scholarly journals d,l-Methadone causes leukemic cell apoptosis via an OPRM1-triggered increase in IP3R-mediated ER Ca2+ release and decrease in Ca2+ efflux, elevating [Ca2+]i

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
JungKwon Lee ◽  
Jesusa L. Rosales ◽  
Hee-Guk Byun ◽  
Ki-Young Lee

AbstractThe search continues for improved therapy for acute lymphoblastic leukemia (aLL), the most common malignancy in children. Recently, d,l-methadone was put forth as sensitizer for aLL chemotherapy. However, the specific target of d,l-methadone in leukemic cells and the mechanism by which it induces leukemic cell apoptosis remain to be defined. Here, we demonstrate that d,l-methadone induces leukemic cell apoptosis through activation of the mu1 subtype of opioid receptors (OPRM1). d,l-Methadone evokes IP3R-mediated ER Ca2+ release that is inhibited by OPRM1 loss. In addition, the rate of Ca2+ extrusion following d,l-methadone treatment is reduced, but is accelerated by loss of OPRM1. These d,l-methadone effects cause a lethal rise in [Ca2+]i that is again inhibited by OPRM1 loss, which then prevents d,l-methadone-induced apoptosis that is associated with activation of calpain-1, truncation of Bid, cytochrome C release, and proteolysis of caspase-3/12. Chelating intracellular Ca2+ with BAPTA-AM reverses d,l-methadone-induced apoptosis, establishing a link between the rise in [Ca2+]i and d,l-methadone-induced apoptosis. Altogether, our findings point to OPRM1 as a specific target of d,l-methadone in leukemic cells, and that OPRM1 activation by d,l-methadone disrupts IP3R-mediated ER Ca2+ release and rate of Ca2+ efflux, causing a rise in [Ca2+]i that upregulates the calpain-1-Bid-cytochrome C-caspase-3/12 apoptotic pathway.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2584-2584
Author(s):  
Julie C. Watt ◽  
Marina Konopleva ◽  
Rooha Contractor ◽  
Ismael Samudio ◽  
David Harris ◽  
...  

Abstract GX15-070 is a novel cycloprodigiosin derived small molecule BH3 inhibitor that binds with moderate affinity to all antiapoptotic Bcl-2 family members, including Mcl-1, and is currently undergoing Phase I clinical trials in leukemias. In this study, we investigated the activity of GX15-070 in acute myeloid leukemia (AML) cell lines and primary AML samples. GX15-070 inhibited cell growth of HL-60, U937, OCI-AML3 and KG-1 cell lines at IC50’s of 0.1, 0.5, 0.5 and 2.5μM, respectively, at 72 hours. Neither overexpression of Bcl-2 or Bcl-XL nor loss of expression of Bax conferred resistance to GX15-070. GX15-070 inhibited Bim/Bcl-2 heterodimerization and induced association of activated Bak with Bax in OCI-AML3 cells, as demonstrated by co-immunoprecipitation studies using CHAPS buffer. This was associated with cytosolic release of cytochrome c followed by an increase in annexin positivity, caspase activation and a decrease in mitochondrial inner membrane potential. Notably, GX15-070 induced cytochrome c release from isolated mitochondria of leukemic cells. GX15-070 synergized with both AraC and the novel BH3 mimetic ABT-737 to induce apoptosis in OCI-AML3 cells, a notoriously chemoresistant cell line (GX15-070 and ABT-737 average CI value 0.3; GX15-070 and AraC average CI value 0.36). In 6/7 primary AML samples, GX15-070 induced apoptosis in CD34+ progenitor cells at an average IC50 of 3.6±1.2μM at 24 hours. GX15-070 potently inhibited clonogenic ability of AML blasts at sub-micromolar doses (58.5±10.6% CFU-Blast at 0.1μM and 38.1±10.5% at 0.25μM, n=7). In summary, BH3 inhibitor GX15-070 induces apoptosis in AML cells via inhibition of association of pro-survival Bcl-2 family proteins and BH3-only proteins, followed by Bax/Bak activation and initiation of the intrinsic apoptotic pathway. Hence, GX15-070 alone or in combination with chemotherapeutic agents may have utility in AML therapy.


2001 ◽  
Vol 280 (5) ◽  
pp. H2292-H2299 ◽  
Author(s):  
Guang-Wu Wang ◽  
Zhanxiang Zhou ◽  
Jon B. Klein ◽  
Y. James Kang

To study possible mechanisms for metallothionein (MT) inhibition of ischemia-reperfusion-induced myocardial injury, cardiomyocytes isolated from MT-overexpressing transgenic neonatal mouse hearts and nontransgenic controls were subjected to 4 h of hypoxia (5% CO2-95% N2, glucose-free modified Tyrode's solution) followed by 1 h of reoxygenation in MEM + 20% fetal bovine serum (FBS) (5% CO2-95% air), and cytochrome c-mediated caspase-3 activation apoptotic pathway was determined. Hypoxia/reoxygenation-induced apoptosis was significantly suppressed in MT-overexpressing cardiomyocytes, as measured by both terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick-end labeling and annexin V-FITC binding. In association with apoptosis, mitochondrial cytochrome c release, as determined by Western blot, was observed to occur in nontransgenic cardiomyocytes. Correspondingly, caspase-3 was activated as determined by laser confocal microscopic examination with the use of FITC-conjugated antibody against active caspase-3 and by enzymatic assay. The activation of this apoptotic pathway was significantly inhibited in MT-overexpressing cells, as evidenced by both suppression of cytochrome c release and inhibition of caspase-3 activation. The results demonstrate that MT suppresses hypoxia/reoxygenation-induced cardiomyocyte apoptosis through, at least in part, inhibition of cytochrome c-mediated caspase-3 activation.


Blood ◽  
2019 ◽  
Vol 133 (20) ◽  
pp. 2222-2232 ◽  
Author(s):  
Jung Kwon Lee ◽  
SungMyung Kang ◽  
Xidi Wang ◽  
Jesusa L. Rosales ◽  
Xu Gao ◽  
...  

Abstract l-Asparaginase (l-ASNase) is a strategic component of treatment protocols for acute lymphoblastic leukemia (ALL). It causes asparagine deficit, resulting in protein synthesis inhibition and subsequent leukemic cell death and ALL remission. However, patients often relapse because of the development of resistance, but the underlying mechanism of ALL cell resistance to l-asparaginase remains unknown. Through unbiased genome-wide RNA interference screening, we identified huntingtin associated protein 1 (HAP1) as an ALL biomarker for l-asparaginase resistance. Knocking down HAP1 induces l-asparaginase resistance. HAP1 interacts with huntingtin and the intracellular Ca2+ channel, inositol 1,4,5-triphosphate receptor to form a ternary complex that mediates endoplasmic reticulum (ER) Ca2+ release upon stimulation with inositol 1,4,5-triphosphate3. Loss of HAP1 prevents the formation of the ternary complex and thus l-asparaginase-mediated ER Ca2+ release. HAP1 loss also inhibits external Ca2+ entry, blocking an excessive rise in [Ca2+]i, and reduces activation of the Ca2+-dependent calpain-1, Bid, and caspase-3 and caspase-12, leading to reduced number of apoptotic cells. These findings indicate that HAP1 loss prevents l-asparaginase–induced apoptosis through downregulation of the Ca2+-mediated calpain-1-Bid-caspase-3/12 apoptotic pathway. Treatment with BAPTA-AM [1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid tetrakis(acetoxymethyl ester)] reverses the l-asparaginase apoptotic effect in control cells, supporting a link between l-asparaginase-induced [Ca2+]i increase and apoptotic cell death. Consistent with these findings, ALL patient leukemic cells with lower HAP1 levels showed resistance to l-asparaginase, indicating the clinical relevance of HAP1 loss in the development of l-asparaginase resistance, and pointing to HAP1 as a functional l-asparaginase resistance biomarker that may be used for the design of effective treatment of l-asparaginase-resistant ALL.


2007 ◽  
Vol 292 (1) ◽  
pp. G28-G38 ◽  
Author(s):  
Yanna Cao ◽  
Lu Chen ◽  
Weili Zhang ◽  
Yan Liu ◽  
Harry T. Papaconstantinou ◽  
...  

Transforming growth factor (TGF)-β-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues in vivo. Previously, we have shown that TGF-β inhibits the growth of rat intestinal epithelial (RIE)-1 cells. However, RIE-1 cells are relatively resistant to TGF-β-induced apoptosis due to a low endogenous Smad3-to-Akt ratio. Overexpression of Smad3 sensitizes RIE-1 cells (RIE-1/Smad3) to TGF-β-induced apoptosis by altering the Smad3-to-Akt ratio in favor of apoptosis. In this study, we utilized a genomic approach to identify potential downstream target genes that are regulated by TGF-β/Smad3. Total RNA samples were analyzed using Affymetrix oligonucleotide microarrays. We found that TGF-β regulated 518 probe sets corresponding to its target genes. Interestingly, among the known apoptotic genes included in the microarray analyses, only caspase-3 was induced, which was confirmed by real-time RT-PCR. Furthermore, TGF-β activated caspase-3 through protein cleavage. Upstream of caspase-3, TGF-β induced mitochondrial depolarization, cytochrome c release, and cleavage of caspase-9, which suggests that the intrinsic apoptotic pathway mediates TGF-β-induced apoptosis in RIE-1/Smad3 cells.


2003 ◽  
Vol 284 (5) ◽  
pp. G821-G829 ◽  
Author(s):  
Wenlin Deng ◽  
De-An Wang ◽  
Elvira Gosmanova ◽  
Leonard R. Johnson ◽  
Gabor Tigyi

We previously showed ( Gastroenterology 123: 206–216, 2002) that lysophosphatidic acid (LPA) protects and rescues rat intestinal epithelial cells (IEC-6) from apoptosis. Here, we provide evidence for the LPA-elicited inhibition of the mitochondrial apoptotic pathway leading to attenuation of caspase-3 activation. Pretreatment of IEC-6 cells with LPA inhibited campothecin-induced caspase-9 and caspase-3 activation and DNA fragmentation. A caspase-9 inhibitor peptide mimicked the LPA-elicited antiapoptotic activity. LPA elicited ERK1/ERK2 and PKB/Akt phosphorylation. The LPA-elicited antiapoptotic activity and inhibition of caspase-9 activity were abrogated by pertussis toxin, PD 98059, wortmannin, and LY 294002. LPA reduced cytochrome c release from mitochondria and prevented activation of caspase-9. LPA prevented translocation of Bax from cytosol to mitochondria and increased the expression of the antiapoptotic Bcl-2 mRNA and protein. LPA had no effect on Bcl-xl, Bad, and Bak mRNA or protein expression. These data indicate that LPA protects IEC-6 cells from camptothecin-induced apoptosis through Gi-coupled inhibition of caspase-3 activation mediated by the attenuation of caspase-9 activation due to diminished cytochrome c release, involving upregulation of Bcl-2 protein expression and prevention of Bax translocation.


2020 ◽  
Vol 38 (6) ◽  
pp. 1664-1676
Author(s):  
Małgorzata Opydo-Chanek ◽  
Iwona Cichoń ◽  
Agnieszka Rak ◽  
Elżbieta Kołaczkowska ◽  
Lidia Mazur

Summary One of the key features of acute myeloid leukemia (AML) is the arrest of differentiation at the early progenitor stage of myelopoiesis. Therefore, the identification of new agents that could overcome this differentiation block and force leukemic cells to enter the apoptotic pathway is essential for the development of new treatment strategies in AML. Regarding this, herein we report the pro-differentiation activity of the pan-Bcl-2 inhibitor, obatoclax. Obatoclax promoted differentiation of human AML HL-60 cells and triggered their apoptosis in a dose- and time-dependent manner. Importantly, obatoclax-induced apoptosis was associated with leukemic cell differentiation. Moreover, decreased expression of Bcl-2 protein was observed in obatoclax-treated HL-60 cells. Furthermore, differentiation of these cells was accompanied by the loss of their proliferative capacity, as shown by G0/G1 cell cycle arrest. Taken together, these findings indicate that the anti-AML effects of obatoclax involve not only the induction of apoptosis but also differentiation of leukemic cells. Therefore, obatoclax represents a promising treatment for AML that warrants further exploration.


Blood ◽  
1999 ◽  
Vol 93 (7) ◽  
pp. 2342-2352 ◽  
Author(s):  
Alexey Ushmorov ◽  
Frank Ratter ◽  
Volker Lehmann ◽  
Wulf Dröge ◽  
Volker Schirrmacher ◽  
...  

Abstract We have previously shown that nitric oxide (NO) stimulates apoptosis in different human neoplastic lymphoid cell lines through activation of caspases not only via CD95/CD95L interaction, but also independently of such death receptors. Here we investigated mitochondria-dependent mechanisms of NO-induced apoptosis in Jurkat leukemic cells. NO donor glycerol trinitrate (at the concentration, which induces apoptotic cell death) caused (1) a significant decrease in the concentration of cardiolipin, a major mitochondrial lipid; (2) a downregulation in respiratory chain complex activities; (3) a release of the mitochondrial protein cytochrome c into the cytosol; and (4) an activation of caspase-9 and caspase-3. These changes were accompanied by an increase in the number of cells with low mitochondrial transmembrane potential and with a high level of reactive oxygen species production. Higher resistance of the CD95-resistant Jurkat subclone (APO-R) cells to NO-mediated apoptosis correlated with the absence of cytochrome c release and with less alterations in other mitochondrial parameters. An inhibitor of lipid peroxidation, trolox, significantly suppressed NO-mediated apoptosis in APO-S Jurkat cells, whereas bongkrekic acid (BA), which blocks mitochondrial permeability transition, provided only a moderate antiapoptotic effect. Transfection of Jurkat cells with bcl-2 led to a complete block of apoptosis due to the prevention of changes in mitochondrial functions. We suggest that the mitochondrial damage (in particular, cardiolipin degradation and cytochrome c release) induced by NO in human leukemia cells plays a crucial role in the subsequent activation of caspase and apoptosis.


2010 ◽  
Vol 38 (02) ◽  
pp. 373-386 ◽  
Author(s):  
Qin Hu ◽  
Ruile Pan ◽  
Liwei Wang ◽  
Bo Peng ◽  
Jingtian Tang ◽  
...  

Platycodon grandiflorum (Jacq.) A. DC., a Chinese food and medicine, has been used as expectorant traditionally. The present study aimed to investigate the effect of Platycodon grandiflorum extract (PGE) on SKOV3 ovarian cancer cells. 3-(4,5- dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay was used to monitor cell numbers, Annexin-V/propidium iodide (PI) staining, RT-PCR and Western blot were used to examine cell apoptosis, caspases activation. Bcl-2 and Bax expressions and mitochondrial cytochrome c release. Our result showed that PGE-induced apoptosis was associated with activation of caspase-3, -8 and -9, down-regulation of Bcl-2, up-regulation of Bax and release of mitochondrial cytochrome c to cytosol. The data indicate that PGE may have anti-tumor effect mainly via caspase-3 and caspase-9 dependent apoptotic pathway.


Blood ◽  
2002 ◽  
Vol 99 (2) ◽  
pp. 655-663 ◽  
Author(s):  
Joya Chandra ◽  
Emma Mansson ◽  
Vladimir Gogvadze ◽  
Scott H. Kaufmann ◽  
Freidoun Albertioni ◽  
...  

Abstract The purine nucleoside 2-chlorodeoxyadenosine (CdA) is often used in leukemia therapy. Its efficacy, however, is compromised by the emergence of resistant cells. In the present study, 3 CdA-resistant cell lines were generated and characterized. Their ability to accumulate 2-chloroadenosine triphosphate (CdATP) varied, reflecting differences in activities of deoxycytidine kinase (dCK) and deoxyguanosine kinase (dGK). Nonetheless, the selected lines were uniformly resistant to CdA-induced apoptosis, as assessed by caspase activation and DNA fragmentation. In contrast, cytosols from resistant cells were capable of robust caspase activation when incubated in the presence of cytochrome c and dATP. Moreover, replacement of dATP with CdATP also resulted in caspase activation in the parental and some of the resistant cell lines. Strikingly, CdA-induced decreases in mitochondrial transmembrane potential and release of cytochrome c from mitochondria were observed in the parental cells but not in any resistant lines. The lack of cytochrome c release correlated with an increased ability of mitochondria from resistant cells to sequester free Ca2+. Consistent with this enhanced Ca2+buffering capacity, an early increase in cytosolic Ca2+after CdA treatment of parental cells but not resistant cells was detected. Furthermore, CdA-resistant cells were selectively cross-resistant to thapsigargin but not to staurosporine- or Fas-induced apoptosis. In addition, CdA-induced caspase-3 activation and DNA fragmentation were inhibited by the Ca2+ chelator BAPTA-AM in sensitive cells. Taken together, the data indicate that the mechanism of resistance to CdA may be dictated by changes in Ca2+-sensitive mitochondrial events.


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