scholarly journals EXTH-70. ENHANCEMENT OF ANTITUMOR ACTIVITY BY USING 5-ALA–MEDIATED SONODYNAMIC THERAPY TO INDUCE APOPTOSIS AND NECROSIS IN A MOUSE GLIOMA MODEL

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi97-vi97
Author(s):  
Satoshi Suehiro ◽  
Takanori Ohnishi ◽  
Akihiro Inoue ◽  
Daisuke Yamashita ◽  
Masahiro Nishikawa ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
High Intensity Focused Ultrasound ◽  
Control Group ◽  
Normal Brain ◽  
Sonodynamic Therapy ◽  
Cytotoxic Effects

Abstract OBJECTIVE High invasiveness of malignant gliomas frequently causes local tumor recurrence. To control such recurrence, novel therapies targeted toward infiltrating glioma cells are required. Here, we examined cytotoxic effects of sonodynamic therapy (SDT) combined with a sonosensitizer, 5-aminolevulinic acid (5-ALA), on malignant gliomas both in vitro and in vivo. METHODS In vitro cytotoxicity of 5-ALA-SDT was evaluated in U87 and U251 glioma cells and in U251Oct-3/4 glioma stemlike cells. Treatment-related apoptosis was analyzed using flow cytometry. Intracellular reactive oxygen species (ROS) were measured and the role of ROS in treatment-related cytotoxicity was examined. Effects of 5-ALA-SDT with high-intensity focused ultrasound (HIFU) on tumor growth, survival of glioma-transplanted mice, and histological features of the mouse brains were investigated. RESULTS The 5-ALA-SDT inhibited cell growth and changed cell morphology. Flow cytometric analysis indicated that 5-ALA-SDT induced apoptotic cell death. The 5-ALA-SDT generated higher ROS than in the control group, and inhibition of ROS generation completely eliminated the cytotoxic effects of 5-ALA-SDT. In the in vivo study, 5-ALA-SDT with HIFU greatly prolonged survival of the tumor-bearing mice compared with that of the control group (p < 0.05). Histologically, 5-ALA-SDT produced mainly necrosis of the tumor tissue in the focus area and induced apoptosis of the tumor cells in the perifocus area around the target of the HIFU-irradiated field. Normal brain tissues around the ultrasonic irradiation field of HIFU remained intact. CONCLUSIONS The 5-ALA-SDT was cytotoxic toward malignant gliomas. Generation of ROS by the SDT was thought to promote apoptosis of glioma cells. The 5-ALA-SDT with HIFU induced tumor necrosis in the focus area and apoptosis in the perifocus area of the HIFU-irradiated field. These results suggest that 5-ALA-SDT with HIFU may present a less invasive and tumor-specific therapy, not only for a tumor mass but also for infiltrating tumor cells in malignant gliomas.

scholarly journals Enhancement of antitumor activity by using 5-ALA–mediated sonodynamic therapy to induce apoptosis in malignant gliomas: significance of high-intensity focused ultrasound on 5-ALA-SDT in a mouse glioma model

2018 ◽  
Vol 129 (6) ◽  
pp. 1416-1428 ◽  
Author(s):  
Satoshi Suehiro ◽  
Takanori Ohnishi ◽  
Daisuke Yamashita ◽  
Shohei Kohno ◽  
Akihiro Inoue ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Tumor Cells ◽  
High Intensity ◽  
Focused Ultrasound ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
High Intensity Focused Ultrasound ◽  
Control Group ◽  
Tunel Staining ◽  
Sonodynamic Therapy

OBJECTIVEHigh invasiveness of malignant gliomas frequently causes early local recurrence of the tumor, resulting in extremely poor outcome. To control such recurrence, novel therapies targeted toward infiltrating glioma cells around the tumor border are required. Here, the authors investigated the antitumor activity of sonodynamic therapy (SDT) combined with a sonosensitizer, 5-aminolevulinic acid (5-ALA), on malignant gliomas to explore the possibility for clinical use of 5-ALA–mediated SDT (5-ALA-SDT).METHODSIn vitro cytotoxicity of 5-ALA-SDT was evaluated in U87 and U251 glioma cells and in U251Oct-3/4 glioma stemlike cells. Treatment-related apoptosis was analyzed using flow cytometry and TUNEL staining. Intracellular reactive oxygen species (ROS) were measured and the role of ROS in treatment-related cytotoxicity was examined by analysis of the effect of pretreatment with the radical scavenger edaravone. Effects of 5-ALA-SDT with high-intensity focused ultrasound (HIFU) on tumor growth, survival of glioma-transplanted mice, and histological features of the mouse brains were investigated.RESULTSThe 5-ALA-SDT inhibited cell growth and changed cell morphology, inducing cell shrinkage, vacuolization, and swelling. Flow cytometric analysis and TUNEL staining indicated that 5-ALA-SDT induced apoptotic cell death in all gliomas. The 5-ALA-SDT generated significantly higher ROS than in the control group, and inhibition of ROS generation by edaravone completely eliminated the cytotoxic effects of 5-ALA-SDT. In the in vivo study, 5-ALA-SDT with HIFU greatly prolonged survival of the tumor-bearing mice compared with that of the control group (p < 0.05). Histologically, 5-ALA-SDT produced mainly necrosis of the tumor tissue in the focus area and induced apoptosis of the tumor cells in the perifocus area around the target of the HIFU-irradiated field. The proliferative activity of the entire tumor was markedly decreased. Normal brain tissues around the ultrasonic irradiation field of HIFU remained intact.CONCLUSIONSThe 5-ALA-SDT was cytotoxic toward malignant gliomas. Generation of ROS by the SDT was thought to promote apoptosis of glioma cells. The 5-ALA-SDT with HIFU induced tumor necrosis in the focus area and apoptosis in the perifocus area of the HIFU-irradiated field, whereas the surrounding brain tissue remained normal, resulting in longer survival of the HIFU-treated mice compared with that of untreated mice. These results suggest that 5-ALA-SDT with HIFU may present a less invasive and tumor-specific therapy, not only for a tumor mass but also for infiltrating tumor cells in malignant gliomas.

scholarly journals Inhibition of Cyclin D1 Expression in Human Glioblastoma Cells is Associated with Increased Temozolomide Chemosensitivity

2018 ◽  
Vol 51 (6) ◽  
pp. 2496-2508 ◽  
Author(s):  
Danfeng Zhang ◽  
Dawei Dai ◽  
Mengxia Zhou ◽  
Zhenxing Li ◽  
Chunhui Wang ◽  
...  
Keyword(s):  
Malignant Glioma ◽  
Cyclin D1 ◽  
Cell Lines ◽  
Effective Means ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
Normal Brain ◽  
Induced Apoptosis

Background/Aims: Cyclin D1 (CCND1) is frequently overexpressed in malignant gliomas. We have previously shown ectopic overexpression of CCND1 in human malignant gliomas cell lines. Methods: Quantitative reverse transcriptase PCR (qRT-PCR) and Western Blot (WB) was performed to investigate the expression of CCND1 in glioma tissues and cell lines. The biological function of CCND1 was also investigated through knockdown and overexpression of BCYRN1 in vitro. Results: Here we reported that CCND1 expression was positively associated with the pathological grade and proliferative activity of astrocytomas, as the lowest expression was found in normal brain tissue (N = 3) whereas the highest expression was in high-grade glioma tissue (N = 25). Additionally, we found that the expression level of CCND1 was associated with IC50 values in malignant glioma cell lines. Forced inhibition of CCND1 increased temozolomide efficacy in U251 and SHG-44 cells. After CCND1 overexpression, the temozolomide efficacy decreased in U251 and SHG-44 cells. Colony survival assay and apoptosis analysis confirmed that CCND1 inhibition renders cells more sensitive to temozolomide treatment and temozolomide-induced apoptosis in U251 and SHG-44 cells. Inhibition of P-gp (MDR1) by Tariquidar overcomes the effects of CCND1 overexpression on inhibiting temozolomide-induced apoptosis. Inhibition of CCND1 inhibited cell growth in vitro and in vivo significantly more effectively after temozolomide treatments than single temozolomide treatments. Finally, inhibition of CCND1 in glioma cells reduced tumor volume in a murine model. Conclusion: Taken together, these data indicate that CCND1 overexpression upregulate P-gp and induces chemoresistance in human malignant gliomas cells and that inhibition of CCND1 may be an effective means of overcoming CCND1 associated chemoresistance in human malignant glioma cells.

scholarly journals TMIC-20. ELIMINATION OF SENESCENT ASTROCYTES IN THE BRAIN TUMOR MICROENVIRONMENT ATTENUATES GLIOBLASTOMA RECURRENCE AFTER RADIOTHERAPY

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi251-vi251
Author(s):  
Eliot Fletcher-Sananikone ◽  
Bipasha Mukherjee ◽  
Sandeep Burma
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Neutralizing Antibodies ◽  
Glioma Cells ◽  
Cell Types ◽  
Normal Brain ◽  
High Doses

Abstract Glioblastomas (GBM) are treated with high doses of ionizing radiation (IR) yet these tumors inevitably recur, and the recurrent tumors are highly therapy resistant. During GBM therapy, the surrounding brain tissue is irradiated along with the tumor. IR induces senescence in multiple cell types, and senescent stromal cells are known to promote the growth of neighboring tumor cells by secreting cytokines which create a senescence-associated secretory phenotype (SASP). We hypothesize that IR-induced senescence of normal brain cells in the tumor microenvironment is a powerful driver of GBM recurrence. We intra-cranially irradiated C57BL/6J mice, and found evidence of widespread senescence, with the astrocytic population being highly susceptible. Genomic analyses of irradiated brains revealed an altered transcriptomic profile which included upregulation of CDKN1A (p21), a key enforcer of senescence, and increased expression of SASP proteins including HGF, the ligand for the RTK Met. We orthotopically implanted mock-irradiated or irradiated mice with a limiting number of syngeneic glioma cells. Pre-irradiation of mouse brains resulted in a striking increase in tumor growth and invasion driven by Met activation in the tumor cells. Importantly, irradiated p21-/- mouse brains did not exhibit SASP and failed to promote tumor growth. Irradiated primary astrocytes underwent senescence in vitro and promoted the migration of glioma cells, and this could be attenuated with HGF-neutralizing antibodies or by the Met inhibitor Crizotinib. These findings indicate that SASP factors (like HGF) in the irradiated brain microenvironment could drive GBM recurrence after radiotherapy via the activation of RTKs (like MET) in the tumor cells. Significantly, we found that senolytic drugs can selectively kill senescent astrocytes both in vitro and in vivo resulting in attenuated growth of glioma cells. These results are of great translational significance as they indicate that adjuvant therapy with senolytic drugs might attenuate GBM recurrence after radiotherapy.

scholarly journals Diamond Nanoparticles Downregulate Expression of CycD and CycE in Glioma Cells

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1549 ◽  
Author(s):  
Marta Grodzik ◽  
Jaroslaw Szczepaniak ◽  
Barbara Strojny-Cieslak ◽  
Anna Hotowy ◽  
Mateusz Wierzbicki ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Glioma Cells ◽  
Migration And Invasion ◽  
Control Group ◽  
Ki 67 ◽  
Normal Cells ◽  
Diamond Nanoparticles ◽  
Dividing Cells

Our previous studies have shown that diamond nanoparticles (NDs) exhibited antiangiogenic and proapoptotic properties in vitro in glioblastoma multiforme (GBM) cells and in tumors in vivo. Moreover, NDs inhibited adhesion, leading to the suppression of migration and invasion of GBM. In the present study, we hypothesized that the NDs might also inhibit proliferation and cell cycle in glioma cells. Experiments were performed in vitro with the U87 and U118 lines of GBM cells, and for comparison, the Hs5 line of stromal cells (normal cells) after 24 h and 72 h of treatment. The analyses included cell morphology, cell death, viability, and cell cycle analysis, double timing assay, and gene expression (Rb, E2F1, CycA, CycB, CycD, CycE, PTEN, Ki-67). After 72 h of ND treatment, the expression level of Rb, CycD, and CycE in the U118 cells, and E2F1, CycD, and CycE in the U87 cells were significantly lower in comparison to those in the control group. We observed that decreased expression of cyclins inhibited the G1/S phase transition, arresting the cell cycle in the G0/G1 phase in glioma cells. The NDs did not affect the cell cycle as well as PTEN and Ki-67 expression in normal cells (Hs5), although it can be assumed that the NDs reduced proliferation and altered the cell cycle in fast dividing cells.

scholarly journals CBMT-48. TARGETING METABOLIC REPROGRAMMING WITH NANOCURCUMIN IN GLIOBLASTOMA MULTIFORME

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi43-vi43
Author(s):  
Hamid Suhail ◽  
Rattan Ramandeep ◽  
Giri Shailendra ◽  
Ana deCarvalho ◽  
Steven Kalkanis ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Water Solubility ◽  
Curcuma Longa ◽  
Glioma Cells ◽  
Metabolic Reprogramming ◽  
Dependent Manner ◽  
Systemic Delivery ◽  
Ampk Activity

Abstract Glioblastoma (GBM) is a highly glycolytic aggressive brain tumor characterized by increased proliferation and resistance to chemotherapy and radiotherapy. AMPK has been reported as tumor suppressor and reprograms the cellular metabolic pathways and produces a metabolic checkpoint on the cell cycle though mTORC1, p53 and other modulators involved in cell proliferation, growth, survival and autophagy. The AMPK activity is diminished in gastric, breast and ovarian tumor cells by activated PI3K-AKT pathways. Cancer cells are able to reprogram their energy metabolism to compensate their high bioenergetic demands needed for their aggressive growth and survival. Curcumin exhibits pleiotropic properties and activate MAPK and leads to suppress p53, Wnt/β-catenin, SHH and PI3K-AKT signaling pathways. Curcumin or diferuloylmethane is a yellow polyphenol extracted from the rhizome of turmeric (Curcuma longa). The absorption, biodistribution, metabolism, and elimination studies of curcumin have, unfortunately, shown only poor absorption, rapid metabolism, and elimination of curcumin as major reasons for poor bioavailability of this interesting polyphenolic compound. We have engineered a curcumin-based nanoparticle (Curc-NP) which demonstrates high water solubility. Curc-NP was effectively transported into the cells by nanoparticles through endocytosis and localized around the nuclei in the cytoplasms. In vitro studies proved that the cytotoxicity of Curc-NP is more effective against U-251 cell line in a dose-dependent manner. Systemic delivery of Curc-NP led to preferentially accumulation in an orthotopic preclinical glioma model minimizing systemic toxic effect. Multicolor microscopy images of the tumor tissue showed that Curc-NP particles were internalized inside tumor cells selectively and localized within nuclei. Curc-NP demonstrated to restore the dysregulated AMPK activity in glioma cells. Curc-NP-induced AMPK activation resulted in inhibition of oncogenic signalling pathways in glioma. Curc-NP-induced metabolic reprograming in glioma cells will be examined and the in vivo therapeutic efficacy of Curc-NP in an experimental rat model of GBM will also be evaluated.

dSLIM Immunomodulators Induce Anti-Tumor Responses Both In Vitro and In Vivo.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1727-1727
Author(s):  
Manuel Schmidt ◽  
Javier de Cristobal ◽  
Astrid Sander ◽  
Bernadette Brzezicha ◽  
Sven A. König Merediz ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Neutralizing Antibodies ◽  
De Novo ◽  
Tumor Cell Line ◽  
Control Group ◽  
Γδt Cells ◽  
Ifn Γ

Abstract Cytosine-guanine (CpG) motifs containing oligonucleotides (ODN) are commonly used for immunomodulatory purpose in cancer therapy and for the treatment of allergic diseases since they resemble bacterial DNA and serve as “danger signals”. These CpG-ODNs promote predominately a TH1-response with secretion of IL-12 and IFN-γ, In addition their broad potential includes activation of B-cell proliferation, monocyte stimulation and secretion of IgM and IL-6, and stimulation of plasmacytoid DC to produce IFN-α/-β and thus γδT-cells and NK-cells to express CD69 and secrete IFN-γ. Usually phosphorothioate (PS) modifications are to enhance the stability, but these are leading to several side-effects, like severe organ enlargements, morphological changes and immunosuppression in mice. We designed immunomodulatory molecules based on short covalently-closed dumbbell-like structures (dSLIM) to stabilize the DNA without the otherwise necessary PS-modification. To evaluate the anti-tumor effect of the dSLIM molecules we developed an in vitro anti-tumor assay. This assay uses supernatant from dSLIM-activated human PBMCs for incubation with tumor cells in vitro. We observed increased apoptosis and necrosis of the HT-29 tumor cell line after incubation with supernatant from dSLIM-treated PBMC which was significantly higher than the effect of supernatant from non-treated PBMC. In addition, supernatant from dSLIM-treated PBMC increased the expression of HLA-ABC on the tumor cells, a pre-requisite for tumor cell recognition by the immune system. These effects were confirmed with human HEK293 and murine Renca cell lines. Analyzing the effect with neutralizing antibodies to various apoptosis-related cytokines, we observed a crucial role of IFN-γ but not IFN-α or TNFα. To investigate the anti-tumor effects of dSLIM in vivo, we employed a SKH1 murine model which is prone to spontaneous development of papillomas. Using chemicals for initiation and weekly promotion of de novo papilloma development we compared groups of weekly s.c. or i.p. dSLIM injections, respectively, with the PBS control group. The number of papilloma developing mice was significantly lower in the dSLIM groups and the total number of papillomas on all mice was reduced by approximately 50%. In conclusion, we showed that dSLIM immunomodulators exhibit potent anti-tumor effects in vitro and in vivo.

scholarly journals Chloroquine enhances temozolomide cytotoxicity in malignant gliomas by blocking autophagy

2014 ◽  
Vol 37 (6) ◽  
pp. E12 ◽  
Author(s):  
Encouse B. Golden ◽  
Hee-Yeon Cho ◽  
Ardeshir Jahanian ◽  
Florence M. Hofman ◽  
Stan G. Louie ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
In Vivo Model ◽  
Autophagosome Formation ◽  
Individual Drug ◽  
In Vivo Experiments ◽  
Associated Proteins

Object In a recent clinical trial, patients with newly diagnosed glioblastoma multiforme benefited from chloroquine (CQ) in combination with conventional therapy (resection, temozolomide [TMZ], and radiation therapy). In the present study, the authors report the mechanism by which CQ enhances the therapeutic efficacy of TMZ to aid future studies aimed at improving this therapeutic regimen. Methods Using in vitro and in vivo experiments, the authors determined the mechanism by which CQ enhances TMZ cytotoxicity. They focused on the inhibition-of-autophagy mechanism of CQ by knockdown of the autophagy-associated proteins or treatment with autophagy inhibitors. This mechanism was tested using an in vivo model with subcutaneously implanted U87MG tumors from mice treated with CQ in combination with TMZ. Results Knockdown of the autophagy-associated proteins (GRP78 and Beclin) or treatment with the autophagy inhibitor, 3-methyl adenine (3-MA), blocked autophagosome formation and reduced CQ cytotoxicity, suggesting that autophagosome accumulation precedes CQ-induced cell death. In contrast, blocking autophagosome formation with knockdown of GRP78 or treatment with 3-MA enhanced TMZ cytotoxicity, suggesting that the autophagy pathway protects from TMZ-induced cytotoxicity. CQ in combination with TMZ significantly increased the amounts of LC3B-II (a marker for autophagosome levels), CHOP/GADD-153, and cleaved PARP (a marker for apoptosis) over those with untreated or individual drug-treated glioma cells. These molecular mechanisms seemed to take place in vivo as well. Subcutaneously implanted U87MG tumors from mice treated with CQ in combination with TMZ displayed higher levels of CHOP/GADD-153 than did untreated or individual drug-treated tumors. Conclusions Taken together, these results demonstrate that CQ blocks autophagy and triggers endoplasmic reticulum stress, thereby increasing the chemosensitivity of glioma cells to TMZ.

scholarly journals Heat Shock Protein 70 Inhibitor, Alone or in Combination with Bortezomib, Prevented Plasmacytoma Development in Immunodeficient Mice Transplanted with Myeloma Cell Lines

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5658-5658
Author(s):  
Mariana Bleker de Oliveira ◽  
Angela Isabel Eugenio ◽  
Veruska Lia Fook Alves ◽  
Daniela Zanatta ◽  
Mihoko Yamamoto ◽  
...  
Keyword(s):  
Cell Line ◽  
Tumor Cells ◽  
Cell Lines ◽  
Proteasome Inhibitor ◽  
Conflicts Of Interest ◽  
Control Group ◽  
Immunodeficient Mice ◽  
Late Apoptosis

Abstract Introduction: HSP70 has an integrative role in protein degradation due to the interaction with many pathways, such as ubiquitin proteasome (UPS), unfolded protein response (UPR) and autophagy. In multiple myeloma (MM) HSP70 is overexpressed and helps to prevent proteotoxic stress and cell death caused by overload of unfolded/misfolded proteins produced by tumor cells. Aims: To explore the role of HSP70 inhibition, isolated or in association with proteasome inhibitor, as therapeutic strategy for MM through in vitro and in vivo analyses. Methods: RPMI8226-LUC-PURO and U266-LUC-PURO bioluminescent cell lines were treated with HSP70 inhibitor (VER155008- 50 μM or 80μM) and proteasome inhibitor (bortezomib 100nM) for evaluation of apoptosis induction by flow cytometry using annexin V and propidium iodide. NOD.Cg-rkdcscid Il2rgtm1Wjl/SzJ immunodeficient mice were used for plasmacytoma xenograft model and treated with intravenous VER155008 (40mg/kg) and bortezomib (1mg/kg), immediately after transplant of RPMI8226-LUC-PURO and U266-LUC-PURO bioluminescent cell lines (N=3 for each group, including controls, bortezomib, VER155008, and combination of bortezomib and VER155008). Bioluminescence was measured in IVIS Kinetic (Capiler Life Science) once a day for seven days. Results: Bortezomib used as single treatment was able to induce apoptosis in RPMI8226-LUC-PURO cell line: the best result for in vitro studies RPMI8226-LUC-PURO was 65% of late apoptosis after treatment with bortezomib. On the other hand, U266-LUC-PURO cell line presented higher percentage of apoptosis when treated with bortezomib and VER155008 combination: U266-LUC-PURO cell line presented more than 60% of late apoptosis after VER155008 (80μM) combined with bortezomib, showing that inhibition of HSP70 could overcome U266-LUC-PURO resistance to bortezomib alone. Mice treated with VER155008, alone or in combination with bortezomib, showed complete inhibition of tumor growth (absence of bioluminescence) for both cell lines when compared with control group after one week of treatment (p<0.001, Two-way ANOVA). Therefore, in vivo studies using mice treated with VER155008, alone or in combination with bortezomib, prevented tumor development after one week of treatment, independent of the cell line used in the xenotransplant. Conclusion: Our study shows that HSP70 and proteasome inhibitors combination induced apoptosis in tumor cells in vivo for both MM cell lines. Since HSP70 is overexpressed in MM and connects several signaling pathways that maintain cell survival, such as UPS, UPR and autophagy, it can represent a key role to establish a new approach for the treatment of MM. Financial support: FAPESP 2010/17668-6 and CNPq (155272/2013-6). UNIFESP Ethics Committee (0219/12). Disclosures No relevant conflicts of interest to declare.

Anti-Myeloma Activity by the Combination of the JAK2 Inhibitor Ruxolitinib with Lenalidomide and Corticosteroids

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2114-2114 ◽  
Author(s):  
Haiming Chen ◽  
Eric Sanchez ◽  
Mingjie Li ◽  
Cathy Wang ◽  
Abby Gillespie ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Cell Viability ◽  
Tumor Cells ◽  
Cell Lines ◽  
Scid Mice ◽  
M Protein ◽  
Cytotoxic Effects ◽  
Jak2 Inhibitor

Abstract Introduction: The JAK2 inhibitor ruxolitinib (RUX) is an inhibitor of the Janus kinase family of protein tyrosine kinases (JAKs) that is effective for the treatment of myeloproliferative diseases. Immunomodulatory drugs (IMiDs) including lenalidomide (LEN) and corticosteroids have shown efficacy for the treatment of multiple myeloma (MM). The JAK-STAT signaling pathway plays key roles in the growth and survival of malignant plasma cells in MM. In this study, we evaluated the preclinical anti-MM effects of RUX in combination with LEN and corticosteroids, both in vitro and in vivo, and in a patient with MM and polycythemia rubra vera (PRV). Methods: The human MM cell lines U266, RPMI8226 and MM1S cells were derived from ATCC. Primary MM tumor cells were isolated from MM patients’ bone marrow aspirates. The cells were seeded at105 cells/100ul/well in 96-well plates and incubated for 24 h in the presence of vehicle, RUX, LEN or dexamethasone (DEX) alone, RUX + LEN, RUX + DEX, or all three drugs together for 48 h. Cell viability was quantified using the MTS cell proliferation assay. In vitro, synergy between ruxolitinib and lenalidomide or dexamethasone was assessed using the median effect method of Chou and Talalay. For the in vivo studies, the human myeloma tumors (LAGκ-1A or LAGκ-2) were surgically implanted into the left superficial gluteal muscle of anaesthetized naive SCID mice. Mice were blindly assigned to one of the experimental groups, and treatment was initiated 7–21 d after tumor implantation. LEN was administered via oral gavage daily (30 mg/kg). RUX (3 mg/kg) was given via intraperitoneal (IP) injection twice daily. Dexamethasone was administered daily (1.5mg/kg) via IP injection. An 88 year old MM patient with PRV who developed MM on RUX alone and then progressed on LEN+DEX was treated with the combination of all three drugs. Results: In vitro, RUX induced concentration-dependent inhibition of viability in all three MM cell lines (U266, RPMI8226 and MM1S) at RUX 50 mM and inhibition of primary MM tumor cells at a higher concentration (100 mM). In contrast, RUX had negligible cytotoxic effects on normal peripheral blood mononuclear cells (PBMCs). We next examined cell viability in the presence of RUX plus LEN or DEX. First, U266 cells were incubated with a fixed concentration of LEN (30 mM) or DEX (40 mM) with increasing concentrations of RUX (0.1–100 mM) for 48 h. At RUX 50 mM, the cytotoxic effects of LEN were enhanced and at RUX 1 mM, the anti-myeloma effect of DEX was increased. Moreover, the cytotoxic effects of RUX, LEN and DEX were greater than RUX in combination with either LEN or DEX in U266 cells. Similar results were obtained using the RPMI8226 and MM1S cell lines as well as primary MM tumor cells. Next, we evaluated RUX in combination with lenalidomide and dexamethasone in vivo using SCID mice bearing either the human LAGκ-1A or LAGκ-2 MM xenografts. RUX (3mg/kg), LEN (15mg/kg) or DEX (1mg/kg) alone did not inhibit tumor growth in either mice bearing LAGκ-1A or LAGκ-2. In contrast, the combination of RUX with DEX but not LEN slightly decreased tumor volume. However, the combination of all three drugs at the same doses showed a marked reduction of tumor size and delay of tumor growth in both human MM xenograft models. In addition, a patient with MM and PRV experienced sustained and ongoing reductions in his serum M-protein, IgG, and 24-urine M-protein with achievement of a partial response on low doses of RUX (2.5 mg twice daily), LEN (2.5 mg daily), and methylprednisolone (20 mg daily) that has been ongoing for more than 12 months after developing MM on RUX alone and then progressing on the combination of LEN and methylprednisolone. Conclusion: This study illustrates that the combination of the JAK2 inhibitor RUX, LEN and corticosteroids shows both preclinical and promising clinical results for the treatment of MM. Disclosures No relevant conflicts of interest to declare.

scholarly journals CSIG-18. CALCIUM COMMUNICATION IN GLIOMA: CRUCIAL PACEMAKER CELLS GOVERN TUMOR PROGRESSION

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii31-ii31
Author(s):  
David Hausmann ◽  
Erik Jung ◽  
Daniel Azorin ◽  
Miriam Ratliff ◽  
Matthias Osswald ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Laser Ablation ◽  
Tumor Cells ◽  
Glioma Cells ◽  
Calcium Oscillations ◽  
Cell Subpopulation ◽  
Pacemaker Cells ◽  
Calcium Activity

Abstract BACKGROUND Gliomas form therapy-resistant multicellular networks, using neurite-like protrusions (called Tumor Microtubes [TMs]), and display intercellular calcium transients, that drive brain tumor malignancy. METHODS A refined in vitro model was established to study calcium communication and its molecular toolkit in patient-derived glioma cells. In vitro results were then validated with longitudinal in vivo two-photon calcium imaging in awake mice. RESULTS Here we first describe the discovery of a small subpopulation of glioma cells that display intrinsically active calcium oscillations and behave like pacemakers. Accordingly, these pacemaker-like glioma cells trigger synchronized calcium activity in tumor cells that are connected with them via TMs. The application of network theory shows that glioma cell networks follow a scale-free and small-world topology, governed by a subpopulation of highly connected hub cells. Interestingly, the pacemaker cells most often act as these hubs, hence communicating with many other network members. Graph theory predicts that such network design displays a high degree of robustness, making it resistant to random damage as seen after radio- and chemotherapy – but extremely vulnerable to selective damage to key hubs. In line with this theory, laser ablation of the pacemaker-like hub cells splintered the malignant tumor network into small isolated cell clusters and led to increased cell death, whereas laser ablation of random tumor cells showed no effect. Among others, KCNN4 channels, which are upregulated in gliomas, were identified as drivers of the pacemaker-like hub cells. Suppressing their pacemaking-abilities by KCNN4 inhibition strongly reduced calcium communication and tumor growth. CONCLUSION In summary, coordinated calcium communication in glioma drives brain tumor malignancy. A specific tumor cell subpopulation was identified that acts as hubs of the multicellular network and initiates global calcium activity. The network’s vulnerability to loosing these pacemaker-like hub cells suggests a novel targeted approach against the resistant networks of gliomas.

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