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  • 1
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 80, No. 16_Supplement ( 2020-08-15), p. 5733-5733
    Abstract: The impact of tumor matrix remodeling to the generation of an “inflamed” microenvironment that modulates responses to immunotherapy is unclear. Versican (VCAN) is a chondroitin sulphate matrix proteoglycan that promotes tolerogenic polarization of intratumoral DC through Toll-like receptor 2 (TLR2). Proteolytic processing of VCAN releases a bioactive N-terminal fragment (matrikine), versikine. In contrast to the tolerogenic actions of parental VCAN, versikine triggers IRF8-dependent transcription in myeloid cells and promotes Batf3-dendritic cell (DC) generation from FLT3L-mobilized bone marrow progenitors in vitro. Consistent with the Batf3-promoting effects of versikine, VCAN proteolysis correlates with T-cell infiltration across multiple cancers.The aims were to 1. define the impact of versikine on the intratumoral myeloid repertoire in vivo and 2. to define the efficacy of versikine as a vaccine adjuvant.4T1 breast carcinoma and Lewis Lung Carcinoma (LLC) empty vector (EV)- and versikine-expressing cells were implanted subcutaneously in syngeneic recipients. 1000mm3 tumors were harvested and intratumoral DC subsets were enumerated. Versikine-expressing tumors were characterized by significantly enhanced Batf3-DC (CD11chigh,MHC IIhigh Ly6C-, CD64-, CD24high,CD11blow) (p =0.0079 for 4T1 model and & lt;0.0001 for LLC model), whereas cDC2 (CD11chigh,MHC IIhigh Ly6C-, CD64-, CD24low, CD11bhigh ) frequency was diminished (p= 0.0079 and & lt;0.0001 respectively). Monocytic-derived DC (Mo-DC: CD11chigh, MHC IIhigh, Ly6C+, CD64+) remained unchanged. To determine the impact of versikine on responses to in situ vaccination using STING agonists, EV- and versikine-replete tumors (B16 and 4T1; 150 mm3), were injected intratumorally (IT) with a single subtherapeutic dose (200 μg) of DMXAA (murine STING agonist) or vehicle. EV-tumors did not significantly respond to 200μg DMXAA, whereas many B16-versikine and 4T1-versikine tumors regressed or growth was inhibited (p & lt;0.001 and p=0.014 respectively). Necrosis was frequently observed in 4T1 versikine-secreting tumors (6/9 mice) within 24 hours after treatment. Versikine extended survival after subtherapeutic DMXAA treatment in 4T1; log rank=p=0.01. Versikine's effects were abrogated in Batf3-null mice. To quantitate antigen-specific responses in the presence or absence of versikine, EV- and versikine-replete LLC tumors were injected IT with 500 μg DMXAA (therapeutic dose) or vehicle. We observed a significant increase in the frequency of CD8+ MHCI:SIINFEKL tetramer+ splenocytes in LLC-versikine-bearing animals as well as a marked increase in central memory T splenocytes (TCM) (CD62LhighCD44high). VCAN matrikines may generate effective adjuvants for in situ vaccination strategies across diverse solid and hematopoietic tumor types. Citation Format: Athanasios Papadas, Evan Flietner, Zachary Morrow, Joshua Wiesner, Alexander Cicala, Adam Pagenkopf, Chelsea Hope, Philip Emmerich, Dustin Deming, Jing Zhang, Peiman Hematti, Natalie Callander, Alexander Rakhmilevich, Mario Otto, Christian Capitini, Fotis Asimakopoulos. Versican proteolytic fragments (matrikines) synergize with STING agonists to elicit robust anti-tumor CD8+ T cell responses [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5733.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2020
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  • 2
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 77, No. 13_Supplement ( 2017-07-01), p. 712-712
    Abstract: Purpose: Lung cancer is the leading cause of cancer deaths worldwide. Most present symptomatically at late stage with high lethality. Early detection reduces mortality but accurate and readily accessible tools for population screening are limited. By whole methylome sequencing, we have identified novel methylated DNA markers (MDMs) for lung cancer in tissue (Giakoumopoulos et al. ASCO 2016). Using top candidate MDMs in the present study, we now explore their clinical accuracy for lung cancer detection when assayed from plasma. Experimental Procedures: Archival plasmas from two independent study groups were tested in blinded fashion. Lung cancer cases and controls (apparently healthy smokers) for each group were balanced on age and sex (Group 1: 64 cases, 231 controls; Group 2: 23 cases, 80 controls). Using multiplex PCR followed by QuARTS (Quantitative Allele-Specific Real-time Target and Signal amplification) assay, a post-bisulfite quantification of MDMs on DNA extracted from plasma was performed. We selected 31 MDM candidates for initial evaluation in Group 1 (1 ml plasma/patient); top individual MDMs were subsequently tested in Group 2 to identify optimal MDM panels for lung cancer detection (2 ml/patient). Results: From Group 1 analyses, 13 high performance MDMs were selected for further testing (CYP26C1, SOBP, SUCLG2, SHOX2, ZDHHC1, NFIX, FLJ45983, HOXA9, B3GALT6, ZNF781, SP9, BARX1, EMX1) with individual areas under the receiver operator curve (AUCs) ranging from 0.593 to 0.939. Discrimination by individual MDMs was corroborated in Group 2 in which data was analyzed using two methods: a logistic regression fit and a regression partition tree approach. The logistic fit model identified a 4-marker panel (ZNF781, BARX1, EMX1, and SOBP) with an AUC of 0.96 and an overall sensitivity of 91% and 90% specificity. Analysis of the data using a regression partition tree approach identified 4 markers (ZNF781, BARX1, EMX1, and HOXA9) with AUC of 0.93 and an overall sensitivity of 96% and specificity of 94%. For both approaches, B3GALT6 was used as a standardizing marker of total DNA input. Conclusion: A panel of MDMs assayed in plasma achieved high sensitivity and specificity for all types of lung cancer. Further clinical evaluation and validation of this promising panel in larger patient groups are clearly indicated. Citation Format: Hatim T. Allawi, Maria Giakoumopoulos, Evan Flietner, Austin Oliphant, Carla Volkmann, Brian Aizenstein, Tamara Sander, Drew Eckmayer, Ashley Poenitzsch Strong, Melissa Gray, Barry Berger, Tracy Yab, William Taylor, Douglas Mahoney, John B. Kisiel, David E. Midthun, David A. Ahlquist, Graham P. Lidgard. Detection of lung cancer by assay of novel methylated DNA markers in plasma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 712. doi:10.1158/1538-7445.AM2017-712
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2017
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  • 3
    In: Leukemia & Lymphoma, Informa UK Limited, Vol. 60, No. 10 ( 2019-08-24), p. 2558-2562
    Type of Medium: Online Resource
    ISSN: 1042-8194 , 1029-2403
    Language: English
    Publisher: Informa UK Limited
    Publication Date: 2019
    detail.hit.zdb_id: 2030637-4
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  • 4
    In: Cell Reports, Elsevier BV, Vol. 40, No. 7 ( 2022-08), p. 111201-
    Type of Medium: Online Resource
    ISSN: 2211-1247
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2022
    detail.hit.zdb_id: 2649101-1
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  • 5
    In: Cancer Letters, Elsevier BV, Vol. 568 ( 2023-08), p. 216284-
    Type of Medium: Online Resource
    ISSN: 0304-3835
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2023
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  • 6
    In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 1006-1006
    Abstract: Multiple myeloma (MM) is characterized by clonal expansion of malignant plasma cells (PCs) and aberrant production of monoclonal immunoglobulin detected as an M spike using serum protein electrophoresis. In the United States, MM represents ~15% of hematologic malignancies and is one of the few cancers increasing in incidence (e.g., 14,400 in 1996 to 30,770 in 2018, from SEER). Previously, a Vk*MYC mouse model was described, in which AID-dependent activation of MYC transgene in germinal center (GC) B cells catalyzes a highly penetrant, indolent MM after a prolonged latency, suggesting that additional genetic mutations are required for the malignant MM progression. Recent sequencing of paired tumor/normal samples from advanced or refractory MM patients identified that constitutive activation of Ras signaling pathway (KRAS: 23%; NRAS:20%; BRAF: 8%) associates with MM progression and therapy resistance. To determine whether oncogenic Nras promotes the progression of Myc-induced indolent MM to a malignant stage, we generated NrasLSL Q61R/+; Vk*MYC; IgG1-Cre (VQ) mice along with single mutant mice Vk*MYC; IgG1-Cre or NrasLSL Q61R/+; IgG1-Cre. To boost NrasQ61R expression in GC B cells, 6-7 weeks old mice were immunized with NP-CGG. A significant fraction of VQ mice developed M-spike after immunization and subsequently died of a highly aggressive MM, which was characterized by high proliferative index, hyperactivation of AKT and ERK pathways, and disease hallmarks (e.g. osteolytic lesions, anemia, and kidney injury). VQ myeloma was readily transplantable into serial syngeneic recipients. In our preliminary study, combined Bortezomib and AZD6244 treatment attenuated MM phenotypes and prolonged the survival of VQ recipients. To facilitate easy molecular or genetic manipulations of VQ MM cells, we established two cell lines from primary cells. These cells could be easily infected (see another abstract from our co-author, Dr. Asimakopoulos's group). The cultured MM cells also express high levels of CD155, a ligand of immune checkpoint TIGIT, which has been recently reported to mediate a significant immune checkpoint blockade in MM patients. We further investigated the transcriptional signature of VQ MM cells (from bone marrow [BM] and from lymph nodes [LN] ) vs wild-type (WT) plasma cells using the Illumina Bio-Rad's Single-Cell Sequencing platform. Illumina's Sure Cell app was used to de-multiplex samples, process barcodes and perform single-cell 3' gene counting. The processed data were then analyzed using Seurat R package to yield cluster information and their associated enriched genes. Our results revealed distinct clusters of CD138+ MM and WT cells, and also showed high similarity & overlap between BM & LN MM samples. Consistent with the genetic changes introduced to VQ MM cells, both Myc and Nras expression levels were significantly elevated in MM clusters compared to WT clusters. We also found that transcriptional levels of several potential therapeutic targets were significantly elevated in MM clusters, including Integrin alpha 4 and metabolic enzymes. Currently we are validating the scRNA-Seq results. Taken together, we generated a novel mouse model in which activation of Vk*MYC and oncogenic Nras in GC B cells results in a highly malignant, transplantable MM. The VQ mouse model represents an important innovation that will serve as a platform to investigate pathogenesis of resistant and refractory multiple myeloma and allow for testing the efficacy of novel therapeutic agents. Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2018
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  • 7
    In: Blood, American Society of Hematology, Vol. 137, No. 1 ( 2021-01-7), p. 61-74
    Abstract: NRAS Q61 mutations are prevalent in advanced/relapsed multiple myeloma (MM) and correlate with poor patient outcomes. Thus, we generated a novel MM model by conditionally activating expression of endogenous NrasQ61R and an MYC transgene in germinal center (GC) B cells (VQ mice). VQ mice developed a highly malignant MM characterized by a high proliferation index, hyperactivation of extracellular signal-regulated kinase and AKT signaling, impaired hematopoiesis, widespread extramedullary disease, bone lesions, kidney abnormalities, preserved programmed cell death protein 1 and T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain immune-checkpoint pathways, and expression of human high-risk MM gene signatures. VQ MM mice recapitulate most of the biological and clinical features of human advanced/high-risk MM. These MM phenotypes are serially transplantable in syngeneic recipients. Two MM cell lines were also derived to facilitate future genetic manipulations. Combination therapies based on MEK inhibition significantly prolonged the survival of VQ mice with advanced-stage MM. Our study provides a strong rationale to develop MEK inhibition–based therapies for treating advanced/relapsed MM.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2021
    detail.hit.zdb_id: 1468538-3
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  • 8
    In: Blood, American Society of Hematology, Vol. 140, No. Supplement 1 ( 2022-11-15), p. 9935-9936
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2022
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 9
    In: Blood, American Society of Hematology, Vol. 134, No. Supplement_1 ( 2019-11-13), p. 1210-1210
    Abstract: Regulated proteolysis of the tolerogenic matrix proteoglycan versican (VCAN) through the actions of ADAMTS-proteases, is associated with enhanced CD8+ infiltration in both hematopoietic and solid tumors. However, it is unclear whether the enhanced CD8+ infiltration results from proteolysis-mediated depletion of precursor VCAN at the tumor site or from generation of bioactive proteolytic fragments ("matrikines") (e.g., the 441-aa N-terminal fragment of V1-VCAN isoform, versikine). We have previously shown that versikine promotes Batf3-dendritic cell (DC) generation from FLT3L-mobilized bone marrow (BM) progenitors in vitro. However, the effects of versikine in DC homeostasis in the tumor microenvironment in vivo are unknown. To investigate the effects of versikine in DC homeostasis in vivo, we utilized the first Ras-driven myeloma (MM) model (VQ model- Rajagopalan et al., Blood 132:1006, 2018) as well as transplantable solid tumor models in both C57BL/6J (LLC lung carcinoma) and Balb/c (4T1 mammary carcinoma) backgrounds. Tumor cells were stably engineered to secrete HA-tagged versikine vs. empty-vector (EV) controls. EV-VQ or versikine-VQ myeloma cells were implanted intracardiacally into C57BL/6J syngeneic recipients and mice were monitored until they developed myeloma-related end-organ damage (hindlimb paralysis). Both groups of mice were paralyzed at similar rates. Intratumoral conventional DCs (CD138-CD45+, CD11chi,MHC IIhiLy6C-, CD64-) clustered into two populations: cDC1 (Batf3-DC: CD24hi,CD11blo), a subset with crucial activity in cross-priming anti-tumor CD8+ T cells, and cDC2 (CD24lo, CD11bhi). Versikine enhanced intratumoral Batf3-DC frequency/infiltration, while cDC2 levels were diminished in versikine-VQ BM (Figure 1A)(Batf3-DC: 48% in EV-VQ vs. 72% in versikine-VQ, p-value= 0.0246; cDC2: 52% in EV-VQ vs. 28% in versikine-VQ, p=0.0312). Monocytic-derived DC (Mo-DC: CD11chi, MHC IIhi, Ly6C+, CD64+) frequency remained unchanged. Versikine's effects were replicated in 2 solid tumor models. Versikine-expressing tumors were characterized by significantly enhanced Batf3-DC infiltration (Fig. 1A, p-value= 0.0079 for 4T1 model and 〈 0.0001 for LLC model), whereas cDC2 numbers were diminished (p-value: 0.0079 and 〈 0.0001 respectively). Adoptive transfer of CD45.2+ pre-DC (SIRPaint, FLIT3+, CD11c+, MHC II-, Celltrace+) in LLC-EV and LLC-versikine tumors in CD45.1+ recipients did not show any differences in 3-day differentiation potential of DC precursors, implicating other mechanisms to explain the steady-state imbalance in DC subset frequencies. To examine whether versikine's effects on the intratumoral DC milieu in vivo could be therapeutically harnessed, we compared responses to STING agonist therapy between versikine-expressing and EV tumors. LLC-EV-OVA and LLC-versikine-OVA (ovalbumin, a model antigen) -expressing tumors received therapeutic intratumoral injections of DMXAA, a murine STING agonist. Analysis of splenocytes 5 days later showed a significant increase in the frequency of OVA antigen-specific, CD8+ (MHCI:SIINFEKL tetramer+) splenocytes in LLC-versikine-bearing animals (Figure 1B). Interestingly, there was a marked increase in total central memory T splenocytes (TCM) (CD62LhiCD44hi) harvested from LLC-versikine tumor-bearing mice. We conclude that versikine influences the DC milieu in the tumor bed with promotion of intratumoral cross-presenting Batf3-DC and depletion of the cDC2 subset. Our findings highlight an unappreciated facet of immune regulation of the tumor microenvironment through matrix proteolytic fragments ("matrikines"). Whereas detection of native VCAN proteolysis on myeloma biopsies (see abstract by Dhakal et al.in this meeting) portends adverse outcomes likely due to the tolerogenic effects of accumulated precursor VCAN at the tumor site, therapeutic use of the isolated, purified fragments may promote tumor innate sensing and effector priming. VCAN-matrikines, through their effects on intratumoral Batf3-DC and antigen-specific CD8+ T cell infiltration, may potentiate in situ vaccination strategies across diverse hematopoietic and solid tumor types. Figure 1 Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2019
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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  • 10
    In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 4480-4480
    Abstract: Background and Aims. Despite the fact that the myeloma mutational landscape was elucidated several years ago, there are yet no approved precision therapies targeting specific driver mutations. The role of common, but somewhat enigmatic, mutational events remains elusive, for example, the loss-of-function mutation of the RNA-processing exosome ribonuclease, DIS3, the third most-common mutation after KRAS and NRAS mutations. Furthermore, complex clonal architectural patterns (such as subclonal BRAF mutations nested within RAS-mutant clones) complicate the design of targeted therapy trials. To generate precision in vivo models that recapitulate the complex clonal and mutational architecture of myeloma, we integrated two powerful technological platforms: the first RAS-driven myeloma in vivo model (VQ model) created through a collaboration between the Zhang and Asimakopoulos labs coupled with flexible avian leukosis virus (ALV)-mediated gene transfer that permits myeloma genome editing in a temporally- and spatially- controlled fashion (Prdm1: TVb-mRFP model)(Asimakopoulos and Varmus, J Virol, 2009; 83(10):4835-43). VQ is based on the state-of-art Vk*MYC model (Chesi et al., Cancer Cell 2008;13(2):167-80). VQ was generated by conditionally activating an NrasQ61R allele in Vk*MYC mice. The resultant VQ model recapitulates an advanced, proliferative and drug-resistant phase of disease characterized by RAS mutations. The transducibility of VQ restored the functionality of the ALV-gene transfer technology. This technology exploits the fact that avian retroviruses cannot transduce mammalian cells unless they are engineered to ectopically express an avian retroviral receptor (in this case, the receptor TVb, driven by a plasma-cell-specific regulatory elements). Recently, the ALV gene transfer technology was adapted to achieve CRISPR-Cas9 mediated gene editing in the tumor niche in vivo (Oldrini et al., Nat Comm 2018;9(1):1466). Approach. We generated TVb-expressing VQ lines (CD138+ B220neg) that home to the bone marrow upon transplantation into Prdm1:TVb-mRFP fully immunocompetent syngeneic recipients in the C57BL6/J background. These VQ cells were engineered to express the nuclease Cas9. To determine the efficiency of gene transfer through ALV vectors (as a prelude to sgRNA delivery), pilot experiments were conducted using two types of ALV vector carrying a fluorescent reporter, GFP (green fluorescent protein): a) an RCAS-type vector that drives reporter expression from the native ALV LTR and b) an RCAN-type vector that drives reporter expression from an internal CMV promoter. Results. ALV titers achieved were routinely in excess of 107-108 infectious units/mL. Parental Vk*MYC cells expressing the avian receptor TVb were poorly transducible with ALV vectors. By contrast, VQ cells expressing TVb were readily transducible. At multiplicity of infection (MOI)=2, 68% of VQ myeloma cells expressed reporter fluorescence after a single round of transduction. At MOI=5 the transduction rate rose to 80%. The mean fluorescence intensity (MFI) positively correlated with MOI, consistent with higher-copy proviral integration at higher MOI. At equivalent MOI, GFP fluorescence from RCAS vectors was more intense than GFP fluorescence driven by an internal CMV promoter in RCAN vectors, suggesting that the ALV LTR is a stronger promoter than CMV in VQ myeloma cells. 100% transduced VQ cells were CD138+B220neg at all conditions tested. Conclusions and Current Focus. We are using ALV-CRISPR technology to generate precision myeloma models to support the next wave of personalized therapy and immunotherapy for this recalcitrant and incurable cancer. Progress on three in vivo models under construction will be presented at the meeting:Subclonal Braf mutation nested within clonal Nras mutation. These models will be treated with next-generation RAF inhibitors (Karoulia Z et al.Nat Rev Cancer 2017;17(11):676-91).Dis3 loss-of function mutation in constellation with co-clonal Ras mutation. The pathogenic consequences of Dis3 disruption remain poorly understood as no parallels exist in other cancers.The murine homolog of the t(4;14) translocation. We are targeting breakpoint cluster regions within perfectly syntenic sequences on mouse chr. 5 (containing Fgfr3 and Mmset loci) and mouse chr.12 (containing the murine Igh locus). Disclosures No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2018
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
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