scholarly journals BST-236, a Novel Cytarabine Prodrug, Is Safer and As Effective As Cytarabine in In Vivo Leukemia Models

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1451-1451 ◽  
Author(s):  
Shoshi Tessler ◽  
Inbal Mishalian ◽  
Ronny Peri-Naor ◽  
Stela Gengrinovitch ◽  
Raphael Mayer ◽  
...  
Keyword(s):  
Weight Loss ◽  
Cell Death ◽  
Systemic Toxicity ◽  
In Vivo Studies ◽  
Leukemia Cells ◽  
Severe Toxicity ◽  
Unfit Patients ◽  
Kinetics Of

Abstract Introduction: Acute myeloid leukemia (AML) is associated with poor outcomes in older and medically unfit patients, largely due to the severe toxicity associated with cytarabine treatment, which precludes the administration of effective cytarabine doses. BST-236 is a prodrug of cytarabine, inactive in its prodrug form and designed to deliver cytarabine to leukemia cells with reduced systemic toxicity, thus to enable delivery of high cytarabine doses to leukemia cells with relative sparing of normal tissues. Results: BST-236 is a conjugate of cytarabine and asparagine (Figure 1). It was demonstrated that BST-236 is inactive as an intact prodrug and that its activity is exerted by release of cytarabine via non-enzymatic hydrolysis. Unlike free cytarabine, the bound cytarabine in BST-236 is not phosphorylated into its active metabolite Ara-CTP and it is protected by the asparagine residue from deamination into its inactive form Ara-U. In vitro studies demonstrate that BST-236 enters into leukemia cells, accompanied by cellular accumulation of free cytarabine, which is released from BST-236 (Figure 2). Like cytarabine, treatment with BST-236 result in induction of cell death of various leukemia cell lines via apoptosis, an activity which is dependent on the human equilibrative nucleoside transporter 1 (hENT1). The in vitro kinetics of BST-236-induced toxicity were found to be delayed compared to administration of free cytarabine, correlating with an observed delayed cellular availability of cytarabine. In vivo studies in mice and dogs demonstrate that BST-236 concentrations in the plasma are dose-proportional, with a prodrug-typical profile and only ~5% of free cytarabine present in the plasma. The maximal tolerated dose of BST-236 was found to be several-fold higher than reported for cytarabine, with mainly hematological effects and no unexpected toxicities. In vivo head-to-head studies in human leukemia mouse models with equimolar doses of cytarabine and BST-236 demonstrate similar efficacy of complete elimination of the leukemia cells in the bone marrow, spleen, and peripheral blood by both molecules (Figure 3A). However, while cytarabine treatment was associated with significant toxicity including weight loss, dramatic reduction in spleen size and number of mouse spleen cells, and delayed normal murine white blood cell recovery, equimolar BST-236 doses enabled spleen and BM recovery with minimal weight loss and no observed clinical signs (Figure 3B, 3C). Summary: in vitro and in vivo studies demonstrate that BST-236 is a prodrug of cytarabine, which enables the delivery of cytarabine to target cells, resulting in elimination of the leukemia with reduced systemic toxicity compared to free cytarabine. The data also suggest that while the mechanism of cell death induced by BST-236 and cytarabine is similar, the observed differential kinetics of the delivery of cytarabine by BST-236 and its metabolism may explain its reduced systemic toxicity. Our nonclinical findings are in line with the clinical results of the BST-236 Phase 1/2 study (ASH 2017 abstract no 893, manuscript in preparation) and suggest that BST-236 may enable delivery of high cytarabine doses to older and medically-unfit patients who currently cannot benefit from an effective cytarabine therapy. This suggestion is to be confirmed by an ongoing Phase 2b study. Disclosures Tessler: Biosight: Employment. Gengrinovitch:Biosight: Employment. Ben Yakar:Biosight: Employment. Peled:Cellect Biotherapeutics Ltd: Consultancy. Flaishon:Biosight: Employment.

scholarly journals Nano-encapsulated tryptanthrin derivative for combined anticancer therapy via inhibiting indoleamine 2,3-dioxygenase and inducing immunogenic cell death

Nanomedicine ◽  
2019 ◽  
Vol 14 (18) ◽  
pp. 2423-2440 ◽  
Author(s):  
Canyu Yang ◽  
Bing He ◽  
Qiang Zheng ◽  
Dakuan Wang ◽  
Mengmeng Qin ◽  
...  
Keyword(s):  
Cell Death ◽  
Single Agent ◽  
Tumor Burden ◽  
Antitumor Efficacy ◽  
In Vivo Studies ◽  
Immunogenic Cell Death ◽  
Indoleamine 2,3 Dioxygenase ◽  
Tumor Tissues

Aim: We developed a polycaprolactone-based nanoparticle (NP) to encapsulate tryptanthrin derivative CY-1-4 and evaluated its antitumor efficacy. Materials & methods: CY-1-4 NPs were prepared and evaluated for their cytotoxicity and associated mechanisms, indoleamine 2,3-dioxygenase (IDO)-inhibitory ability, immunogenic cell death (ICD)-inducing ability and antitumor efficacy. Results: CY-1-4 NPs were 123 nm in size. In vitro experiments indicated that they could both induce ICD and inhibit IDO. In vivo studies indicated that a medium dose reduced 58% of the tumor burden in a B16-F10-bearing mouse model, decreased IDO expression in tumor tissues and regulated lymphocytes subsets in spleen and tumors. Conclusion: CY-1-4 is a potential antitumor candidate that could act as a single agent with combined functions of IDO inhibition and ICD induction.

KINETICS OF DNA-INDUCED BREAKS BY REDUCTONE TREATMENT: IN VITRO AND IN VIVO STUDIES

1981 ◽  
Vol 34 (6) ◽  
pp. 745-748 ◽  
Author(s):  
A. C. Leitão ◽  
H. C. Mottat ◽  
R. Alcantara Gomes
Keyword(s):  
In Vivo Studies ◽  
Kinetics Of

scholarly journals P06.01 Delta24-ACT oncolytic adenovirus as a therapeutic approach for DIPG

2019 ◽  
Vol 21 (Supplement_3) ◽  
pp. iii36-iii36
Author(s):  
V Laspidea ◽  
M Puigdelloses ◽  
M García-Moure ◽  
I Iñigo-Marco ◽  
J Gallego ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Cell Lines ◽  
In Vivo Studies ◽  
Immunogenic Cell Death ◽  
Murine Models ◽  
Antitumoral Effect ◽  
Infected Cells

Abstract BACKGROUND Diffuse intrinsic pontine glioma (DIPG) is an aggressive brain tumor, being the leading cause of pediatric death caused by cancer. We previously showed that administration of the oncolytic virus Delta-24-RGD to DIPG murine models was safe and led to an increase in the median survival of these animals. However, not all the animals responded, underscoring the need to improve this therapy. In order to increase the antitumoral effect of the virus, we have engineered Delta-24-RGD with the costimulatory ligand 4-1BBL (Delta24-ACT). 4-1BB is a costimulatory receptor that promotes the survival and expansion of activated T cells, and the generation and maintenance of memory CD8+ T cells. In this project, we evaluated the oncolytic effect of Delta24-ACT and the antitumor immune response in DIPG murine models. MATERIALS AND METHODS We use the NP53 and XFM murine DIPG cell lines. Flow cytometry was used to assess cell infectivity and ligand expression. We analyzed viral replication using a method based in hexon detection, and viral cytotoxic effect using the MTS assay. For immunogenic cell death analysis, we measured ATP secretion by a luminometric assay and calreticulin location by flow cytometry and immunofluorescence. For in vivo studies, cells and virus were injected in the pons of the mice, using the screw-guided system. RESULTS In vitro, Delta24-ACT was able to infect and induce cell death in a dose-dependent manner in murine DIPG cell lines. In addition, Delta24-ACT was able to replicate in these tumor cells and to express viral proteins. Moreover, infected cells expressed 41BBL in their membranes. Delta24-ACT could induce immunogenic cell death due to an increased secretion of ATP and calreticulin translocation to the membrane of infected cells (in no-infected cells it located in the ER), DAMPs that can trigger the immune response activation. In vivo, Delta24-ACT demonstrated to be safe in all the tested doses and was able to induce a significant increase in the median survival of the treated animals. Moreover, long-term survivors display immunological memory. CONCLUSIONS Delta24-ACT treatment led to antitumoral effect in DIPG murine cell lines in vitro. Of significance, we have demonstrated that in vivo administration of Delta24-ACT is safe and results in an enhanced antitumor effect. Future in vivo studies will explore the underlying immune mechanism of the virus.

The Potential Role of the Six1/Eya1 Pathway in the Establishment of Leukemia Stem Cells in MLL-ENL – Induced Leukemia

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1362-1362 ◽  
Author(s):  
Sylvia Takacova ◽  
Pavla Luzna ◽  
Viktor Stranecky ◽  
Vladimir Divoky
Keyword(s):  
Bone Marrow ◽  
Cellular Transformation ◽  
Leukemia Cells ◽  
Leukemia Stem Cells ◽  
Transcription Profile ◽  
Self Renewal ◽  
Kinetics Of

Abstract Abstract 1362 During the multistep pathogenesis of acute leukemia (AL), a pool of leukemia stem cells (LSCs) emerges that is capable of limitless self-renewal and ensuring disease maintenance. The molecular mechanism that controls the kinetics of cellular transformation and development of LSCs is largely unknown. Using our MLL-ENL-ERtm mouse model, we have previously shown (Takacova et al., Blood 2009, 114 (22): 947–947, ASH abstract) activation of the ATR/ATM-Chk1/Chk2-p53/p21 checkpoint leading to senescence at early stages of cellular transformation (myeloproliferation), thereby preventing AL development in vivo. Experimental ATM/ATR inhibition accelerated the transition to immature cell states, acquisition of LSC properties and AL development in these mice. The MLL-ENL-ERtm mouse model allows us to study the kinetics of MLL-ENL-ERtm LSC development. We raised the questions how the transformation process progresses from the pre-LSC to the LSC state, and how DNA damage response (DDR) - mediated senescence affects the transition in gene expression. Given that the threshold of DDR signaling events is rate-limiting, we determined the transcription profile of the pre- LSC–enriched cell states derived from bone marrow and spleen of the MLL-ENL-ERtm mice at the early disease stage, and we correlated this transcription profile with the level of DDR, proliferation rate and induction of senescence. Pair-wise comparisons revealed up-regulation of the Six1 transcription factor gene and its cofactor Eya1 in the MLL-ENL-ERtm pre-LSCs in association with aberrant proliferation in both tissues. The notable difference between the two tissues concerning the barrier induction was the higher threshold of DDR and senescence in the bone marrow due to cooperation with inflammatory cytokines that fine-tune the DDR level. Interestingly, the expression of Six1 and Eya1 genes was down-regulated in senescence exclusively in the bone marrow. Consistent with these in vivo data, we found Six1 expression decreased in response to inflammation/DDR-induced senescence in the MLL-ENL-ERtm bone marrow cells cultured in vitro and correlated with SA-beta-gal positivity and p16 up-regulation. Six1 mRNA level was decreased only transiently after ionizing radiation (4 Gy)-induced DDR in the same cell line. These data suggest that Six1 expression is down-regulated in response to high DDR and permanent cell-cycle arrest in the MLL-ENL-ERtm pre-LSCs. Furthermore, we identified the transcription profile of the LSC-enriched cell state after inhibition of DDR in caffeine-treated MLL-ENL-ERtm mice in vivo. Interestingly, the expression level of Six1 and Eya1 was significantly increased in the bone marrow and spleen of the MLL-ENL-ERtm AML mice compared to the early (preleukemia) stage. High expression of Six1 and Eya1 and higher cell number expressing these genes was further confirmed by immunohistochemical staining on tissue sections. The MLL-ENL-ERtm LSC-enriched spleen cells showed increased colony forming ability in vitro and leukemia-initiating potential in serial transplantation experiments compared to pre-LSCs. Moreover, we detected Six1 and Eya1 expression in the infiltrating leukemia cells in tissues of the caffeine-treated MLL-ENL-ERtm AML mice and in a subset of leukemia cells in transplanted mice. Based on these findings and correlations, we hypothesized that the Six1/Eya1 pathway might be involved in regulation of some of the aspects of LSC development as well as invasion and maintenance of leukemia in our MLL-ENL-ERtm mice. Notably, our data indicate that senescence represses a subset of the MLL-ENL-downstream transcription response and prevents full activation of self-renewal. Experiments leading to more detailed understanding of the role of the Six1/Eya1 pathway in the MLL-ENL-induced cellular transformation are ongoing. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Assessment of In Vitro Bioaccessibility and In Vivo Oral Bioavailability as Complementary Tools to Better Understand the Effect of Cooking on Methylmercury, Arsenic, and Selenium in Tuna

Toxics ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 27
Author(s):  
Tania Charette ◽  
Danyel Bueno Dalto ◽  
Maikel Rosabal ◽  
J. Jacques Matte ◽  
Marc Amyot
Keyword(s):  
Oral Bioavailability ◽  
Fish Muscle ◽  
In Vitro Models ◽  
In Vivo Studies ◽  
In Vivo Models ◽  
Exposure Pathway ◽  
In Vitro Bioaccessibility ◽  
Kinetics Of

Fish consumption is the main exposure pathway of the neurotoxicant methylmercury (MeHg) in humans. The risk associated with exposure to MeHg may be modified by its interactions with selenium (Se) and arsenic (As). In vitro bioaccessibility studies have demonstrated that cooking the fish muscle decreases MeHg solubility markedly and, as a consequence, its potential absorption by the consumer. However, this phenomenon has yet to be validated by in vivo models. Our study aimed to test whether MeHg bioaccessibility can be used as a surrogate to assess the effect of cooking on MeHg in vivo availability. We fed pigs raw and cooked tuna meals and collected blood samples from catheters in the portal vein and carotid artery at: 0, 30, 60, 90, 120, 180, 240, 300, 360, 420, 480 and 540 min post-meal. In contrast to in vitro models, pig oral bioavailability of MeHg was not affected by cooking, although the MeHg kinetics of absorption was faster for the cooked meal than for the raw meal. We conclude that bioaccessibility should not be readily used as a direct surrogate for in vivo studies and that, in contrast with the in vitro results, the cooking of fish muscle did not decrease the exposure of the consumer to MeHg.

scholarly journals Mechanizmy śmierci od komórki do całego organizmu

2019 ◽  
Author(s):  
Sylwia Ciesielska
Keyword(s):  
Cell Death ◽  
Living Organism ◽  
Cell Types ◽  
In Vivo Studies ◽  
Whole Body ◽  
Natural Phenomenon ◽  
Human Organism ◽  
Living Organisms

In vitro studies are alternative for in vivo studies carried on living organisms. They involve cell populations for both normal and cancer cells. The processes inside cells might be base for defining whole body processes. Starting with fundamental unit of every living organism which is cell, we can distinguish two main types of cell death – apoptosis and necrosis. Human organism is built from 1013–1014 cells of 300 different cell types. During cell division new cells are created and their number is strictly controlled in programmed cell death – apoptosis. Mainly old or damaged cells commit suicide and are removed from organism. This is natural phenomenon and every change in mechanisms of proliferation or apoptosis cause changes and damage in whole organism. Homeostasis in organism depends on correct action of death and survival system. The patterns of equilibrium in nature relies on similar regulation profiles, in which it is similar to death of singular organisms in population or species. It implicates death as natural phenomenon maintaining balance in the world.

scholarly journals Targeting glutamine metabolism and redox state for leukemia therapy

2018 ◽  
Author(s):  
Mark A. Gregory ◽  
Travis Nemkov ◽  
Vadym Zaberezhnyy ◽  
Hae J. Park ◽  
Sarah Gehrke ◽  
...  
Keyword(s):  
Cell Death ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Redox State ◽  
Glutamine Metabolism ◽  
Leukemia Cells ◽  
Mitochondrial Redox State ◽  
Acute Myeloid

AbstractAcute myeloid leukemia (AML) is a hematological malignancy characterized by the accumulation of immature myeloid precursor cells. AML is poorly responsive to conventional genotoxic chemotherapy and a diagnosis of AML is usually fatal. More effective and less toxic forms of therapy are desperately needed. AML cells are known to be highly dependent on the amino acid glutamine for their survival. Here, we show that blocking glutamine metabolism through the use of a glutaminase inhibitor (CB-839) significantly impairs antioxidant glutathione production in multiple types of AML, resulting in accretion of mitochondrial reactive oxygen species (mitoROS) and apoptotic cell death. Moreover, glutaminase inhibition makes AML cells susceptible to adjuvant drugs that further perturb mitochondrial redox state, such as arsenic trioxide (ATO) and homoharringtonine (HHT). Indeed, the combination of ATO or HHT with CB-839 exacerbates mitoROS and apoptosis, and leads to more complete cell death in AML cell lines, primary AML patient samples andin vivousing mouse models of AML. In addition, these redox-targeted combination therapies are effective in eradicating acute lymphoblastic leukemia cellsin vitroandin vivo. Thus, targeting glutamine metabolism in combination with drugs that perturb mitochondrial redox state represents an effective and potentially widely applicable therapeutic strategy for treating multiple types of leukemia.Key PointsGlutaminase inhibition commonly impairs glutathione metabolism and induces mitochondrial oxidative stress in acute myeloid leukemia cellsA glutaminase inhibitor synergizes with pro-oxidant drugs in inducing apoptosis and eliminating leukemia cellsin vitroandin vivo

scholarly journals Novel estradiol analogue induces apoptosis and autophagy in esophageal carcinoma cells

2014 ◽  
Vol 19 (1) ◽  
Author(s):  
Elize Wolmarans ◽  
Thandi Mqoco ◽  
Andre Stander ◽  
Sandra Nkandeu ◽  
Katherine Sippel ◽  
...  
Keyword(s):  
Cell Death ◽  
Esophageal Carcinoma ◽  
Ex Vivo ◽  
Apoptotic Cell ◽  
Critical Role ◽  
Carcinoma Cells ◽  
In Vivo Studies ◽  
Apoptotic Pathway

AbstractCancer is the second leading cause of death in South Africa. The critical role that microtubules play in cell division makes them an ideal target for the development of chemotherapeutic drugs that prevent the hyperproliferation of cancer cells. The new in silico-designed estradiol analogue 2-ethyl-3-O-sulfamoylestra-1,3,5(10)16-tetraene (ESE-16) was investigated in terms of its in vitro antiproliferative effects on the esophageal carcinoma SNO cell line at a concentration of 0.18 μM and an exposure time of 24 h. Polarization-optical differential interference contrast and triple fluorescent staining (propidium iodide, Hoechst 33342 and acridine orange) revealed a decrease in cell density, metaphase arrest, and the occurrence of apoptotic bodies in the ESE-16-treated cells when compared to relevant controls. Treated cells also showed an increase in the presence of acidic vacuoles and lysosomes, suggesting the occurrence of autophagic processes. Cell death via autophagy was confirmed using the Cyto-ID autophagy detection kit and the aggresome detection assay. Results showed an increase in autophagic vacuole and aggresome formation in ESE-16 treated cells, confirming the induction of cell death via autophagy. Cell cycle progression demonstrated an increase in the sub-G1 fraction (indicative of the presence of apoptosis). In addition, a reduction in mitochondrial membrane potential was also observed, which suggests the involvement of apoptotic cell death induced by ESE-16 via the intrinsic apoptotic pathway. In this study, it was demonstrated that ESE-16 induces cell death via both autophagy and apoptosis in esophageal carcinoma cells. This study paves the way for future investigation into the role of ESE-16 in ex vivo and in vivo studies as a possible anticancer agent.

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