In vitro activity of dimethylarsinic acid against human leukemia and multiple myeloma cell lines

2003 ◽  
Vol 51 (5) ◽  
pp. 427-432 ◽  
Author(s):  
Hatice Duzkale ◽  
Iman Jilani ◽  
Nada Orsolic ◽  
Ralph A. Zingaro ◽  
Mirna Golemovic ◽  
...  
Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2848-2848
Author(s):  
Vijay Ramakrishnan ◽  
Jessica Haug ◽  
Teresa Kimlinger ◽  
Timothy Halling ◽  
Linda Wellik ◽  
...  

Abstract Abstract 2848 Poster Board II-824 Background: Multiple myeloma remains incurable with current therapies and novel approaches based on disease biology are needed. IL-6 is a critical cytokine involved in myeloma cell proliferation and survival and exerts its activity primarily through the JAK/STAT pathway. In addition to IL6, other cytokines are also believed to cross talk with the JAK/STAT pathway, making it a crucial interface for survival signals. It has been implicated in myeloma cell interaction with the microenvironment and resistance to apoptotic stimuli from different drugs, and represents a potential therapeutic target. We examined the pre-clinical activity of a novel JAK2 tyrosine kinase inhibitor TG101209. Methods: TG101209 (N-tert-butyl-3-(5-methyl-2-[4-(4-methyl-piperazin-1-yl)-phenylamino]-pyrimidin-4-ylamino)-benzenesulfonamide) was synthesized by TargeGen Inc. (San Diego, CA, USA). Stock solutions were made in DMSO, and subsequently diluted in RPMI-1640 medium for use. MM cell lines were cultured in RPMI 1640 containing 10% fetal bovine serum (20% serum for primary patient cells) supplemented with L-Glutamine, penicillin, and streptomycin. Cytotoxicity was measured using the MTT viability assay and proliferation using thymidine uptake. Apoptosis was measured using flow cytometry upon cell staining with Annexin V-FITC and propidium iodide (PI) for cell lines and using Apo2.7 in primary patient cells. CD45 expression was estimated using flow cytometry and cells were gated by their CD45 expression to assess differential effects of the drug. Immunoblotting was done on cell extracts at various time points following incubation with the drug in order to study the cell signaling pathways. Results: TG101209 resulted in a dose and time dependent inhibition of cell growth in the MM cell lines tested. Most of the cytotoxicity was evident by 48 hours, with minimal increase seen up to 96 hours of incubation. At 48 hours of incubation, the median inhibitory concentration was between 2 and 4uM with similar IC50 seen for myeloma cell lines sensitive or resistant to conventional therapies. The IC50s were maintained when the cells were treated in co-culture with stromal cells or in the presence of IL6, IGF or VEGF. Increasing doses of IL6 was not able to rescue the cells from the drug. Dose dependent decrease in proliferation of the cell lines was evidenced by decreased thymidine incorporation. Apoptotic changes in cells following drug treatment was confirmed by flow cytometry for Annexin and PI. Cleavage of caspases 3, 8 and 9 were confirmed on flow cytometry. Addition of the pan-caspase inhibitor zvad-fmk did not prevent drug-induced apoptosis confirming non-caspase mediated mechanisms of cell death as well. Primary myeloma cells from several patients were treated with increasing doses of the drug and IC50 similar to cell lines were seen in 8/10 patient samples tested. Interestingly, evaluation of U266 cell lines, which have a mix of CD45+ and negative cells as well as primary patient cells demonstrated more profound cytotoxicity and anti-proliferative activity of the drug on the CD45+ population relative to the CD45- cells. Immunoblotting studies demonstrated significant down regulation of IL-6 induced pSTAT3 with minor effects on the pERK and pAkt. The effect on pSAT3 was sustained compared to that on pERK and pAkt. This was accompanied by significant down regulation of Bcl-xL. Studies in a mouse model of myeloma are planned. Conclusion: These studies demonstrate significant in-vitro activity of JAK2 inhibition in multiple myeloma. In particular, the preferential targeting of CD45 cells, considered to reflect the proliferative compartment in myeloma holds out the promise for more sustained impact on the disease from a therapeutic standpoint. This is likely explained by the increased sensitivity of the CD45 cells to cytokines as a result of higher expression of different cytokine receptors as has been previously shown. This leads to increased activity of and dependence of the cells on the JAK-STAT pathway and likely explains the increased effect of the pathway inhibition. These studies form the framework for clinical evaluation of the drug in the setting of myeloma. Disclosures: Kumar: CELGENE: Research Funding; MILLENNIUM: Research Funding; BAYER: Research Funding; GENZYME: Research Funding; NOVARTIS: Research Funding.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5190-5190
Author(s):  
Shaji Kumar ◽  
Michael Timm ◽  
Terry Kimlinger ◽  
Michael Kline ◽  
Jessica L. Haug ◽  
...  

Abstract Background: Multiple myeloma is a plasma cell malignancy that remains incurable with current approaches and newer therapies are needed to improve the outcome of patients with MM. While monoclonal antibody base therapies have been successful in some of the hematological malignancies, especially lymphoma, such approaches have not been very useful in the setting of myeloma. Targeting of antigens like CD138 on the myeloma cell surface has been hampered by the ubiquitous nature of this protein in the body. Thymoglobulin (polyclonal rabbit antithymocyte globulin, Genzyme) has been extensively evaluated in the setting of allogeneic blood and marrow transplantation and is currently in clinical use. Given the polyclonal nature of this product, it has antibodies against several B cell antigens and forms the rationale for its evaluation in B cell malignancies like myeloma. Methods: MM cell lines were cultured in RPMI 1640 containing 10% fetal bovine serum supplemented with L-Glutamine, penicillin, and streptomycin. The KAS-6/1 cell line was also supplemented with 1 ng/ml IL-6. Cytotoxicity following drug treatment was measured using the MTT viability assay. Drug induced apoptosis in the cell lines was measured by flow cytometry after staining with Annexin V-FITC and propidium iodide (PI). Apoptosis in primary patient derived plasma cells following treatment was measured after staining for Apo 2.7. Results: rATG was cytotoxic in vitro to several MM cell lines (RPMI 8226, U266, OPM1, OPM2) including the IL-6 dependent cell line Kas6/1. The LC50 in most of the cytotoxicity assays was around 1 mg/mL. Additionally, rATG was cytotoxic MM cell lines resistant to conventional agents such as doxorubicin (Dox40), melphalan (LR5) and dexamethasone (MM1R). The drug retained its cytotoxicity when myeloma cells were grown in the presence of various cytokines like IL-6, IGF-1 and VEGF. rATG treatment resulted in a time and dose dependent induction of apoptosis in MM cell lines. rATG was also able to induce apoptosis of freshly isolated myeloma cells from patient marrows. When tested in combination with other anti-myeloma agents an additive effect was seen with doxorubicin, PS341 and melphalan. Conclusions: Thymoglobulin appear to have in vitro activity against various myeloma cell lines as well as patient derived primary myeloma cells. Ability of the drug to overcome resistance to conventional drugs as well as the effect of combining rATG with these agents points towards non-overlapping mechanisms of action. Ongoing studies are trying to identify the particular B-cell antigens that are targeted by correlating response to expression of various B cell antigens expressed by these cell lines. These studies will provide the rational for future clinical development of this agent in myeloma alone or in combination with other agents.


2004 ◽  
Vol 52 (5) ◽  
pp. 335-344 ◽  
Author(s):  
Naomi Gronich ◽  
Liat Drucker ◽  
Hava Shapiro ◽  
Judith Radnay ◽  
Shai Yarkoni ◽  
...  

BackgroundAccumulating reports indicate that statins widely prescribed for hypercholesteromia have antineoplastic activity. We hypothesized that because statins inhibit farnesylation of Ras that is often mutated in multiple myeloma (MM), as well as the production of interleukin (IL)-6, a key cytokine in MM, they may have antiproliferative and/or proapoptotic effects in this malignancy.MethodsU266, RPMI 8226, and ARH77 were treated with simvastatin (0-30 μM) for 5 days. The following aspects were evaluated: viability (IC50), cell cycle, cell death, cytoplasmic calcium ion levels, supernatant IL-6 levels, and tyrosine kinase activity.ResultsExposure of all cell lines to simvastatin resulted in reduced viability with IC50s of 4.5 μM for ARH77, 8 μM for RPMI 8226, and 13 μM for U266. The decreased viability is attributed to cell-cycle arrest (U266, G1; RPMI 8226, G2M) and cell death. ARH77 underwent apoptosis, whereas U266 and RPMI 8226 displayed a more necrotic form of death. Cytoplasmic calcium levels decreased significantly in all treated cell lines. IL-6 secretion from U266 cells was abrogated on treatment with simvastatin, whereas total tyrosine phosphorylation was unaffected.ConclusionsSimvastatin displays significant antimyeloma activity in vitro. Further research is warranted for elucidation of the modulated molecular pathways and clinical relevance.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3493-3493
Author(s):  
Ahmad-Samer Samer Al-Homsi ◽  
Zhongbin Lai ◽  
Tara Sabrina Roy ◽  
Niholas Kouttab

Abstract Introduction Constitutive and immunoproteasome inhibitors (C&IPI) were thought to suppress nuclear factor-κB (NF-κB) pathway by preventing IκB degradation, which prevents NF-κB translocation into the nucleus. This mechanism of action has since been questioned by a number of studies. First, bortezomib promoted constitutive NF-κB activity in endothelial cell carcinoma. Second, NF-κB constitutive activity was resistant to bortezomib in multiple myeloma cell lines. Third, bortezomib increased IκB mRNA but post-transcriptionally downregulated IκB in normal cells and in multiple myeloma cell lines resulting in induced canonical NF-κB activation. Lastly, bortezomib increased nuclear levels of IκB as opposed to lowering cytoplasmic levels in cutaneous T cell lymphoma cell line suggesting that nuclear translocation of IκB was possibly responsible for NF-κB inhibition. The inhibitory activity of C&IPI on dendritic cells (DC) is of interest in the prevention of graft versus host disease (GvHD). It has been shown that different C&IPI impede DC maturation and T cell priming both in vitro and in vivo. Herein we sought to understand the mechanism of action of proteasome and immunoproteasome inhibitors on DC and to test their effect on IκB and NF-IκB expression. Materials and Methods We first performed RT PCR on lysates of DC obtained from the peripheral blood of 7 patients who received post-transplant cyclophosphamide and bortezomib as prevention of GvHD on a phase I clinical trial. Patients received allogeneic transplantation from matched-related or unrelated donors. Patients received no other immunosuppressive therapy except for rabbit anti-thymocyte globulin for those receiving graft from unrelated donor. Steroids were not allowed on the study. Samples were obtained on days +1, +4, and +7. The results were analyzed in comparison to samples obtained on day 0 before stem cell infusion. We then performed the same experiment on lysates of DC obtained from the peripheral blood of healthy volunteer donors. DC were untreated or incubated with bortezomib (10 nM for 4 h), carfilzomib (30 nM for 1 h), oprozomib (100 nM and 300 nM for 4 h), ONX 0914 (200 nM for 1 h), PR-825 (125 nM for 1 h), or PR-924 (1000 nM for 1 h). The drug concentration and duration of exposure were chosen based on the IC50 on proteasome activity and to reproduce in vivo conditions. We also performed IκB western blot on DC isolated from peripheral blood of healthy volunteers, untreated or incubated with bortezomib (10 nM for 4 h) or oprozomib (300 nM for 4 h). Each experiment was performed at least in triplicate. Results We found that the combination of cyclophosphamide and bortezomib significantly and progressively increased IκB mRNA while decreasing NF-κB mRNA in DC studied ex vivo. We also found that all studied C&IPI increased IκB mRNA to a variable degree while only oprozomib (300 nM) decreased NF-κB mRNA in DC in vitro. Finally, both bortezomib and oprozomib increased IκB protein level in DC in vitro (figure). Conclusion Our data suggest that C&IPI increase IκB expression in DC. As opposed to the previously reported data in other cell types, the effect is not associated with post-transcriptional downregulation. Cyclophosphamide and bortezomib also decrease NF-κB expression in DC in vivo while only oprozomib had the same effect in vitro. The effect of C&IPI on IκB and NF-κB expression may represent a new mechanism of action and suggests their effect may be cell-type dependent. Disclosures: Al-Homsi: Millennium Pharmaceuticals: Research Funding. Off Label Use: The use of cyclophosphamide and bortezomib for GvHD prevention. Lai:Millennium Pharmaceuticals: Research Funding.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2084-2084 ◽  
Author(s):  
Joel G Turner ◽  
Jana L Dawson ◽  
Steven Grant ◽  
Kenneth H. Shain ◽  
Yun Dai ◽  
...  

Abstract Introduction High-dose melphalan chemotherapy with autologous stem cell transplant remains the standard of care for the treatment of multiple myeloma. However, patients eventually develop drug resistance and die from progressive disease despite the introduction of therapies using proteosome inhibitors (PIs) and immunomodulatory drugs (IMIDs). The incurable nature of multiple myeloma clearly demonstrates the need for novel agents and treatments. Here, our aim was to investigate whether the use of XPO1 (exportin 1, CRM1) inhibitors (XPO1i) could sensitize de novo and acquired drug-resistant multiple myeloma cells both in vitro and ex vivo to the alkylating agent melphalan. Materials and Methods Human multiple myeloma cell lines NCI-H929, RPMI-8226, U266 and PBMC controls were treated in vitro with the XPO1i KOS-2464 and the orally available Selective Inhibitor of Nuclear Export (SINE) selinexor (KPT-330) or) +/- melphalan. Multiple myeloma cells were grown at high-density conditions (>3-5x106 cells/mL). High-density multiple myeloma cells have been shown to possess de novo drug resistance. Sensitivity of the XPO1i/melphalan-treated NCI-H929 cells was measured by cell viability assay (CellTiter-Blue). Apoptosis in XPO1i/melphalan-treated NCI-H929, RPMI-8226, and U266 cells was assayed using flow cytometry (activated caspase 3). Proximity ligation assays were performed to assess XPO1-p53 binding in the presence of an XPO1i. Western blots of XPO1i-treated myeloma cells were performed for nuclear and total p53. Drug-resistant U266 (PSR) and 8226 (8226/B25) myeloma cell lines were developed by incremental exposure to bortezomib. PSR cells are able to grow in 15 nM bortezomib and the 8226/B25 in 25 nM. These resistant myeloma cells were treated in vitro with XPO1i +/- melphalan. Sensitivity to therapy was measured by apoptosis and cell viability assay. Multiple myeloma cells isolated from patients with newly diagnosed, relapsed, or refractory disease were treated with XPO1i +/- melphalan and CD138+/light chain+ myeloma cells and assayed for apoptosis. Results Multiple myeloma cell (NCI-H929) viability was decreased synergistically by XPO1i when used in combination with melphalan, as shown by the calculated combinatorial index (CI) values. We examined sequencing of the drugs and found that concurrent treatment with melphalan (10 µM) and selinexor (300 nM) for 48 hours produced the best results (CI value 0.370, n=6). Sequential treatment (selinexor for 24 hours followed by melphalan for an additional 24 hours) or the reverse sequence had slightly less synergy, with CI values of 0.491 (n=9) and 0.565 (n=3), respectively. Normal PBMC control cells were unaffected by XPO1i/melphalan treatment as shown by viability and apoptotic assays. Proximity ligation assay demonstrated that XPO1i blocks XPO1/p53 binding. Western blot showed that the XPO1i treatment of myeloma cells increased nuclear and total p53. Drug-resistant 8226/B25 myeloma cells but not PSR cells were found to be resistant to melphalan when compared to parental cell lines. Both resistant myeloma cell lines were sensitized by XPO1i to melphalan as shown by apoptosis assay (3- to 10-fold). CD138+/light chain+ myeloma cells derived from newly diagnosed, relapsed, and refractory myeloma patients were also sensitized by XPO1 inhibitors to melphalan as demonstrated by apoptotic assays (e.g. activated caspase 3). Conclusions XPO1i synergistically improved the response of de novo and acquired drug-resistant myeloma cells to melphalan in vitro and ex vivo. It is possible that this synergy may be due to an increase of nuclear p53 by XPO1i and the reported activation of p53 by melphalan. Future studies include in vitro experiments using drug-resistant human U266 myeloma cells in NOD-SCID-gamma mice and clinical trials using melphalan in combination with the SINE selinexor. Combination therapies using selinexor and melphalan may significantly improve the treatment of myeloma. Disclosures Kauffman: Karyopharm Therapeutics: Employment. Shacham:Karyopharm Therapeutics: Employment.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5543-5543
Author(s):  
Harish Kumar ◽  
Ujjal Kumar Mukherjee ◽  
Li Chen ◽  
Amit Kumar Mitra

Drug resistance is a major cause of concern in cancer chemotherapy that not only reduces efficacy but also causes toxicity through overdosing. Multiple myeloma (MM) is the second-most common haematological malignancy in the USA that remains a challenging disease to cure due to the presence of significant complexity and heterogeneity at molecular level with high treatment cost. Proteasome inhibitor, the standard of care drug, has proven to remarkably improve myeloma patient outcomes but is associated with dose limiting toxicities and drug resistance. Therefore, new combination treatment regimens are urgently needed for the treatment of PI-resistant MM that can lower the required dose of standard-of-care drug without compromising on treatment efficacy. We have created an optimization-regularization based computational prediction method called secDrug that uses large-scale pharmacogenomics databases to identify novel secondary drugs against PI-resistance when used as single agent or in combination. We applied secDrug to PIs-resistant cell lines (>100) in the Genomics of Drug Sensitivity in Cancer (GDSC) database and predicted the top drugs that can be best combined with PIs to overcome PI-resistance in MM. These include: Survivin inhibitor (YM155), Nicotinamide phospho ribosyl transferase or Nampt inhibitor (FK866), PIKfyve inhibitor (YM201636), Raf inhibitor (PLX-4720), Bcl2 inhibitor (Navitoclax),HSP90 inhibitor (17-AAG), AKT inhibitor (KIN00102), HDAC inhibitors (Panobinostat, SAHA), S6K1-specific inhibitor (PF-4708671), and the neddylation inhibitor (MLN4924). To validate our prediction results, we treated human multiple myeloma cell lines (HMCLs) highly resistant to the proteasome inhibitors Bortezomib, Carfilzomob, Oprozomib and Ixazomib and >10 clonally derived acquired resistant cells with the top predicted best secondary drugs. Next, we treated three pairs of parental PI-sensitive (P) and clonally-derived PI-resistant (R) cell lines from PI-sensitive (P) HMCLs representing acquired PI-response with the top predicted drug combinations. Our preliminary in vitro data confirmed our in silico predictions of secondary drugs based on secDrug analysis. Among these, YM155 and YM155 + Ixazomib showed strikingly very high in vitro cytotoxicity against PI- resistant MM cell lines (Figure 1). The results, based on Chou-Talalay's combination index (CI) theorem, show that this combination works highly synergistically where the IC50 of ixazomib in MM cells was significantly reduced in presence of YM155. Similar results were obtained for the other top predicted combination regimens. Our findings provide a strong case for combining YM155 with ixazomib to enhance sensitivity or overcome resistance to ixazomib and thereby improve patient outcome. Further, this study provides additional support towards using secDrug for predicting secondary drugs in cancers resistant to the standard-of-care therapy. Currently, we are exploring the molecular mechanisms behind the synergism between proteasome inhibitors and the top drugs identified by our algorithm as candidates for secondary combination therapies using next-gen transcriptomics and single-cell analysis approaches. Earlier studies have shown that YM155 potentially induces selective cell death in human pluripotent stem cells. Further, the presence of cancer stem cells sub population/ MM-CSCs in drug-resistant tumors have been shown to significantly contribute to the development of PI-resistance in MM. Hence, we propose that YM155 reverses PI-resistance by reducing the stem cell load in multiple myeloma cell line model system. Therefore, our future plan is to assess the effects of YM155 on MM-cancer stem cells like subclones/ sub population/ MM-CSCs including CD19- CD138- quiescent stem cells, ALDH+ and side populations/SP) in drug-resistant tumors. Overall, our in vitro validation results corroborated with our in silico prediction of secondary drugs. Disclosures No relevant conflicts of interest to declare.


Biomolecules ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 107
Author(s):  
Giorgio Santoni ◽  
Consuelo Amantini ◽  
Federica Maggi ◽  
Oliviero Marinelli ◽  
Matteo Santoni ◽  
...  

Multiple myeloma (MM) is a haematological B cell malignancy characterised by clonal proliferation of plasma cells and their accumulation in the bone marrow. The aim of the present study is the evaluation of biological effects of Ibrutinib in human MM cell lines alone or in combination with different doses of Bortezomib. In addition, the relationship between the expression of TRPML2 channels and chemosensitivity of different MM cell lines to Ibrutinib administered alone or in combination with Bortezomib has been evaluated. By RT-PCR and Western blot analysis, we found that the Ibrutinib-resistant U266 cells showed lower TRPML2 expression, whereas higher TRPML2 mRNA and protein levels were evidenced in RPMI cells. Moreover, TRPML2 gene silencing in RPMI cells markedly reverted the effects induced by Ibrutinib alone or in combination with Bortezomib suggesting that the sensitivity to Ibrutinib is TRPML2 mediated. In conclusion, this study suggests that the expression of TRPML2 in MM cells increases the sensitivity to Ibrutinib treatment, suggesting for a potential stratification of Ibrutinib sensitivity of MM patients on the basis of the TRPML2 expression. Furthermore, studies in vitro and in vivo should still be necessary to completely address the molecular mechanisms and the potential role of TRPML2 channels in therapy and prognosis of MM patients.


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