The Diterpenoid Lactone Andrographolide (ANDRO) Stimulates Autophagy and Induces Reactive Oxygen Species (ROS)-Dependent Apoptosis in Lymphoma Cell Lines

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4991-4991
Author(s):  
Shuo Yang ◽  
Andrew M. Evens ◽  
Sheila Prachand ◽  
Leo I. Gordon
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Cell Lines ◽  
Redox State ◽  
Annexin V ◽  
Lymphoma Cell ◽  
Time Dependent ◽  
Cellular Redox ◽  
Forkhead Transcription Factors ◽  
Induced Apoptosis

Abstract ANDRO is a diterpenoid lactone isolated from Andrographis paniculata (King of Bitters), an important herbal medicine used in China. It has been reported to have anti-inflammatory, anti-hypertensive, anti-viral and immunostimulant properties. It has also been shown to inhibit cancer cell proliferation and induce apoptosis in HL-60 (leukemia), PC-3 (prostatic adenocarcinoma), MDA-MB-231 (breast cancer), HepG2 (liver cancer), HeLa (cervical cancer) and HCT116 (colorectal cancer) cell lines. The diterpenoids have been found to generate ROS and may increase apoptosis by altering the cellular redox state. We hypothesized that ANDRO would lead to cell death in lymphoma cell lines and that the effect may be related to altered cellular redox state. We studied the Burkitt p53 mutated Ramos cell line, the mantle cell lymphoma line Granta and L428, a resistant EBV-negative Hodgkin lymphoma cell line. We found that after incubation with increasing concentrations of ANDRO, there was dose and time-dependent cell death as measured by MTT. The IC50 (concentration that achieved 50% cell proliferation inhibition) at 48h was 20μM for Ramos, 40μM for Granta, and 50μM for L428. ROS was measured by oxidation of 2’7’dichlorofluorescein diacetate (DCFDA) to dichlorofluorescein (DCF) and analyzed by fluorescence-activated cell sorting (FACS) following incubation at 1hour (h), 2h, 3h, 5h, 38h, and 48h with ANDRO (20–80μM). ANDRO increased ROS production in all lymphoma cell lines, which was abrogated by the antioxidant N-acetyl-L-cysteine (NAC). Maximum ROS generation with ANDRO was seen at 48h for Ramos (1.7 fold), 5h for Granta (1.6 fold), and 38h for L428 (2.4 fold). To determine the mechanism of cell death, we measured apoptosis by Annexin-V/propidium iodide (PI), and detected by flow cytometry (FACS). Cells were treated with ANDRO in the presence or absence of the reduced glutathione (GSH) depleting agent buthionine sulfoximine (BSO) (100μM) for 28h, 48h, and 72h. We found that the AC50 (concentration that achieved 50% apoptosis) was 40μM for Ramos at 72h, 40μM for Granta at 48h and >80μM for L428 at 48h, while in the presence of BSO it was <10μM for Ramos at 72h, between 30–40μM for Granta at 28h and between 30–40μM for L428 at 48h. Apoptosis was completely blocked, by NAC, both in the presence and absence of BSO. Further, ANDRO induced PARP cleavage and activation of caspases 3, 8, and 9 in Granta and Ramos. Next, we explored the relationship of ANDRO and Forkhead transcription factors. ANDRO caused dephosphorylation of FOXO3a or FOXO1, in a dose- and time-dependent manner, and this was reversible by NAC. Downstream proteins of FOXO3a, Bim, p27kip1 and the isoforms of the autophagy-related protein LC3B were upregulated, and this was reversed by NAC. The LC3B isoform-II, which is cleaved from LC3B-I, is a marker of autophagy activation. To determine the role of autophagy in cell death related to ANDRO, we inhibited autophagy with 3-methyladenine (1–2mM) and found significant enhancement of ANDRO-induced apoptosis in Granta and Ramos. Finally, ANDRO induced apoptosis (>60% Annexin-V+/PI+) in malignant B-cells from a patient with chronic lymphocytic leukemia/small lymphocytic lymphoma (trisomy 12, peripheral blood absolute lymphocyte count 95.2 K/uL, bulky adenopathy) very low concentrations (5μM at 18h) in vitro, which was also reversible with NAC. We conclude that ANDRO induces ROS-dependent apoptosis in lymphoma cell lines and in a primary tumor sample, which is enhanced by depletion of GSH and inhibited by the antioxidant NAC. These effects appear to proceed through caspase activation and inhibition of autophagy, and are in part dependent on signaling through forkhead transcription factors and altered cellular redox pathways. Further studies of diterpenoids as single agents or in combination with other anti-lymphoma agents are warranted.

Motexafin Gadolinium Induces Apoptosis in Lymphoid Cell Lines and Demonstrates Enhanced Biological Activity with Akt Kinase Inhibitors.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3406-3406
Author(s):  
Louie Naumovski ◽  
Jason Ramos ◽  
Jun Chen ◽  
Mint Sirisawad ◽  
David Lucas ◽  
...  
Keyword(s):  
Cell Death ◽  
Chronic Lymphocytic Leukemia ◽  
Cell Lines ◽  
Specific Inhibitor ◽  
Annexin V ◽  
Lymphocytic Leukemia ◽  
Jurkat Cells ◽  
Motexafin Gadolinium ◽  
Akt Phosphorylation ◽  
Induced Apoptosis

Abstract Motexafin gadolinium (MGd, Xcytrin®) is a tumor-selective redox mediator that catalytically oxidizes intracellular reducing metabolites and produces reactive oxygen species (ROS). In this report, we demonstrate that MGd induces apoptosis or growth inhibition in several hematopoietic tumor-derived cell lines and tumor cells from patients with chronic lymphocytic leukemia. Lymphoma (HF-1, Ramos, DHL-4, DB, Hut78 and Raji) and leukemia (Jurkat, HL-60) cell lines were cultured in RPMI 1640 media with 10% heat inactivated fetal bovine serum with or without 50 uM MGd. MGd inhibited the growth of 6 of the cell lines (HF-1, Ramos, HL-60, DHL-4, Jurkat and DB) and was cytotoxic to HF-1. ROS were implicated in MGd-induced cell death since their presence was detected by dichlorofluorescein diacetate staining and peroxiredoxin oxidation in MGd treated HF-1 cells that undergo apoptosis, but not in Jurkat cells that do not undergo MGd-induced apoptosis. MGd triggered an apoptotic pathway in HF-1 cells as demonstrated by loss of mitochondrial membrane potential, release of cytochrome c from mitochondria, activation of caspases, cleavage of PARP and annexin-V binding. MGd also induced cell death and activated caspases in vitro in primary chronic lymphocytic leukemia cells. Protein lysates from cultured cell lines (HF-1, Ramos) were subjected to immunoblot analysis to determine caspase cleavage patterns, and the phosphorylation status of Akt, a kinase that regulates survival pathways. In MGd treated HF-1, phospho-Akt protein levels initially increased 2–3 fold between 30 min and 1 hr (n=4) and then decreased to 40–50% of control levels by 24–48 hrs (n=4). The drop in phospho-Akt protein coincided with an increase in apoptotic cell death as indicated by morphology, staining with Annexin-V and activation of caspases. Addition of a specific inhibitor of Akt phosphorylation (SH-5) reduced Akt phosphorylation in MGd treated HF-1 cells by 90% and enhanced the cytotoxic effect of MGd. In Ramos cells, which do not undergo apoptosis when treated with MGd, co-treatment with MGd and SH-5 decreased phospho Akt levels by only 15% and did not result in cytotoxicity. These data point to a potential role for Akt in MGd-induced apoptosis and suggest that MGd activity may be enhanced by inhibition of Akt. These data show that the pro-apoptotic effects of MGd involve caspase activation and provide a rationale to evaluate MGd in the treatment of lymphoma and leukemia patients.

In Vitro Evaluation of Apoptosis and Cell Death of Neuroblastoma Cell Lines Exposed to Busulfan.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4459-4459
Author(s):  
Morris Kletzel ◽  
Sarah C. Tallman ◽  
Marie Olszewski ◽  
Wei Huang
Keyword(s):  
Cell Death ◽  
Cell Viability ◽  
Cell Lines ◽  
Neuroblastoma Cell ◽  
Annexin V ◽  
Resistant Cell ◽  
Primary Tumors ◽  
Induced Apoptosis ◽  
Neuroblastoma Cell Lines

Abstract Objective: While busulfan is a commonly used chemotherapeutic agent in the treatment of many hematological diseases, its effectiveness against neuroblastoma is still in question. This study aims to assess the degree of apoptosis and cell death in neuroblastoma cell lines and primary neuroblastoma tumors when exposed to varying doses of busulfan. Materials and Methods: Cultures from established cell lines SKN-SH, SKN-DOX-R, IMR-5, and NGP (n=4), as well as cultures from primary tumors (n=2) were seeded at 106 cells/ml in RPMI640 supplemented with 10% fetal bovine serum (FBS) and transferred to 24-well plates, where cells were exposed to 1ml of busulfan at 0, 0.001, 0.005, 0.01, 0.05, and 0.1mg/ml per well. Cells were incubated at 37°C in a humidified atmosphere of 5% CO2 for 72 hours. Wells were sacrificed after 0, 6, 24, 48 and 72 hours and tested with Annexin V and PI; 10,000 events were measured by flow cytometry. The percentage of apoptotic and dead cells was plotted in a graph and a t-test was performed against the untreated control. Results: After 24 hours, there was a significant decrease in cell viability of each dose when compared to the control untreated cells (p<0.005). 24 Hour % Cell Viability for Varying Doses of Busulfan (mg/ml) Dose 0 Dose 0.001 Dose 0.005 Dose 0.01 Dose 0.05 Dose 0.1 Mean 66.1 44.4 40.3 40.7 37.7 39 SEM 5.56 5.17 5.96 6.17 6.03 5.60 Median 65 33.5 38 39 37 31 Range 39 to 97 14 to 87 4 to 89 6 to 93 4 to 77 5 to 88 The overall mean decrease in cell viability when compared to the control was 25.7%. However, there were only modest differences in effectiveness when comparing the doses, with an average of only 5–7% difference between doses. Further, there was much variability between the different cell lines, some with changes in apoptosis and cell death of over 50%, while other lines showed no changes at all. Limited differences were seen after 6 hours, and after 72 hours any effect of busulfan was masked by cell death due to other factors, as seen through increased cell death in untreated cells. Conclusion: Busulfan induced apoptosis and cell death in vitro in neuroblastoma cell lines at a mean of 76.43% for non-resistant lines, 59.33% for primary tumors and 35% for resistant cell lines (at middle dose 0.01mg/ml). The resistance of certain cell lines confirms the difficulties of treating multi-drug resistant cells in often heterogeneous neuroblastoma tumors. That some cell lines were responsive shows the potential of using busulfan to treat neuroblastoma in the future.

scholarly journals PNU-74654 Suppresses TNFR1/IKB Alpha/p65 Signaling and Induces Cell Death in Testicular Cancer

2022 ◽  
Vol 44 (1) ◽  
pp. 222-232
Author(s):  
Wen-Jung Chen ◽  
Wen-Wei Sung ◽  
Chia-Ying Yu ◽  
Yu-Ze Luan ◽  
Ya-Chuan Chang ◽  
...  
Keyword(s):  
Cell Death ◽  
Testicular Cancer ◽  
Cell Viability ◽  
Cell Lines ◽  
Cancer Progression ◽  
Treatment Strategies ◽  
Annexin V ◽  
Western Blots ◽  
Execution Phase ◽  
Induced Apoptosis

Testicular cancer (TC) is a rare malignancy worldwide and is the most common malignancy in males aged 15–44 years. The Wnt/β-catenin signaling pathway mediates numerous essential cellular functions and has potentially important effects on tumorigenesis and cancer progression. The search for drugs to inhibit this pathway has identified a small molecule, PNU-74654, as an inhibitor of the β-catenin/TCF4 interaction. We evaluated the therapeutic role of PNU-74654 in two TC cell lines, NCCIT and NTERA2, by measuring cell viability, cell cycle transition and cell death. Potential pathways were evaluated by protein arrays and Western blots. PNU-74654 decreased cell viability and induced apoptosis of TC cells, with significant increases in the sub G1, Hoechst-stained, Annexin V-PI-positive rates. PNU-74654 treatment of both TC cell lines inhibited the TNFR1/IKB alpha/p65 pathway and the execution phase of apoptosis. Our findings demonstrate that PNU-74654 can induce apoptosis in TC cells through mechanisms involving the execution phase of apoptosis and inhibition of TNFR1/IKB alpha/p65 signaling. Therefore, small molecules such as PNU-74654 may identify potential new treatment strategies for TC.

scholarly journals Induction of Apoptosis by Gluconasturtiin-Isothiocyanate (GNST-ITC) in Human Hepatocarcinoma HepG2 Cells and Human Breast Adenocarcinoma MCF-7 Cells

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1240
Author(s):  
Asvinidevi Arumugam ◽  
Muhammad Din Ibrahim ◽  
Saie Brindha Kntayya ◽  
Nooraini Mohd Ain ◽  
Renato Iori ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Cell Lines ◽  
Chromatin Condensation ◽  
Time Dependent ◽  
Breast Adenocarcinoma ◽  
Dependent Manner ◽  
Human Breast ◽  
Human Breast Adenocarcinoma ◽  
Mcf 7

Gluconasturtiin, a glucosinolate present in watercress, is hydrolysed by myrosinase to form gluconasturtiin-isothiocyanate (GNST-ITC), which has potential chemopreventive effects; however, the underlying mechanisms of action have not been explored, mainly in human cell lines. The purpose of the study is to evaluate the cytotoxicity of GNST-ITC and to further assess its potential to induce apoptosis. GNST-ITC inhibited cell proliferation in both human hepatocarcinoma (HepG2) and human breast adenocarcinoma (MCF-7) cells with IC50 values of 7.83 µM and 5.02 µM, respectively. Morphological changes as a result of GNST-ITC-induced apoptosis showed chromatin condensation, nuclear fragmentation, and membrane blebbing. Additionally, Annexin V assay showed proportion of cells in early and late apoptosis upon exposure to GNST-ITC in a time-dependent manner. To delineate the mechanism of apoptosis, cell cycle arrest and expression of caspases were studied. GNST-ITC induced a time-dependent G2/M phase arrest, with reduction of 82% and 93% in HepG2 and MCF-7 cell lines, respectively. The same treatment also led to the subsequent expression of caspase-3/7 and -9 in both cells demonstrating mitochondrial-associated cell death. Collectively, these results reveal that GNST-ITC can inhibit cell proliferation and can induce cell death in HepG2 and MCF-7 cancer cells via apoptosis, highlighting its potential development as an anticancer agent.

Birinapant Enhances Bendamustine-Induced Apoptosis In Activated B Cell-Diffuse Large Cell Lymphoma Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5150-5150
Author(s):  
Indira D Joshi ◽  
Mitchell R Smith
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Conflicts Of Interest ◽  
Cell Lymphoma ◽  
Single Agent ◽  
Annexin V ◽  
B Cell Lymphoma ◽  
Lymphoma Cell ◽  
Low Level ◽  
Induced Apoptosis

Abstract Birinapant (TL32711), a Smac mimetic in clinical testing, potently targets Inhibitor of Apoptosis Proteins (IAPs, including cIAPs and XIAP) to unblock intrinsic and extrinsic pathways, enabling caspase-dependent apoptosis via multiple signals. Birinapant also inactivates canonical NF-kB signaling through cIAPs. We investigated the pro-apoptotic effects of birinapant, alone and in combination with bendamustine (BDM), an active lymphoma therapeutic agent, in a panel of B cell lymphoma cell lines representing germinal center/follicular (GC) vs. activated B cell (ABC) subtypes. We hypothesized that the efficacy of this potential combination therapeutic strategy might differ between GC and ABC lymphoma types, as ABC are reported to be NF-kB-dependent. We used the following EBV negative cell lines: WSU-FSCCL t(14:18)+ follicular lymphoma (FL), FC-TxFL2 t(14:18)+ transformed FL, and SU-DHL4 GC-type diffuse large B cell lymphoma (DLBCL) as examples of GC origin lymphomas. U2932 and TMD8 cell lines represent ABC-type DLBCL.  Apoptosis was determined by annexin V staining and confirmed by caspase-3 activation, each assessed by flow cytometric methods following 48 h incubation. Birinapant had little effect (<5% annexin V+ cells) as a single agent on any of these B cell lymphoma cell lines at ≤ 100 nM, though a low level of apoptosis (7-12% annexin V+ cells) was detectable at 10-20 µM in GC types. Addition of birinapant 30-60 minutes prior to BDM did not further enhance the already high level (>50% annexin V+) of apoptosis induced by 10 uM BDM in WSU-FSCCL and FC-TxFL2,  and only slightly enhanced the low level of BDM-induced apoptosis in the GC DLBCL cell line DHL-4 (to 10-15%). In the ABC DLBCL cell lines, however, whereas 10uM BDM induced <5% annexin V+ cells for U2932 and 10-15% for TMD8, addition  of 100 nM birinapant 30-60 minutes prior to 10 uM BDM induced 35-40% annexin V+ cells in each of these ABC-DLBCL cell lines. This enhancement was schedule-dependent, not observed when birinapant was added after BDM. Thus, the cell lines representing FL and transformed FL are sensitive to BDM at clinically-achievable concentrations, without further enhancement by birinapant. The 3 DLBCL lines were relatively insensitive to BDM compared with FL cells, but BDM-induced apoptosis was markedly enhanced when birinapant was added before (but not after) BDM in the 2 ABC type DLBCL lines. Further explorations into the mechanism of birinapant sensitization of ABC-DLBCL to BDM, issues of dose and schedule, and role of NF-kB-dependency are ongoing. These data suggest that therapeutic trials of BDM plus birinapant would be of interest in ABC type DLBCL. Disclosures: No relevant conflicts of interest to declare.

Targeting ß-Catenin Signaling in DLBCL with ICG-001 and PAM-1 Suppresses Cell Proliferation and Induces Apoptosis

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5382-5382
Author(s):  
Angela A. Fachel ◽  
Ashlesha Shrikant Muley ◽  
Cem Meydan ◽  
Xabier Agirre ◽  
Leandro Cerchietti ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Lines ◽  
Transcriptional Activity ◽  
Annexin V ◽  
Transcript Abundance ◽  
Current Treatment ◽  
Creb Binding Protein ◽  
Treatment Regimens ◽  
P21 Activated Kinase ◽  
Induced Apoptosis

Abstract Introduction: DLBCL is a fast-growing, aggressive form of NHL and ~30% of the patients are not cured with the current treatment regimens. Recently Wnt/ ß-catenin signaling has been identified as a new target pathway for lymphoma. To specifically target B-catenin we picked two drugs that act downstream of the Wnt/B-catenin pathway. ICG-001 inhibits TCF/β-catenin mediated transcription by competing specifically with β-catenin for CREB binding protein (CBP), but not for p300. PAM-1 is a p21-activated kinase 4 (PAK4) allosteric modulator acting as a nucleo-cytoplasmic shuttling protein. PAK4 interacts with and phosphorylates β-catenin on Ser675, promoting TCF/B-catenin transcriptional activity and stabilizing β-catenin through inhibition of its degradation. We conducted a pre-clinical study with ICG-001 and PAM-1 ß-catenin inhibitors on 16 ABC and GCB DLBCL cell lines and provided a molecular rationale for Wnt/ß-catenin directed therapy. Material & Methods: RNAseq data from DLBCL cell lines, patient and normal B-cell samples were used to profile transcript abundance of the Wnt pathway in DLBCL. Western blotting was used to measure ß-catenin expression in 16 ABC and GCB DLBCL cell lines. Pharmacological inhibition of ß-catenin-signaling was tested using ICG-001 and PAM-1 compounds. A metabolically active cellular assay (CellTiter Glo) and flow cytometry with annexin V staining were used to determine cell viability and apoptosis. To address the specificity of the drug response, DLBCL cells were transduced with a ß-catenin/TCF pathway reporter, knocked down for ß-catenin, and canonical Wnt target expression was assessed using quantitative real-time (qRT-PCR) and Western blot. Results: ß-catenin is expressed on all DLBCL cell lines at different levels that do not correlate with the ABC/GCB classification. The ß-catenin inhibitors ICG-001 and PAM-1 significantly reduced viability in all ABC and GCB DLBCL cell lines, regardless of DLBCL subtype. The EC50 after 48h of treatment ranged from 1.4 μM to 6.3 μM for ICG001 and from 80 nM to 870 nM for PAM-1. Both compounds suppressed cell proliferation, induced apoptosis, and reduced Wnt/ß-catenin transcriptional activity. Conclusions: Our data indicate that targeting ß-catenin pathway with ICG-001 and PAM-1 could be therapeutically beneficial to DLBCL patients. Disclosures Melnick: Janssen: Research Funding.

Gene Profile during Arsenic Trioxide-Induced Apoptosis in Multiple Myeloma: Strong Anti-Oxidantive Response and Pro-Apoptotic Imbalance.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 5175-5175
Author(s):  
Alejo A. Morales ◽  
Delia Gutman ◽  
Pedro J. Cejas ◽  
Kelvin P. Lee ◽  
Lawrence H. Boise
Keyword(s):  
Multiple Myeloma ◽  
Cell Proliferation ◽  
Cell Death ◽  
Arsenic Trioxide ◽  
Cell Lines ◽  
Heme Oxygenase ◽  
Metal Ion ◽  
Time Course ◽  
Heme Oxygenase 1 ◽  
Induced Apoptosis

Abstract Arsenic Trioxide (ATO) has been successfully used for the treatment of acute promyelocytic leukemia (APL) and has promising activity in multiple myeloma (MM). The purpose of the present study was to evaluate the changes in the gene expression profile in four human MM cell lines (U266, MM.1S, RPMI 8226 and KMS11) following exposure to ATO in a 48H time-course to gain further insight into the mechanism of action in MM. U266 and 8226 show some resistance to ATO, while MM.1S and KMS11 are more sensitive to ATO-induced apoptosis. Two μM ATO resulted in 45.3, 74.2, 48.3 and 76.4 percent apoptosis for U266, MM.1S, 8226 and KMS11, at 48H respectively. Affymetrix Hu133 2.0 Plus Chips containing 54,675 probe sets were used for the mRNA expression profiling at 0, 6, 24 and 48H after ATO treatment. A total of 654, 478 and 600 common up or down-regulated genes showed a clustered expression pattern in response to ATO at 6, 24 and 48H, respectively. The pattern was consistent with strong anti-oxidative and heavy metal responses and pro-apoptotic imbalance. Altered cell processes included: protein folding, response to metal ion, cation and amino acids transport, heme metabolism, cell proliferation, cysteine metabolism, fatty acid metabolism, cell proliferation and apoptosis. Common up-regulated genes including clusterin (apolipoprotein J), ferritin, biliverdin reductase B, glutamate-cysteine ligase, heme oxygenase (decycling) 1, metallothionein 1, NAD(P)H dehydrogenase quinone 1, and solute carrier family 7 imply a clear anti-oxidative response. Heme oxygenase-1 (HO-1) and metallothioneins (MTs) expression has been suggested to be associated with ATO-resistance. HO-1 baseline expression is 5 fold higher in U266 and 8226 cell lines compared to MM.1S and KMS11, also suggesting a possible role of HO-1 in ATO-resistance. However, the strong up-regulation of this protein (greater than 50 fold in MM.1S and KMS11 as early as 6H) could not protect cells from ATO-induced apoptosis. Similarly the strong up-regulation of MT-1 did not correlate with cell survival. Moreover, up-regulation of HO-1 and MT-1 prior to ATO treatment (using Hemin and ZnCl2, respectively) only marginally and transiently protected MM.1S from ATO-induced apoptosis. Common down-regulated genes such as bcl-x, survivin and insulin induced gene 1 suggest a pro-apoptotic imbalance in the cell fate. Bcl-x was down-regulated in all the four cell lines during ATO-induced apoptosis while one of its ligands, Bmf, a BH3-only pro-apoptotic Bcl-2 family member was up-regulated significantly (2.5 and 3.0 fold) in MM.1S and KMS11 while to a lesser extent in U266 and 8226 (1.5 and 1.6 fold). Additionally, Bmf baseline expression is higher in MM.1S and KMS11 compared to U266 and 8226, while Bim is highly expressed in the four cell lines and did not show any transcriptional regulation during ATO-induced apoptosis. Bim and Bmf are induced following JNK activation. JNK1 is phosphorylated in all cell lines in response to ATO. Taken together these data indicate that while the cells initially respond to ATO treatment in a manner consistent with oxidative stress, the compensatory mechanisms are not sufficient to block cell death. The mechanism(s) of cell death are not completely clear although changes in the expression of Bcl-2 family members suggest that activation of the intrinsic apoptotic pathway is likely to be important.

Interleukin-21-Induced Apoptosis and Cell Death of Diffuse Large B-Cell Lymphoma (DLBCL) Cell Lines and Primary Tumors Are Associated with an Induction of Bim.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2503-2503
Author(s):  
Kristopher A. Sarosiek ◽  
Jun Chen ◽  
Dien G. Pham ◽  
Hovav Nechushtan ◽  
E. Avisar ◽  
...  
Keyword(s):  
Cell Death ◽  
Animal Models ◽  
Cell Line ◽  
Cell Lines ◽  
Cellular Proliferation ◽  
Lymphoma Cell ◽  
Primary Tumors ◽  
Protein Levels ◽  
Induced Apoptosis ◽  
Anti Tumor Activity

Abstract IL-21, a member of the IL-2 cytokine family, is reported to have an immune-mediated anti-tumor activity against renal cell carcinoma, malignant melanoma and Non-Hodgkin’s Lymphoma (NHL) cell lines in xenograph animal models. Whether IL-21 exhibits direct anti-tumor activity against NHL cell lines and primary tumors is presently unknown. We analyzed seven DLBCL and two Burkitt’s lymphoma cell lines for IL-21 receptor (IL-21R) expression. IL-21R was expressed at high levels in the two Burkitt’s lymphoma cell lines (RAJI and RAMOS). Out of the seven DLBCL lines, four expressed high levels of the receptor (OCI-LY-3, OCI-LY-7, OCI-LY-19, and RCK-8) while three had low receptor expression levels (OCI-LY-10, SU-DHL-4, and SU-DHL-6). IL-21 stimulation induced tyrosine phosphorylation of STAT-1, -3, and -5 as early as fifteen minutes post treatment in DLBCL lines expressing either high (OCI-LY-3 and RCK-8) or low (SU-DHL-6 and OCI-LY-10) levels of IL-21R. In six of the seven DLBCL lines tested, IL-21 dramatically inhibited or completely abolished cellular proliferation at 25 ng/mL and 100 ng/mL concentrations, respectively. In contrast, one DLBCL cell line (OCI-LY-3) exhibited a threefold increase in cellular proliferation after stimulation with 25 ng/mL IL-21, but proliferation was effectively inhibited by 100 ng/mL IL-21. Marked apoptosis and cell death were observed by flow cytometry at 72 hours post IL-21 exposure in all nine NHL cell lines tested with the exception of OCI-LY-3 which exhibited no significant change in cell viability. The IL-21-induced apoptosis was associated with an activation of caspases 3/7, 8, and 9, detected as early as 12 hours post IL-21 exposure. IL-21 also induced an increase in the levels of the pro-apoptotic protein Bim in all the cell lines exhibiting marked apoptosis. In contrast, Bim protein levels decreased in response to the IL-21 stimulation in the resistant OCI-LY-3 DLBCL cell line. IL-21 treatment led to a decrease in the protein levels of Bcl-2 in all the analyzed cell lines except OCI-LY-3. An increase in expression of Bcl-6 protein in three of the four tested DLBCL cell lines was observed in response to IL-21 exposure. In primary tumors, IL-21 induced apoptosis in two of two DLBCLs, two of three follicular lymphomas, and two of six chronic lymphocytic leukemias. No apoptosis or cell death was induced in normal peripheral B-lymphocytes or in the HeLa or 293T control cells. These results suggest that IL-21 exhibits a direct anti-tumor effect on the DLBCL cell lines and primary tumors and point to a potential applicability of IL-21 in anti-DLBCL therapy. Further work interrogating the molecular mechanism of the IL-21-induced apoptosis of DLBCL cells in vitro and in animal models is in progress.

Identification of the TAK1-NF-κB Axis As Critical Regulator of AML Stem and Progenitor Cell Survival.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2982-2982
Author(s):  
Matthieu C.J. Bosman ◽  
Jan J. Schuringa ◽  
Wim J. Quax ◽  
Edo Vellenga
Keyword(s):  
Stem Cells ◽  
Cell Death ◽  
Cell Survival ◽  
Cell Lines ◽  
Combined Treatment ◽  
Annexin V ◽  
Fold Increase ◽  
Dependent Manner ◽  
Leukemic Stem Cells ◽  
Induced Apoptosis

Abstract Abstract 2982 A small population of leukemic stem cells is resistant to chemotherapy and is responsible for the leukemic out-growth and relapse in acute myeloid leukemia (AML) patients. Evasion of apoptosis might be one of the essential mechanisms involved in this process. In order to gain more insight into the differences in the apoptotic programming between normal and leukemic (stem) cells, we recently performed gene array analysis by comparing CD34+ AML cells versus CD34+ normal bone marrow (NBM) cells. Gene ontology (GO) analysis of the differentially expressed genes between AML and NBM cells revealed differences in GO terms metabolic processes and apoptosis. In order to characterize differences in apoptotic programming in more detail 429 apoptotic related genes were selected and cluster analysis showed that CD34+ AML and CD34+ NBM cells could be separated into two distinct groups. In particular TGF-β activated kinase 1 (TAK1)/MAP3K7 was one of the apoptosis-related genes that was significantly higher expressed in CD34+ AML cells compared to CD34+ NBM cells (p = 1.8e−7). This increased expression of TAK1 could be confirmed by Q-PCR, showing an increase of on average 5.8 fold in TAK1 expression in the studied CD34+ AML cells. In mice it has been demonstrated that TAK1 is required for the survival of hematopoietic cells which is largely dependent on TNFR1 and TNFR2. In accordance with these data, we showed that TAK1 is also necessary in human hematopoiesis. Colony-forming cell (CFC) assays showed that inhibition of TAK1 in human cord blood CD34+cells, either by shRNAs targeting TAK1 or the TAK1 inhibitor 5z–7-oxozeaenol, resulted in a 2 fold reduction in CFU-GM and BFU-E frequencies compared to control cells. The efficacy was strongly further enhanced by the addition of TNFα, which resulted in a 9.4 fold decrease in CFC colonies upon TAK1 inhibition. Subsequently, we questioned whether TAK1 inhibition would affect CD34+ AML cell survival. Treatment of the AML cell lines MOLM13, OCI-M3 and HL60 with the TAK1 inhibitor 5z–7-oxozeaenol alone only induced modest effects, but in combination with TNFα for 24 hrs a strong induction of apoptosis was observed (IC50 respectively = 23nM, 215nM and 60 nM). Comparable results were observed in HL60 cells transduced with shRNAs targeting TAK1 whereby a downmodulation of TAK1 resulted in a 5.4 fold increase in Annexin V+ cells upon TNFα addition. In accordance with previous data, Western blot analysis showed that TAK1 inhibition reduced the levels of p-IκBα, p-p38, p-ERK and p-C-JUN. To test which of these pathways would be important for cell survival, AML cell lines were treated with either the p38 inhibitor SB203580, MEK/ERK inhibitor U0126, JNK inhibitor SP600125 and the NF-κB inhibitor BMS-345541, alone or in combination with TNFα. Addition of the NF-κB inhibitor BMS-345541 induced apoptosis in OCI-M3 and MOLM13 which was significantly increased in combination with TNFα (2.4 fold, p = 0.02). In contrast, inhibition of p38, MEK/ERK and JNK, either alone or in combination with TNFα, did not induce cell death in the AML cell lines. These data suggest that cell death induced by TAK1 inhibition is mainly due to inhibition of the NF-κB pathway. To determine the effects of TAK1 inhibition on primary AML cells, long-term expansion of the leukemic stem cell enriched CD34+ AML cell fraction was evaluated in MS5 stromal co-cultures in the absence or presence of TAK1 inhibitor and/or TNFα. Combined treatment for a period of 2 weeks completely abrogated the out-growth of CD34+ AML cells, indicating that both leukemic progenitors as well as leukemic stem cells were targeted. In contrast, addition of the single agents did not efficiently reduce cell growth. Similarly, downmodulation of TAK1 using shRNAs strongly sensitized primary CD34+ AML cells for TNFα-induced apoptosis, showing a 6 fold increase in Annexin V+ cells compared to control cells. Results on the in vivo efficacy of TAK1 inhibition on primary AML cells are in progress. In conclusion, our results show that TAK1 is frequently overexpressed in CD34+ AML cells, and that inhibition of TAK1 in combination with TNFα is highly efficient in inducing apoptosis of leukemic stem/progenitor cells in a NF-κB-dependent manner. Disclosures: No relevant conflicts of interest to declare.

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