scholarly journals Molecular Resistance Mechanisms in Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 471-471
Author(s):  
Santiago Barrio Garcia ◽  
Umair Munawar ◽  
Thorsten Stuehmer ◽  
Hermann Einsele ◽  
K. Martin Kortüm
Keyword(s):  
Multiple Myeloma ◽  
High Risk ◽  
Disease Progression ◽  
Tp53 Mutation ◽  
Conflicts Of Interest ◽  
Clonal Selection ◽  
Tumor Therapy ◽  
Genetic Alterations ◽  
Detection Range

Abstract Mechanisms of drug resistance in Multiple Myeloma (MM) are poorly understood. Mutations and/or changes in the protein expression of the CRBN pathway and proteasome subunits have been identified to induce resistance to IMiDs and PIs. However, only few patients are affected by these alterations. To determine the specific genomic fingerprint of MM relapse we selected 57 MM patients from the CoMMpass trial (version IA11) that have genomic data of paired samples available (diagnosis/relapse). 35 of them have also sequential FISH-seq data. We focused on acquired mutations in first relapse and filtered all mutations and genetic alterations already present at diagnosis. Doing so, we found 1.274 mutations, representing an average of 23 new mutations/patient (range; 2-76). Of interest, 66% of the acquired mutations were present in a sub-clonal level (Variant read frequency (VRF) < 25%). Most common mutations include known hotspots of the RAS pathway (NRAS 12%, KRAS 7% and BRAF 4%). Notably, all 7 NRAS mutations in relapse were located at Q61K, suggesting a functional role of disease progression for this specific and known hotspot location. In total 5 of 35 cases (14%) with FISH-seq data developed a 17p13 deletion in relapse. Of these, three patients acquired a bi-allelic alteration in addition to a preexisting TP53 mutation and one developed a biallelic inactivation of TP53 (VRF = 100%), through parallel acquisition of del17p and TP53 mutation. Gain of 1q21 was observed in relapse in 5 of 35 (14%) cases, and one 1q gain was lost from diagnosis to relapse. Two cases (4%) presented mutations in IMiD treatment related genes, with two mutations in the CRBN pathway. One harbored a missense mutation in the Lenalidomide (LEN) degron sequence of IKZF3 (G159A) (VRF = 36%), known to be essential for the IMiD action in vitro, 45 months after continuous exposition to LEN . The other case presented two subclonal frameshift mutations in CUL4B (VRF = 5% and 32%), detected after more than three years of LEN containing therapy. We functionally validated in vitro LEN resistance through CRISPR/Cas9 knockout of CUL4B, suggesting a resistance inducing effect of the acquired CUL4B mutations. Six cases (11%) harbored acquired mutations in proteasome subunit genes (PSMC2, PSMC6, PSMD8, PSME4, PSMB9 (two mutations)), all of them had undergone prior proteasome inhibitor (PI) containing therapy. We validated earlier the 19S protein subunits PSMC6 and PSMC2 (KO and/or point mutations) as inducers of PI resistance in vitro, thus we hypothesize contribution to resistance induction / disease progression through these 19s mutations. Remarkably ubiquitin (E3, E2 and SUBs) and histone related genes (histones and histone methylases and deacetylases) were found mutated in 51% and 19% of the relapsed patients. Genes for drug transporters (ATP-binding cassette (ABC) and Solute Carrier (SLC) transporters) were hit in 32% of cases and genes for mucins (previously related with genotoxic agents and immunotherapy resistance) in 19%. Notably, RRBP1 presented 10 mutations in 6 patients (11%) with the mutations clustering within 30 amino-acids (aa) of exons 9 and 10 and 3 hotspots (2 patients each) in aa Q426P, K430R and Q436P. RRBP1 is involved in the binding of the ribosome to the endoplasmic reticulum (ER) and is related with the unfolded protein response and ER stress via GRP78. All the patients with RRBP1 mutations were pretreated with PI inhibitors and exhibited worst survival outcome affecting PFS (Pval<0.001) and OS (Pval=0.0016) in this limited dataset. The mutations were detected on average 433 days (range: 258-568) after diagnosis. Five of the 6 patients died on average 180 days after RRBP1 mutation detection (range: 18-446) further suggesting high risk features of such acquired mutations. In summary, we observe clonal selection of known high-risk related alterations like TP53 mutations, 17p deletions or 1q13 in early relapse data of the CoMMpass trial. Furthermore we identify RRBP1 mutations as a new acquired high-risk biomarker of MM. Alterations are specifically related to subclonal selection by therapy, thus we suggest that the definition of high-risk disease in MM needs to be revisited and should also include clonal selection processes under anti-tumor therapy. Figure. Figure. Disclosures No relevant conflicts of interest to declare.

scholarly journals Implications of TP53 alterations for Therapy Response in Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3189-3189 ◽  
Author(s):  
Umair Munawar ◽  
Santiago Barrio ◽  
Markus Roth ◽  
Hermann Einsele ◽  
Ralf C Bargou ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
High Risk ◽  
Cell Viability ◽  
Conflicts Of Interest ◽  
Clonal Selection ◽  
Proteasome Inhibition ◽  
Sleeping Beauty ◽  
Targeted Sequencing ◽  
Fish Analysis ◽  
Increased Risk

Abstract Deletion of the tumor suppressor gene TP53is significantly associated with an unfavorable clinical course of Multiple Myeloma (MM). In addition, point mutations that abrogate p53 function similarly shorten survival. Most recently 'double hit', bi-allelic TP53inactivated MM was identified as an ultimate high risk feature of MM, affecting 3.7% of newly diagnosed MM patients (NDMM, Walker et al., Leukemia 2018). For TP53genetic analysis we combined data from two targeted sequencing M3P cohorts with targeted sequencing and FISH data, one of NDMM (n=142, Kortüm et al. Blood Cancer J. 2016), and one of multirefractory patients (rMM, n=40; Kortüm et al. Blood 2016). We also included two independent cohorts with paired NDMM and rMM, one with mutational data (n=43; Corre J et al 2017) and one with paired FISH analysis (Merz M et al. Haematologica 2017). We confirmed an increase of mutations in TP53 (8% NDMM / 16.9% rrMM), as well as del17p (12.6% / 22%). Similarly, mono- (12.7% / 22.5%) and bi-allelic events (5.6% / 17.5%) both demonstrated a significant increase over time (Figure, top). Importantly we observed deletion after mutation and vice versa in our cohorts. Next we established an AMO-1 MM cell line model (TP53+/+) mimicking mono and bi-allelic TP53-inativation. After CRISPR/Cas9-mediated TP53destruction, we introduced a modified Sleeping Beauty (SB) vector with two separate expression cassettes (p53 wt / wt and mutant p53 (R282W or R175H). Functionality of the p53 system was confirmed using nutlin-3, as inhibitor of MDM2-p53 interaction, as described elsewhere. Results: Doxorubicin and Melphalan are commonly used compounds in the treatment of MM. The IC50 of Melphalan in AMO1 naïve cells was 5µM and 5.5 µM after the reintroduction of 2 copies of wt TP53 in the KO model, with cell viability at 10µM of 30% and 31% respectively, measured by AlamarBlue Assay. Strikingly, we observed significant resistance induction in our hemizygous systems (del/wt p53; cell viability at 10µM 60% and mut/wt (62%). This furthermore increased within our homozygous models (TP53 del/del (85%); TP53 mut/del 80%) (Figure, bottom). Similar results were observed under doxorubicin treatment. Remarkably, this effect was absent against proteasome inhibition. Conclusions Here we present first evidence of TP53 inactivation impacting drug response to Melphalan and Doxorubicin, which might lead to the clonal selection of MM subclones harboring increased risk. The fact, that response to proteasome inhibition was not affected in our model might, at least in part, might explain their ability to confine high risk in MM. Figure. Figure. Disclosures No relevant conflicts of interest to declare.

scholarly journals Genomic Profiling of Smoldering Multiple Myeloma Identifies Patients at a High Risk of Disease Progression

2020 ◽  
Vol 38 (21) ◽  
pp. 2380-2389 ◽  
Author(s):  
Mark Bustoros ◽  
Romanos Sklavenitis-Pistofidis ◽  
Jihye Park ◽  
Robert Redd ◽  
Benny Zhitomirsky ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
High Risk ◽  
Disease Progression ◽  
Genetic Alterations ◽  
Copy Number Variations ◽  
Mitogen Activated Protein Kinase ◽  
Prognostic Models ◽  
Single Nucleotide Variants ◽  
Smoldering Multiple Myeloma ◽  
Risk Of Progression

PURPOSE Smoldering multiple myeloma (SMM) is a precursor condition of multiple myeloma (MM) with a 10% annual risk of progression. Various prognostic models exist for risk stratification; however, those are based on solely clinical metrics. The discovery of genomic alterations that underlie disease progression to MM could improve current risk models. METHODS We used next-generation sequencing to study 214 patients with SMM. We performed whole-exome sequencing on 166 tumors, including 5 with serial samples, and deep targeted sequencing on 48 tumors. RESULTS We observed that most of the genetic alterations necessary for progression have already been acquired by the diagnosis of SMM. Particularly, we found that alterations of the mitogen-activated protein kinase pathway ( KRAS and NRAS single nucleotide variants [SNVs]), the DNA repair pathway (deletion 17p, TP53, and ATM SNVs), and MYC (translocations or copy number variations) were all independent risk factors of progression after accounting for clinical risk staging. We validated these findings in an external SMM cohort by showing that patients who have any of these three features have a higher risk of progressing to MM. Moreover, APOBEC associated mutations were enriched in patients who progressed and were associated with a shorter time to progression in our cohort. CONCLUSION SMM is a genetically mature entity whereby most driver genetic alterations have already occurred, which suggests the existence of a right-skewed model of genetic evolution from monoclonal gammopathy of undetermined significance to MM. We identified and externally validated genomic predictors of progression that could distinguish patients at high risk of progression to MM and, thus, improve on the precision of current clinical models.

scholarly journals Excess Serine from the Microenvironment Caused the Impaired Megakaryopoiesis and Thrombocytopia in Multiple Myeloma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4331-4331
Author(s):  
Chunmei Kuang ◽  
Meijuan Xia ◽  
Gang An ◽  
Cuicui Liu ◽  
Dan Wu ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Prognostic Factor ◽  
Mouse Model ◽  
Disease Progression ◽  
Plasma Cells ◽  
Conflicts Of Interest ◽  
Major Complication ◽  
Progression Free Survival ◽  
Erythroid Progenitors

Background: Thrombocytopenia is major complication in a subset of patients with multiple myeloma (MM). However, a lack of detailed studies about the megakaryopoiesis, thrombopoiesis as well as their connections with the survival of patients limits us to explore whether thrombocytopenia could be used as a reliable prognostic factor for MM. Materials and Methods: In this study, 1393 newly diagnosed MM patients were selected for investigating the potential connection between PLT counts and clinical characteristics including ISS stage, overall survival as well as progression free survival. Besides, 5T33MMvt-KaLwRij mouse model were also used to examine the megakaryopoiesis and thrombopoiesis during disease progression. The proportion and function of different subpopulations of cells including megakaryocytes, megakaryocytic-erythroid progenitors (MEPs), common myeloid progenitors (CMPs) and Lin-Sca-1+c-kit+ (LSK) cells were measured both in MM patients and mouse models. Gas chromatography-time-of-flight mass spectrometry (GC-TOFMS)-based metabolomics was used to analyze the metabolites. Results: Of the 1393 studied patients, 298 cases of MM patients are found with thrombocytopenia at the time of diagnosis. PLT counts were lower both in stage Ⅱ (P<0.01) and Ⅲ patients (P<0.001) than stageⅠpatients. Interesting, we found MM patients with thrombocytopenia had a significantly lower OS (P<0.001) and PFS (P<0.001). In mouse model, we also found PLT counts gradually decreased in peripheral blood during the disease progression (P<0.001). Further analysis demonstrated the proportion and the absolute numbers of megakaryocytes and MEPs were diminished both in mouse and MM patients with thrombocytopenia. PLT counts were negative correlated with the percentage of plasma cells or IgG2b levels (P<0.001), suggesting a potential connection of malignant cells infiltration and thrombocytopenia. In mechanism, metabolomics analysis with BM plasma identified 16 differential metabolites in MM patients with thrombopoiesis (VIP > 1.2, P < 0.05). Among them, serine was observed significantly be elevated in MM mouse and suffice to inhibit the megakaryopoieis and thrombopoiesis in vitro. Conclusion: PLT counts might be used as a reliable prognostic factor for MM patients since the thrombocytopenia was associated with poor survival in MM patients. The thrombocytopenia in MM might attribute to, at least partially, the inhibition by serine from the microenvironment. Our findings revealed novel mechanism of MM and might eventually shed light on the treatment of MM patients. Disclosures No relevant conflicts of interest to declare.

scholarly journals Phase II Trial of the Combination of Ixazomib, Lenalidomide, and Dexamethasone in High-Risk Smoldering Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 804-804 ◽  
Author(s):  
Mark Bustoros ◽  
Chia-jen Liu ◽  
Kaitlen Reyes ◽  
Kalvis Hornburg ◽  
Kathleen Guimond ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
High Risk ◽  
Disease Progression ◽  
Board Of Directors ◽  
Rna Sequencing ◽  
Research Funding ◽  
Response Rate ◽  
Advisory Committees ◽  
Equity Ownership

Abstract Background. This study aimed to determine the progression-free survival and response rate using early therapeutic intervention in patients with high-risk smoldering multiple myeloma (SMM) using the combination of ixazomib, lenalidomide, and dexamethasone. Methods. Patients enrolled on study met eligibility for high-risk SMM based on the newly defined criteria proposed by Rajkumar et al., Blood 2014. The treatment plan was designed to be administered on an outpatient basis where patients receive 9 cycles of induction therapy of ixazomib (4mg) at days 1, 8, and 15, in combination with lenalidomide (25mg) at days 1-21 and Dexamethasone at days 1, 8, 15, and 22. This induction phase is followed by ixazomib (4mg) and lenalidomide (15mg) maintenance for another 15 cycles. A treatment cycle is defined as 28 consecutive days, and therapy is administered for a total of 24 cycles total. Bone marrow samples from all patients were obtained before starting therapy for baseline assessment, whole exome sequencing (WES), and RNA sequencing of plasma and bone marrow microenvironment cells. Moreover, blood samples were obtained at screening and before each cycle to isolate cell-free DNA (cfDNA) and circulating tumor cells (CTCs). Stem cell collection is planned for all eligible patients. Results. In total, 26 of the planned 56 patients were enrolled in this study from February 2017 to April 2018. The median age of the patients enrolled was 63 years (range, 41 to 73) with 12 males (46.2%). Interphase fluorescence in situ hybridization (iFISH) was successful in 18 patients. High-risk cytogenetics (defined as the presence of t(4;14), 17p deletion, and 1q gain) were found in 11 patients (61.1%). The median number of cycles completed was 8 cycles (3-15). The most common toxicities were fatigue (69.6%), followed by rash (56.5%), and neutropenia (56.5%). The most common grade 3 adverse events were hypophosphatemia (13%), leukopenia (13%), and neutropenia (8.7%). One patient had grade 4 neutropenia during treatment. Additionally, grade 4 hyperglycemia occurred in another patient. As of this abstract date, the overall response rate (partial response or better) in participants who had at least 3 cycles of treatment was 89% (23/26), with 5 Complete Responses (CR, 19.2%), 9 very good partial responses (VGPR, 34.6%), 9 partial responses (34.6%), and 3 Minimal Responses (MR, 11.5%). None of the patients have shown progression to overt MM to date. Correlative studies including WES of plasma cells and single-cell RNA sequencing of the bone microenvironment cells are ongoing to identify the genomic and transcriptomic predictors for the differential response to therapy as well as for disease evolution. Furthermore, we are analyzing the cfDNA and CTCs of the patients at different time points to investigate their use in monitoring minimal residual disease and disease progression. Conclusion. The combination of ixazomib, lenalidomide, and dexamethasone is an effective and well-tolerated intervention in high-risk smoldering myeloma. The high response rate, convenient schedule with minimal toxicity observed to date are promising in this patient population at high risk of progression to symptomatic disease. Further studies and longer follow up for disease progression are warranted. Disclosures Bustoros: Dava Oncology: Honoraria. Munshi:OncoPep: Other: Board of director. Anderson:C4 Therapeutics: Equity Ownership; Celgene: Consultancy; Bristol Myers Squibb: Consultancy; Takeda Millennium: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Oncopep: Equity Ownership. Richardson:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Ghobrial:Celgene: Consultancy; Takeda: Consultancy; Janssen: Consultancy; BMS: Consultancy.

Engineering VSV-IFN-NIS for the Treatment of Multiple Myeloma.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 378-378
Author(s):  
Shruthi Naik ◽  
Rebecca A. Nace ◽  
Elizabeth A. Hadac ◽  
David Dingli ◽  
Mark Federspiel ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Conflicts Of Interest ◽  
Tumor Regression ◽  
Oncolytic Viruses ◽  
Sodium Iodide Symporter ◽  
Viral Spread ◽  
Nis Gene ◽  
Immunocompetent Mice

Abstract Abstract 378 The need for new and more effective long-term treatments for Multiple Myeloma (MM) has led to the utilization and engineering of replication competent (oncolytic) viruses as potential therapies. Vesicular stomatitis virus (VSV) is a potent oncolytic agent with several features that make it a favorable choice as a potential myeloma therapy. Specifically, (i) VSV replicates rapidly and can be grown to high titers (for effective clinical use) (ii) VSV undergoes transcription and replication exclusively in the cytoplasm avoiding host genome integration (iii) there is low/absent pre-existing immunity against VSV among the general population, (iv) naturally occurring human VSV infections are generally asymptomatic or result in minimal flu-like symptoms, (v) VSV is not easily transmitted between individuals (natural transmission is by hematophagous insects). Previously we showed weak oncolytic efficacy with an attenuated strain of VSV coding for the sodium iodide symporter (NIS) gene, VSV-D51-NIS, in the immune competent 5TGM1 syngeneic MM mouse model (C57Bl/KalwRijHsd) (Goel at. al. Blood. 2007 Oct 1;110(7):2342-50). Since VSV replication is strongly inhibited by IFN-induced innate immune responses in normal cells, but not in myeloma cells and IFN has known anti-myeloma activity, we hypothesized that the IFN-coding VSVs would be safer and more potent than previously tested VSV recombinants. We therefore constructed and tested the efficacy of VSVs coding for b-Interferon (VSV-IFN) or b-IFN and NIS (VSV-IFN-NIS). Interestingly, all of the newly constructed viruses, including VSV-IFN-NIS, showed greatly superior replication kinetics compared to the previously reported VSV-D51-NIS virus. Furthermore, compared to VSV-D51-NIS, VSV-IFN-NIS vectors induced higher NIS expression in vitro. In vivo therapy studies showed that a single intravenous dose of each of the IFN-coding VSVs promoted tumor regression and significantly prolonged survival of immunocompetent mice bearing subcutaneous or orthotopic 5TGM1 myeloma tumors. Tc-99m imaging studies conducted in mice treated with VSV-IFN-NIS, showed tumor specific virus mediated NIS expression and radio-isotope uptake that increased concurrently with intratumoral viral spread. Most importantly, there was no evidence of neurotoxicity following treatment with the IFN-coding VSVs. These studies indicate that VSV-IFN-NIS has potential as a novel therapeutic agent for multiple myeloma that can be combined with radio-isotopes for both non-invasive imaging of viral biodistribution and radiovirotherapy. A phase I clinical study is currently planned. Disclosures: No relevant conflicts of interest to declare.

Incidence of Febrile Episodes During Stem Cells Mobilization After High Dose Cyclophosphamide Chemotherapy and G-CSF (filgrastim or lenograstim) Administration in Multiple Myeloma Patients: Preliminary Final Results.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4560-4560
Author(s):  
Enrico Orciuolo ◽  
Gabriele Buda ◽  
Emerenziana Marturano ◽  
Elisa Mauro ◽  
Giuseppe Milone ◽  
...  
Keyword(s):  
Stem Cells ◽  
Multiple Myeloma ◽  
Conflicts Of Interest ◽  
Treatment Plan ◽  
High Dose ◽  
Absolute Count ◽  
Functional Block ◽  
Grade 3 ◽  
Febrile Episodes

Abstract Abstract 4560 Introduction The G-CSF, primary regulator of granulopoiesis, has shown its efficacy in reducing duration of neutropenia after chemotherapy or myelosuppressive therapy. In these situations G-CSF, accelerating the granulocytous reconstitution, may enable a significant reduction of the incidence, duration and severity of infection. Commercially formulations of rHu-G-CSF include lenograstim, a glycosylated form, and filgrastim, a non-glycosylated form. Glycosylation of the molecule contribute to pharmacokynetis advantages and to higher affinity to specific receptor. Additionally, lenograstim exposed neutrophils maintain unchanged all their functions in vitro, while filgrastim exposed neutrophils present functional defects due to higher adhesivity, cytoscheletric alterations and a more immature phenotype. Aim On these bases, we hypotized that lenograstim may prevent febrile episodes (FE) and reduce their lasting in patients with chemotherapy derived neutropenia more efficiently than filgrastim. Primary endpoint is the incidence of FE (ClinicalTrials.gov ID: NCT00932217). Patients and methods starting from April 2005, 180 multiple myeloma patients achieving high dose cyclophosphamide for stem cells mobilization were enrolled in 11 Italian Centers. Treatment plan consisted in: high dose cyclophosphamide (3 or 4 g/sqm) on day 1, G-CSF (random 1:1 on the base of a generated random list: filgrastim or lenograstim) 30 MU/day from day +4 to +9, 60 MU/day from day +10 to the achievement of an optimal CD34+ cell count for staminoapheresis. FE, significant if equal or higher than 38 °C for at least 2 different determinations, were recorded till day +30. Results 176 of 180 patients received scheduled treatment and are eligible for final analyses. All 176 patients underwent post-chemo grade 4 neutropenia and G-CSF was administered starting from day +4. FE were recorded in 26 pts, 16 in the filgrastim arm (89 total patients) and 10 in the lenograstim arm (87 total patients). The global fever incidence was 14.77%, 17.98% with filgrastim and 11.49% with lenograstim. However, to demonstrate functional block of filgrastim exposed neutrophils, FE have been related to neutrophil absolute count. Related to the neutropenia grade, 8 FE are recorded with filgrastim (8.99%) and 1 FE with lenograstim (1.15%) with absolute neutrophil count >500/μL (grade 3) (chi square test with Yates' correction: p=0.0436); this difference is still evident when neutrophils are >1000/μL (grade 2), with 7 episodes with filgrastim (7.87%) versus 1 (1.15%) with lenograstim. Conclusions Lenograstim is associated with a reduced global incidence of FE in multiple myeloma patients undergoing to high dose cyclophosphamide and stem cells mobilization when compared to filgrastim. Additionally, excluding the time frame when neutrophils are not yet recovered (neutrophils <500/μL; grade 4 neutropenia) and G-CSF effects may not be demonstrated, filgrastim treated patients present, when compared to lenograstim treated patients, an higher FE incidence at neutrophil absolute count recovery (both with grade 3 and grade 2 neutropenia), confirming the functional block of filgrastim exposed neutrophils described in vitro. On the contrary, lenograstim allows to recovery normally functional neutrophils as demonstrated by the very low incidence of FE (1.15% with neutrophils >500/μL) in treated patients. Disclosures: No relevant conflicts of interest to declare.

Thymic Stromal Lymphopoietin Stimulation of Pediatric Acute Lymphoblastic Leukemias with CRLF2 Alterations Induces JAK/STAT and PI3K Phosphosignaling

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 410-410 ◽  
Author(s):  
Sarah K Tasian ◽  
Michelle Y Doral ◽  
Brent L Wood ◽  
Michael J Borowitz ◽  
J. Racquel Collins-Underwood ◽  
...  
Keyword(s):  
High Risk ◽  
Lymphoblastic Leukemia ◽  
Genetic Alterations ◽  
Thymic Stromal Lymphopoietin ◽  
Jak Inhibitor ◽  
Oncology Group ◽  
Term Survival ◽  
Phosphoflow Cytometry ◽  
Stimulation Of

Abstract Abstract 410 Collaborative genomic profiling efforts though the National Cancer Institute's TARGET Initiative and the Children's Oncology Group have identified CRLF2 and JAK mutations in a subset of children with high-risk acute lymphoblastic leukemia (ALL), but few biochemical studies have assessed the functional sequelae of these genetic alterations. CRLF2 encodes the thymic stromal lymphopoietin (TSLP) receptor chain, which heterodimerizes with the IL-7 receptor alpha chain (IL-7Rα). Children with high CRLF2-expressing ALL detected by gene expression profiling have high rates of minimal residual disease at end-induction (Day 29), and approximately 70% of these patients ultimately relapse (Harvey et al., Blood 2010). We hypothesize that characterization of aberrant signaling networks in these leukemias will facilitate identification of potential targets for small molecule inhibitor therapies. Using phosphoflow cytometry, we analyzed the phosphorylation status of key signaling molecules after stimulation with TSLP, IL-7, or pervanadate (an irreversible proximal membrane phosphatase inhibitor used as a positive control) in 2 human ALL cell lines with CRLF2 and JAK2 mutations and in 43 fresh or cryopreserved diagnostic primary patient samples, 27 of which overexpressed CRLF2 through P2RY8-CRLF2 fusion or CRLF2-IgH translocation and 16 of which did not have CRLF2 or JAK mutations (controls). Cells were rested in serum-free media for 60 minutes at 37°C, then stimulated with TSLP, IL-7, or pervanadate for 30 minutes to induce signaling. Cells were also exposed to the JAK inhibitor XL019 (Exelixis) for 60 minutes and/or subsequently stimulated with the aforementioned cytokines or pervanadate to determine the effects of JAK inhibition on signaling. Cells were then processed for phosphoflow cytometry according to our previously published methodologies (Kotecha et al., Cancer Cell 2008). High CRLF2-expressing leukemias (n = 27) with or without concomitant JAK mutations demonstrated strong surface staining of the TSLP receptor, as well as CD10, CD19, and CD127 (IL-7Rα). In vitro stimulation of leukemic blasts with TSLP elicited phosphorylation of STAT5 and S6, but not ERK 1/2, in leukemias with JAK and/or CRLF2 alterations. Control leukemias without CRLF2 and JAK mutations (n=16) did not stain for the TSLP receptor, and TSLP stimulation did not elicit phosphosignaling through the JAK/STAT, PI3K, or MAPK pathways. STAT5 and S6 phosphorylation in the high CRLF2-expressing leukemias was further abrogated by in vitro JAK inhibition with XL019. Surprisingly, despite flow cytometric staining for CD127, stimulation with IL-7 did not elicit phosphosignaling through these epitopes in high CRLF2-expressing or control leukemic blasts, although it did predictably phosphorylate STAT5 in control T and non-blast B cells contained within the primary patient leukemia samples. These results suggest that the JAK/STAT and PI3K pathways, but not the MAPK pathway, are involved in TSLP receptor signaling in high CRLF2-expressing ALL +/− JAK mutations and may represent druggable targets. Phosphoflow cytometry is an efficient method of interrogating intracellular signaling at a single-cell level in primary human samples and, furthermore, can be used for rapid identification of patients at time of leukemia diagnosis with high CRLF2-expressing ALL who exhibit the TSLP phosphosignature. Therapy for this subset of high-risk patients might be modified to include a targeted therapeutic (such as a JAK inhibitor) to improve initial treatment responses and, ultimately, to enhance long-term survival. To this end, we have developed a Children's Oncology Group Phase I clinical trial of JAK inhibition for patients with relapsed or refractory leukemias (including those with CRLF2 and JAK mutations) and will validate the use of phosphoflow cytometry and other biologic assays to assess in vivo target inhibition during therapy. We ultimately envision incorporation of JAK inhibitor therapy into a systemic chemotherapy backbone for patients with high CRLF2-expressing ALL. Disclosures: No relevant conflicts of interest to declare.

Codon 72 Polymorphism Of TP53 Gene Is a Novel Prognostic Marker For Thalidomide Therapy In Multiple Myeloma

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1891-1891
Author(s):  
Yutaka Hattori ◽  
Yurika Ikeda ◽  
Yuya Suzuki ◽  
Daiju Ichikawa ◽  
Maiko Matsushita
Keyword(s):  
Multiple Myeloma ◽  
Overall Survival ◽  
High Risk ◽  
Prognostic Marker ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Tp53 Gene ◽  
Codon 72 ◽  
Codon 72 Polymorphism ◽  
Significant Difference

Abstract Backgrounds and purpose Recently, newly developed drugs such as thalidomide, lenalidomide and bortezomib have significantly improved survival of the patients with multiple myeloma (MM). However, certain group of the patients who have characteristic high-risk cytogenetic changes such as deletion of TP53 tumor suppressor gene revealed significantly shorter survival. In patients with deletion of TP53 gene, the somatic point mutation in the residual TP53 gene has been reported to be rare. Thus, the exact role of alteration of TP53 gene in high-risk myeloma remains unclear. Polymorphism of TP53 gene at codon 72 in exon 4, CGC to CCC transition, leads to arginine (Arg) to proline (Pro) amino-acid substitution. Biological analyses showed that the Arg variant more efficiently induces expression of P21 and apoptosis via Ser-6 and 20 phosphorylation of p53 protein. In contrast the Pro variant is less resistant to MDM-2-mediated degradation and more potently induced cell-cycle arrest and DNA damage repair. Recently, clinical significance of this polymorphism has been extensively studied in solid tumors as well as hematological malignancies including non-Hodgkin lymphoma and leukemia. However, consistent association of the polymorphism with cancer risk has not been elucidated. The purpose of this study is to examine codon 72 polymorphism in patients with refractory multiple myeloma (MM) treated with thalidomide, and to elucidate its association with myeloma risk and outcome of thalidomide-therapy. Patients & methods A total of 37 Japanese patients with refractory or relapsed MM who were treated with thalidomide monotherapy were included in this study. Three cases showed deletion of TP53 gene by fluorescence in situ hybridization (FISH) analyses. The codon 72 polymorphism was evaluated in the rest of 34 patients. Genomic DNA was isolated from bone marrow mononuclear cells. The genomic TP53 gene was amplified by polymerase chain reaction, and the amplified DNAs were directly sequenced. Results Direct DNA sequence showed that the Pro/Pro homozygote was observed in six patients (18%), Pro/Arg heterozygote in 12 (35%) and Arg/Arg homozygote in 16 (47%). There was no significant difference in the frequency of the polymorphism between the 34 Japanese MM patients and the healthy Japanese individuals (P=0.44). Thus, association of codon 72 polymorphism with myeloma risk has failed to be elucidated. The response rate to thalidomide therapy was 33% in the patients with Pro/Pro, 27% in Pro/Arg and 44% in Arg/Arg (P=0.49), respectively. Other clinical backgrounds including age, sex, Durie-Salomon stage, ISS stage, serum creatinine, albumin, b2M, calcium, hemoglobin levels and M-protein type were not correlated with TP53 codon 72 polymorphism, either. Progression free survival (PFS), overall survival (OS) and post-relapse survival were shown in Figure 1. The patients with Pro allele tended to show shorter PFS; 5 weeks for the patients with Pro/Pro versus 32 weeks for those with Pro/Arg plus Arg/Arg (P=0.07) (Figure 1). Overall survival (OS) of the patients with Pro/Pro, Pro/Arg and Arg/Arg allele was 18 weeks, 49 weeks and 133 weeks, respectively (P=0.027). Especially, the patients with Pro/Pro allele revealed significantly shorter OS compared with those with Pro/Arg plus Arg/Arg (18 weeks versus 100 weeks, P=0.023) (Figure 1). Significant difference of OS in patients with Pro/Pro+Pro/Arg vs Arg/Arg (P= 0.032) suggested the dominant effect of Pro allele for poorer prognosis. Post-relapse survival of the patients with Pro/Pro, Pro/Arg and Arg/Arg allele was 11, 42 and 64 weeks, respectively (P=0.054). Post-relapse survival for Pro/Pro versus Pro/Arg plus Arg/Arg were 11 weeks versus 64 weeks (P=0.029). Conclusion These results indicated that codon 72 polymorphism did not correlated with myeloma risk, but significantly associated with therapeutic outcome. Namely, the patients with Pro allele revealed earlier relapse and shorter post-relapse survival, resulted in shorter OS in thalidomide therapy. Further evaluation is needed to clarify whether the codon 72 polymorphism will be a new prognostic marker for the treatment with novel drugs. Disclosures: No relevant conflicts of interest to declare.

Bortezomib-Induced Proinflammatory Macrophages Contribute to Multiple Myeloma Cell Aggressiveness

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5367-5367
Author(s):  
Ofrat Beyar Katz ◽  
Neta Ben-Tsedek ◽  
Irit Avivi ◽  
Dror Alishekevitz ◽  
Michael Timaner ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Tumor Growth ◽  
Host Response ◽  
De Novo ◽  
Imaging System ◽  
Conflicts Of Interest ◽  
Scid Mice ◽  
Tail Vein ◽  
Inflammatory Macrophages

Abstract Multiple myeloma (MM) is a chronic progressive malignancy of plasma cells. Although treatment with the novel proteasome inhibitor, bortezomib, significantly improves patient survival, some patients fail to respond due to the development of de novo resistance. Previous studies revealed that chemotherapy induces pro-tumorigenic host-mediated effects which could explain tumor re-growth and metastasis(Gingis-Velitski, Loven et al. 2011, Katz, Shaked 2014). Here we show that plasma from bortezomib-treated mice significantly increases migration, viability and proliferation of human MM cells in vitro, compared to plasma from control untreated mice. Comparable results were demonstrated with plasma obtained from patients with MM treated with bortezomib. Additionally, bortezomib induces the mobilization of pro-angiogenic bone marrow cells. Mice treated with bortezomib and subsequently intravenously injected with MM cells succumb to MM aggressiveness earlier than mice treated with the vehicle control(Figure 1). We show that pro-inflammatory macrophages contribute to MM cell aggressiveness in response to bortezomib treatment, in part by secreting interleukin-16(IL-16). Blocking IL-16 in conditioned medium obtained from bortezomib-treated macrophages generated reduced viability of MM cells in vitro. Accordingly, co-inoculation of MM cells with pro-inflammatory macrophages from bortezomib-treated mice accelerates MM disease progression. Taken together, our results suggest that, in addition to the known effective anti-tumor activity of bortezomib, this drug can induce host-driven pro-tumorigenic effects that may promote MM aggressiveness. Figure 1. Host response to bortezomib promotes MM aggressiveness in mice. Eight week old CB.17 SCID mice were injected intravenously with 1mg/kg bortezomib or vehicle (veh). Four and 24 hours later mice were inoculated through the tail vein with 5x106 CAG-luciferase+ cells (n=6-7mice/group). Tumor growth and expansion was assessed by IVIS imaging system. Figure 1. Host response to bortezomib promotes MM aggressiveness in mice. Eight week old CB.17 SCID mice were injected intravenously with 1mg/kg bortezomib or vehicle (veh). Four and 24 hours later mice were inoculated through the tail vein with 5x106 CAG-luciferase+ cells (n=6-7mice/group). Tumor growth and expansion was assessed by IVIS imaging system. Disclosures No relevant conflicts of interest to declare.

MK2 Is a Therapeutic Target for High-Risk Multiple Myeloma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5612-5612
Author(s):  
Chunyan Gu ◽  
Hongbao Yang ◽  
Hailin Peng ◽  
Zhiye Xu ◽  
Ruini Chen ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
High Risk ◽  
Therapeutic Target ◽  
Conflicts Of Interest ◽  
Mitogen Activated Protein Kinase ◽  
Comparative Genomic ◽  
Mechanism Study ◽  
Akt Phosphorylation ◽  
Protein Levels

Abstract p38 mitogen-activated protein kinase (MAPK) is constitutively activated in human multiple myeloma (MM). However, a major substrate of p38, MAPKAPK2 (MK2) has received little attention in MM. In this study, we disclosed that elevation of MK2 on DNA, mRNA and protein levels in MM cells compared to normal plasma control cells by array-based comparative genomic hybridization (aCGH), Gene expression profiling (GEP) and immunohistochemistry (IHC) respectively. High MK2 expression prognosticated inferior outcome of newly diagnosed myelomas, particularly in patients with high-risk disease based on GEP. Follow-up study demonstrated that enforced overexpressing MK2 promoted MM cell proliferation, drug-resistance and xenograft tumorigenesis in vivo, while knockdown MK2 expression by shRNA abrogated these characteristics. Further mechanism study showed MK2 directly bound and activated AKT signaling in MM, while specific MK2 inhibitor inhibited MM cell growth and clonogenicity through suppressing AKT phosphorylation. Our findings not only indicate that MK2 is a potential therapeutic target in high-risk MM but also suggest the clinical relevance of MK2 inhibition in MM. Disclosures No relevant conflicts of interest to declare.

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