CLL Mesenchymal Stromal Cells Have Decreased Replicative Potential and Senescent Phenotype: Clinical and Biologic Implications

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3282-3282 ◽  
Author(s):  
Wei Ding ◽  
Charla Secreto ◽  
Xiaosheng Wu ◽  
Esteban Braggio ◽  
Yuji Zhang ◽  
...  

Abstract Introduction We have previously developed a primary human bone marrow model in CLL which allows us to study marrow derived mesenchymal stroma cells (MSC) and mimic in vivoMSC-leukemic interactions in CLL (Ding, Blood, 2010) These interactions proved to be bidirectional with functional implications for both cell types. However the biologic and clinical implications of these bilateral cellular interactions in relation to MSC function in CLL patients have not been completely studied. MSC are clearly established as an essential component in forming supportive marrow niches for hematopoiesis. Our focus in this study thus was to further investigate on the status of CLL MSC function in comparison with normal MSC and the impact of the leukemic CLL B cell on MSC function and its role in forming marrow niches in CLL. Methods Bone marrow (BM) aspirates of CLL patients or normal age-matched subjects were used to generate MSC and these MSC were then assessed for various functions. Specifically we assessed the growth, differentiation capacity, gene expression, cytokine secretion profile and transcriptome analysis of CLL and normal MSC using colony forming unit (CFU) assay, MSC differentiation assay, Affymetrix U133 2.0 plus array and RNA sequencing respectively. To determine MSC CFU frequency, fixed number of nucleated cells (5 or 10 million) from BM aspirates were added in MSC growth medium for 10 days to form CFU. CFU frequency was then calculated by dividing the number of MSC colonies by the fixed number of inputted nucleated cells. In order to test the specific gene changes that occurred in MSC after their interaction with CLL leukemic cells, normal MSC were co-cultured with CLL cells for 1 week and subsequently followed by cell growth, gene expression analysis with RNA sequencing and cytokine profiles using a multiplex assay. Results CLL MSC generated significantly lower CFU colonies compared to normal subjects (CLL [n=24] vs normal [n=6] mean: 2.2 vs. 22 CFU per million nucleated cells, p=0.01). In order to test if the lower number of CLL MSC CFU was due to their reduced growth capacity or lower frequency, we then performed the CFU assay using identical numbers of CLL and normal MSC at the start of culture. CLL MSC was found to have significantly lower CFU capacity compared to normal MSC (mean: 2.1 [CLL] vs 4.5 [normal] CFU/10 input cell, n=7 in each group, p=0.03). To investigate the mechanism(s) for the reduced growth capacity of CLL MSC, we compared the gene expression profiles of non-stimulated CLL vs. normal MSC (n=10 for each group) with the following outcomes: CLL MSC had increased expression of cell cycle inhibitor: p16(Ink4a) and p57, both key markers of cell senescence (Baker, Nature, 2011); CLL MSC overexpressed homeobox B cluster of transcription factors, key regulator for cell development and differentiation. Wnt inhibitors DKK1/DKK2 and non-canonical Wnt 5b known to be associated with aging were found to be 10 and 2 fold more elevated in CLL MSC. In addition, MSC abundantly produced a milieu of the cytokines MCP-1/IL-8/IL-6/IL-1Ra after interaction with CLL leukemic cells. These cytokines are associated with a senescent associated secretory phenotype (SASP). Co-culture experiments of normal MSC with CLL Leukemic cells revealed significant impact of leukemic cells on normal MSC functions. Co-culture with a low density of CLL leukemic cells (CLL to MSC ratio: ≤10,000/1) increased MSC growth (1.2 fold). However, high density co-culture of CLL cells with MSC (CLL to MSC ratio of 100,000/1) inhibited MSC growth (0.8 fold). Transcriptome analysis of normal MSC before and after one week of co-culture with CLL leukemic cells showed that normal MSC had alteration of ~1500 genes. Many of the modified genes (CDKN2B, DKK2, LIF, HGF, FOXQ1 etc) are known to be involved in regulation of cell growth and senescence. Conclusion Collectively, these results demonstrated that bone marrow derived CLL MSC have decreased proliferative potential and possess senescent phenotypes. Importantly these senescent features were inducible in normal MSC after their interaction with CLL leukemic cells implying that leukemic B cells can educate MSC to become senescent. The implications of the CLL MSC senescence status are multiple and include: defective hematopoietic niches due to dysfunctional MSC, immune dysregulation and the enhanced nurturing of CLL B cell by these MSC. We are now investigating several of these latter features in our current work. Disclosures Shanafelt: Genentech: Research Funding; GlaxoSmithKline: Research Funding; Celegene: Research Funding; Cephalon: Research Funding; Pharmacyclics/Jannsen: Research Funding; Hospira: Research Funding; Polyphenon E Int'l: Research Funding. Kay:Genetech: Research Funding; Pharmacyclics: Research Funding; Hospira: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees.

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 30-31
Author(s):  
Hanyin Wang ◽  
Shulan Tian ◽  
Qing Zhao ◽  
Wendy Blumenschein ◽  
Jennifer H. Yearley ◽  
...  

Introduction: Richter's syndrome (RS) represents transformation of chronic lymphocytic leukemia (CLL) into a highly aggressive lymphoma with dismal prognosis. Transcriptomic alterations have been described in CLL but most studies focused on peripheral blood samples with minimal data on RS-involved tissue. Moreover, transcriptomic features of RS have not been well defined in the era of CLL novel therapies. In this study we investigated transcriptomic profiles of CLL/RS-involved nodal tissue using samples from a clinical trial cohort of refractory CLL and RS patients treated with Pembrolizumab (NCT02332980). Methods: Nodal samples from 9 RS and 4 CLL patients in MC1485 trial cohort were reviewed and classified as previously published (Ding et al, Blood 2017). All samples were collected prior to Pembrolizumab treatment. Targeted gene expression profiling of 789 immune-related genes were performed on FFPE nodal samples using Nanostring nCounter® Analysis System (NanoString Technologies, Seattle, WA). Differential expression analysis was performed using NanoStringDiff. Genes with 2 fold-change in expression with a false-discovery rate less than 5% were considered differentially expressed. Results: The details for the therapy history of this cohort were illustrated in Figure 1a. All patients exposed to prior ibrutinib before the tissue biopsy had developed clinical progression while receiving ibrutinib. Unsupervised hierarchical clustering using the 300 most variable genes in expression revealed two clusters: C1 and C2 (Figure 1b). C1 included 4 RS and 3 CLL treated with prior chemotherapy without prior ibrutinib, and 1 RS treated with prior ibrutinib. C2 included 1 CLL and 3 RS received prior ibrutinib, and 1 RS treated with chemotherapy. The segregation of gene expression profiles in samples was largely driven by recent exposure to ibrutinib. In C1 cluster (majority had no prior ibrutinb), RS and CLL samples were clearly separated into two subgroups (Figure 1b). In C2 cluster, CLL 8 treated with ibrutinib showed more similarity in gene expression to RS, than to other CLL samples treated with chemotherapy. In comparison of C2 to C1, we identified 71 differentially expressed genes, of which 34 genes were downregulated and 37 were upregulated in C2. Among the upregulated genes in C2 (majority had prior ibrutinib) are known immune modulating genes including LILRA6, FCGR3A, IL-10, CD163, CD14, IL-2RB (figure 1c). Downregulated genes in C2 are involved in B cell activation including CD40LG, CD22, CD79A, MS4A1 (CD20), and LTB, reflecting the expected biological effect of ibrutinib in reducing B cell activation. Among the 9 RS samples, we compared gene profiles between the two groups of RS with or without prior ibrutinib therapy. 38 downregulated genes and 10 upregulated genes were found in the 4 RS treated with ibrutinib in comparison with 5 RS treated with chemotherapy. The top upregulated genes in the ibrutinib-exposed group included PTHLH, S100A8, IGSF3, TERT, and PRKCB, while the downregulated genes in these samples included MS4A1, LTB and CD38 (figure 1d). In order to delineate the differences of RS vs CLL, we compared gene expression profiles between 5 RS samples and 3 CLL samples that were treated with only chemotherapy. RS samples showed significant upregulation of 129 genes and downregulation of 7 genes. Among the most significantly upregulated genes are multiple genes involved in monocyte and myeloid lineage regulation including TNFSF13, S100A9, FCN1, LGALS2, CD14, FCGR2A, SERPINA1, and LILRB3. Conclusion: Our study indicates that ibrutinib-resistant, RS-involved tissues are characterized by downregulation of genes in B cell activation, but with PRKCB and TERT upregulation. Furthermore, RS-involved nodal tissues display the increased expression of genes involved in myeloid/monocytic regulation in comparison with CLL-involved nodal tissues. These findings implicate that differential therapies for RS and CLL patients need to be adopted based on their prior therapy and gene expression signatures. Studies using large sample size will be needed to verify this hypothesis. Figure Disclosures Zhao: Merck: Current Employment. Blumenschein:Merck: Current Employment. Yearley:Merck: Current Employment. Wang:Novartis: Research Funding; Incyte: Research Funding; Innocare: Research Funding. Parikh:Verastem Oncology: Honoraria; GlaxoSmithKline: Honoraria; Pharmacyclics: Honoraria, Research Funding; MorphoSys: Research Funding; Ascentage Pharma: Research Funding; Genentech: Honoraria; AbbVie: Honoraria, Research Funding; Merck: Research Funding; TG Therapeutics: Research Funding; AstraZeneca: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Kenderian:Sunesis: Research Funding; MorphoSys: Research Funding; Humanigen: Consultancy, Patents & Royalties, Research Funding; Gilead: Research Funding; BMS: Research Funding; Tolero: Research Funding; Lentigen: Research Funding; Juno: Research Funding; Mettaforge: Patents & Royalties; Torque: Consultancy; Kite: Research Funding; Novartis: Patents & Royalties, Research Funding. Kay:Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Acerta Pharma: Research Funding; Juno Theraputics: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Oncotracker: Membership on an entity's Board of Directors or advisory committees; Sunesis: Research Funding; MEI Pharma: Research Funding; Agios Pharma: Membership on an entity's Board of Directors or advisory committees; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Cytomx: Membership on an entity's Board of Directors or advisory committees. Braggio:DASA: Consultancy; Bayer: Other: Stock Owner; Acerta Pharma: Research Funding. Ding:DTRM: Research Funding; Astra Zeneca: Research Funding; Abbvie: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Membership on an entity's Board of Directors or advisory committees; alexion: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 9-9
Author(s):  
Shanye Yin ◽  
Gregory Lazarian ◽  
Elisa Ten Hacken ◽  
Tomasz Sewastianik ◽  
Satyen Gohil ◽  
...  

A hotspot mutation within the DNA-binding domain of IKZF3 (IKZF3-L162R) has been identified as a putative driver in chronic lymphocytic leukemia (CLL); however, its functional effects are unknown. We recently confirmed its role as a CLL driver in a B cell-restricted conditional knock-in model. IKZF3 mutation altered mature B cell development and signaling capacity, and induced CLL-like disease in elderly mice (~40% penetrance). Moreover, we found IKZF3-L162R acts as a gain-of-function mutation, altering DNA binding specificity and target selection of IKZF3, and resulting in overexpression of multiple B-cell receptor (BCR) genes. Consistent with the murine data, RNA-sequencing analysis showed that human CLL cells with mut-IKZF3 [n=4] have an enhanced signature of BCR-signaling gene expression compared to WT-IKZF3 [n=6, all IGHV unmutated] (p<0.001), and also exhibited general upregulation of key BCR-signaling regulators. These results confirm the role of IKZF3 as a master regulator of BCR-signaling gene expression, with the mutation contributing to overexpression of these genes. While mutation in IKZF3 has a clear functional impact on a cardinal CLL-associated pathway, such as BCR signaling, we note that this driver occurs only at low frequency in patients (~3%). Because somatic mutation represents but one mechanism by which a driver can alter a cellular pathway, we examined whether aberrant expression of IKZF3 could also yield differences in BCR-signaling gene expression. We have observed expression of the IKZF3 gene to be variably dysregulated amongst CLL patients through re-analysis of transcriptomic data from two independent cohorts of human CLL (DFCI, Landau et al., 2014; ICGC, Ferreira et al., 2014). We thus examined IKZF3 expression and BCR-signaling gene expression, or the 'BCR score' (calculated as the mean expression of 75 BCR signaling-associate genes) in those cohorts (DFCI cohort, n=107; ICGC cohort, n=274). Strikingly, CLL cells with higher IKZF3 expression (defined as greater than median expression) had higher BCR scores than those with lower IKZF3 expression (<median) (p=0.0015 and p<0.0001, respectively). These findings were consistent with the notion that IKZF3 may act as a broad regulator of BCR signaling genes, and that IKZF3 overexpression, like IKZF3 mutation, may provide fitness advantage. In support of this notion, our re-analysis of a gene expression dataset of 107 CLL samples (Herold Leukemia 2011) revealed that higher IKZF3 expression associated with poorer prognosis and worse overall survival (P=0.035). We previously reported that CLL cells with IKZF3 mutation appeared to increase in cancer cell fraction (CCF) with resistance to fludarabine-based chemotherapy (Landau Nature 2015). Instances of increase in mut-IKZF3 CCF upon treatment with the BCR-signaling inhibitor ibrutinib have been reported (Ahn ASH 2019). These studies together suggest an association of IKZF3 mutation with increased cellular survival following either chemotherapy or targeted treatment. To examine whether higher expression of IKZF3 was associated with altered sensitivity to ibrutinib, we performed scRNA-seq analysis (10x Genomics) of two previously treatment-naïve patients undergoing ibrutinib therapy (paired samples, baseline vs. Day 220). We analyzed an average of 11,080 cells per patient (2000 genes/cell). Of note, following ibrutinib treatment, remaining CLL cells expressed higher levels of IKZF3 transcript compared to pretreatment baseline (both p<0.0001), whereas no such change was observed in matched T cells (n ranging between 62 to 652 per experimental group, p>0.05), suggesting that cells with high expression of IKZF3 were selected by ibrutinib treatment. Moreover, we showed that ibrutinib treatment resulted in consistent upregulation of BCR-signaling genes (e.g., CD79B, LYN, GRB2, FOS, RAC1, PRKCB and NFKBIA) (n ranging between 362 to 1374 per experimental group, all p<0.0001), which were likewise activated by mutant IKZF3. Altogether, these data imply that IKZF3 mutation or overexpression may influence upregulation of BCR-signaling genes and enhance cellular fitness even during treatment with BCR-signaling inhibitors. We highlight our observation that IKZF3 mutation appears to be phenocopied by elevated IKZF3 expression, and suggest that alterations in mRNA or protein level that mimic genetic mutations could be widespread in human cancers. Disclosures Kipps: Pharmacyclics/ AbbVie, Breast Cancer Research Foundation, MD Anderson Cancer Center, Oncternal Therapeutics, Inc., Specialized Center of Research (SCOR) - The Leukemia and Lymphoma Society (LLS), California Institute for Regenerative Medicine (CIRM): Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech/Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; VelosBio: Research Funding; Oncternal Therapeutics, Inc.: Other: Cirmtuzumab was developed by Thomas J. Kipps in the Thomas J. Kipps laboratory and licensed by the University of California to Oncternal Therapeutics, Inc., which provided stock options and research funding to the Thomas J. Kipps laboratory, Research Funding; Ascerta/AstraZeneca, Celgene, Genentech/F. Hoffmann-La Roche, Gilead, Janssen, Loxo Oncology, Octernal Therapeutics, Pharmacyclics/AbbVie, TG Therapeutics, VelosBio, and Verastem: Membership on an entity's Board of Directors or advisory committees. Wu:BionTech: Current equity holder in publicly-traded company; Pharmacyclics: Research Funding.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3620-3620
Author(s):  
Yang Liu ◽  
Min Ni ◽  
Aldo M. Roccaro ◽  
Xavier Leleu ◽  
Yong Zhang ◽  
...  

Abstract Abstract 3620 Introduction: Waldenstrom macroglobulinemia (WM) is a rare indolent non-Hodgkin lymphoma, characterized by bone marrow infiltration of clonal lymphoplasmacytic cells. Despite recent advances in understanding the pathogenesis of this disease, the molecular basis of WM etiology has not been clearly defined. We therefore performed genome-wide analysis of RNA polymerase II (pol II) binding sites and gene expression profiling in primary WM cells in order to comprehensively define the aberrant transcriptional regulation and related genes in WM. Methods: Primary CD19+ bone marrow derived WM cells and normal primary bone marrow were used. Genomic DNA was extracted using genome isolation kit (QIAGEN) after cross linking. All the DNA samples were sent for Chip assay and human promoter 1.0R array (Genepathway Inc.) which comprised of over 4.6 million probes tiled through over 25.500 human promoter regions. Each promoter region covers approximately 7.6kb upstream through 2.45kb downstream of the transcription start sites. For over 1,300 cancer associated genes, coverage of promoter regions was expanded to additional genomic content; for selected genes total coverage spans from 10kb upstream through 2.45kb downstream of transcription start sites. The published gene expression datasets (GDS2643) which included 10 CD19+ B cell from bone marrow of 10 WM patients and 8 normal controls was analyzed by d-chip software and normalized to normal control. The motif analysis was performed using Cistrome online tools from the Dana Farber Cancer Institute. The gene sets enrichment analysis (GSEA) was performed using GSEA online software from Broad institute. Results: A total of 13,546 high-confidence pol II sites were identified in WM samples and share a small percentage of overlap (11.5%) with the binding sites identified in normal controls. Combining the expression microarray data of WM patient samples and normal controls, we demonstrated a significant correlation between high levels of gene expression and enriched promoter binding of pol II. Notably, we also observed that the WM-unique pol II binding sites are localized in the promoters of 5,556 genes which are involved in important signaling pathways, such as Jak/STAT and MAPK pathways by applying gene set enrichment analysis (GSEA). Interestingly, we found that STAT, FOXO and IRF family binding sites motifs were enriched in the pol II-bound promoter region of IL-6 which plays a crucial role in cell proliferation and survival of WM cells. Moreover, the CpG island associated c-fos promoter was enriched for Pol II binding as compared to the normal control. Conclusion: The presence of increased Pol II binding and the identification of transcription factor motifs in the promoters of key oncogenes may lead to a better understanding of WM. Our findings suggest that altered transcriptional regulation may play an important role in the pathogenesis of WM. In addition, this study will provide novel insights into the molecular mechanism of WM etiology, and may lead to discovery of novel diagnostic molecular biomarkers and therapeutic targets for WM. Disclosures: Leleu: Celgene: Consultancy, Research Funding; Janssen Cilag: Consultancy, Research Funding; Leo Pharma: Consultancy; Amgen: Consultancy; Chugai: Research Funding; Roche: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Ghobrial:Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2424-2424
Author(s):  
Yang Liu ◽  
Yong Zhang ◽  
Phong Quang ◽  
Hai T Ngo ◽  
Feda Azab ◽  
...  

Abstract Abstract 2424 Introduction Tumor necrosis factor receptor super families (TNFRSFs) play an important role in activation of lymphocyte and cell apoptosis. However the function of TNFRSFs in multiple myeloma (MM) remains unknown. Loss of function mutation of Fas antigen (TNFRSF6) was identified in MM cells, thus suggesting the possible role of TNFRSFs in regulating MM pathogenesis. We therefore investigated the epigenetic mechanisms that may mediate inactivation of TNFRSFs and its functional role in MM. Methods Dchip software was utilized for analyzing gene expression dataset. DNA was extracted from both primary CD138+ MM plasma cells and MM cell lines using blood & tissue DNA isolation kit (Qiagen, Inc.). Expression of GITR in primary CD138+ plasma cells was detected by Imunohistochemistry (IHC) DNA methylation was analyzed by methylated DNA immunoprecipitation (Medip) assay and bisulfate sequencing. 5'azacytidine was used to demethylate genomic DNA. Gene expression was detected by qRT-PCR and confirmed at the protein level by flow cytometry and western-blot. Over-expression of GITR was obtained in MM1.S cells by using GITR recombinant plasmid and electroporation. Apoptosis was determined using Annexin/PI staining and flow cytometry analysis. Activation of apoptotic signaling was studied by western blot. Cell survival and proliferation were analyzed by MTT and BrdU assay, respectively. Recombinant GITR-lentivirus was obtained from the supernatant of culture medium after 72 hours transfection in 293 cells. GFP positive MM cells were sorted and analyzed by flow cytometry. In vivo effect of GITR on MM tumor growth was determined by injection of GITR over-expressing MM cells in null mice. Mice skull, femur and vertebrae were isolated after 4 weeks injection. Anti-human CD138+ mAb microbead was used to detect MM cells extracted from mice tissue by flow cytometry. Results Gene-expression profiling showed down-regulation of TNFRSFs, including TNFRSF11A, TNFRSF11B, TNFRSF8, TNFRSF10C, TNFRSF9, TNFRSF21, TNFRSF1B, TNFRSF1A and TNFRSF18, compared to normal plasma cells. Moreover, Our IHC results also showed that GITR expression was positive in primary CD138+ plasma cells from 9 normal bone marrow, but negative in 9 MM samples. Importantly, we found that low GITR expression significantly correlated with MM progression. Indeed, GITR gene levels were lower in smoldering and active MM patients compared to MGUS patients and normal donors. Promoter CpG island (CGI) methylation of GITR was indentified in 5 out of 7 MM primary bone marrow (BM)-derived CD138+ cells but not in normal BM-derived plasma cells. Bisulfate sequencing and Medip assay showed that methylation of GITR was significantly associated with GITR expression in 5 MM cell lines, including MM1.S, OPM1, U266, RPMI and INA6. Promoter CGI of GITR was highly methylated leading to complete silencing of GITR in MM1.S cell line. GITR expression was significantly up-regulated in MM cells upon treatment with the 5'azacytidine. MTT and BrdU assay revealed that the proliferation and survival of MM1.S cells was disrupted in the GITR over-expressing MM1.S cells, notably with inhibition of cell proliferation compared to control vector infected cells. Moreover induction of cytotoxicity in GITR over-expressing cells was confirmed by using GFP competition assay. GITR-induced apoptosis was supported by induction of caspase 8 and 3 cleavage. The inhibition of human CD138+ plasma cell growth in the bone marrow of SCID mice using a disseminated MM xenograft model was observed in the experimental group injected with GITR expressing cells compared to the control group after 4 weeks injection. Conclusion Our findings uncovered a novel epigenetic mechanism contributing to MM pathogenesis, showing the role of GITR methylation as a key regulator of MM cell survival. Disclosures: Roccaro: Roche:. Ghobrial:Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Noxxon: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 883-883
Author(s):  
Yu-Tzu Tai ◽  
Betty Y Chang ◽  
Sun-Young Kong ◽  
Mariateresa Fulciniti ◽  
Guang Yang ◽  
...  

Abstract Abstract 883 Specific expression of Bruton's tyrosine kinase (Btk) in osteoclasts (OC), but not osteoblasts (OB), suggests its role in regulating osteoclastogenesis. Although Btk is critical in B cell maturation and myeloid function, it has not been characterized in plasma cell malignancies including multiple myeloma (MM) and Waldenström Macroglobulinemia (WM). We here investigate effects of PCI-32765, an oral, potent, and selective Btk inhibitor with promising clinical activity in B-cell malignancies, on OC differentiation and function within MM bone marrow (BM) microenvironment, as well as on MM and WM cancer cells. We further define molecular targets of Btk signaling cascade in OCs and MM in the BM milieu. In CD14+ OC precursor cells, RANKL and M-CSF stimulate phosphorylation of Btk in a time-dependent fashion; conversely, PCI-32765 abrogates RANKL/M-CSF-induced activation of Btk and downstream PLCγ2. Importantly, PCI-32765 decreased number of multinucleated OC (>3 nuclei) by tartrate-resistant acid phosphatase (TRAP) staining and the secretion of TRAP5b (ED50 = 17 nM), a specific mature OC marker. It increased size of OCs and number of nuclei per OC, with significantly defective bone resorption activity as evidenced by diminished pit formation on dentine slices. Moreover, lack of effect of Dexamethasone on OC activity was overcome by combination of Dexamethasone with PCI-32765. PCI-32765 significantly reduced cytokine and chemokine secretion from OC cultures, including MIP1α, MIP1β, IL-8, TGFβ1, RANTES, APRIL, SDF-1, and activin A (ED50 = 0.1–0.48 nM). It potently decreased IL-6, SDF-1, MIP1α, MIP1β, and M-CSF in CD138-negative cell cultures from active MM patients, associated with decreased TRAP staining in a dose-dependent manner. In MM and WM cells, immunoblotting analysis confirmed a higher Btk expression in CD138+ cells from majority of MM patients (4 out of 5 samples) than MM cell lines (5 out of 9 cell lines), whereas microarray analysis demonstrated a higher expression of Btk and its downstream signaling components in WM cells than in CD19+ normal bone marrow cells. PCI-32765 significantly inhibits SDF-1-induced adhesion and migration of MM cells. It further blocked cytokine expression (MIP1a, MIP-1β) at mRNA level in MM and WM tumor cells, correlated with inhibition of Btk-mediated pPLCγ2, pERK and NF-kB activation. Importantly, PCI-32765 inhibited growth and survival triggered by IL-6 and coculture with BM stromal cells (BMSCs) or OCs in IL-6-dependent INA6 and ANBL6 MM cells. Furthermore, myeloma stem-like cells express Btk and PCI-32765 (10–100 nM) blocks their abilities to form colonies from MM patients (n=5). In contrast, PCI-32765 has no adverse effects on Btk-negative BMSCs and OBs, as well as Btk-expressing dendritic cells. Finally, oral administration of PCI-32765 (12 mg/kg) in mice significantly suppresses MM cell growth (p< 0.03) and MM cell-induced osteolysis on implanted human bone chips in a humanized myeloma (SCID-hu) model. Together, these results provide compelling evidence to target Btk in the BM microenvironment against MM and WM., strongly supporting clinical trials of PCI-32765 to improve patient outcome in MM and WM. Disclosures: Chang: Pharmacyclics Inc: Employment. Buggy:Pharmacyclics, Inc.: Employment, Equity Ownership. Elias:Pharmacyclics Inc: Consultancy. Treon:Millennium: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Genentech: Honoraria. Richardson:Millennium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Johnson & Johnson: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Munshi:Millennium: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Anderson:Millennium Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Onyx: Consultancy; Merck: Consultancy; Bristol-Myers Squibb: Consultancy; Actelion: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1773-1773
Author(s):  
Ranjit Banwait ◽  
Yosra Aljawai ◽  
Joseph Cappuccio ◽  
Serena McDiarmid ◽  
Salomon Manier ◽  
...  

Abstract Introduction Disease assessment in Waldenstrom’s Macroglobulinemia (WM) is dependent on percent involvement of B-cell neoplasm in bone marrow and immunoglobulin M (IgM) paraprotein in the serum. A subset of patients also demonstrate extramedullary involvement and is infrequently examined. Its role in diagnosis and prognosis of WM is poorly understood. In this study, we sought to understand the role of extramedullary disease (EMD) in patients with WM. Methods Database for patients seen at Dana-Farber Cancer Institute was searched and 985 documented WM cases were identified between June 1994 and April 2013. Medical charts were reviewed for patients who had biopsy of one or more extramedullary sites during the course of disease. Involvement of lymph nodes, spleen and amyloid deposits were excluded. Results Among the 985 WM patients screened, 50 (5%) had evidence of extramedullary involvement during the course of disease. 28 (56%) were male and 22 (44%) were female, with median age of 57 years (min 37.8; max 71.1) at the time of diagnosis. At diagnosis, 11 (22%) patients were asymptomatic with monoclonal gammopathy of unknown significance (MGUS) or smoldering WM, 21 (42%) were low risk, 15 (30%) were intermediate risk, and 3 (6%) were high risk based on the Morel ISS-WM study (ISS-WM). Laboratory data included median beta-2 microglobulin of 3.7 g/dL (min 1.26; max 10.9), IgM of 3.3 g/dL (min 0.4; max 10.1), and percent bone marrow involvement of 37% (min 5%; max 90%). At the time of data collection, one patient was previously untreated, 14 (28%) had 1 line of therapy, 9 (18%) had 2 lines, 9 (18%) had 3 lines, 8 (16%) had 4 lines, and 9 (18%) had 5 or more lines of therapy. Among the 50 patients identified with EMD, 12 (24%) patients presented with involvement at diagnosis, while 38 (76%) developed EMD after receiving therapy. One patient had EMD at diagnosis, which continued post-diagnosis. 7 patients were identified with multiple sites of involvement during the course of disease. Overall, 60 extramedullary samples were noted with 47 (78%) occurring post-therapy. Extramedullary sites involved included: Pulmonary (n=14; 23%), Soft tissue (n=12; 20%), Cerebrospinal fluid (n=10; 17%), Renal (n=5; 8%), Bone (n=4; 7%), Peripheral blood (n=3; 5%), Neck mass (n=3; 5%), Skin (n=2; 3%), Breast (n=1; 2%), Conjunctiva (n=1; 2%), Liver (n=1; 2%), Gallbladder (n=1; 2%), Small Bowel (n=1; 2%), Prostate (n=1; 2%), and Colon (n=1; 2%). Immunophenotypic data was obtained for 58 of the 60 extramedullary samples and was analyzed by flow cytometry (n=24), immunohistochemistry (n=17), or both (n=17). All samples were of B-cell lineage (CD19+, CD20+). Monotypic surface immunoglobulin kappa or lambda light chain was analyzed in 49 samples, of which 43 were kappa (88%) and 6 were lambda (12%). In the group of 38 patients that presented with EMD post-therapy median time to EMD presentation from diagnosis was 75.7 months (min 1.5; max 213.7 or approximately 6 years) with a median of 2 lines of treatment (min 1; max 6). Therapies prior to EMD presentation in this group included rituximab based regimen in 31 of 38 cases (82%), cyclophosphamide based regimen in 15 cases (39%), fludarabine/cladribine based regimen in 12 cases (32%), and bortezomib based regimen in 11 cases (29%). Treatments for EMD in both groups included bendamustine based regimen resulting in minimal response (MR) or better in 8 of 9 cases (89%), rituximab based regimen resulting in MR or better in 24 of 30 cases (80%), cyclophosphamide based regimen resulting in MR or better in 11 of 14 cases (79%), and bortezomib based regimen resulting in MR or better in 6 of 8 cases (75%). At the time of data collection, 32 of 50 patients were alive (64%), 10 patients were lost to follow-up (20%), and 8 patients died due to progressive disease (16%). Conclusion This is the first description and analysis of the EMD in WM as a clinical entity and further studies in understanding the molecular mechanisms that govern EMD in WM should be examined. Disclosures: Treon: Millennium: Consultancy. Ghobrial:Onyx: Membership on an entity’s Board of Directors or advisory committees; BMS: Membership on an entity’s Board of Directors or advisory committees; BMS: Research Funding; Sanofi: Research Funding; Novartis: Membership on an entity’s Board of Directors or advisory committees.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1882-1882 ◽  
Author(s):  
Samuel A Danziger ◽  
Mark McConnell ◽  
Jake Gockley ◽  
Mary Young ◽  
Adam Rosenthal ◽  
...  

Abstract Introduction The multiple myeloma (MM) tumor microenvironment (TME) strongly influences patient outcomes as evidenced by the success of immunomodulatory therapies. To develop precision immunotherapeutic approaches, it is essential to identify and enumerate TME cell types and understand their dynamics. Methods We estimated the population of immune and other non-tumor cell types during the course of MM treatment at a single institution using gene expression of paired CD138-selected bone marrow aspirates and whole bone marrow (WBM) core biopsies from 867 samples of 436 newly diagnosed MM patients collected at 5 time points: pre-treatment (N=354), post-induction (N=245), post-transplant (N=83), post-consolidation (N=51), and post-maintenance (N=134). Expression profiles from the aspirates were used to infer the transcriptome contribution of immune and stromal cells in the WBM array data. Unsupervised clustering of these non-tumor gene expression profiles across all time points was performed using the R package ConsensusClusterPlus with Bayesian Information Criterion (BIC) to select the number of clusters. Individual cell types in these TMEs were estimated using the DCQ algorithm and a gene expression signature matrix based on the published LM22 leukocyte matrix (Newman et al., 2015) augmented with 5 bone marrow- and myeloma-specific cell types. Results Our deconvolution approach accurately estimated percent tumor cells in the paired samples compared to estimates from microscopy and flow cytometry (PCC = 0.63, RMSE = 9.99%). TME clusters built on gene expression data from all 867 samples resulted in 5 unsupervised clusters covering 91% of samples. While the fraction of patients in each cluster changed during treatment, no new TME clusters emerged as treatment progressed. These clusters were associated with progression free survival (PFS) (p-Val = 0.020) and overall survival (OS) (p-Val = 0.067) when measured in pre-transplant samples. The most striking outcomes were represented by Cluster 5 (N = 106) characterized by a low innate to adaptive cell ratio and shortened patient survival (Figure 1, 2). This cluster had worse outcomes than others (estimated mean PFS = 58 months compared to 71+ months for other clusters, p-Val = 0.002; estimate mean OS = 105 months compared with 113+ months for other clusters, p-Val = 0.040). Compared to other immune clusters, the adaptive-skewed TME of Cluster 5 is characterized by low granulocyte populations and high antigen-presenting, CD8 T, and B cell populations. As might be expected, this cluster was also significantly enriched for ISS3 and GEP70 high risk patients, as well as Del1p, Del1q, t12;14, and t14:16. Importantly, this TME persisted even when the induction therapy significantly reduced the tumor load (Table 1). At post-induction, outcomes for the 69 / 245 patients in Cluster 5 remain significantly worse (estimate mean PFS = 56 months compared to 71+ months for other clusters, p-Val = 0.004; estimate mean OS = 100 months compared to 121+ months for other clusters, p-Val = 0.002). The analysis of on-treatment samples showed that the number of patients in Cluster 5 decreases from 30% before treatment to 12% after transplant, and of the 63 patients for whom we have both pre-treatment and post-transplant samples, 18/20 of the Cluster 5 patients moved into other immune clusters; 13 into Cluster 4. The non-5 clusters (with better PFS and OS overall) had higher amounts of granulocytes and lower amounts of CD8 T cells. Some clusters (1 and 4) had increased natural killer (NK) cells and decreased dendritic cells, while other clusters (2 and 3) had increased adipocytes and increases in M2 macrophages (Cluster 2) or NK cells (Cluster 3). Taken together, the gain of granulocytes and adipocytes was associated with improved outcome, while increases in the adaptive immune compartment was associated with poorer outcome. Conclusions We identified distinct clusters of patient TMEs from bulk transcriptome profiles by computationally estimating the CD138- fraction of TMEs. Our findings identified differential immune and stromal compositions in patient clusters with opposing clinical outcomes and tracked membership in those clusters during treatment. Adding this layer of TME to the analysis of myeloma patient baseline and on-treatment samples enables us to formulate biological hypotheses and may eventually guide therapeutic interventions to improve outcomes for patients. Disclosures Danziger: Celgene Corporation: Employment, Equity Ownership. McConnell:Celgene Corporation: Employment. Gockley:Celgene Corporation: Employment. Young:Celgene Corporation: Employment, Equity Ownership. Schmitz:Celgene Corporation: Employment, Equity Ownership. Reiss:Celgene Corporation: Employment, Equity Ownership. Davies:MMRF: Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; TRM Oncology: Honoraria; Abbvie: Consultancy; ASH: Honoraria; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria. Copeland:Celgene Corporation: Employment, Equity Ownership. Fox:Celgene Corporation: Employment, Equity Ownership. Fitch:Celgene Corporation: Employment, Equity Ownership. Newhall:Celgene Corporation: Employment, Equity Ownership. Barlogie:Celgene: Consultancy, Research Funding; Dana Farber Cancer Institute: Other: travel stipend; Multiple Myeloma Research Foundation: Other: travel stipend; International Workshop on Waldenström's Macroglobulinemia: Other: travel stipend; Millenium: Consultancy, Research Funding; European School of Haematology- International Conference on Multiple Myeloma: Other: travel stipend; ComtecMed- World Congress on Controversies in Hematology: Other: travel stipend; Myeloma Health, LLC: Patents & Royalties: : Co-inventor of patents and patent applications related to use of GEP in cancer medicine licensed to Myeloma Health, LLC. Trotter:Celgene Research SL (Spain), part of Celgene Corporation: Employment, Equity Ownership. Hershberg:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties. Dervan:Celgene Corporation: Employment, Equity Ownership. Ratushny:Celgene Corporation: Employment, Equity Ownership. Morgan:Takeda: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Research Funding.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1641-1641 ◽  
Author(s):  
Elias Jabbour ◽  
Kathryn G. Roberts ◽  
Koji Sasaki ◽  
Yaqi Zhao ◽  
Chunxu Qu ◽  
...  

Background: Ino showed significant activity in phase II trials in pts with R/R ALL, that was subsequently confirmed in Phase III trial where Ino demonstrated higher response rates and superior overall survival vs standard of care chemotherapy (SOC) in adults with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (R/R ALL).Ph-like or BCR-ABL1-like ALL possesses a gene expression profile similar to that of BCR-ABL1 ALL but lacks the BCR-ABL1 fusion protein. It is characterized by increased expression of hematopoietic stem-cell genes, deletion of B-cell lineage genes and kinase-activating alterations. Ph-like ALL is associated with refractoriness to standard induction/consolidation chemotherapy and poor prognosis. Aim: To evaluate the outcomes of pts with R/R Ph-like ALL treated in phase II trial with Ino monotherapy. Methods: We performed an integrated analysis of whole genome sequencing (to identify sequence mutations, structural variations and DNA copy number alterations), and transcriptome sequencing (RNAseq; to quantify gene expression, determine Ph-like gene expression profile and identify fusions) on 53 patients' samples treated with Ino between June 2010 and September 2012. Results: Fifty-three evaluable pts with R/R ALL with stored baseline samples were analyzed. Pts characteristics are summarized in Table 1. Median age was 50 years. Ino was given as Salvage 1, Salvage 2, and Salvage 3 and beyond in 20 (38%), 18 (34%), and 15 (28%) pts, respectively. Figure 1 reflects the different genomic subgroups identified among 53 evaluable pts. Ph-like gene signature was found in 12 pts (22.6%). Among these 12 pts, 6 had IGH-CRLF2, 2 IGH-EPOR, 1 SNX2-ABL1, and 3 had no fusions identified. The overall response rates (ORR) were 54% [complete remission (CR) 20%, CR with partial hematologic recovery (CRh) 32%, and marrow CR (CRi) 2%]. Among pts with morphologic remission, 46% and 82% achieved minimal residual disease (MRD) negativity at CR and at any time, respectively. The ORR for pts with Ph-like ALL, Ph-positive ALL, ALL with KMT2A, and others were 58% (CR=25%; CRh=33%), 42% (CR=8%; CRh=33%), 57% (CR=14%; CRh=29%; CRi=14%), and 56% (CR=26%; CRh=30%), respectively. The respective overall MRD negativity rates were 71%, 100%, 75%, and 83% (Table 1). The median follow-up was 60 months. The median event-free (EFS) and overall survival (OS) were 3.3 and 5.4 months, respectively. There was no difference in EFS and OS between the subgroups analyzed (P=0.464; P=0.824). The median EFS and OS were 4.5 and 4.5 months for pts with Ph-like, 3.1 and 7.2 months for those with Ph-positive ALL, 2.8 and 4.4 months for those with KMT2A, and 2.2 and 4.6 months for others (Table 1). 21 (40%) pts had subsequent allogeneic stem cell transplant; 6 (50%), 3 (25%), 4 (57%), and 8 (36%) in each subgroup, respectively. The rate of VOD was 3 (6%) with no difference among different subgroups. Conclusion: The current analysis suggest that Ino therapy may overcome the impact of Ph-like phenotype in pts with ALL. Confirmation of these findings in a larger cohort and in frontline ALL patients is needed. Disclosures Jabbour: Takeda: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Adaptive: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Cyclacel LTD: Research Funding. Sasaki:Pfizer: Consultancy; Otsuka: Honoraria. Jain:Precision Biosciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics, an AbbVie company: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen Pharmaceuticals, Inc.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Research Funding; Adaptive Biotechnologies: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cellectis: Research Funding; AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Ravandi:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Xencor: Consultancy, Research Funding; Macrogenix: Consultancy, Research Funding; Menarini Ricerche: Research Funding; Selvita: Research Funding; Cyclacel LTD: Research Funding. Short:AstraZeneca: Consultancy; Takeda Oncology: Consultancy, Research Funding; Amgen: Honoraria. Garcia-Manero:Amphivena: Consultancy, Research Funding; Helsinn: Research Funding; Novartis: Research Funding; AbbVie: Research Funding; Celgene: Consultancy, Research Funding; Astex: Consultancy, Research Funding; Onconova: Research Funding; H3 Biomedicine: Research Funding; Merck: Research Funding. Konopleva:Cellectis: Research Funding; Agios: Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Ascentage: Research Funding; Eli Lilly: Research Funding; Calithera: Research Funding; Stemline Therapeutics: Consultancy, Honoraria, Research Funding; Forty-Seven: Consultancy, Honoraria; Reata Pharmaceuticals: Equity Ownership, Patents & Royalties; Kisoji: Consultancy, Honoraria; Ablynx: Research Funding; Genentech: Honoraria, Research Funding; Amgen: Consultancy, Honoraria; F. Hoffman La-Roche: Consultancy, Honoraria, Research Funding; Astra Zeneca: Research Funding. Mullighan:Illumina: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: sponsored travel; Pfizer: Honoraria, Other: speaker, sponsored travel, Research Funding; AbbVie: Research Funding; Loxo Oncology: Research Funding; Amgen: Honoraria, Other: speaker, sponsored travel. Kantarjian:Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Agios: Honoraria, Research Funding; Ariad: Research Funding; Novartis: Research Funding; Amgen: Honoraria, Research Funding; Immunogen: Research Funding; AbbVie: Honoraria, Research Funding; Astex: Research Funding; BMS: Research Funding; Cyclacel: Research Funding; Daiichi-Sankyo: Research Funding; Pfizer: Honoraria, Research Funding; Jazz Pharma: Research Funding; Takeda: Honoraria.


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.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 867-867
Author(s):  
Riikka Karjalalainen ◽  
Tea Pemovska ◽  
Muntasir Mamun Majumder ◽  
Bhagwan Yadav ◽  
Jing Tang ◽  
...  

Abstract BACKGROUND AND OBJECTIVES: The bone marrow (BM) microenvironment supports the survival of leukemic cells and influences their response to therapeutic agents by promoting drug tolerance and resistance. Novel therapeutic strategies are therefore needed that can override the BM mediated protection of AML cells in patients undergoing drug treatment. To address this we used a high-throughput drug screening method to identify novel drug combinations to reverse stromal-induced cytoprotection against the BCL2 antagonist venetoclax in primary AML samples. METHODS: Sensitivity of mononuclear cells collected from 18 AML BM aspirates or peripheral blood samples to a range of BCL2 inhibitors and tyrosine kinase inhibitors (TKIs) was assessed either in mononuclear cell medium (MCM, Promocell) or in a 25% HS-5 stromal cell-conditioned medium plus 75% RPMI medium mix (CM) to mimic cytoprotective bone marrow conditions. Cell viability was measured after 72 h and dose response curves generated for each tested drug. Drug sensitivity scores were calculated based on the area under the dose response curve. For the drug combination studies single agents (venetoclax, WEHI-539, ruxolitinib) were added simultaneously at fixed concentrations to AML cells and incubated for 72 h either in the MCM or CM medium. Cell viability was measured using the CellTiter-Glo assay. The expression of BCL2 genes was measured by qPCR after incubating the AML patient cells in either MCM or CM for 48 h. RESULTS: Incubation of primary AML cells in the CM culture condition led to reduced sensitivity to BCL2 family inhibitors, suggesting that stromal-derived factors in the CM promote cytoprotection. This effect was particularly pronounced for the selective BCL2 inhibitor venetoclax, where the CM-induced loss of sensitivity coincided with decreased BCL2 expression and increased BCL2L1 expression. In contrast, JAK inhibitors showed improved efficacy in CM compared to MCM culture conditions. To determine if the protective effects of CM stromal-like conditions against venetoclax could be diminished, the drug was tested in combination with the JAK1/2 inhibitor ruxolitinib using AML cells cultured in MCM or CM. When tested on AML cells from 4 patients with the FLT3-ITD alteration, we found that ruxolitinib rescued the sensitivity of venetoclax in leukemic cells in the presence of CM and the combination of two drugs exhibited synergistic effects in this setting. The combinatorial activity, however, was not recapitulated in the MCM condition. Since CM was found to induce BCL2L1 expression, venetoclax was also tested in combination with a BCLXLspecific inhibitor WEHI-539. Analogously to the ruxolitinib-venetoclax combination, synergistic activity between venetoclax and WEHI-539 was observed towards leukemic cells in the presence of CM. CONCLUSIONS: By applying a functional, drug-based approach to understand microenvironment-induced mechanisms of drug resistance in AML, we found that the activity of the selective BCL2 inhibitor venetoclax towards AML cells is adversely affected in stromal-based conditions, while JAK inhibitors, in contrast, exhibit increased efficacy in these conditions. Our results suggest stroma-derived cytokines induce JAK-STAT signaling in AML cells, which results in increased BCL2L1 expression and drives resistance to venetoclax. However, blocking JAK1/2 with ruxolitinib restores the sensitivity of AML cells to venetoclax. We found that JAK1/2 inhibitors such as ruxolitinib can act synergistically with BCL2/BCLXL inhibitors, suggesting clinically useful combination treatments. Disclosures Gjertsen: BerGenBio AS: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Boehringer Ingelheim: Membership on an entity's Board of Directors or advisory committees; Kinn Therapeutics AS: Equity Ownership. Porkka:Pfizer: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Kallioniemi:Vysis-Abbot: Patents & Royalties; Medisapiens: Membership on an entity's Board of Directors or advisory committees; IMI-Project Predect: Research Funding; Roche: Research Funding; Pfizer: Research Funding. Wennerberg:Pfizer: Research Funding. Heckman:Celgene: Honoraria, Research Funding.


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