Membrane Lipid Biosynthesis As a Potential Therapeutic Target in Multiple Myeloma

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1836-1836
Author(s):  
Carolyne Bardeleben ◽  
Alan Lichtenstein
Keyword(s):  
Multiple Myeloma ◽  
Er Stress ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Plasma Cells ◽  
Conflicts Of Interest ◽  
Membrane Lipid ◽  
Dependent Manner ◽  
Kennedy Pathway ◽  
Phosphatidylcholine Synthesis

Abstract Abstract 1836 Phosphatidylcholine (PC) is the most prominent phospholipid in mammalian endoplasmic reticulum (ER) membranes. The rate-limiting step in PC synthesis through the Kennedy pathway is the conversion of phosphocholine + cytidine triphosphate (CTP) to cytidine diphosphocholine, (CDP)-choline, via the enzyme CTP:phosphocholine cytidylyltransferase (CCT) (see figure). Multiple myeloma (MM) cells may be particularly dependent on this biosynthetic reaction because of their high consistent level of ER stress and requirement to continuously replenish ER membranes. Indeed, CCT-null mice have a defect in differentiation of B lymphocytes to plasma cells and deficiencies in Ig synthesis. To test whether this pathway remains critical in survival of malignant MM cells, we exposed MM cell lines to an inhibitor shown to inhibit CCT activity, HexPC. HexPC induced apoptosis in all MM cell lines in a concentration- and time-dependent manner. The addition of lysophosphatidylcholine (LPC), presumably converted to PC independently of the Kennedy pathway, completely rescued MM cell apoptosis. In contrast, similar concentrations of LPC in the same cell lines could not rescue apoptosis induced by bortezomib. An additional intervention to inhibit phosphatidylcholine synthesis, namely inducing pyrimidine starvation, also resulted in MM cell apoptosis and down-regulation of CDP-choline levels. Apoptosis of MM cells induced by HexPC was associated with induction of ER stress as shown by enhanced phosphorylation of IRE1 and eIF-2alpha. This ER stress was also prevented when LPC was added to HexPC although LPC could not prevent similar ER stress induced by bortezomib. These results underscore the importance of this phosphatidylcholine synthesis pathway in MM cells and provide new targets for future therapy. Disclosures: No relevant conflicts of interest to declare.

scholarly journals 5-Azacitidine Remolds the Methylation Status and Inhibits Growth in Multiple Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4817-4817
Author(s):  
Wenming Wang ◽  
Jing Wang ◽  
Mingyi Chen ◽  
Yaoxian Liang ◽  
Zhengqian Li ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Methylation ◽  
Multiple Myeloma ◽  
Cell Lines ◽  
Methylation Level ◽  
Plasma Cells ◽  
Conflicts Of Interest ◽  
Methylation Status ◽  
Dependent Manner ◽  
M Cell

Abstract Multiple myeloma (MM) is a malignant disorder characterized by the proliferation of a single clone of plasma cells derived from B cells. Previous studies have demonstrated that both gene-specific hypermethylation and global hypomethylation characterizes the multiple myeloma epigenome. 5-azacytidine as a DNA methylation inhibitor has therapeutic efficacy in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Nevertheless,the effects of 5-azacytidine on MM remains unclear. We used RT-PCR to detect the expression of PTPL1 and used MS-PCR to determine the methylation status of PTPL1 in MM cell lines and after 5-azacytidine treatment. ELISA-like reaction was used to detect global DNA methylation level. The cytotoxic activity of 5-azacytidine was tested using cell viability and apoptosis assays. Flow cytometry was used to detect cell cycle after 5-azacytidine treatment. Our experiments discovered that the PTPL1 gene was hypermethylated in the U266 and H929 cell lines, and the expression of PTPL1 mRNA could be re-inducible by 5-azacytidine. 5-azacytidine also inhibited the proliferation of multiple myeloma cell lines U266 and H929 in a time- and dose-dependent manner, induced G2/M cell cycle arrest and caspase-dependent apoptosis. But in our study 5-azacytidine increased the methylation level for both cell lines. Our study showed that PTPL1 was epigenetically regulated in MM which can be reversed by 5-azacytidine, and highlights 5-azacytidine is a potential therapeutic candidate for MM, but additional studies are needed to determine the effects of genome-wide methylation changes in MM. Disclosures No relevant conflicts of interest to declare.

scholarly journals Dihydrochalcone Derivative Induces Breast Cancer Cell Apoptosis via Intrinsic, Extrinsic, and ER Stress Pathways but Abolishes EGFR/MAPK Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Wasitta Rachakhom ◽  
Patompong Khaw-on ◽  
Wilart Pompimon ◽  
Ratana Banjerdpongchai
Keyword(s):  
Breast Cancer ◽  
Er Stress ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Mapk Pathway ◽  
Annexin V ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Mcf 7

Dihydrochalcone derivatives are active compounds that have been purified from the Thai medicinal plant Cyathostemma argenteum. The objectives of this study were to investigate the effects of two dihydrochalcone derivatives on human breast cancer MDA-MB-231 and MCF-7 cell proliferation and to study the relevant mechanisms involved. The two dihydrochalcone derivatives are 4′,6′-dihydroxy-2′,4-dimethoxy-5′-(2″-hydroxybenzyl)dihydrochalcone (compound 1) and calomelanone (2′,6′-dihydroxy-4,4′-dimethoxydihydrochalcone, compound 2), both of which induced cytotoxicity toward both cell lines in a dose-dependent manner by using MTT assay. Treatment with both derivatives induced apoptosis as determined by annexin V-FITC/propidium iodide employing flow cytometry. The reduction of mitochondrial transmembrane potential (staining with 3,3′-dihexyloxacarbocyanine iodide, DiOC6, employing a flow cytometer) was established in the compound 1-treated cells. Compound 1 induced caspase-3, caspase-8, and caspase-9 activities in both cell lines, as has been determined by specific colorimetric substrates and a spectrophotometric microplate reader which indicated the involvement of both the extrinsic and intrinsic pathways. Calcium ion levels in mitochondrial and cytosolic compartments increased in compound 1-treated cells as detected by Rhod-2AM and Fluo-3AM intensity, respectively, indicating the involvement of the endoplasmic reticulum (ER) stress pathway. Compound 1 induced cell cycle arrest via enhanced atm and atr expressions and by upregulating proapoptotic proteins, namely, Bim, Bad, and tBid. Moreover, compound 1 significantly inhibited the EGFR/MAPK signaling pathway. In conclusion, compound 1 induced MDA-MB-231 and MCF-7 cell apoptosis via intrinsic, extrinsic, and ER stress pathways, whereas it ameliorated the EGFR/MAPK pathway in the MCF-7 cell line. Consequently, it is believed that compound 1 could be effectively developed for cancer treatments.

Serum/Glucocorticoid-Regulated Kinase 1 (SGK1) Is a Prominent Target Gene of the Transcriptional Response to Cytokines In Multiple Myeloma and Supports the Growth of Myeloma Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1915-1915
Author(s):  
Unn-Merete Fagerli ◽  
Thorsten Stühmer ◽  
Toril Holien ◽  
Randi Utne Holt ◽  
Ove Bruland ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Growth Factors ◽  
Cell Lines ◽  
Plasma Cells ◽  
Conflicts Of Interest ◽  
Transcriptional Response ◽  
Myeloma Cell ◽  
Myeloma Cells ◽  
Growth And Survival ◽  
Stat3 Phosphorylation

Abstract Abstract 1915 Multiple myeloma is a paradigm for a malignant disease that exploits external stimuli of the microenvironment for growth and survival. A thorough understanding of the complex interactions between malignant plasma cells and their surrounding requires a detailed analysis of the transcriptional response of myeloma cells to environmental signals. We hypothesized that the intracellular signals evoked by cytokines converge and regulate transcription of a set of genes that are common targets for several growth factors and therefore constitute pivotal mediators of the tumor-promoting effects of autocrine or paracrine stimuli. To identify such targets, we determined the changes in gene expression induced by IL-6, TNFalpha, IL-21 or co-culture with bone marrow stromal cells in myeloma cell lines. Among a limited set of genes that were consistently activated in response to growth factors, a prominent transcriptional target of cytokine-induced signaling in myeloma cells was the gene encoding the serine/threonine kinase SGK1, which is a down-stream effector of PI3-kinase and highly homologous to AKT. We could demonstrate a rapid, strong and sustained induction of SGK1 in the cell lines INA-6, ANBL-6, IH-1, OH-2 and MM.1S as well as in primary myeloma cells. Pharmacologic inhibition of the JAK/STAT pathway abolished STAT3 phosphorylation and SGK1 induction. In addition, shRNA-mediated knock-down of STAT3 reduced basal and induced SGK1 levels, demonstrating the involvement of the JAK/STAT3 signaling pathway in SGK1 induction. Furthermore, down-regulation of SGK1 by shRNAs resulted in decreased proliferation and viability of myeloma cell lines. Our results indicate that SGK1 is a highly cytokine-responsive gene in myeloma cells promoting their growth and survival and represents an attractive candidate for further evaluation as a therapeutic target. Disclosures: No relevant conflicts of interest to declare.

Inhibition Of PI3K Classia Kinases Using GDC0941 Overcomes Protection Of Multiple Myeloma Cells In The Bone Marrow Microenvironment

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3169-3169
Author(s):  
Hugh Kikuchi ◽  
Amofa Eunice ◽  
Maeve McEnery ◽  
Farzin Farzaneh ◽  
Stephen A Schey ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Cell Proliferation ◽  
Bone Resorption ◽  
Cell Lines ◽  
Stromal Cells ◽  
Conflicts Of Interest ◽  
Pi3k Pathway ◽  
Dependent Manner ◽  
Dose Dependent

Abstract Despite of newly developed and more efficacious therapies, multiple myeloma (MM) remains incurable as most patient will eventually relapse and become refractory. The bone marrow (BM) microenvironment provides niches that are advantageous for drug resistance. Effective therapies against MM should ideally target the various protective BM niches that promote MM cell survival and relapse. In addition to stromal mesenchymal/myofibroblastic cells, osteoclasts play a key supportive role in MM cell viability. Additionally, 80% of patients develop osteolytic lesions, which is a major cause of morbidity. Increased osteoclast activity is characteristic in these patients and targeting osteoclast function is desirable to improve therapies against MM. Osteoclasts need to form an F-actin containing ring along the cell margin that defines a resorbing compartment where protons and degradative enzymes are secreted for dissolution of bone mineral. Remodelling of F-actin and vesicle secretion are regulated by the class IA PI3K pathway during osteoclastic bone resorption. Additionally, it has recently been shown that inhibition of the class IA PI3K pathway in MM cells with GDC0941 induces apoptosis-mediated killing. We hypothesised that GDC0941 could be used as a therapeutic agent to overcome MM-induced osteoclast activation. GDC0941 inhibited maturation of osteoclasts derived from BM aspirates from MM patients in a dose dependent manner. This correlated with decreased bone resorption of osteoclasts cultured on dentine discs. Exposure of mature osteoclasts to GC0941 resulted in abnormal organisation of larger F-actin rings, suggesting a negative effect on the dynamics of the actin cytoskeleton required for bone resorption. We also found that GDC-0941 can prevent protection of the MM cell lines MM1.S and MM1.R by osteoclasts against killing. GDC-0941 alone blocked MM cell proliferation independently of the presence of BM stromal cells and synergised with other therapeutic agents including Lenalidomide, Pomalidomide, Bortezomid and Dexamethasone. We also found that in the presence of MM cells, Dexamethasone (a drug commonly used alone or in combination with new drugs against MM) induced the proliferation of BM stromal cells and adhesion of MM cells on this protective stroma in a dose dependent manner. Dexamethasone is highly effective at MM cell killing when cells are cultured alone. However, we found that at low doses (below 1 uM) and in the presence of BM stromal cells, Dexamethasone could induce MM cell proliferation. GDC0941 enhanced Dexamethasone killing even in the presence of BM stromal cells by blocking Dexamethasone-induced stromal cell proliferation and adhesion of MM cells on the stroma. Targeting individual the PI3K Class IA isoforms alpha, beta, delta or gamma proved to be a less efficient strategy to enhance Dexamethasone killing. Previous work has shown that efficacy of targeting individual PI3K Class I A isoforms would be low for activation of caspases in MM cells as it would be dependent on relative amounts of isoforms expressed by the MM patient. GDC-0941 also inhibited the proliferation of MM1.R and RPMI8266 MM cell lines, which are less sensitive to treatment to Dexamethasone. Co-culture of MM cells with BM stromal cells induced the secretion of IL-10, IL-6, IL-8, MCP-1 and MIP1-alpha. The dose-dependant increased proliferation of Dexamethasone-treated MM cells in the presence of the BM stroma correlated with the pattern of secretion of IL-10 (a cytokine that can induce B-cell proliferation) and this was blocked by the combination of Dexamethasone with GDC0941. GDC-0941 alone or in combination with Dexamethasone was more efficacious at inducing MM cell apoptosis in the presence of the BM stroma cells vs treatment of MM cells alone. These are very encouraging results as they suggest that GDC-0941 in combination with Dexamethasone would be potentially highly efficacious for targeting MM cells in the BM microenvironment. We are currently performing in vivo data using C57BL/KaLwRij mice injected with 5T33-eGFP MM cells that will be discussed at the meeting. We propose that MM patients with active bony disease may benefit from treatment with GDC0941 alone or in combination with currently used therapeutic drugs against MM. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Oxymatrine Induces Apoptosis in Human Myeloma Cells By Cell Cycle Arrest and Activation of Caspase-Dependent Apoptosis

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5727-5727
Author(s):  
Wenjun Wu ◽  
Cai Wu ◽  
Fuming Zi ◽  
Yi Li ◽  
Li Yang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Flow Cytometry ◽  
Growth Inhibition ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Western Blotting ◽  
Cell Apoptosis ◽  
Conflicts Of Interest ◽  
Dependent Manner ◽  
Rt Pcr

Abstract Background : Multiple myeloma (MM) is a B cell malignant hematologic cancer. Despite the introduction of new drugs and improvement of chemotherapy, MM is still an incurable disease. Oxymatrine (OMT), the active ingredients of traditional Chinese herbal medicine sophora, has been reported to have antitumor activity. This study was to estimate the therapeutic efficacy of OMT in MM. Methods: The growth inhibition of myeloma cell lines (RPMI8226, U266, ARP-1) or primary cells by OMT was assessed by MTT assay. Apoptosis of MM cells was examined by annexin V-FITC using flow cytometry analysis. DNA content was analyzed by flow cytometry. RT-PCR and western-blot analysis were used to assess the expression of Bcl-2 family proteins and the IAP family proteins. Western blotting was also used to elucidate the signaling pathway that may mediate OMT-induced apoptosis of MM cells. Results: OMT treatment resulted in cell growth inhibition and apoptosis in primary MM cells and all tested MM cell lines in a dose-dependent manner (P <0.05). To elucidate OMT -induced MM cell apoptosis, MM cell lines were treated with or without OMT for 24h and assessed for caspase activation and signaling pathway by Western blotting. The results showed the cleavage of PARP, caspase-3, and caspase-9, and p-AKT were down-regulated after OMT treatment. The mRNA expression of survivin and HIAP by RT-PCR was down-regulated. OMT treatment at 5mM for 48h resulted in increased G-phase cells and decreased S-phase cells in MM cell lines (P <0.05). Cell cycle repressor P21 protein was up-regulated while CDK4, CDK6 and CyclinD1 expression was down-regulated. Our finding also showed a synergistic anti-MM activity of OMT and dexamethasone or adriamycin at a low does (CI<1). In addition, LC3-II expression was significantly increased both in RPMI8226 and U266 cells after treatment with OMT. However, treatment with different doses of OMT and 5 mM autophagy inhibitor 3-MA, significant increased cell apoptosis (P <0.05). Conclusion: Our findings demonstrate the anti-MM activity of OMT and indicate that OMT alone or together with other MM chemotherapeutics may be a prospective treatment for MM. Disclosures No relevant conflicts of interest to declare.

scholarly journals De Novo Nethyltransferases, DNMT3a and DNMT3b Are Underexpressed in Multiple Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4818-4818 ◽  
Author(s):  
Pavla Latalova ◽  
Jiri Minarik ◽  
Katerina Smesny Trtkova
Keyword(s):  
Dna Methylation ◽  
Multiple Myeloma ◽  
Cell Lines ◽  
Plasma Cells ◽  
De Novo ◽  
Conflicts Of Interest ◽  
Myeloma Cell ◽  
Dna Methyltransferases ◽  
Rt Pcr ◽  
Cpg Dinucleotides

Abstract Background and aims: Presently, there is growing evidence that along with the important role of genetic abnormalities, epigenetic aberrations are relevant factors in multiple myeloma (MM). As was recently found, genome-wide analysis of DNA methylation reveals epigenetic alterations in plasma cells from patients with MM and individuals with monoclonal gammopathy of undetermined significance (MGUS). MGUS is characterized by predominant hypomethylation. Transformation into MM is accompanied by progressive hypermethylation with maximum methylation seen in relapsed disease. DNA methyltransferases (DNMTs) catalyze DNA methylation through transfer of methyl group to cytosine of the CpG dinucleotides, resulting in 5-methylcytostine. DNMT1 maintains patterns of methylated cytosine residues in human genome. DNMT3A and DNMT3B are de novo DNA methyltransferases, whose role is to maintain new methylation pattern that forms due to formation of the cancer. Methods: 30 bone-marrow aspirates from individuals with MGUS or MM patients before the treatment initiation were used. The cDNA was synthesized using 100 ng of total RNA in a 20 µl reaction volume (Roche, Diagnostics, Basel, Switzerland). Quantification of DNMT1, DNMT3a and DNMT3b levels by TaqMan® probes (Life Technologies, Grand Island, NY) with Xceed qPCR Master Mix (IAB, BioTech-Europe, Czech Republic) was performed. For normalization, the GAPDH was used. Results: Although MM is characterized by widespread alterations in DNA methylation, we observed that DNMT3a and DNMT3b de novo methyltransferases were underexpressed in both, MGUS individuals and MM patients when compared to DNMT1 expression level (Figure 1). The transcribed genes have increased levels of 5-hydroxymethylcytosine, then the DNMTs activities might compensate for active hydroxymethylation - demethylation. Conclusions: Our results confirm that the expression of de novo DNA methyltransferases is deregulated in MM cell lines. The presented analysis is first of its kind that was performed on human myeloma cell lines, especially with the focus on the residual expression of Dnmt3a. With support of the grant NT14393. Figure 1. Quantitative RT-PCR for DNMT1, DNMT3a and DNMT3b in MGUS individuals and MM patients. Figure 1. Quantitative RT-PCR for DNMT1, DNMT3a and DNMT3b in MGUS individuals and MM patients. Disclosures No relevant conflicts of interest to declare.

An Investigational Proteasome Inhibitor MLN9708 (MLN2238) Induces Apoptosis In Human Multiple Myeloma Cells In Vitro

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3066-3066
Author(s):  
Aisha Masood ◽  
Kasyapa Chitta ◽  
Kiersten M Miles ◽  
Nazmul H Khan ◽  
Remi Adelaiye ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Proteasome Inhibitor ◽  
Conflicts Of Interest ◽  
Active Form ◽  
Biologically Active ◽  
Mitochondrial Outer Membrane ◽  
Dependent Manner ◽  
In Vivo Models

Abstract Abstract 3066 Targeting the proteasome has proven to be one of the most effective therapeutic strategies in the treatment of multiple myeloma (MM), and the proteasome inhibitor bortezomib is approved for treatment of MM. However its clinical efficacy is compromised by the acquired resistance in patients, necessitating the development of new therapeutics. Several new proteasome inhibitors are under investigation for their therapeutic efficacy in MM. MLN9708 (Millennium Pharmaceuticals, Inc., Cambridge, MA) is a proteasome inhibitor which shows refined pharmacokinetic and pharmacodynamic properties in preclinical studies and is currently in Phase I clinical development. Upon exposure to aqueous solutions or plasma, MLN9708 rapidly hydrolyzes to MLN2238, the biologically active form. MLN2238 was used for all of the studies reported here, in which we report the efficacy of MLN2238 on three established MM cell lines-KMS11, OPM2 and U266. MLN2238 was found to inhibit the chymotrypsin-like proteasomal activity of all MM cell lines in a dose dependent manner. Investigation of the IC50 of MLN2238 on these cell lines demonstrated that KMS11 is the most sensitive (IC50 of 15.9 nM) while U266 was found to be the least sensitive cell line (IC50 of 511 nM). OPM2 cells also showed intermediate sensitivity with an IC50 of 58.6 nM. MLN2238 induced apoptosis in KMS11 cells as evidenced by annexin V staining and PARP-1 cleavage. Cleavage of caspases 9 and 3 suggested activation of the intrinsic apoptotic pathway by MLN2238. Furthermore, MLN2238 treatment was shown to increase the mitochondrial outer membrane permeability (MOMP) and decrease BCL-2 levels. Evaluation of the expression of PSMB5, the preferred proteasomal subunit target for both bortezomib and MLN2238, revealed that it is expressed at approximately 3 fold more in KMS11 cells as compared to U266, suggesting a possible mechanism for higher sensitivity of KMS11 to the proteasomal inhibitor, MLN2238. This preclinical evaluation confirms the anti-myeloma effects of MLN2238, warranting further in-depth evaluation in both in vitro and in vivo models of MM. Disclosures: No relevant conflicts of interest to declare.

Prohibitin Serves as a Novel Target Mitochondrial Protein of Phenyl-Chloroethyl Ureas Involved In Their Antiproliferative Effect on Multiple Myeloma Cells

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3002-3002
Author(s):  
Hye-Ran Kim ◽  
Ha-Young Eom ◽  
Dong Min Kim ◽  
Il-Chul Kim ◽  
Manian Rajesh Kumar ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Bone Marrow Cells ◽  
Conflicts Of Interest ◽  
Mitochondrial Protein ◽  
Mitochondrial Proteins ◽  
Leukemia Cells ◽  
Dependent Manner ◽  
Morphological Transformation ◽  
Novel Target

Abstract Abstract 3002 Background: Prohibitin (PHB) is localized to the mitochondria where it might have a role in the maintenance of mitochondrial function. The diverse function of PHB, together with the emerging evidence that its function can be modulated specifically in certain diseases, implies that PHB would be a potential target for new therapeutics. Materials and Methods: We analyzed mitochondrial proteins and develop new anti-proliferative agents targeting multiple myeloma (MM) cells. Mitochondria were isolated from primary leukemia and MM cell lines (RPMI8226, ARH77, U266 and IM9) by density-gradient ultracentrifugation using swelling buffer and sucrose buffer. Dysregulated mitochondrial protein was identified using 2-DE and mass spectrometry (MALDI-TOF/TOF technology). Results: Out of 38 remarkable deregulated mitochondrial proteins in MM cell lines, prohibitin (PHB) (gi4505773) was highly expressed in primary MM and leukemia cells, which was confirmed by Western blot, immunohistochemistry and immunofluorecenct study in the primary bone marrow cells and sections. Potent chemical substances that can alkylate PHB, two molecules of phenyl-chloroethyl urea family such as cyclohexylphenyl-chloroethyl urea (CCEU) and iodophenyl-chloroethyl urea (ICEU), were synthesized independently from the reaction with 2-ethylisocyanate and 4-cyclohexylaniline and 4-iodoaniline, respectively. They were characterized by 1H NMR and 13C NMR. Time and dose dependent manner of proliferation suppression when treated with CCEU and ICEU was observed in MM and leukemia cells. Moreover, notable morphological transformation of MM cells was observed when treated with 10 – 100 umol of CCEU and ICEU for 24 hours. The half of maximal inhibitory concentration (IC50) was 25umol of most MM cell lines. Cell cycle analysis of CCEU-and-ICEU-treated- MM cells showed a remarkable increase of the sub-G1 phase. Immunoblotting experiment revealed the change of cytoplasmic and nucleoplasmic PHB. Expression of cleaved caspase3 and poly ADP-ribose polymerases were also observed to have increased in MM cell lines. Conclusions: By analyzing mitochondrial protein in leukemia and MM cell, we discovered a new molecular marker, PHB, characteristically overexpressed in leukemia and MM cells and developed new anti-cancer agents such as CCEU and ICEU that target against PHB in MM cells. Disclosures: No relevant conflicts of interest to declare.

CD69 Expression Predicts Favorable Outcome in Multiple Myeloma Patients Treated with VTD

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1768-1768
Author(s):  
Gabriele Buda ◽  
Giovanni Carulli ◽  
Enrico Orciuolo ◽  
Paola Sammuri ◽  
Sara Galimberti ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Plasma Cells ◽  
Conflicts Of Interest ◽  
Clinical Status ◽  
Prognostic Impact ◽  
Clinical Report ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cd69 Expression

Abstract Multiple myeloma is an incurable disease characterized by proliferation of clonal malignant plasma cells (PC). Molecular characterization of malignant plasma cells is increasingly important for diagnostic and therapeutic stratification but the clinical and prognostic value of immunophenotyping in MM remains questionable. We have analyzed the prognostic impact of a relatively new marker as CD69. CD69 is a type II membrane protein. T cells express CD69 rapidly upon stimulation of the T-cell receptor (TCR), which is why CD69 has been mostly regarded as an activation marker. The precise role of CD69 in immunity has not been determined because its ligand is unknown, but an emerging role of CD69 in Multiple Myeloma (MM) has been postulated. Previous laboratoristic data, using tumor lines derived from murine model with genotypic and immunophenotypic features of resistance to bortezomib, showed that as the neoplastic plasma cells (PC) develop bortezomib resistance, they have a germinal center B cell like immunophenotype, including decreased to absent expression of CD69. Interestingly the activation antigen CD69 associates with and inhibits the function of Sphingosine 1-phosphate (S1P). S1P is a bioactive lysophospholipid which is known to induce diverse cellular responses through at least five G-protein-coupled receptors on various cell types. Other data showed that MM cells express the S1P receptors, S1P1, S1P2 and S1P3. Furthermore, S1P protects MM cells against dexametason-induced apoptosis. Importantly, S1P upregulates Mcl-1 expression in a time and concentration-dependent manner in human MM cell lines. In a previous abstract, we described for the first time in a clinical report, the CD69 expression on pathological PCs of MM patients. Our preliminary data also suggested an intriguing role of CD69 in patients treated with chemotherapy in different stages of disease. In this study, we report a larger setting of 97 patients where we confirmed the expression of CD 69 in 48 of them (49%) (see table I). Immunophenotyping was carried out by a 6-color method, using a FacsCanto II cytometer and the FacsDiva software. PCs were identified as CD138+/CD38+ events after an initial gate which included events with low SSC in the CD45/SSC cytogram. The MoAb panel also included CD19, CD20, CD117, CD56, cytoplasmic light chains K and Lambda. PerCP-Cy5.5-conjugated CD69 was evaluated on phenotypically abnormal plasma cells (i.e. CD19-, CD45- or dim), which were resulted to be clonally restricted. Results were considered positive when the percentage of positive cells was > 20%. After an induction regimen of treatment with four cycles of VDT (bortezomib, dexametasone, thalidomide), 69 patients were evaluable. 40/69 (65%) of patients obtained at least of a very good partial response or better (Responding pts). In this subgroup of patients 30/45 (66.6%) showed the expression of CD 69. On the contrary only in a little part of partial or less responding patients (NR pts) 9/24 (37.5%) CD69 was detected (see table II) (p=0.02 using a chi squared test and p=0.019 using a Fisher's exact test). Data on cytogenetic abnormalities, including del(13q), t(4;14) and del(17p), detected by fluorescence in situ hybridization, were available in >90% of patients. Clinical data were available in all patients and CD69 maintained its association with different response, independently of other prognostic variables. In conclusion CD69 is often expressed in PCM cases, and the expression of this marker is useful to reveal poor prognostic categories and delineate a risk stratification. This molecule could represent an emerging clinical factor to identify different outcomes in patients affected by MM and treated with the modern drugs. Table I Pts Characteristics Total CD69+ 97 48/97 Sex Male 51(52%) Female 46(48%) Clinical status MM non evaluableMM after VTD 28/9769/97 in VGPR/CR 45/69 in PR/SD/PD 24/69 Table II Pts treated with VTD Responding pts NRpts 45 24 CD69+ 39/69 30/45 9/24 CD69- 30/69 15/45 15/24 Disclosures No relevant conflicts of interest to declare.

Preclinical Evaluation of a Potent Anti-Bcma CD3 Bispecific Molecule for the Treatment of Multiple Myeloma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 383-383 ◽  
Author(s):  
Siler H Panowski ◽  
Tracy Kuo ◽  
Amy Chen ◽  
Tao Geng ◽  
Thomas J Van Blarcom ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Cell Lines ◽  
Half Life ◽  
Plasma Cells ◽  
Target Cells ◽  
Dependent Manner ◽  
Human Igg

Abstract Multiple myeloma (MM) is a debilitating disease characterized by the abnormal accumulation of malignant plasma cells in the bone marrow. Despite recent advances in myeloma therapy, including proteasome inhibitors, immunomodulatory drugs, and targeted antibody therapies, patients relapse and the disease remains incurable and one of high unmet need. T cell redirecting therapies are a new and exciting class of therapeutics that harness the potent cytotoxic activity of T cells and redirect it to target tumor cells. T cell redirecting therapies are only as good as their targeted tumor associated antigen (TAA) and the potent nature of the therapy requires a lack of TAA expression in essential normal tissue. B-cell Maturation Antigen, BCMA, is a tumor necrosis factor superfamily member highly expressed on the surface of myeloma cells. Detectable normal BCMA tissue expression appears limited to plasmablasts and mature plasma cells, making it an ideal T cell redirecting target for the treatment of MM. Other groups have developed T cell redirecting therapies against BCMA, including CAR T and BiTE therapy (a short half-life CD3 bispecific). Here we present preclinical studies on a fully-human IgG CD3 bispecific molecule targeting BCMA (half-life in mice of ~3 days). This molecule utilizes anti-BCMA and anti-CD3 targeting arms paired through hinge mutation technology and placed in an IgG2A backbone. The molecule binds to BCMA-expressing myeloma cell lines and to T cells with affinities of 20pM and ~40nM, respectively. T cells co-cultured with MM cell lines were activated and de-granulated in the presence of BCMA bispecific. In vitro cytotoxicity assays revealed the high potency of the molecule, as it was able to drive lysis of MM target cells with an EC50 of 6± 8 pM (mean ± SD). We also observed strong in vitro potency with the BCMA bispecific in four different MM primary patient samples, EC50 =0.093±0.1 nM (mean ± SD). When the same four samples were targeted with a BCMA antibody drug conjugate (ADC), 3 of the samples gave EC50 values of 1.25±0.7 nM (mean ± SD) - i.e. a 43 fold decrease in potency compared to the CD3 bispecific. The fourth patient did not respond to the ADC. Together, these results illustrate the potential advantages of a CD3 bispecific over an ADC for targeting BCMA. In orthotopic, established, tumor mouse models utilizing three different MM cell lines, (OPM2, MM.1S and MOLP8), a single injection of BCMA bispecific effectively treated tumors in a dose-dependent manner. Re-dosing the bispecific was able to provide additional and prolonged efficacy. The extreme potency of T cell redirecting therapies results in outstanding efficacy, but can also lead to lysis of normal cells expressing even minute levels of target. The species cross-reactivity of the BCMA bispecific allowed for exploratory toxicity studies in cynomologus monkeys. The molecule was able to effectively deplete normal plasma B cells expressing low levels of BCMA, providing evidence of activity. Activity was accompanied by a cytokine spike following initial dosing. No cytokine release was observed following a second bispecific dose. Encouragingly, animals experienced no additional adverse events (AEs), confirming the favorable safety profile of BCMA as a target for MM. In summary, we report on a fully human IgG CD3 bispecific molecule targeting BCMA for the treatment of multiple myeloma. Our BCMA bispecific is expected to have an antibody-like half-life in humans and, taken together, our findings support that the molecule has the potential to be both a potent and safe therapeutic. Disclosures Panowski: Pfizer Inc.: Employment. Kuo:Alexo Therapeutics: Employment. Chen:Alexo Therapeutics: Employment. Geng:Kodiak Sciences: Employment. Van Blarcom:Pfizer Inc.: Employment. Lindquist:Pfizer Inc.: Employment. Chen:Pfizer Inc.: Employment. Chaparro-Riggers:Pfizer Inc.: Employment. Sasu:Pfizer Inc.: Employment.

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