scholarly journals Zinc Supplementation Enhances the Pro-Death Function of UPR in Lymphoma Cells Exposed to Radiation

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 132
Author(s):  
Roberta Gonnella ◽  
Luisa Guttieri ◽  
Maria Saveria Gilardini Montani ◽  
Roberta Santarelli ◽  
Erica Bassetti ◽  
...  

We have previously shown that Zinc supplementation triggered ER stress/UPR in cancer cells undergoing treatment by genotoxic agents, reactivated wtp53 in cancer cells harboring mutant p53 (mutp53) and potentiated the activity of wtp53 in those carrying wtp53. In this study, we used Zinc chloride alone or in combination with 2 Gy radiation to treat Primary Effusion Lymphoma (PEL) cells, an aggressive B-cell lymphoma associated with KSHV that harbors wt or partially functioning p53. We found that Zinc triggered a mild ER stress/UPR in these lymphoma cells and activated ERK1/2, molecule known to sustain cell survival in the course of UPR activation. In combination with radiations, Zinc triggered a stronger p53 activation that counteracted its mediated ERK1/2 phosphorylation, further upregulating the UPR molecule CHOP and promoting cell death. These data suggest that Zinc supplementation could be a promising strategy to reduce the doses of radiation and possibly of other DNA-damaging agents to obtain an efficient capacity to induce lymphoma cell death.

2018 ◽  
Vol 155 ◽  
pp. 639-650 ◽  
Author(s):  
Feng-Yang Wang ◽  
Xiao-Ming Tang ◽  
Xia Wang ◽  
Ke-Bin Huang ◽  
Hai-Wen Feng ◽  
...  

Proceedings ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 9
Author(s):  
Amani Abdulmunem ◽  
Pınar Obakan-Yerlikaya ◽  
Elif-Damla Arisan ◽  
Ajda Coker-Gurkan

Breast cancer is the most common cancer in women worldwide and the second most common cancer overall. Autocrine growth hormone (GH) expression induced cell proliferation, growth, invasion-metastasis in vitro and in vivo breast cancer models. Moreover, forced GH signaling acts as a drug resistance profile in breast cancer cell lines against chemotherapeutic drugs such as tamoxifen, mitomycin C, doxorubicin and curcumin. Triptolide, an active plant extract from Tripterygium wilfordii, has been shown to induce apoptotic cell death in various cancer cells such a prostate, colon, breast cancer. Metformin, a common therapeutic agent for type II Diabetes mellitus, has been shown to induce autophagy, endoplasmic reticulum (ER) stress and apoptotic cell death in cancer cells. Our aim is to demonstrate the potential effect of metformin on triptolide-mediated drug resistance in autocrine GH expressing MDA-MB-231 breast cancer cells through Endoplasmic reticulum (ER) stress. Autocrine GH-mediated triptolide (20 nM) resistance overcame by metformin (2 mM) co-teatment in MDA-MB231 breast cancer cells through accelerating cell viability loss, growth inhibition compared to alone triptolide treatment. Combined treatment increased apoptotic cell death via CHOP activation, IRE1α upregulation. Consequently, we suggest that triptolide can be more effective with metformin combination in MDA-MB-231 GH+ drug resistant breast cancer cells.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3288-3288
Author(s):  
Brian Gaudette ◽  
Neal N Iwakoshi ◽  
Lawrence H. Boise

Abstract Abstract 3288 Understanding factors that control plasma cell survival is important for the development of therapeutic approaches to diseases including multiple myeloma and autoimmune disorders. As part of the program that allows for B cell differentiation to a plasma cell, a required signal includes the activation of an unfolded protein response (UPR). However unlike stress-induced activation of the UPR, induction of apoptosis does not occur, suggesting that compensatory survival signals are also activated during plasma cell differentiation. The compensatory survival pathways are less defined and require further research. Therefore we employed a model of plasma cell differentiation to better define the survival signaling during this process. The murine B cell lymphoma cell line, Bcl1 can be stimulated to secrete immunoglobulin using IL-5 and LPS. To determine the effects of exogenous ER stress on plasma cell differentiation, we treated the cells with the inhibitor of N-linked glycosylation, tunicamycin, for 5 hours prior to the differentiation signal. The 5 hour pulse of tunicamycin was sufficient to induce significant apoptosis in undifferentiated cells or cells treated with IL-5, resulting in 78% and 74% cell death respectively by 24 hours post treatment. However, if LPS was included in the differentiation stimulus the cells were able to differentiate into IgM-secreting plasma cells with similar kinetics as cells differentiated in the absence of tunicamycin pretreatment. Thus LPS-induced differentiation is sufficient to block ER stress-induced cell death. Since these cells also activate a UPR during differentiation, we hypothesized that part of the differentiation program included protection from UPR-associated cell death. To investigate this effect, we first examined the levels of the antiapoptotic proteins Bcl-2, Bcl-xL and Mcl-1 during plasma cell differentiation. We found that differentiation induced Bcl-xL and caused the loss of Mcl-1. From this data we hypothesized that the differentiation of these cells resulted in Bcl-xL dependence during plasma cell differentiation. To test this we used ABT-737, which selectively blocks the binding pocket of Bcl-xL and Bcl-2 but not Mcl-1 and kills cells that are dependent on Bcl-2 or Bcl-xL. Undifferentiated Bcl1 cells were insensitive to ABT-737 with an IC50 > 2μM. However ABT-737 sensitized LPS-treated Bcl1 cells to tunicamycin pretreatment resulting in 89% death in 24 h compared to 23% in untreated cells. These data suggest that the induction of Bcl-xL is responsible for the survival of cells undergoing ER stress. Most importantly, cells treated with LPS and IL-5 for differentiation became sensitive to ABT-737 with 59% cell death versus 26% in untreated cells, thus demonstrating that during plasma cell differentiation, cells switch to a Bcl-xL-dependent state. To determine the molecular basis for these findings we investigated the effects of ABT-737 on the expression levels of Bcl-2 proteins as well as the effects of differentiation on their interactions. ABT-737 did not induce changes in the expression of Bcl-2 family proteins. However, co-immunoprecipitation demonstrated a shift in Bim binding from Mcl-1 in untreated cells to Bcl-xL in differentiating cells. This latter finding is consistent with a shift from Mcl-1 dependence to Bcl-xL during plasma cell differentiation. To validate these data, primary C57BL/6 splenocytes were isolated, depleted of non-B cells and subsequently stimulated with IL-4 and LPS to differentiate into plasmablasts. Realtime qPCR showed an increase in Bcl-xL mRNA and loss of Mcl-1 and Bcl-2 mRNA in both the primary B cells and the Bcl1 cell line. Western blotting of primary B cell lysates also showed an increase in Bcl-xL protein and loss of Bcl-2 and Mcl-1 protein. Together these data indicate that during plasma cell differentiation the cell enters a Bcl-xL-dependent state that protects against differentiation-induced apoptosis. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Author(s):  
Ajda Coker-Gurkan ◽  
Esin Can ◽  
Semanur Sahin ◽  
PINAR OBAKAN YERLIKAYA ◽  
Elif-Damla ARISAN

Abstract Purpose: The constitutive activation of STAT3 through receptor tyrosine kinases triggered breast cancer cell growth, and invasion-metastasis. Atiprimod impacts anti-proliferative, anti-carcinogenic effects in hepatocellular carcinoma, lymphoma, multiple myeloma via hindering the biological activity of STAT3. Dose-dependent atiprimod evokes first autophagy as a survival mechanism and then apoptosis due to prolonged ER stress in pituitary adenoma cells. The therapeutic efficiency and mechanistic action of atiprimod in breast cancer cells have not been investigated yet. Thus, we aimed to modulate the pivotal role of ER stress in atiprimod-triggered apoptosis in MDA-MB-231 and MDA-MB-468 breast cancer cells. Results: Dose- and time-dependent atiprimod treatment inhibits cell viability and colony formation in MDA-MB-468 and MDA-MB-231 breast cancer cells. A moderate dose of atiprimod (2 mM) inhibited STAT3 phosphorylation at Tyr705 residue and also suppressed the total expression level of p65. In addition, nuclear localization of STAT1, 3 and NF-kB was prevented by atiprimod exposure in MDA-MB-231 and MDA-MB-468 cells. Atiprimod evokes PERK, BiP, ATF-4, CHOP upregulation, and PERK (Thr980), eIF2a (Ser51) phosphorylation’s. However, atiprimod suppressed IRE1a-mediated Atg-3, 5, 7, 12 protein expressions and no alteration were observed on Beclin-1, p62 expression levels. PERK/eIF2a/ATF4/CHOP axis pivotal role in atiprimod-mediated G1/S arrest and apoptosis via Bak, Bax, Bim and PUMA upregulation in MDA-MB-468 cells. Moreover, atiprimod renders MDA-MB-231 more vulnerable to type I programmed cell death by plasmid-mediated increased STAT3 expression. Conclusion: Atiprimod induced prolonged ER stress-mediated apoptosis via both activating PERK/eIF2a/ATF4/CHOP axis and suppressing STAT3/NF-kB transcription factors nuclear migration in TBNC cells.


Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4173
Author(s):  
Faustino Mollinedo ◽  
Consuelo Gajate

Pancreatic ductal adenocarcinoma (PDAC), the most common malignancy of the pancreas, shows a dismal and grim overall prognosis and survival rate, which have remained virtually unchanged for over half a century. PDAC is the most lethal of all cancers, with the highest mortality-to-incidence ratio. PDAC responds poorly to current therapies and remains an incurable malignancy. Therefore, novel therapeutic targets and drugs are urgently needed for pancreatic cancer treatment. Selective induction of apoptosis in cancer cells is an appealing approach in cancer therapy. Apoptotic cell death is highly regulated by different signaling routes that involve a variety of subcellular organelles. Endoplasmic reticulum (ER) stress acts as a double-edged sword at the interface of cell survival and death. Pancreatic cells exhibit high hormone and enzyme secretory functions, and thereby show a highly developed ER. Thus, pancreatic cancer cells display a prominent ER. Solid tumors have to cope with adverse situations in which hypoxia, lack of certain nutrients, and the action of certain antitumor agents lead to a complex interplay and crosstalk between ER stress and autophagy—the latter acting as an adaptive survival response. ER stress also mediates cell death induced by a number of anticancer drugs and experimental conditions, highlighting the pivotal role of ER stress in modulating cell fate. The alkylphospholipid analog prototype edelfosine is selectively taken up by tumor cells, accumulates in the ER of a number of human solid tumor cells—including pancreatic cancer cells—and promotes apoptosis through a persistent ER-stress-mediated mechanism both in vitro and in vivo. Here, we discuss and propose that direct ER targeting may be a promising approach in the therapy of pancreatic cancer, opening up a new avenue for the treatment of this currently incurable and deadly cancer. Furthermore, because autophagy acts as a cytoprotective response to ER stress, potentiation of the triggering of a persistent ER response by combination therapy, together with the use of autophagy blockers, could improve the current gloomy expectations for finding a cure for this type of cancer.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1625-1625 ◽  
Author(s):  
Aine McCarthy ◽  
Vincent Yeung ◽  
John G. Gribben ◽  
Li Jia

Abstract Abstract 1625 Diffuse large B-cell lymphoma (DLBCL) is characterised by overexpression of the anti-apoptotic protein Bcl-2. It has been recently observed that Bcl-2 also inhibits autophagy by binding and sequestering Beclin-1, an essential autophagy protein, but it is unclear whether Bcl-2 inhibits both apoptosis and autophagy in DLBCL cells. We aimed to determine the dual role of Bcl-2 in both apoptosis and autophagy in Bcl-2 positive cell lines (Su-DHL4 and CRL) and Bcl-2 negative cell lines (Su-DHL8 and Su-DHL10) using the BH3 mimetic compound ABT-737. The sensitivity of Bcl-2 positive and Bcl-2 negative cell lines to ABT-737-mediated mitochondrial depolarization (ΔΨmLOW) and cell death (DAPI positive) was assessed by flow cytometry. Treatment of the Bcl-2 positive cell lines Su-DHL4 and CRL with ABT-737 significantly increased (p<0.01) the percentage of both ΔΨmLOW cells, indicating mitochondrial damage as well as DAPI positive cells indicating cell death. Treatment with ABT-737 increased Bax activation and PARP cleavage in Bcl-2 positive cells, indicating that as expected, ABT-737-induced cell death is via apoptosis. ABT-737-induced cell death was not detected in Bcl-2 negative cell lines Su-DHL8 and Su-DHL10, demonstrating that, as expected, the sensitivity of DLBCL cell lines to ABT-737-induced apoptosis is Bcl-2 dependent. Treatment of Bcl-2 positive cells with ABT-737 also resulted in a decreased cellular co-localisation of Bcl-2 and Beclin-1 as detected by immunofluorescent staining. Degradation of p62 and LC3-II, selective substrates of autophagy, was detected by Western blotting in Bcl-2 positive but not in Bcl-2 negative cell lines after treatment with ABT-737 for 15 hours. LC3-I is a diffuse cytoplasmic protein which upon activation of autophagy becomes cleaved and lipidated to LC3-II which becomes punctate within cells. Punctuate LC3-II is a widely used marker of active autophagy. ABT-737-induced autophagosome formation was determined at an earlier time point (3 hours after ABT-737 treatment) using immune-fluorescent microscopy. ABT-737 induced increased numbers of larger punctate LC3-II in Bcl-2 positive Su-DHL4 and CRL cell lines but not in Bcl-2 negative cells, indicating that inhibition of Bcl-2 induces autophagy in Bcl-2 positive cells. We then determined whether autophagy affects ABT-737-induced apoptosis by blocking autophagy using an autophagy inhibitor chloroquine (CQ). Co-treatment with ABT-737 and CQ resulted in an increase in the percentage of ΔΨmLOW cells, DAPI positive cells and PARP cleavage compared to cells treated with ABT-737 alone in Bcl-2 positive cell lines. Combined, these results indicate that inhibition of autophagy by chloroquine further sensitises Bcl-2 positive cells to ABT-737-induced apoptosis. In summary, our results indicate that Bcl-2 inhibits autophagy in lymphoma cells by sequestering Beclin-1. Disruption of this interaction by ABT-737 induces autophagy which in turn inhibits apoptosis. Inhibition of autophagy results in increased sensitivity of Bcl-2 positive cells to ABT-737-induced apoptosis, suggesting a role for autophagy inhibitors in lymphoma treatment. Disclosures: No relevant conflicts of interest to declare.


2015 ◽  
Vol 48 (4) ◽  
pp. 453-464 ◽  
Author(s):  
JeenJoo S. Kang ◽  
Peter B. Dervan

AbstractMeans to cause an immunogenic cell death could lead to significant insight into how cancer escapes immune control. In this study, we screened a library of five pyrrole–imidazole polyamides coding for different DNA sequences in a model of B-cell lymphoma for the upregulation of surface calreticulin, a pro-phagocytosis signal implicated in immunogenic cell death. We found that hairpin polyamide 1 triggers the release of the damage-associated molecular patterns calreticulin, ATP and HMGB1 in a slow necrotic-type cell death. Consistent with this signaling, we observed an increase in the rate of phagocytosis by macrophages after the cancer cells were exposed to polyamide 1. The DNA sequence preference of polyamide 1 is 5′-WGGGTW-3′ (where W = A/T), indicated by the pairing rules and confirmed by the Bind-n-Seq method. The close correspondence of this sequence with the telomere-repeat sequence suggests a potential mechanism of action through ligand binding at the telomere. This study reveals a chemical means to trigger an inflammatory necrotic cell death in cancer cells.


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