scholarly journals ET-09 ACQUIRED MALIGNANT BEHAVIORS OF NPE6-PDT-SURVIVED GLIOBLASTOMA CELLS ARE SUPPRESSED BY USING MEK1/2 INHIBITOR TRAMETINIB

2019 ◽  
Vol 1 (Supplement_2) ◽  
pp. ii9-ii9
Author(s):  
Tatsuya Kobayashi ◽  
Yoshihiro Muragaki ◽  
Masamichi Takahashi ◽  
Kojiro Wada ◽  
Kentaro Mori ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Wave Length ◽  
Boyden Chamber ◽  
Concomitant Treatment ◽  
Dependent Manner ◽  
Molecular Signaling ◽  
Talaporfin Sodium ◽  
Human Gbm

Abstract INTRODUCTION In this study, we tried to investigate alteration of oncogenic properties and their molecular regulatory mechanism of talaporfin sodium (NPe6)-mediated photodynamic therapy (NPe6-PDT)-survived glioblastoma (GBM) cells. METHODS As the in-vitro NPe6-PDT model, human GBM cell lines (T98G, U87MG, U343), and patient derived GBM stem cells (GSY03, GSC23, MGG152) were pretreated with 0-30ug/ml NPe6 for 4 hours followed by laser irradiation (wave length 664 nm, laser-power 33 mW/cm2, total amount of irradiation 10 J/cm2) using a semiconductor laser irradiator (Panasonic Healthcare Co., Ltd., Tokyo, Japan). Cell death after PDT was evaluated by vital dye exclusion assay using Hoechst3342 and propidium iodide or CellTiter-Glo. Survived cells after NPe6-PDT (PDT-R cells) were repropagated, and alteration of intracellular molecular signaling or migration/invasion capability were analyzed by immunoblotting or Boyden chamber assay. RESULTS In both human GBM cell lines and patient derived GBM cells, cellular viability after NPe6-PDT was decreased with dose-dependent manner of pretreated NPe6. PDT-R cells showed not only resistance against NPe6-PDT-induced cell death but also higher invasiveness and migration capability compared with pre-PDT treated cells (PDT-Con cells), and immunoblot analysis demonstrated upregulation of ERK1/2 phosphorylation in PDT-R cells in comparison with PDT-Con cells. Furthermore, these acquired malignant behavior of PDT-R cells were repressed by concomitant use of MEK1/2 inhibitor Trametinib with NPe6-PDT. CONCLUSION We discovered PDT-R cells demonstrated higher malignant phenotypes via ERK1/2-dependent machinery compared with parent pre-PDT-treated cells. It was also suggested concomitant treatment with MEK1/2 inhibitor during PDT therapy in GBM cases would contribute to better outcome.

scholarly journals Enhanced Malignant Phenotypes of Glioblastoma Cells Surviving NPe6-Mediated Photodynamic Therapy are Regulated via ERK1/2 Activation

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3641
Author(s):  
Tatsuya Kobayashi ◽  
Makoto Miyazaki ◽  
Nobuyoshi Sasaki ◽  
Shun Yamamuro ◽  
Eita Uchida ◽  
...  
Keyword(s):  
Cell Death ◽  
Photodynamic Therapy ◽  
Migration And Invasion ◽  
Dependent Manner ◽  
Potential Therapeutic Target ◽  
Talaporfin Sodium ◽  
Polymerase Inhibitor ◽  
Human Gbm ◽  
Dose Dependent

To manage refractory and invasive glioblastomas (GBM)s, photodynamic therapy (PDT) using talaporfin sodium (NPe6) (NPe6-PDT) was recently approved in clinical practice. However, the molecular machineries regulating resistance against NPe6-PDT in GBMs and mechanisms underlying the changes in GBM phenotypes following NPe6-PDT remain unknown. Herein, we established an in vitro NPe6-mediated PDT model using human GBM cell lines. NPe6-PDT induced GBM cell death in a NPe6 dose-dependent manner. However, this NPe6-PDT-induced GBM cell death was not completely blocked by the pan-caspase inhibitor, suggesting NPe6-PDT induces both caspase-dependent and -independent cell death. Moreover, treatment with poly (ADP-ribose) polymerase inhibitor blocked NPe6-PDT-triggered caspase-independent GBM cell death. Next, it was also revealed resistance to re-NPe6-PDT of GBM cells and GBM stem cells survived following NPe6-PDT (NPe6-PDT-R cells), as well as migration and invasion of NPe6-PDT-R cells were enhanced. Immunoblotting of NPe6-PDT-R cells to assess the behavior of the proteins that are known to be stress-induced revealed that only ERK1/2 activation exhibited the same trend as migration. Importantly, treatment with the MEK1/2 inhibitor trametinib reversed resistance against re-NPe6-PDT and suppressed the enhanced migration and invasion of NPe6-PDT-R cells. Overall, enhanced ERK1/2 activation is suggested as a key regulator of elevated malignant phenotypes of GBM cells surviving NPe6-PDT and is therefore considered as a potential therapeutic target against GBM.

scholarly journals TB-4 Antitumor effects of a novel curcumin derivative curcumin monoglucuronide on glioblastoma cells in vitro and in vivo

2021 ◽  
Vol 3 (Supplement_6) ◽  
pp. vi6-vi6
Author(s):  
Takashi Fujii ◽  
Shun Yamamuro ◽  
Masamichi Takahashi ◽  
Akihide Kondo ◽  
Yoshitaka Narita ◽  
...  
Keyword(s):  
Cell Death ◽  
Water Soluble ◽  
Dependent Manner ◽  
Antitumor Effects ◽  
Multiple Cell ◽  
Human Gbm ◽  
Dose Dependent ◽  
Novel Therapeutic

Abstract The therapeutic outcome of glioblastomas (GBMs) is still very poor. Therefore, invention of novel therapeutic methods against GBM cases is considered urgent. The antitumor effects of naturally-derived compounds are attracting attention recently, and therapeutic efficacy of curcumin, a plant-derived compound previously used for multiple purpose, has been indicated in many cancer systems; however, clinical application of curcumin is considered difficult because of its poor bioavailability (under 1 %). Curcumin monoglucuronide (CMG), a water-soluble prodrug of curcumin recently developed for overcoming this weakness, has been demonstrated excellent antitumor effects for several malignancies in vitro and in vivo; therefore, we investigated the effects of CMG against GBM cells. CMG induced cell death of human GBM cells lines (T98G, U251MG, and U87MG) by dose dependent manner by triggering multiple forms of cell death such as apoptosis and perthanatos. Immunoblotting of CMG-treated GBM cell lysates demonstrated activation of multiple cell death signaling. Furthermore, immunodeficiency mice harboring intracerebral U87MG cell xenografts systemically treated by CMG showed significantly prolonged survival compared with control mice. These results suggest CMG would be a novel therapeutic agent against GBM cases.

scholarly journals TGF-β Promotes the Proliferation of Microglia In Vitro

2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Costansia Bureta ◽  
Takao Setoguchi ◽  
Yoshinobu Saitoh ◽  
Hiroyuki Tominaga ◽  
Shingo Maeda ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Transforming Growth Factor Beta ◽  
Microglial Cell ◽  
Transforming Growth Factor ◽  
Dependent Manner ◽  
In Vitro Proliferation ◽  
Inhibition Of Proliferation ◽  
Significant Difference

The activation and proliferation of microglia is characteristic of the early stages of brain pathologies. In this study, we aimed to identify a factor that promotes microglial activation and proliferation and examined the in vitro effects on these processes. We cultured microglial cell lines, EOC 2 and SIM-A9, with various growth factors and evaluated cell proliferation, death, and viability. The results showed that only transforming growth factor beta (TGF-β) caused an increase in the in vitro proliferation of both microglial cell lines. It has been reported that colony-stimulating factor 1 promotes the proliferation of microglia, while TGF-β promotes both proliferation and inhibition of cell death of microglia. However, upon comparing the most effective doses of both (assessed from the proliferation assay), we identified no statistically significant difference between the two factors in terms of cell death; thus, both have a proliferative effect on microglial cells. In addition, a TGF-β receptor 1 inhibitor, galunisertib, caused marked inhibition of proliferation in a dose-dependent manner, indicating that inhibition of TGF-β signalling reduces the proliferation of microglia. Therefore, galunisertib may represent a promising therapeutic agent for the treatment of neurodegenerative diseases via inhibition of nerve injury-induced microglial proliferation, which may result in reduced inflammatory and neuropathic and cancer pain.

The Histone Deacetylase (HDAC) Inhibitor Entinostat (SNDX-275) Targets Hodgkin Lymphoma through a Dual Mechanism of Immune Modulation and Apoptosis Induction.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1562-1562 ◽  
Author(s):  
Noor M Khaskhely ◽  
Daniela Buglio ◽  
Jessica Shafer ◽  
Catherine M. Bollard ◽  
Anas Younes
Keyword(s):  
Immune Response ◽  
Cell Death ◽  
Protein Expression ◽  
Cell Lines ◽  
Dependent Manner ◽  
Chemokine Production ◽  
Apoptosis Pathway ◽  
Gene And Protein Expression ◽  
Combination Studies

Abstract Abstract 1562 Poster Board I-585 Purpose SNDX-275 is an oral, class 1 isoform selective HDACi. Phase 1 studies in leukemia demonstrated the agent has a long half-life and that weekly or every other week dosing is sufficient for antitumor activity. Based on recent favorable in vitro and in vivo activity of several HDAC inhibitors in HL, we investigated the in vitro activity of SNDX275 in HL-derived cell lines. Methods For apoptosis and gene expression analysis 05 × 106 cells were incubated with 0.1-2 μM of SNDX-275 for 24-72 hours before they were examined for proliferation and cell death by the MTS assay and the annexin-PI and FACS analysis. For combination studies, cells were incubated with 0.1-2 uM of SNDX-275 and 1-20 nM of either gemcitabine or bortezomib for 48-72 hours. Gene and protein expression were measured by RT-PCR, western blot, and immunohistochemistry. SNDX-275 effects on a panel of 30 cytokines and chemokines was assayed on 05 × 106 cells after incubation of 48 hrs using a multiplex assay. Results SNDX-275 induced cell death in a dose and time dependent manner with an IC50 of 0.4 μM. At the molecular level, SNDX-275 increased H3 acetylation, up-regulated p21 protein expression, and activated the intrinsic apoptosis pathway by down-regulating the anti-apoptotic X-linked inhibitor or apoptosis (XIAP) protein, which was associated with activation of caspase 9 and 3. Combination studies demonstrated that SNDX-275 had synergistic effects when combined with gemcitabine and bortezomib. To further investigate the potential for SNDX-275 activity in HL we measured the effect of SNDX-275 on pathways that may contribute to an anti-tumor immune response. Dysregulated cytokine/chemokine production has been shown to contribute to HL pathology, including immune tolerance of the cancer cells. SNDX-275 increased IL12 p40-70, IP10, and RANTES, and decreased the level of IL13 and IL4, thus favoring Th1-type cytokines/chemokines. In addition, recent data has demonstrated that a variety of epigenetic-modulating drugs may up-regulate the expression of cancer testis tumor associated antigens, leading to a favorable immune response. None of the lines expressed the CTAs without induction. SNDX275 was able to induce CTA expression of SSX2 in L428 but not HDLM2 whereas MAGE-A was induced in both HL cell lines. NY-ESO expression was not induced. Conclusions Our studies demonstrate that SNDS-275 has dual effect on apoptotic and immunomodulatory pathways in HL. Furthermore, this data demonstrates that SNDX-275 may upregulate CTAs suggesting that this treatment may render the tumor more immunogeneic and susceptible to immune mediated killing with tumor-specific cytotoxic T lymphocytes. The selectivity profile of SNDX-275 also suggests that HDAC1 and 2 are the primary targets for HDAC inhibition in these cells. Phase 2 studies with SNDX-275 in HL are ongoing. Disclosures Younes: MethylGene: Honoraria, Research Funding.

scholarly journals Dexamethasone Treatment Limits Efficacy of Radiation, but Does Not Interfere With Glioma Cell Death Induced by Tumor Treating Fields

2021 ◽  
Vol 11 ◽  
Author(s):  
Benedikt Linder ◽  
Abigail Schiesl ◽  
Martin Voss ◽  
Franz Rödel ◽  
Stephanie Hehlgans ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Clinical Analysis ◽  
Concomitant Treatment ◽  
Tumor Treating Fields ◽  
Cell Counts ◽  
Anti Cancer ◽  
Massive Cell Death ◽  
Human Gbm ◽  
Massive Cell

PurposeDexamethasone (Dex) is the most common corticosteroid to treat edema in glioblastoma (GBM) patients. Recent studies identified the addition of Dex to radiation therapy (RT) to be associated with poor survival. Independently, Tumor Treating Fields (TTFields) provides a novel anti-cancer modality for patients with primary and recurrent GBM. Whether Dex influences the efficacy of TTFields, however, remains elusive.MethodsHuman GBM cell lines MZ54 and U251 were treated with RT or TTFields in combination with Dex and the effects on cell counts and cell death were determined via flow cytometry. We further performed a retrospective analysis of GBM patients with TTFields treatment +/- concomitant Dex and analysed its impact on progression-free (PFS) and overall survival (OS).ResultsThe addition of Dex significantly reduced the efficacy of RT in U251, but not in MZ54 cells. TTFields (200 kHz/250 kHz) induced massive cell death in both cell lines. Concomitant treatment of TTFields and Dex did not reduce the overall efficacy of TTFields. Further, in our retrospective clinical analysis, we found that the addition of Dex to TTFields therapy did not influence PFS nor OS.ConclusionOur translational investigation indicates that the efficacy of TTFields therapy in patients with GBM and GBM cell lines is not affected by the addition of Dex.

The Histone Deacetylase Inhibitor Entinostat (SNDX-275) Targets Hodgkin Lymphoma through a Dual Mechanism of Immune Modulation and Apoptosis Induction

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2850-2850 ◽  
Author(s):  
Adam Jona ◽  
Noor Khaskhely ◽  
Daniela Buglio ◽  
Jessica A. Shafer ◽  
Enrico Derenzini ◽  
...  
Keyword(s):  
Immune Response ◽  
Cell Death ◽  
Hodgkin Lymphoma ◽  
Histone Deacetylase ◽  
Cell Lines ◽  
Dependent Manner ◽  
Gene And Protein Expression ◽  
Combination Studies ◽  
20 Nm

Abstract Abstract 2850 Introduction: Based on recent favorable in vitro and in vivo activity of several HDACi (histone deacetylase inhibitors) in HL (Hodgkin lymphoma), we investigated the in vitro activity of SNDX-275, an oral, class 1 isoform of selective HDACi in HL-derived cell lines. Materials and methods: Proliferation and cell death were examined by MTS assay, Annexin-V/PI and FACS analysis. For combination studies, cells were incubated with SNDX-275 (0.1-2 μM) and either ABT-737 (0.01-0.2 μM), Obatoclax (0.1-2 μM), Gemcitabine (1-20 nM) or Bortezomib (1-20 nM) for 72 hours. Gene and protein expression were measured by RT-PCR, Western blot, and immunohistochemistry. A multiplex assay was used to determine 30 cytokines and chemokines. Results: SNDX-275 induced cell death in a dose and time dependent manner with an IC50 of 0.4 μM. At the molecular level, SNDX-275 increased histone-3 acetylation, up-regulated p21 expression, and activated the intrinsic apoptosis pathway by down-regulating the XIAP (X-linked inhibitor of apoptosis protein), which was associated with activation of Caspase 9 and 3. Similarly to other HDACis, SNDX-275 decreased the expression of anti-apoptotic Bcl-2 and Bcl-xL, while level of Mcl-1 and pro-apoptotic Bax remained the same level. Combination studies demonstrated that SNDX-275 had more synergistic effect when combined with Bcl-2 inhibitors ABT-737 or Obatoclax and less when combined with Gemcitabine or Bortezomib. Dysregulated cytokine/chemokine production has been shown previously to contribute to HL pathology, including immune tolerance of the cancer cells. Hence, we measured the effect of SNDX-275 on pathways that may contribute to an anti-tumor immune response. Increased IL12 p40-70, IP10, and RANTES, and decreased IL13, IL4 and TARC levels were found, thus favoring Th1-type cytokines/chemokines. Recent data has demonstrated that a variety of epigenetic-modulating drugs may up-regulate the expression of CTAs (cancer testis antigens), leading to a favorable immune response. SNDX-275 was able to induce CTA expression of SSX2 and NY-ESO only in one cell line whereas MAGE-A4 was induced in both HL cell lines. Conclusion: Our studies demonstrate that SNDX-275 has a dual effect on apoptotic and immunomodulatory pathways in HL, which can be enhanced by the addition of agents targeting cell survival pathways. Phase II studies with SNDX-275 in HL are ongoing, future clinical studies should investigate combinations with SNDX-275. Disclosures: No relevant conflicts of interest to declare.

Effect of sunitinib and pazopanib on necrosis and autophagic cell death in cancer cells: Role of cathepsin B.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e15513-e15513 ◽  
Author(s):  
Matteo Santoni ◽  
Consuelo Amantini ◽  
Maria Beatrice Morelli ◽  
Valerio Farfariello ◽  
Massimo Nabissi ◽  
...  
Keyword(s):  
Cell Death ◽  
Western Blot ◽  
Cancer Cells ◽  
Cell Lines ◽  
Cathepsin B ◽  
Kinase Inhibitors ◽  
Autophagic Cell Death ◽  
Dependent Manner ◽  
Acridine Orange Staining

e15513 Background: Tyrosine kinase inhibitors (TKI), such as sunitinib, sorafenib and pazopanib, have replaced immunotherapy as the standard of care for metastatic renal cell carcinoma (mRCC). However, their use in sequential or combined strategies is limited by the lack of evidences on TKI-induced cell death in cancer cells. Aim of our study was to evaluate the different mechanisms responsible of the anti-proliferative and cytotoxic effects induced in vitro by µM doses of sunitinib, sorafenib and pazopanib in 5637 and J82 bladder cancer (BC) cell lines. Methods: The viability of BC cell lines were tested by MTT assay. Autophagy was evaluated by western blot analysis with anti-LC3 and anti-p62 antibodies, acridine orange staining and cytofluorimetric analysis. Necrotic cell death was evaluated by Annexin-V/PI staining and FACS analysis. The cathepsin B activation was evaluated by western blot using an anti-cathepsin B antibody; the cathepsin B proteolytic activity was determined using the fluorogenic Z-Arg-Arg-AMC peptide and the fluorescence of the hydrolyzed 7-amino-4-methyl-coumarin was detected by a SpectraMax Gemini XPS microplate reader. Results: We found that sunitinib and pazopanib markedly reduced at mM dose the viability of BC cells. Treatment for 24h with 20µM of sunitinib, by triggering “Incomplete autophagy”, induced necrosis of BC cells. In addition, sunitinib as a lysosomotropic agent, entered free within the lysosomes, where by increasing lysosomal pH and impairing cathepsin B activity, induced lysosomal-dependent necrosis. By contrast, treatment of BC cells for 72h with 20µM of pazopanib induced autophagic cell death, which was markedly reversed in a dose-dependent manner by the autophagic inhibitor 3-MA. The pazopanib-induced autophagic cell death was associated with increased procathepsin B cleavage and enhanced cathepsin B activity. Conclusions: Overall, our results show different cathepsin B-dependent cancer cell death mechanisms induced by sunitinib or pazopanib, providing the biological basis for novel molecularly targeted approaches.

Different effects of sunitinib, sorafenib, and pazopanib on inducing cancer cell death: The role of autophagy.

2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 270-270 ◽  
Author(s):  
Matteo Santoni ◽  
Consuelo Amantini ◽  
Maria Beatrice Morelli ◽  
Valerio Farfariello ◽  
Massimo Nabissi ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Cathepsin B ◽  
Kinase Inhibitors ◽  
Annexin V ◽  
Standard Of Care ◽  
Ros Generation ◽  
Dependent Manner ◽  
Acridine Orange Staining

270 Background: Tyrosine kinase inhibitors (TKI), such as sunitinib, sorafenib and pazopanib, have replaced immunotherapy as the standard of care for metastatic renal cell carcinoma (mRCC). However, their use in sequential or combined strategies is limited by the lack of evidences on the ability of TKIs to induce cell death in cancer cells. Aim of our study was to evaluate the different mechanisms responsible of the cytotoxic effects induced in vitro by µM doses of sunitinib, sorafenib and pazopanib in 5637 and J82 bladder cancer (BC) cell lines. Methods: The viability of BC cell lines were tested by MTT assay. Autophagy was evaluated by western blot analysis with the anti-LC3 and anti-p62 antibodies, acridine orange staining and cytofluorimetric analysis. Necrosis and apoptosis, (ΔΨm) dissipation and ROS generation were determined by Annexin-V/PI, JC-1 and DCFDA staining, respectively and cytofluorimetric analysis. The cathepsin B activity was evaluated by ELISA. Finally, by mRNA estraction and RT-PCR array the pazopanib-induced gene profile expression was evaluated. Results: We found that treatment of 5637 and J82 BC cells with the three TKI agents markedly reduced cell viability. Treatment for 24 h with sunitinib and sorafenib at 20 µM dose, triggers an incomplete autophagy of BC cells. In addition, inhibition of autophagy induced by sunitinib and sorafenib triggers cell death of BC cells. Thus, sunitinib by imparing the cathepsin B activity induces lysosomal-dependent necrosis. Similarly, sorafenib by defective lysosomial degradation triggers ROS- and mitochondrial-dependent apoptosis. As regard to pazopanib, we first demonstrate that treatment of BC cells for 72 hrs (20 µM) induces autophagic Type II cell death, which was markedly reversed in a dose-dependent manner by 3MA and chloroquine autophagic inhibitors. Finally, pazopanib upregulates the mRNA expression of α-glucosidase (GAA) and TP73 belonging to the p53 tumor suppressor genes. Conclusions: Overall, our results showing different TKI-induced cell death mechanisms provide the rationale for the sequential use of these agents and the biological basis for novel molecularly targeted approaches.

scholarly journals Fisetin Induced Cell Death in Human Ovarian Cancer Cell Lines via ZBP1 Mediated Necroptosis.

2021 ◽  
Author(s):  
Yaxian Liu ◽  
Wenhong Cao ◽  
Yanhui Zhao ◽  
Lijuan Shan ◽  
Shuhai Lan
Keyword(s):  
Ovarian Cancer ◽  
Cell Death ◽  
Cell Growth ◽  
Cell Lines ◽  
Annexin V ◽  
Dependent Manner ◽  
Apoptotic Process ◽  
Ovarian Cancer Cell Lines ◽  
And Migration

Abstract Background: Ovarian cancer leads to severe female mortality among all reproductive cancers. Fisetin, a natural flavonoid, exerts pharmacological characteristics on inhibiting cancer growth from various origins. Although multiple mechanisms involving in regulating cell death, there is still unclear if and how fisetin exhibits anti-cancer effect on ovarian cancer. The presented study aimed to evaluate cell apoptotic and necroptotic processes occurring in ovarian carcinoma (OC) cell lines induced by fisetin Methods: Cell growth was evaluated by MTT assay in both OC cell lines treated with or without fisetin. Annexin V/Propidium iodide staining followed by flow cytometry were used to characterize fisetin induced cell death. The apoptotic process was suppressed by z-VAD intervention then cell necroptosis was assessed by introducing ZBP1 knockdown OC cell lines coupled with fisetin intervention. The expression of necroptosis-related mediators and migration capability of respective cells were evaluated by western blotting and in vitro cell invasion assay. Result: Fisetin successfully reduced cell growth on both OC cell lines in a dose-dependent manner. Both apoptosis and necroptosis were induced by fisetin. Suppression on cell apoptotic process failed to enhance proliferation of fisetin treated cells. The induced cell death as well as robust expression of necroptotic markers RIP3 and MLKL were alleviated by knocking down the expression of ZBP1 protein in both OC cell lines.Conclusion: The present study demonstrated in vitro evidence supporting that both apoptosis and necroptosis were involved in fisetin induced OC cell death, while ZBP1 regulates necroptotic process via RIP3/MLKL pathway.

Stew in its Own Juice: Protein Homeostasis Machinery Inhibition Reduces Cell Viability in Multiple Myeloma Cell Lines

2019 ◽  
Vol 19 (2) ◽  
pp. 112-119 ◽  
Author(s):  
Mariana B. de Oliveira ◽  
Luiz F.G. Sanson ◽  
Angela I.P. Eugenio ◽  
Rebecca S.S. Barbosa-Dantas ◽  
Gisele W.B. Colleoni
Keyword(s):  
Multiple Myeloma ◽  
Cell Death ◽  
Cell Viability ◽  
Cell Lines ◽  
Treatment Options ◽  
Compensatory Mechanism ◽  
Protein Homeostasis ◽  
Protein Response ◽  
Rpmi 8226

Introduction:Multiple myeloma (MM) cells accumulate in the bone marrow and produce enormous quantities of immunoglobulins, causing endoplasmatic reticulum stress and activation of protein handling machinery, such as heat shock protein response, autophagy and unfolded protein response (UPR).Methods:We evaluated cell lines viability after treatment with bortezomib (B) in combination with HSP70 (VER-15508) and autophagy (SBI-0206965) or UPR (STF- 083010) inhibitors.Results:For RPMI-8226, after 72 hours of treatment with B+VER+STF or B+VER+SBI, we observed 15% of viable cells, but treatment with B alone was better (90% of cell death). For U266, treatment with B+VER+STF or with B+VER+SBI for 72 hours resulted in 20% of cell viability and both treatments were better than treatment with B alone (40% of cell death). After both triplet combinations, RPMI-8226 and U266 presented the overexpression of XBP-1 UPR protein, suggesting that it is acting as a compensatory mechanism, in an attempt of the cell to handle the otherwise lethal large amount of immunoglobulin overload.Conclusion:Our in vitro results provide additional evidence that combinations of protein homeostasis inhibitors might be explored as treatment options for MM.

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