scholarly journals Myeloma Cells Addicted to Glutamine for Biomass Production Are Sensitive to Lenalidomide

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4410-4410
Author(s):  
Sinto Chirackal ◽  
Esteban Braggio ◽  
Rahman Atiqur ◽  
Gregory J Ahmann ◽  
Yuan Xiao Zhu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Proliferation ◽  
Western Blot ◽  
Cell Line ◽  
Cell Lines ◽  
Biomass Production ◽  
Antibody Production ◽  
Research Funding ◽  
Sensitive Cell ◽  
H2o2 Decomposition

Introduction We have shown that in myeloma (MM) the immunomodulatory drugs (IMiDs) lenalidomide and pomalidomide, in a CRBN dependent fashion, inhibit thioredoxin reductase and thus increase intracellular oxidative stress as a consequence of peroxide accumulation (Sebastian et al. 2017). Accordingly, we have also shown that CRBN expression alone does not fully correlate with lenalidomide sensitivity, as the cells ability to decompose H2O2 is important - MM cells with lower H2O2 decomposition capacity are more sensitive to IMiDs. We hypothezised that the specific metabolic pathways used by cells for biomass production would influence IMiD sensitivity since they also influence this cellular oxidative capacity. Cellular proteins are key elements of this biomass, and required for the proliferation of MM cells and production of immunoglobulin proteins. Methods We cultured MM cells under various nutrients conditions to understand its effect on cell proliferation and drug responses. Cell viability was assessed by MTT assay, the Luminescent Assay, and direct cell counting. MM cells glycolytic rate was measured using the Seahorse XF analyzer. Western blots were performed to quantify various protein expression levels in MM cells cultured under different nutrients conditions. CRBN CRISPR/Cas9 KO plasmid was used to generate CRBN knockout cells and a lentivirus system was used to over-express CRBN in MM cells. Results MM cells resistant to lenalidomide, but still expressing functional CRBN, show a higher glycolytic pathway use than sensitive cells. We found that the lenalidomide sensitive cell line MM1.S is highly dependent on extracellular glutamine for cell proliferation. In contrast, JJN3, a lenalidomide resistant cells line with wild type CRBN, preferentially consumes glucose. We found that glutamine depletion from culture media completely abolished lenalidomide sensitivity in MM1.S cell line. Western blot analysis revealed that antibody production by MM1.S was primarily dependent on glutamine availability, and that JJN3 antibody production was dependent upon glucose availability. While glutamine depletion from culture medium completely abolished lenalidomide sensitivity in MM1.S cell line, IKZF1, and IKZF3 degradation was unchanged. We further studied the role of CRBN in glutamine dependent cellular biomass protein production using isogenic cell lines (+/- wtCRBN). We found that wtCRBN expressing cells proliferate more and show higher antibody production in the presence of glutamine, over CRBN negative isogenic cell lines. Lenalidomide treatment further increased glutamine dependent antibody production in wtCRBN expressing cells. One possibile explanation is that activation of glutamine catabolism can facilitate protein demethylation via the supplementation α-ketoglutarate (α-KG). Therefore, we tested whether lenalidomide treatment could induce protein demethylation in sensitive cell lines. Western blot probed with mono-methyl lysine antibody showed lenalidomide induced protein demethylation. We further confirmed that protein demethylation, and lenalidomide sensitivity is a consequence of elevated α-KG by treating cells with cell-permeable 5-octyl- α-ketoglutarate which act as a substrate of the lysine demethylases. 5-Octyl-α-ketoglutarate treatment inhibited cell proliferation preferentially in wtCRBN expressing cells, and also enhanced lenalidomide induced sensitivity. Protein demethylation is associated with protein ubiquitination and proteasomal degradation. We thus hypothesize that lenalidomide induced protein demethylation also likely increases proteasome inhibitors sensitivity in MM. Conclusion MM cells with preferential glutamine consumption are likely to be more sensitive to lenalidomide, and extracellular glutamine depletion can induce lenalidomide resistance. MM cells expressing CRBN, but not dependent on glutamine for protein biomass production are more likely to be resistant to lenalidomide. Our study postulates that CRBN protein requirement in lenalidomide sensitivity cells is restricted to high glutamine dependency, and that it is quite likely CRBN has a role in glutamine metabolism. Moreover, MM cells that consume more glutamine are under higher oxidative stress and exhibit less H2O2 decomposition capacity and therefore increasing sensitivity to IMiDs. References Sebastian , S., et al., Blood 2017 129:991-1007 Disclosures Stewart: Ono: Consultancy; Roche: Consultancy; Seattle Genetics: Consultancy; Takeda: Consultancy; Amgen: Consultancy, Research Funding; Bristol Myers-Squibb: Consultancy; Celgene: Consultancy, Research Funding; Ionis: Consultancy; Janssen: Consultancy, Research Funding; Oncopeptides: Consultancy. Bergsagel:Janssen Pharmaceuticals: Consultancy; Ionis Pharmaceuticals: Consultancy; Celgene: Consultancy. Fonseca:AbbVie, Amgen, Bayer, Celgene, Kite, Janssen, Juno, Merck, Pharmacylics, Sanofi, Takeda: Other: Consultant/Advisor; Prognosticatin of MM based on Genetic Categorization by FISH: Patents & Royalties; Adaptive Biotechnologies: Other: Scientific Advisory Board.

scholarly journals Sirtuin 2 in Endometrial Cancer: A Potential Regulator for Cell Proliferation, Apoptosis and RAS/ERK Pathway

2020 ◽  
Vol 19 ◽  
pp. 153303382098078
Author(s):  
Yanjuan Guo ◽  
Nannan Zhao ◽  
Jianli Zhou ◽  
Jianxin Dong ◽  
Xing Wang
Keyword(s):  
Cell Proliferation ◽  
Endometrial Cancer ◽  
Western Blot ◽  
Cell Line ◽  
Cell Lines ◽  
Erk Pathway ◽  
Uterine Epithelial Cell ◽  
Knock Down ◽  
Ishikawa Cells ◽  
And Control

Objective: The present study aimed to explore the function of sirtuin 2 (SIRT2) on cell proliferation, apoptosis, rat sarcoma virus (RAS)/ extracellular signal-regulated kinase (ERK) pathway in endometrial cancer (EC). Methods: SIRT2 expression in human EC cell lines and human endometrial (uterine) epithelial cell (HEEC) line was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. SIRT2 knock-down and control knock-down plasmids were transfected into HEC1A cells, respectively; SIRT2 overexpression and control overexpression plasmids were transfected into Ishikawa cells, respectively. After transfection, SIRT2, HRas proto-oncogene, GTPase (HRAS) expressions were evaluated by RT-qPCR and western blot. ERK and phosphorylated ERK (pERK) expressions were evaluated by western blot. Meanwhile, cell proliferation and cell apoptosis were measured. Results: Compared to normal HEEC cell line, SIRT2 mRNA and protein expressions were increased in most human EC cell lines (including HEC1A, RL952 and AN3CA), while were similar in Ishikawa cell line. In HEC1A cells, SIRT2 knock-down decreased cell proliferation but increased apoptosis. In Ishikawa cells, SIRT2 overexpression induced cell proliferation but inhibited apoptosis. For RAS/ERK pathway, SIRT2 knock-down reduced HRAS and inactivated pERK in HEC1A cells, whereas SIRT2 overexpression increased HRAS and activated pERK in Ishikawa cells, suggesting that SIRT2 was implicated in the regulation of RAS/ERK pathway in EC cells. Conclusion: SIRT2 contributes to the EC tumorigenesis, which appears as a potential therapeutic target.

scholarly journals Tolinapant (ASTX660), a Non-Peptidomimetic Antagonist of cIAP1/2 and XIAP, and the HDAC Inhibitor Romidepsin Are Synergistic in in Vitro Models of T Cell Lymphoma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4356-4356
Author(s):  
John S Manavalan ◽  
Ipsita Pal ◽  
Aidan Pursley ◽  
George A. Ward ◽  
Tomoko Smyth ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Line ◽  
Board Of Directors ◽  
Cell Lines ◽  
Research Funding ◽  
Cell Lymphoma ◽  
T Cell Lymphoma ◽  
Tnf Alpha ◽  
Sensitive Cell ◽  
Advisory Committees

Abstract Background: The PTCL are a heterogeneous group of non-Hodgkin lymphomas originating from mature T-lymphocytes. They are aggressive diseases, often resistant to conventional chemotherapy. Despite the fact that a number of new agents have been approved, treatment paradigms tailored to the biology of the disease have yet to emerge. Tolinapant (ASTX660) is a potent antagonist of both cellular and X-linked inhibitors of apoptosis proteins (cIAP1/2 and XIAP), and is presently in phase I/II trials in patients with advanced solid tumors and lymphomas (NCT02503423). IAP antagonists enhance tumor necrosis factor (TNF) receptor superfamily mediated apoptosis (Ward GA, et al. Mol Cancer Ther. 2018), are potent anti-tumor immune enhancers and induce markers of immunogenic cell death such as damage associated molecular patterns (DAMPs; Ye W, et al, Oncoimmunology, 2020). Objectives: We explored the sensitivity of a range of T-cell lymphoma (TCL) cell lines to tolinapant. We establish the synergy coefficient between tolinapant and the HDAC inhibitor, romidepsin, and interrogated the molecular basis of their synergistic interaction. Methods: A panel of human T-cell lymphoma cell lines were tested in proliferation assays (CellTiterGlo) for sensitivity to tolinapant in the presence or absence of 10ng/ml of TNF alpha. For combination studies, with tolinapant and romidepsin, each drug was tested at the IC10 and IC40 concentrations in the presence or absence of TNF alpha. Synergy scores using the Excess over Bliss (EOB) model were calculated using SynergyFinder (Aleksandr Ianevski et al; Nucleic Acids Research, 2020). Additionally, the effects of tolinapant and romidepsin on the IAPs and caspases were analyzed by western blots. TNFR1 receptor expression and induction of DAMPs were also analyzed by flow cytometry. Results: TCL Lines demonstrated varying sensitivities to tolinapant in the presence or absence of TNF alpha. The most sensitive cell lines, ALK+ ALCL and SUP-M2, had IC50 concentrations ranging from 200nM ± 100nM to 20nM ± 1nM in the absence or presence of TNF alpha, respectively, at 24, 48 and 72hrs, while a resistant CTCL cell line HH had an IC50 concentration of over 20mM, even in the presence of TNF alpha. Interestingly, using western blot analysis, we found that the presence of TNF alpha increased the levels of cIAP1 in the tolinapant sensitive SUP-M2 cell line, but not in the resistant HH cell line. However, there was a concentration dependent decrease in cIAP1 but not in XIAP in both cell lines treated with tolinapant. Flow cytometry analysis demonstrated that tolinapant increases the expression of TNFR1 and DAMPs in a dose dependent manner on the sensitive SUP-M2, but not in the resistant HH cells. In combination experiments, using the EOB model, tolinapant plus romidepsin was found to be synergistic in the absence of TNF alpha, at 36hrs, in both the sensitive cell line SUP-M2 and the resistant cell line HH. In the presence of TNF alpha, synergism was seen only in the sensitive cell line SUP-M2 and antagonistic in the HH cell line (Fig. 3). In the tolinapant plus romidepsin treated samples, cIAP1 levels decreased in the SUP-M2 cell line, in the absence of TNF alpha, however, addition of TNF alpha did not alter the levels of cIAP1 in the SUP-M2 cells. The cIAP1 levels decreased in the HH cells treated with the combination, in both the presence or absence of TNF alpha (Figure). Our findings indicate that the synergy of the tolinapant plus romidepsin is not dependent on the presence of TNF alpha. Conclusion: Tolinapant has demonstrated potent cytotoxic effects against a broad range of TCL lines both as a monotherapy and in combination with the HDAC Inhibitor, romidepsin. In in vitro studies, T cell lymphoma cell lines demonstrated varying sensitivity to tolinapant with certain cell lines being more resistant, even in the presence of TNF alpha. Interestingly, the addition of romidepsin appeared to overcome the intrinsic resistance to tolinapant in the absence of TNF alpha. These data provide the rationale to continue to explore the combination of tolinapant and romidepsin in vivo and to investigate additional combinations with T-cell specific agents (e.g. pralatrexate, belinostat, azacitidine and decitabine). Figure 1 Figure 1. Disclosures Smyth: Astex Pharmaceuticals: Current Employment. Sims: Astex Pharmaceuticals: Current Employment. Loughran: Kymera Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bioniz Therapeutics: Membership on an entity's Board of Directors or advisory committees; Keystone Nano: Membership on an entity's Board of Directors or advisory committees; Dren Bio: Membership on an entity's Board of Directors or advisory committees. Marchi: Kyowa Kirin: Honoraria; Myeloid Therapeutics: Honoraria; Astex: Research Funding; BMS: Research Funding; Merck: Research Funding; Kymera Therapeutics: Other: Scientific Advisor.

Molecular and Functional Effects of the Novel MEK Inhibitor PD0325901 in Preclinical Models of Human Leukemias.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 254-254
Author(s):  
Michele Milella ◽  
Maria Rosaria Ricciardi ◽  
Chiara Gregorj ◽  
Fabiana De Cave ◽  
Steven L. Abrams ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Line ◽  
Cell Lines ◽  
Therapeutic Target ◽  
Hematological Malignancies ◽  
Mek Inhibitor ◽  
Sensitive Cell ◽  
Fold Reduction

Abstract The Raf/MEK/ERK signaling module plays a pivotal role in the regulation of cell proliferation, survival, and differentiation. Our group, among others, has recently demonstrated that this pathway is frequently dysregulated in hematological malignancies and may constitute an attractive therapeutic target, particularly in AML. Here we investigated the effects of PD0325901, a novel MEK inhibitor, on phospho-protein expression, gene expression profiles, cell proliferation, and apoptosis in cell line models of AML, ALL, multiple myeloma (MM), ex vivo-cultured primary AML blasts, and oncogene-transformed hematopoietic cells. AML cell lines (OCI-AML2, OCI-AML3, HL-60) were strikingly sensitive to PD0325901 (IC50: 5–19 nM), NB4 (APL) and U266 (MM) showed intermediate sensitivity (IC50: 822 and 724 nM), while all the lymphoid cell lines tested and the myeloid cell lines U937 and KG1 were resistant (IC50 > 1000 nM). Cell growth inhibition was due to inhibition of cell cycle progression and induction of apoptosis. A statistically significant reduction in the proportion of S-phase cells (p=0.01) and increase in the percentage of apoptotic cells (p=0.019) was also observed in 18 primary AML samples in response to 100 nM PD0325901. Analysis of the correlation between sensitivity/resistance to PD0325901 and Ras/Raf mutation status is currently ongoing. PD0325901 effects were also examined in a panel of IL-3-dependent murine myeloid FDC-P1 cell lines transformed to grow in response to 11 different oncogenes in the absence of IL-3. Fms-, Ras-, Raf-1-, B-Raf-, MEK1-, IGF-1R-, and STAT5a-transformed FDC-P1 cells were very sensitive to PD0325901 (IC50: ~ 1 nM), while A-Raf-, BCR-ABL-, EGFR- or Src-transformed cells were 10 to 100 fold less sensitive (IC50: 10 to 100 nM); the parental, IL-3 dependent FDC-P1 cell line had an IC50 > 1000 nM. Analysis of the phosphorylation levels of 18 different target proteins after treatment with 10 nM PD0325901 showed a 5- to 8-fold reduction in ERK-1/2, observed only in sensitive cell lines, and a 2-fold reduction in JNK and STAT3 phosphorylation. PD0325901 (10 nM) treatment also profoundly altered the gene expression profile of the sensitive cell line OCI-AML3: 96 genes were modulated after 24 h (37 up- and 59 down-regulated), most of which involved in cell cycle regulation. Changes in cyclin D1 and D3, cyclin E, and cdc 25A were also validated at the protein level. Overall, PD0325901 shows potent growth-inhibitory and pro-apoptotic activity, indicating that MEK may be an appropriate therapeutic target in an array of different hematological malignancies. Further preclinical/clinical development of this compound is warranted, particularly in myeloid leukemias.

Antileukemic Effects of the Novel Agent Elesclomol.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2736-2736 ◽  
Author(s):  
Sue Chow ◽  
Masazumi Nagai ◽  
Suqin He ◽  
Ronald K Blackman ◽  
James Barsoum ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Cell Line ◽  
Mitochondrial Membrane Potential ◽  
Cell Lines ◽  
Research Funding ◽  
Mitochondrial Membrane ◽  
Membrane Integrity ◽  
Employment Equity ◽  
Equity Ownership

Abstract Abstract 2736 Poster Board II-712 Elesclomol (N-malonyl-bis (N′-methyl-N′-thiobenzoyl hydrazide)) is an investigational first-in-class oxidative stress inducer that triggers apoptosis in cancer cells (Kirshner et al., Mol Cancer Ther 2008;7:2319–27). In the clinic, elesclomol is well tolerated in humans and showed activity in combination with paclitaxel in patients with refractory solid tumors (Berkenblit et al., Clin Cancer Res 2007;13:584–90). The aims of the current study are to examine the activity of elesclomol against a range of AML cell lines, including primary patient blast cultures, to investigate the mechanisms of drug action and the potential to combine elesclomol with other agents, and to identify candidate biomarkers for monitoring effects during treatment of leukemia patients with elesclomol. Here we describe the effects of elesclomol treatment in 4 AML cell lines selected based on their varying molecular attributes. Effects on cellular redox state and mitochondrial function were monitored using a flow cytometry incorporating the glutathione (GSH) probe monobromobimane, the reactive oxygen species (ROS) probe carboxy-dichlorofluorescin and the mitochondrial membrane potential stain DiIC(1)5. In addition, outer cell membrane integrity was determined by propidium iodide exclusion. Dual staining of fixed, permeabilized cells with phospho-specific antibodies to p38 and SAPK/JNK was used to determine if elesclomol treatment results in activation of the stress-activated MAP kinase pathways. Elesclomol showed potent anti-leukemic effects in vitro at concentrations as low as 10nM, which is well below the concentrations achieved in cancer patients, and greater toxicity was achieved with prolonged drug exposure. In OCI-AML2, a factor-independent, poorly differentiated AML cell line, toxicity was associated with loss of reduced GSH that coincided with a large increase in ROS generation and depolarization of the mitochondrial inner membrane, and later with loss of surface membrane integrity. A similar pattern was seen in OCI-M2, a p53-deficient erythroblastic leukemia cell line, except that during the early stages of drug effect these cells showed a large increase in reduced GSH, suggesting that initially they are able to compensate for drug-induced oxidative stress through enhanced cellular antioxidant production. In contrast, the factor-dependent line OCI-AML5, which appeared most sensitive to elesclomol, showed loss of outer membrane integrity without obvious prior oxidative stress while the Flt-3 ITD mutant line MV4-11 showed an initial loss of mitochondrial membrane potential without accompanying oxidative stress. Strikingly, we did not observe activation of the stress-responsive p38 or SAPK/JNK pathways in any of these 4 cell lines tested, suggesting that this is not a prominent response to elesclomol activity in AML and that additional mechanisms may be at work for the activity of elesclomol in these cells. Further investigations are ongoing and additional studies, including evaluation of elesclomol activity in primary leukemic cells from AML patients, will be presented. In summary, elesclomol is a potent novel compound that exerts anti-leukemic effects in tissue culture at drug concentrations that are well below those achieved in patients, suggesting that it might be active in leukemia patients. Disclosures: Chow: Synta Pharmaceuticals Inc.: Research Funding. Nagai:Synta Pharmaceuticals Inc.: Employment. He:Synta Pharmaceuticals Inc.: Employment. Blackman:Synta Pharmaceuticals Inc.: Employment, Equity Ownership. Barsoum:Synta Pharmaceuticals Inc.: Employment, Equity Ownership. Vukovic:Synta Pharmaceuticals Inc.: Employment, Equity Ownership. Hedley:Synta Pharmaceuticals Inc.: Research Funding.

Simultaneous Inhibition of cIAP1, cIAP2 and XIAP Is Required for Inducing Apoptosis in Multiple Myeloma Cells.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2943-2943
Author(s):  
Vijay G. Ramakrishnan ◽  
Teresa K. Kimlinger ◽  
Utkarsh Painuly ◽  
Jessica Haug ◽  
S. Vincent Rajkumar ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Signaling Pathways ◽  
Cell Line ◽  
Cell Lines ◽  
Research Funding ◽  
Sensitive Cell ◽  
Sensitive Cell Line ◽  
Nfkb Pathway ◽  
Stat Pathway

Abstract Abstract 2943 Background: Inhibitor of apoptosis (IAP) proteins represents a conserved group of proteins that are important regulators of cell survival and apoptosis. X-linked IAP (XIAP) is the best studied IAP that inhibits pro-apoptotic caspases 3, 7 and 9. Multiple myeloma (MM) cell lines express high levels of XIAP. The levels of XIAP are further increased when stimulated by cytokines IL6 and IGF-1, both secreted in copious amounts in myeloma microenvironment. The other two main IAP proteins, namely cIAP1 and cIAP2 are not direct inhibitors of caspases. Instead, they modulate the levels of various signaling pathways by ubiquitinating proteins within the pathways. The NFKB pathway could be activated or inhibited by cIAP1 and 2. In MM, deletions of cIAP1 and cIAP2 have been shown to activate non-canonical NFKB pathway, which indicates a possible tumor suppressor role of these proteins. We wanted to investigate the role of the three IAPs by using a small molecule inhibitor. Our studies clearly indicate the importance of inhibiting all the three IAPs for the induction of apoptosis in MM cells. Methods: LCL161 was synthesized by Novartis Inc. (Basel, Switzerland). Stock solutions were made in DMSO, and subsequently diluted in RPMI-1640 medium for use. MM cell lines were cultured in RPMI 1640 containing 10% fetal bovine serum (20% serum for primary patient cells) supplemented with L-Glutamine, penicillin, and streptomycin. Cytotoxicity was measured using the MTT viability assay and proliferation using thymidine uptake. Apoptosis was measured using flow cytometry with Annexin V-FITC and propidium iodide (PI) for cell lines and patient cells. Immunoblotting was done on cell extracts at various time points following incubation with the drug in order to study the cell signaling pathways. siRNA to cIAP2 was purchased from Invitrogen and was electroporated into MM1S cells. Results: We first examined baseline levels of cIAP1, cIAP2 and XIAP in several MM cell lines and a few patient cells. We observed that the IAPs were constitutively expressed in MM cells. We then wanted to examine the functional significance of these IAP proteins in MM cells. For this, we used an IAP inhibitor LCL161. We observed that LCL161 was able to induce cytotoxicity and inhibit proliferation of MM cells, albeit with differences observed between cell lines. We then examined the factors contributing to resistance in the less sensitive cell lines. For this we chose H929, a sensitive cell line and MM1S, a less sensitive cell line to LCL161. Upon treatment with LCL161, cIAP1 and XIAP were down regulated accompanied by increase in levels of activated caspases 9, 8 and 3 in both H929 and MM1S cells. Using LCL161 in combination with a caspase 9 or a caspase 8 or a pan caspase inhibitor showed clearly that the extrinsic pathway is more involved in the LCL161 induced cell death process. LCL161, however, was unable to inhibit cIAP2 in the less sensitive cell line MM1S whereas cIAP2 was not found to be expressed in H929 cells. It has been shown that cIAP1 is required for ubiquitination and degradation of cIAP2. Therefore, cIAP1 down regulation by LCL161 could actually be contributing to the lack of down regulation of cIAP2 and the observed resistance to LCL161. In order to test this, we used a siRNA to cIAP2 and transfected it into MM1S cells by electroporation. We observed that the siRNA reduced cIAP2 levels and in combination with LCL161 led to marked increase in cells undergoing apoptosis. We also examined signaling pathways after treatment with LCL161 and observed upregulation of both canonical and non-canonical NFKB pathways and Jak/Stat pathway in MM1S cells and not in H929 cells. Combining LCL161 with a Jak2 specific inhibitor SD-1029 synergized in inducing cell death in MM1S and other cell lines less sensitive to LCL161. We are currently testing this combination in MM patient cells. Conclusion: These studies demonstrate the importance of inhibiting cIAP1, cIAP2 and XIAP together in MM cells. Furthermore, by this study we were able to identify resistance mechanisms that are upregulated due to inhibiting the IAP proteins and the importance of using agents that inhibit the IAPs along with inhibitors of these pathways in inducing apoptosis in MM cells. The findings from these studies form the basis of evaluation of IAP inhibitors in combination with a Jak/Stat pathway inhibitor in patients with MM. Disclosures: Kumar: Celgene: Consultancy, Research Funding; Merck: Consultancy, Honoraria; Millennium Pharmaceuticals, Inc.: Research Funding; Novartis: Research Funding; Genzyme: Research Funding; Cephalon: Research Funding.

Synergistic Antilymphoma Effect of Protein Kinase C Beta (PKCβ) and mTOR Inhibition in Mantle Cell Lymphoma.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4780-4780
Author(s):  
Grit Hutter ◽  
Yvonne Zimmermann ◽  
Malte Rieken ◽  
Elena Hartmann ◽  
Vindi Jurinovic ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Line ◽  
Cell Lines ◽  
Research Funding ◽  
Cell Lymphoma ◽  
Pi3k Inhibitor ◽  
Cell Cycle Profile ◽  
Kinase C ◽  
Deutschland Gmbh ◽  
Mantle Cell

Abstract Abstract 4780 Introduction The protein kinase C (PKC) family of enzymes are serine/threonine kinases essential to the cell signal cascades effecting cellular growth, proliferation and apoptosis. Accordingly PKCβ overexpression correlates with poor clinical prognosis in diffuse large cell lymphoma. The pivotal role of PKCb in neoplastic transformation renders it a potential therapeutic target in the therapy of hematologic malignancies. Aim To determine drugs which are efficiently inhibiting cell proliferation in combination with enzastaurin in MCL. Methods Five MCL cell lines (HBL-2, GRANTA 519, Jeko-1, Z138, Rec-1) and patient samples were cultured in the presence of LY317615 (PKCb inhibitor), rapamycin (mTOR inhibitor) and LY294002 (PI3K inhibitor). Cell proliferation and viability was assessed by cell count and WST-1 proliferation assay. Analysis of cell cycle profile and apoptosis was performed by flow cytometry (PI and Annexin V FITC staining). mRNA expression was measured before and after treatment (8h) by microarray and real time PCR in cell lines. Protein expression was analysed by Western blot. Results In a panel of mantle cell lymphoma cell lines, with IC50 values ranging from 2 to 5 microM for enzastaurin treatment, a refractory to enzastaurin cell line (Rec-1) was characterized. Treatment of the cell lines with enzastaurin induced apoptosis and lead to accumulation of cells in the G2, M phase in susceptible cell lines (Hbl-2, Jeko-1), whereas cell cycle profile remained unaltered in the refractory cell line (Rec-1). While enzastaurin induced increased phosphorylation of mTOR and MEK and decrease of p90RSK phosphorylation in all MCL cell lines, mTOR phosphorylation was twice as high in the refractory cell line (Rec-1). In line with this observation the combination of enzastaurin with rapamycin lead to a synergistic effect on the inhibition of cell proliferation in the Rec-1 cell line as well as in an additional MCLpatient sample. Protein expression levels (low CCND1, phAkt, php90RSK, phPDK) achieved in Rec-1 after treatment with enzastaurin were also characteristic for the cell lines more sensitive to rapamycin. In contrast in some cell lines combination of enzastaurin and the PI3K inhibitor (LY294002) displayed antagonism. Further mRNAand proteinexpression analysis of patient samples are ongoing to determine molecular predictors of drug sensitivity. Conclusion In our study a combination of rapamycin and enzastaurin acted synergistically in MCL cell lines and a patient samples whereas the combination with a PI3K inhibitor displayed partial antagonism. Based on this results we have identified the underlying signal pathways to develop new synergistic molecular combinations in MCL. Disclosures: Hutter: Lilly Deutschland GmbH: Research Funding. Zimmermann:Lilly Deutschland GmbH: Research Funding. Rieken:Lilly Deutschland GmbH: Research Funding. Weinkauf:Lilly Deutschland GmbH: Research Funding. Dreyling:Lilly Deutschland GmbH: Research Funding.

Synthesis and Characterization of Quinoline-3-Carboxamide Derivatives as Inhibitors of the ATM Kinase

2020 ◽  
Vol 20 (23) ◽  
pp. 2070-2079
Author(s):  
Srimadhavi Ravi ◽  
Sugata Barui ◽  
Sivapriya Kirubakaran ◽  
Parul Duhan ◽  
Kaushik Bhowmik
Keyword(s):  
Western Blot ◽  
Cancer Cells ◽  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Cancer Cell Lines ◽  
Atm Kinase ◽  
Cytotoxicity Studies

Background: The importance of inhibiting the kinases of the DDR pathway for radiosensitizing cancer cells is well established. Cancer cells exploit these kinases for their survival, which leads to the development of resistance towards DNA damaging therapeutics. Objective: In this article, the focus is on targeting the key mediator of the DDR pathway, the ATM kinase. A new set of quinoline-3-carboxamides, as potential inhibitors of ATM, is reported. Methods: Quinoline-3-carboxamide derivatives were synthesized and cytotoxicity assay was performed to analyze the effect of molecules on different cancer cell lines like HCT116, MDA-MB-468, and MDA-MB-231. Results: Three of the synthesized compounds showed promising cytotoxicity towards a selected set of cancer cell lines. Western Blot analysis was also performed by pre-treating the cells with quercetin, a known ATM upregulator, by causing DNA double-strand breaks. SAR studies suggested the importance of the electron-donating nature of the R group for the molecule to be toxic. Finally, Western-Blot analysis confirmed the down-regulation of ATM in the cells. Additionally, the PTEN negative cell line, MDA-MB-468, was more sensitive towards the compounds in comparison with the PTEN positive cell line, MDA-MB-231. Cytotoxicity studies against 293T cells showed that the compounds were at least three times less toxic when compared with HCT116. Conclusion: In conclusion, these experiments will lay the groundwork for the evolution of potent and selective ATM inhibitors for the radio- and chemo-sensitization of cancer cells.

scholarly journals Underutilized Mexican Plants: Screening of Antioxidant and Antiproliferative Properties of Mexican Cactus Fruit Juices

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 368
Author(s):  
Elda M. Melchor Martínez ◽  
Luisaldo Sandate-Flores ◽  
José Rodríguez-Rodríguez ◽  
Magdalena Rostro-Alanis ◽  
Lizeth Parra-Arroyo ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Liver Cancer ◽  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Lines ◽  
In Vitro Assays ◽  
Total Phenolic ◽  
Liver Cancer Cell ◽  
Antiproliferative Activities

Cacti fruits are known to possess antioxidant and antiproliferative activities among other health benefits. The following paper evaluated the antioxidant capacity and bioactivity of five clarified juices from different cacti fruits (Stenocereus spp., Opuntia spp. and M. geomettizans) on four cancer cell lines as well as one normal cell line. Their antioxidant compositions were measured by three different protocols. Their phenolic compositions were quantified through high performance liquid chromatography and the percentages of cell proliferation of fibroblasts as well as breast, prostate, colorectal, and liver cancer cell lines were evaluated though in vitro assays. The results were further processed by principal component analysis. The clarified juice from M. geomettizans fruit showed the highest concentration of total phenolic compounds and induced cell death in liver and colorectal cancer cells lines as well as fibroblasts. The clarified juice extracted from yellow Opuntia ficus-indica fruit displayed antioxidant activity as well as a selective cytotoxic effect on a liver cancer cell line with no toxic effect on fibroblasts. In conclusion, the work supplies evidence on the antioxidant and antiproliferative activities that cacti juices possess, presenting potential as cancer cell proliferation preventing agents.

Downregulation of Sulfiredoxin (Srx) Suppressed Cell Proliferation Migration and Invasion Through Inhibiting Extracellular Signal-Regulated Kinase/Nrf2 Pathway in Hepatocellular Carcinoma

2021 ◽  
Vol 11 (11) ◽  
pp. 2137-2145
Author(s):  
Xuejuan Zhu ◽  
Danqian Lu
Keyword(s):  
Cell Proliferation ◽  
Western Blot ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Colony Formation ◽  
Migration And Invasion ◽  
Related Factor ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Nrf2 Signaling Pathway

Background: Sulfiredoxin (Srx) has been identified to play important roles in the development of various cancers. However, the precise effects and underlying mechanism of Srx on the progression of HCC are far from being fully understood. Materials and Methods: The abundances of Srx in THLE-2 cell and HCC cell lines were determined by western blot and RT-qPCR. Next, SK-Hep-1 cells were transfected with shRNA-Srx or shRNA-NC and treated with TBHQ (an extracellular signal-regulated kinase (ERK) activator) for functional experiments. Then, CCK8 and colony formation assays were used to determine cell proliferation and clone-forming abilities in vitro. Cell migration and invasion were assessed via wound healing and transwell assays. The expression of MMP2, MMP9 and key members in ERK/nuclear factor E2 related factor (Nrf2) signaling pathway was detected by performing western blot analysis. Results: We reported evidence that Srx was frequently up-regulated in HCC cell lines. Srx interference constrained cell proliferation, colony formation rate, migration and invasion of SK-Hep-1 cells. Moreover, mechanistic investigations indicated that Srx interference significantly inhibited the activation of ERK/Nrf2 signaling pathway, and ERK activator TBHQ can reverse the functions of Srx interference in SK-Hep-1 cells. Conclusion: Overall, Downregulation of Srx might impede HCC progression by suppressing ERK/Nrf2 signaling pathway. Findings in the current study reported the functional involvement and molecular mechanism of Srx in HCC, suggesting that Srx might have a potential therapeutic value in HCC treatment.

scholarly journals Knockdown of NOLC1 Inhibits PI3K-AKT Pathway to Improve the Poor Prognosis of Esophageal Carcinoma

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Fanguo Kong ◽  
Yansheng Shang ◽  
Xingyuan Diao ◽  
Jiaguo Huang ◽  
Hui Liu
Keyword(s):  
Overall Survival ◽  
Western Blot ◽  
Esophageal Carcinoma ◽  
Cell Line ◽  
Cell Lines ◽  
Poor Prognosis ◽  
Caspase 3 ◽  
Cyclin B1 ◽  
Akt Pathway ◽  
Pi3k Inhibitor Ly294002

Objective. Esophageal carcinoma (ESCA) is a common malignant gastrointestinal tumor. The abnormal expression of NOLC1 is involved in the tumorigenesis of various human tumors, whereas the function and mechanism of NOLC1 in ESCA remain unclear. In this study, we explored the relationship between NOLC1 and poor prognosis of ESCA, and its role and mechanism in the occurrence of ESCA. Methods. The NOLC1 expression in ESCA tissues and cell lines was determined by qRT-PCR, immunohistochemistry, or western blot. The Kaplan–Meier method was conducted to estimate the overall survival. Cox regression analysis was carried out to examine the association between patient characteristics and prognosis. A recombined lentiviral vector containing NOLC1 was applied for transfecting ESCA cells (Eca109 and TE-13) and established a stable cell line with low NOLC1 expression or high NOLC1 expression, in the absence or presence of PI3K inhibitor (LY294002) treatment. Cell proliferation, apoptosis rate, invasion ability, migration ability, and PI3K/AKT pathway were detected by CCK8 assay, flow cytometry, Transwell assay, wound-healing assay, and western blot. Results. NOLC1 overexpression was observed in ESCA tissues and ESCA cell lines (EC9706, Eca109, TE-13, Kyse170, T.TN) compared with adjacent normal tissues and normal esophageal cell line HEEC. NOLC1 overexpression was markedly associated with bigger tumor size, lymph node metastasis, and advanced TNM stage. Patients with NOLC1 overexpression have shorter overall survival than that of those with low NOLC1 expression. NOLC1 overexpression was considered to be an independent poor prognostic factor affecting overall survival. NOLC1 knockdown inhibited proliferation, migration, invasion, and cyclin B1 expression and promoted the apoptosis and cleaved-caspase-3 expression of Eca109 and TE-13 cells. NOLC1 overexpression accelerated proliferation, migration, invasion, and cyclin B1 expression and inhibited the apoptosis and cleaved-caspase-3 expression of ESCA cells via activating PI3K/AKT pathway. Rescue experiments showed that PI3K inhibitor (LY294002) could reverse the phenomenon caused by NOLC1 overexpression. Conclusion. NOLC1 may be a marker for poor prognosis. It can participate in the occurrence and development of ESCA via the PI3K/AKT pathway.

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