BCL2/BCL-XL inhibition induces apoptosis, disrupts cellular calcium homeostasis, and prevents platelet activation

Blood ◽  
2011 ◽  
Vol 117 (26) ◽  
pp. 7145-7154 ◽  
Author(s):  
Meike Vogler ◽  
Hassan A. Hamali ◽  
Xiao-Ming Sun ◽  
Edward T. W. Bampton ◽  
David Dinsdale ◽  
...  
Keyword(s):  
Platelet Activation ◽  
Specific Inhibitor ◽  
Leukemia Cells ◽  
Calcium Stores ◽  
Selective Toxicity ◽  
Reticulated Platelets ◽  
Apoptotic Pathways ◽  
Induced Apoptosis ◽  
First Time

Abstract Apoptosis in megakaryocytes results in the formation of platelets. The role of apoptotic pathways in platelet turnover and in the apoptotic-like changes seen after platelet activation is poorly understood. ABT-263 (Navitoclax), a specific inhibitor of antiapoptotic BCL2 proteins, which is currently being evaluated in clinical trials for the treatment of leukemia and other malignancies, induces a dose-limiting thrombocytopenia. In this study, the relationship between BCL2/BCL-XL inhibition, apoptosis, and platelet activation was investigated. Exposure to ABT-263 induced apoptosis but repressed platelet activation by physiologic agonists. Notably, ABT-263 induced an immediate calcium response in platelets and the depletion of intracellular calcium stores, indicating that on BCL2/BCL-XL inhibition platelet activation is abrogated because of a diminished calcium signaling. By comparing the effects of ABT-263 and its analog ABT-737 on platelets and leukemia cells from the same donor, we show, for the first time, that these BCL2/BCL-XL inhibitors do not offer any selective toxicity but induce apoptosis at similar concentrations in leukemia cells and platelets. However, reticulated platelets are less sensitive to apoptosis, supporting the hypothesis that treatment with ABT-263 induces a selective loss of older platelets and providing an explanation for the transient thrombocytopenia observed on ABT-263 treatment.

scholarly journals Tumor Suppressive Role of miR-342-5p in Human Chondrosarcoma Cells and 3D Organoids

2021 ◽  
Vol 22 (11) ◽  
pp. 5590
Author(s):  
Clément Veys ◽  
Abderrahim Benmoussa ◽  
Romain Contentin ◽  
Amandine Duchemin ◽  
Emilie Brotin ◽  
...  
Keyword(s):  
Luciferase Reporter ◽  
Functional Screening ◽  
Western Blots ◽  
Egfr Expression ◽  
Reporter Assays ◽  
Direct Target ◽  
Induced Apoptosis ◽  
First Time

Chondrosarcomas are malignant bone tumors. Their abundant cartilage-like extracellular matrix and their hypoxic microenvironment contribute to their resistance to chemotherapy and radiotherapy, and no effective therapy is currently available. MicroRNAs (miRNAs) may be an interesting alternative in the development of therapeutic options. Here, for the first time in chondrosarcoma cells, we carried out high-throughput functional screening using impedancemetry, and identified five miRNAs with potential antiproliferative or chemosensitive effects on SW1353 chondrosarcoma cells. The cytotoxic effects of miR-342-5p and miR-491-5p were confirmed on three chondrosarcoma cell lines, using functional validation under normoxia and hypoxia. Both miRNAs induced apoptosis and miR-342-5p also induced autophagy. Western blots and luciferase reporter assays identified for the first time Bcl-2 as a direct target of miR-342-5p, and also Bcl-xL as a direct target of both miR-342-5p and miR-491-5p in chondrosarcoma cells. MiR-491-5p also inhibited EGFR expression. Finally, only miR-342-5p induced cell death on a relevant 3D chondrosarcoma organoid model under hypoxia that mimics the in vivo microenvironment. Altogether, our results revealed the tumor suppressive activity of miR-342-5p, and to a lesser extent of miR-491-5p, on chondrosarcoma lines. Through this study, we also confirmed the potential of Bcl-2 family members as therapeutic targets in chondrosarcomas.

scholarly journals Inhibition of Autophagy Enhances the Antitumor Effect of Thioridazine in Acute Lymphoblastic Leukemia Cells

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 365
Author(s):  
Carina Colturato-Kido ◽  
Rayssa M. Lopes ◽  
Hyllana C. D. Medeiros ◽  
Claudia A. Costa ◽  
Laura F. L. Prado-Souza ◽  
...  
Keyword(s):  
Cell Death ◽  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Clinical Problem ◽  
Jurkat Cells ◽  
Leukemia Cells ◽  
Peripheral Mononuclear Blood ◽  
Induced Apoptosis ◽  
Cure Rates

Acute lymphoblastic leukemia (ALL) is an aggressive malignant disorder of lymphoid progenitor cells that affects children and adults. Despite the high cure rates, drug resistance still remains a significant clinical problem, which stimulates the development of new therapeutic strategies and drugs to improve the disease outcome. Antipsychotic phenothiazines have emerged as potential candidates to be repositioned as antitumor drugs. It was previously shown that the anti-histaminic phenothiazine derivative promethazine induced autophagy-associated cell death in chronic myeloid leukemia cells, although autophagy can act as a “double-edged sword” contributing to cell survival or cell death. Here we evaluated the role of autophagy in thioridazine (TR)-induced cell death in the human ALL model. TR induced apoptosis in ALL Jurkat cells and it was not cytotoxic to normal peripheral mononuclear blood cells. TR promoted the activation of caspase-8 and -3, which was associated with increased NOXA/MCL-1 ratio and autophagy triggering. AMPK/PI3K/AKT/mTOR and MAPK/ERK pathways are involved in TR-induced cell death. The inhibition of the autophagic process enhanced the cytotoxicity of TR in Jurkat cells, highlighting autophagy as a targetable process for drug development purposes in ALL.

2181The prothrombotic transcriptome of reticulated platelets

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Bongiovanni ◽  
G Santamaria ◽  
M Klug ◽  
D Santovito ◽  
A Felicetta ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Platelet Activation ◽  
Small Rna ◽  
Peripheral Blood ◽  
Cardiovascular Events ◽  
Platelet Reactivity ◽  
Gene Set Enrichment Analysis ◽  
Small Rna Sequencing ◽  
Reticulated Platelets ◽  
First Time

Abstract Introduction Reticulated platelets (RPs) are young, hyper-reactive platelets that are larger and contain significantly more RNA compared to older mature platelets. High levels of RPs in peripheral blood are predictors of an insufficient response to dual antiplatelet therapy in cardiovascular patients and of adverse cardiovascular events also in non-cardiac patients. However, the mechanisms underlying these correlations remains widely unknown and the biology of RPs has not been investigated yet. Purpose We aimed to compare for the first time the transcriptomic profiles of RPs and mature platelets (MPs). Methods RPs and MPs from peripheral blood of healthy donors were identified and isolated using FACS/Sorting based on their RNA-content. Immediately after sorting, RNA was extracted and quality, concentration and integrity was assessed with the Tapestation 4200 platform (Agilent). Total- and small-RNA libraries were prepared, multiplexed and sequenced on a NextSeq 500 Illumina platform Results Total-RNA-sequencing revealed 1744 differentially expressed genes (670 downregulated 1074 upregulated) in RPs compared to MPs (Figure 1A, B). In particular, transcripts for the collagen receptor GP6, thromboxane receptor A2 (TBXA2R), thrombin receptor PAR4 (F2RL3) and ATP receptor P2RX1 were significantly enriched in RPs, whereas several RNA regulators as the ribonuclease PARN, the RISC-component TNRC6A and the splicing factor LUC7L3 were downregulated in RPs. Gene ontology analysis revealed an enrichment of relevant biological categories in RPs including platelet activation and blood coagulation (Figure 1C). Gene Set Enrichment Analysis showed an enrichment of several activation pathways like thrombin, thromboxane and GPIIb/IIIa signaling in RPs. Small-RNA-sequencing reported 9 miRNAs significantly downregulated in RPs with targets involved in platelet reactivity. Figure 1 Conclusions This study represents the first comparative transcriptome analysis of RPs and MPs and reports for the first time a differential enrichment of transcripts involved in platelet activation. The clear upregulation of prothrombotic signaling in RPs could explain, at least in part, their hyper-activity and their correlation with cardiovascular events in different pathological settings (trancripts enriched in RPs: Figure 1D). Acknowledgement/Funding German Society of Cardiology (DGK Nr.102018) ESC First conctact initiative grant 2018

scholarly journals Mechanistic insight into WEB-2170-induced apoptosis in human acute myelogenous leukemia cells: The crucial role of PTEN

2009 ◽  
Vol 37 (10) ◽  
pp. 1176-1185.e21 ◽  
Author(s):  
Cristina Cellai ◽  
Anna Laurenzana ◽  
Elisa Bianchi ◽  
Sara Sdelci ◽  
Rossella Manfredini ◽  
...  
Keyword(s):  
Acute Myelogenous Leukemia ◽  
Crucial Role ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Mechanistic Insight ◽  
Acute Myelogenous ◽  
Induced Apoptosis ◽  
Insight Into

An Alternatively Spliced Survivin Variant Is Positively Regulated by p53 and Sensitizes Leukemia Cells to Chemotherapy.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3497-3497
Author(s):  
Ningxi Zhu ◽  
Lubing Gu ◽  
Harry W. Findley ◽  
Fengzhi Li ◽  
Muxiang Zhou
Keyword(s):  
Cell Line ◽  
Lymphocytic Leukemia ◽  
Leukemia Cells ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Doxorubicin Treatment ◽  
Cryptic Exon ◽  
Apoptosis Protein ◽  
Induced Apoptosis

Abstract Survivin is a unique member of the inhibitor of apoptosis protein (IAP) family, and its expression is regulated by p53. Recent identification of several functionally divergent survivin variants augments the complexity of survivin action as well as its regulation. Here we report that survivin-2B (retaining a part of intron 2 as a cryptic exon) is positively regulated by p53, and its overexpression plays a role in sensitizing leukemia cells to chemotherapeutic drug doxorubicin. Doxorubicin treatment activated p53, downregulated survivin and survivin-DEx3 but upregulated survivin-2B in EU-3, an acute lymphocytic leukemia (ALL) cell line with wild type (wt)-p53 phenotype. In contrast, doxorubicin treatment failed to induce these alterations in EU-6 cells, a mutant-p53 ALL cell line. To specify the role of wt-p53 in regulating survivin and its variants, a temperature-sensitive p53 mutant plasmid p53–143 was transfected into EU-4, a p53-null ALL cell line, to establish a subline EU-4/p53–143. When EU-4/p53–143 cell culture was shifted from 37.5°C to the wt-p53-permissive temperature (32.5°C), the expression of survivin and survivin-DEx3 was decreased whereas survivin-2B expression was increased, confirming the distinct regulatory effect of p53 on survivin and its variants. To clarify the role of survivin-2B in the process of apoptosis, survivin-2B cDNA was cloned into pcDNA3HA vector and transfected into EU-4 cells. Enforced expression of survivin-2B in EU-4 cells inhibited cell growth and sensitized these cells to doxorubicin-induced apoptosis. These results suggest that survivin-2B variant is a pro-apoptotic factor and its expression is upregulated by p53.

2-Methoxyestradiol Sensitizes B-NHL Cells to TRAIL-Mediated Apoptosis Via Inhibition of HIF-1α, NF-κ B, YY1 and Induction of DR5 Expression.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4642-4642
Author(s):  
Sara Huerta-Yepez ◽  
Mario I. Vega ◽  
Stavroula Baritaki ◽  
Eriko Suzuki ◽  
Theresa La Vallee ◽  
...  
Keyword(s):  
Annexin V ◽  
Nuclear Accumulation ◽  
Microtubule Disruption ◽  
Low Concentrations ◽  
Combination Studies ◽  
Apoptotic Activity ◽  
Induced Apoptosis ◽  
Patients Experience ◽  
First Time

Abstract There have been many advances in the treatment of B-NHL by both chemotherapy and immunotherapy. However, many patients experience recurrences and relapses and develop resistance to further treatments. Therefore, there is a need for new therapies. TRAIL and mAbs directed against DR4 or DR5 are currently being examined clinically, either alone or in combination with other therapies, for the treatment of resistant cancers. The objective of our study is to examine whether B-NHL can be sensitized to respond to TRAIL. 2-Methoxyestradiol (2ME2), a naturally occurring metabolite of estradiol, is known to have apoptotic activity and anti-angiogenic activity and has been examined for its therapeutic efficacy, both preclinically and in humans. Further, we and others have shown that 2ME2 can sensitize solid tumors to TRAIL-induced apoptosis. Thus, we hypothesized that 2ME2 may also sensitize B-NHL cells to TRAIL-induced apoptosis and that 2ME2-induced microtubule disruption and inhibition of NF-κ B activity may be involved in 2ME2-induced sensitization. The present study examined the role of 2ME2 in TRAIL-sensitization of the B-NHL cell line, Ramos, as a model for B-NHL. Ramos cells were treated with 2ME2 (0.1, 1.0 μ m for 5 h) and then treated with TRAIL (2.5–10 ng/ml for 18 h). The cells were harvested and examined for apoptosis by Annexin V/PI and for activation of caspase-3. The findings demonstrate that, while single agents were not cytotoxic, the combination treatment resulted in significant cytotoxicity demonstrating synergy in apoptosis. The synergy was obtained with very low concentrations of 2ME2 (0.1μ m) and TRAIL (2.5 ng/ml), concentrations that were not effective in other tumor cell lines studied. We examined the potential mechanism involved in synergy induced by 2ME2 and TRAIL. Surface DR-5 expression was upregulated following treatment with 2ME2. In addition, the transcription repressor YY1 protein expression was inhibited as assessed by Western and immunohistochemistry (IHC). Microtubule disruption by 2ME2 results in inhibition of HIF-1α transcriptional activity through impairment of HIF-1α nuclear accumulation. Additionally, we have found that 2ME2 inhibits HIF-1α accumulation in the nucleus as assessed by IHC. Inhibition of HIF-1α has been shown to regulate apoptosis via upregulation of BID and phosphorylyzation of Bcl-2. The present findings demonstrate, for the first time, that 2ME2 sensitizes B-NHL cells to TRAIL-induced apoptosis via inhibition of both HIF-1α and YY1 and upregulation of DR5. The findings support potential therapeutic combination studies of 2ME2 with TRAIL for the treatment of resistant B-NHL In addition, we suggest that HIF-1α, YY1, and DR5 may serve as targets for therapeutic intervention and potentially as biomarkers for activity.

Role of specific apoptotic pathways in the restoration of paclitaxel-induced apoptosis by valspodar in doxorubicin-resistant MCF-7 breast cancer cells

2000 ◽  
Vol 59 (3) ◽  
pp. 231-244 ◽  
Author(s):  
Antony Chadderton ◽  
David J. Villeneuve ◽  
Stefan Gluck ◽  
Angie F. Kirwan-Rhude ◽  
Brian R. Gannon ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Apoptotic Pathways ◽  
Induced Apoptosis ◽  
Mcf 7

Role of SLC12A10.2, a Na-Cl cotransporter-like protein, in a Cl uptake mechanism in zebrafish (Danio rerio)

2009 ◽  
Vol 296 (5) ◽  
pp. R1650-R1660 ◽  
Author(s):  
Yi-Fang Wang ◽  
Yung-Che Tseng ◽  
Jia-Jiun Yan ◽  
Junya Hiroi ◽  
Pung-Pung Hwang
Keyword(s):  
Specific Inhibitor ◽  
In Vivo Model ◽  
Zebrafish Embryos ◽  
Uptake Mechanism ◽  
Ion Regulation ◽  
Specific Expression ◽  
Net Uptake ◽  
First Time

The thiazide-sensitive Na+-Cl− cotransporter (NCC), a member of the SLC12 family, is mainly expressed in the apical membrane of the mammalian distal convoluted tubule (DCT) cells, is responsible for cotransporting Na+ and Cl− from the lumen into DCT cells and plays a major role in the mammalian renal NaCl reabsorption. The NCC has also been reported in fish, but the functional role in fish ion regulation is yet unclear. The present study used zebrafish as an in vivo model to test the hypothesis of whether the NCC plays a role in Na+ and/or Cl− uptake mechanisms. Four NCCs were cloned, and only one of them, zebrafish (z) slc12a10.2 was found to predominately and specifically be expressed in gills. Double in situ hybridization/immunocytochemistry in zebrafish skin/gills demonstrated that the specific expression of zslc12a10.2 mRNA in a novel group of ionocytes differed from those of the previously-reported H+-ATPase-rich (HR) cells and Na+-K+-ATPase-rich (NaR) cells. Gill mRNA expression of zslc12a10.2 was induced by a low-Cl environment that stimulated fish Cl− influx, while a low-Na environment suppressed this expression. Incubation with metolazone, a specific inhibitor of the NCC, impaired both Na+ and Cl− influx in 5-day postfertilization (dpf) zebrafish embryos. Translational knockdown of zslc12a10.2 with a specific morpholino caused significant decreases in both Cl− influx and Cl− content of 5-dpf zebrafish embryos, suggesting that the operation of zNCC-like 2 results in a net uptake of Cl− in zebrafish. On the contrary, zslc12a10.2 morphants showed increased Na+ influx and content that resulted from upregulation of mRNA expressions of Na+-H+ exchanger 3b and carbonic anhydrase 15a in HR cells. These results for the first time provide in vivo molecular physiological evidence for the possible role of the NCC in the Cl− uptake mechanism in zebrafish skin/gills.

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