEPTOR expression was decreased in MM.1S cells cultured with IL-6, IGF-1 or bone marrow stromal cells (BMSCs), which stimulate PI3K/Akt/mTOR signaling, evidenced by enhanced P70S6K and Akt phosphorylation. Unlike rapamycin, AZD8055 reversed those effects and inhibited MM.1S proliferation, even in the presence of these cytokines or BMSCs. AZD8055-induced growth inhibition was associated with apoptosis, evidenced by caspase-9, -3 and PARP cleavage in a time-dependent fashion (80% apoptotic cells at 72 hour culture as detected by Annexin V/PI staining). Moreover, AZD8055 induced cytotoxicity even in rapamycin resistant MM cell lines and primary patient MM cells. Finally, AZD8055 demonstrated significant anti-MM activity in an in vivo human MM cell xenograft SCID mouse model. Taken together, our data show that disruption of DEPTOR/mTORC1/mTORC2 cascade in MM cells results in significant anti-tumor effects, providing the framework for future clinical trials of AZD8055 to improve patient outcome in MM. Disclosures: Guichard: AstraZeneca: Employment, Shareholder AstraZeneca. Anderson:Millenium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy; Merck: Consultancy; BMS: Consultancy; Acetylon: Membership on an entity's Board of Directors or advisory committees, Ownership interest (inc stock options) in a Start up company. Raje:AstraZeneca: Research Funding; Acetylon: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees.


2011 ◽  
Vol 22 (9) ◽  
pp. 1463-1472 ◽  
Author(s):  
Kathleen E. Lambert ◽  
Huang Huang ◽  
Karthikeyan Mythreye ◽  
Gerard C. Blobe

Transforming growth factor-β (TGF-β) plays an important role in regulating hematopoiesis, inhibiting proliferation while stimulating differentiation when appropriate. We previously demonstrated that the type III TGF-β receptor (TβRIII, or betaglycan) serves as a novel suppressor of cancer progression in epithelial tumors; however, its role in hematologic malignancies is unknown. Here we demonstrate that TβRIII protein expression is decreased or lost in the majority of human multiple myeloma specimens. Functionally, restoring TβRIII expression in myeloma cells significantly inhibited cell growth, proliferation, and motility, largely independent of its ligand presentation role. In a reciprocal fashion, shRNA-mediated silencing of endogenous TβRIII expression enhanced cell growth, proliferation, and motility. Although apoptosis was not affected, TβRIII inhibited proliferation through induction of the cyclin-dependent kinase inhibitors p21 and p27. TβRIII further regulated myeloma cell adhesion, increasing homotypic myeloma cell adhesion while decreasing myeloma heterotropic adhesion to bone marrow stromal cells. Mechanistically, live cell imaging of myeloma and stroma cell cocultures revealed that TβRIII-mediated inhibition of heterotropic adhesion was associated with decreased duration of myeloma/bone marrow stromal cell interaction. These results suggest that loss of TβRIII expression during multiple myeloma progression contributes to disease progression through its functional effects on increased cell growth, proliferation, motility, and adhesion.


Blood ◽  
2003 ◽  
Vol 101 (2) ◽  
pp. 703-705 ◽  
Author(s):  
Teru Hideshima ◽  
Masaharu Akiyama ◽  
Toshiaki Hayashi ◽  
Paul Richardson ◽  
Robert Schlossman ◽  
...  

p38 mitogen-activated protein kinase (MAPK) is a member of the MAPK family which is activated by cytokines and growth factors, but its role in pathogenesis of multiple myeloma (MM) is unknown. In this study, we demonstrate that the specific p38 MAPK inhibitor VX-745 inhibits interleukin 6 (IL-6) and vascular endothelial growth factor (VEGF) secretion in bone marrow stromal cells (BMSCs), without affecting their viability. Tumor necrosis factor alpha (TNF-α)–induced IL-6 secretion in BMSCs is also inhibited by VX-745. Importantly, VX-745 inhibits both MM cell proliferation and IL-6 secretion in BMSCs triggered by adherence of MM cells to BMSCs, suggesting that it can inhibit paracrine MM cell growth in the BM milieu and overcome cell adhesion–related drug resistance. These studies therefore identify p38 MAPK as a novel therapeutic target to overcome drug resistance and improve patient outcome in MM.


Blood ◽  
2010 ◽  
Vol 115 (18) ◽  
pp. 3772-3775 ◽  
Author(s):  
Teru Hideshima ◽  
Constantine Mitsiades ◽  
Hiroshi Ikeda ◽  
Dharminder Chauhan ◽  
Noopur Raje ◽  
...  

Abstract Constitutive B-cell lymphoma 6 (Bcl-6) expression was undetectable in multiple myeloma (MM) cell lines, except U266 cells. However, it was up-regulated by coculture with bone marrow (BM) stromal cell-culture supernatant (SCCS). Bcl-6 expression in patient MM cells in the BM was positive. Anti–interleukin-6 (IL-6)–neutralizing antibody significantly blocked SCCS-induced Bcl-6 in MM cells. Indeed, IL-6 strongly triggered Bcl-6 expression in MM cells, whereas Janus kinase inhibitor and STAT3 siRNA down-regulated Bcl-6. Tumor necrosis factor-α (TNF-α) also triggered Bcl-6, but independently of STAT3, whereas IκB kinaseβ inhibitor down-regulated TNF-α–induced Bcl-6, indicating that the canonical nuclear factor-κB pathway mediates TNF-α–induced Bcl-6 expression. Importantly, down-regulation of Bcl-6 by shRNA significantly inhibited MM cell growth in the presence of SCCS. Our results therefore suggest that Bcl-6 expression in MM cells is modulated, at least in part, via Janus kinase/STAT3 and canonical nuclear factor-κB pathways and that targeting Bcl-6, either directly or via these cascades, inhibits MM cell growth in the BM milieu.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. sci-7-sci-7
Author(s):  
Lori Hazlehurst ◽  
William S. Dalton ◽  
Danielle Yarde ◽  
Yulia Nefedova ◽  
Dmitry Gabrilovich

Abstract Multiple myeloma is a disease that typically responds to initial treatment; however, the disease is not cured by chemotherapy, and drug resistance ultimately develops. Most studies investigating the problem of drug resistance have focused on acquired resistance or resistance that occurs after response to prior therapy as a result of residual disease. Intrinsic factors, such as reduced drug uptake, enhanced damage response (i.e., DNA repair), altered drug metabolism, or inhibition of programmed cell death pathways are known to contribute to acquired drug resistance. For example, it was recently reported that the acquired melphalan resistant phenotype in myeloma cell lines was associated with over-expression of the Fanconi anemia (FA)/BRCA pathway genes. Enhanced interstrand cross-link (ICL) repair via the FA/BRCA pathway was causally related to melphalan resistance and disruption of this pathway using knock-down techniques reversed drug resistance. Furthermore, bortezomib (Velcade) has been reported to enhance melphalan treatment, and recent pre-clinical data has shown that bortezomib reduces FA/BRCA gene expression and function. Clinical trials are necessary to determine the role of the FA/ BRCA pathway in acquired drug resistance for myeloma patients and whether targeting this pathway enables prevention of or the ability to overcome acquired melphalan resistance in myeloma patients. Conversely, factors that promote tumor cell survival and drug resistance that are external to the tumor cell itself might exist. Evidence supporting the importance of understanding the influence of the tumor microenvironment on drug sensitivity has been reported by several investigators. The tumor microenvironment for hematologic malignancies, including myeloma, is principally the bone marrow. The bone marrow contains candidate components that contribute to reduced drug activity, minimal residual disease, and emergence of drug resistant cells. Cell adhesion molecules expressed by myeloma cells, including the β integrins, bind to fibronectin and other extracellular matrix components of the bone marrow, and this interaction contributes to a reversible, de novo drug resistance phenotype called “cell adhesion mediated drug resistance” or CAMDR. Adhesion via integrins is known to activate a network of signal transduction pathways that influence cell survival, growth, and differentiation. Several targets that are influenced by integrin adhesion and may contribute to CAM-DR include the following: reduced proapoptotic Bim levels, alterations in nuclear topoisomerase II levels, increased p27 kip1 levels, and changes in FLIP1 levels. In addition, myeloma cell adhesion to bone marrow stroma (BMS) involves other adhesion molecules and signaling events that promote CAMDR. For example, Notch1 receptors expressed on multiple myeloma cells when stimulated by Jagged causes growth arrest and protection from drug-induced apoptosis. Recently, approaches to inhibit integrin and Notch signaling associated with CAM-DR have been examined pre-clinically. Clinical trials are necessary to determine if these approaches will prevent or overcome CAM-DR in patients.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3737-3737
Author(s):  
Seiichi Okabe ◽  
Tetsuzo Tauchi ◽  
Seiichiro Katagiri ◽  
Yuko Tanaka ◽  
Kazuma Ohyashiki

Abstract Abstract 3737 ABL kinase inhibitor, imatinib is highly effective therapy against chronic myeloid leukemia (CML) patients and eliminates disease progression and transformation. However, imatinib is not curative for most CML patients. Residual CML cells are present in bone marrow microenvironment. Bone marrow microenvironment is a source of soluble factors and regulates the proliferation of leukemia cells. These leukemia cells are contained within a niche in the bone marrow and are often impervious to current treatments, thus maintaining their proliferative activity when the treatment is ceased, suggests that the new therapeutic strategies designed to override stroma-associated drug resistance are required to treat against Philadelphia (Ph)-positive leukemia patients. The hematopoietic cytokine receptor signaling is mediated by tyrosine kinases termed Janus kinases (Jaks) and downstream transcription factors, signal transducers and activators of transcription (STATs). Jak-STAT signaling is also activated in CML cells. One of the Jak kinase inhibitor, TG101348 (SAR302503) is an orally available inhibitor of Jak2 and developed for the treatment of patients with myeloproliferative diseases. Therefore, combination therapy using a BCR-ABL tyrosine kinase inhibitors and a Jak inhibitor, TG101348 may help prevent stroma-associated drug resistance and these approaches may be expected to improve the outcomes of CML patients. In this study, we investigated the ABL tyrosine kinase inhibitor, imatinib and TG101348 efficacy by using the BCR-ABL positive cell lines, K562 and primary CML samples when leukemic cells were protected by the feeder cell lines (HS-5 and S9). 72 hours treatment of imatinib exhibits cell growth inhibition and induced apoptosis against K562 cells in a dose dependent manner. However, the treatment of imatinib exhibits cell growth inhibition partially against K562 cells in the presence of HS-5 conditioned media. We found that the treatment of TG101348 did not exhibit cell growth inhibition against K562 cells directly, but the combination treatment with imatinib and TG101348 abrogated the protective effects of HS-5 conditioned media in K562 cells. We next investigated the intracellular signaling of imatinib and TG101348. Phosphorylation of BCR-ABL, Crk-L was not reduced after TG101348 treatment. However, phosphorylation of BCR-ABL, Crk-L was significantly reduced and increased apoptosis after combination treatment with imatinib and TG101348. We next investigated the efficacy between imatinib and TG101348 by using CD34 positive primary CML samples. The treatment of imatinib exhibits cell growth inhibition partially against CD34 positive CML samples in the presence of feeder cells. Combined treatment of CD34 positive primary samples with imatinib and TG101348 caused significantly more cytotoxicity and induced apoptosis. We also found that mitogen-activated protein kinase (MAPK) was also inhibited by imatinib and TG101348 treatment. We next investigated the intracellular signaling of imatinib and TG101348 by using the CD34 positive primary samples. Phosphorylation of BCR-ABL, Crk-L was significantly reduced and increased apoptosis after treatment with imatinib and TG101348. Moreover, combination of imatinib and TG101348 inhibited the colony growth of Ph-positive primary samples. We also investigated the TG101348 activity against feeder cell. Phosphorylation of STAT5 was reduced by TG101348 in a dose dependent manner. The cytokine production was analyzed by using cytokine array systems. The cytokine production such as granulocyte macrophage colony-stimulating factor (GM-CSF) from HS-5 was also reduced by TG101348 treatment. Data from this study suggested that administration of the imatinib and Jak inhibitor, TG101348 may be a powerful strategy against stroma-associated drug resistance of Ph-positive cells and enhance cytotoxic effects of imatinib in those residual CML cells. Disclosures: No relevant conflicts of interest to declare.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 8591-8591 ◽  
Author(s):  
Maurizio Chiriva-Internati ◽  
Leonardo Mirandola ◽  
Elisa Lazzari ◽  
Michela Colombo ◽  
Marialuigia Lancellotti ◽  
...  

8591 Background: Multiple myeloma (MM) originates from post-germinal center B cells, and is caused by malignant plasma cells accumulating in the bone marrow. Interactions of MM cells with the bone marrow stroma promote tumor growth, migration and drug resistance. The chemokine receptor CXCR4 and its ligand SDF1 are critical regulators of this process. MM cells frequently hyper-express CXCR4 and respond to SDF1,2 enhancing MM cell infiltration, proliferation and osteolysis. Notch receptors similarly promote MM cell growth, drug resistance and the associated osteolytic process. We hypothesized that the CXCR4/SDF1 axis mediates the effects of Notch signals in MM. Methods: We used real-time PCR, flow-cytometry, E.L.I.S.A. and chemotaxis assay to explore the effects of CXCR4 in cultured human MM cell lines after Notch inhibition or over-stimulation. Additionally, we validated our findings in a NOD/SCID murine model xenografted with human MM cells. Results: Our results show that Notch blocking reduced CXCR4 and SDF1 expression by MM cells. Further, Notch activation was required for MM cell chemotactic and proliferative response to SDF1 in vitro. We then investigated the outcome of anti-Notch treatment on human MM cells bone invasion in NOD/SCID mice. Interfering with Notch activity dramatically reduced xenografted MM cell ability to infiltrate the bone marrow, ultimately resulting in diminished tumor burden. Notably, such effect was associated with a decrease of CXCR4 expression. Conclusions: This was the first time that Notch receptors were reported to regulate the CXCR4/SDF1 axis and bone marrow invasion in human MM. These findings indicate that specific Notch-tailored therapies may effectively hamper CXCR4-mediated bone infiltration and associated lesions, and are expected to significantly improve treatment outcome and survival.


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