Complement-mediated cell death induced by rituximab in B-cell lymphoproliferative disorders is mediated in vitro by a caspase-independent mechanism involving the generation of reactive oxygen species

Blood ◽  
2001 ◽  
Vol 98 (9) ◽  
pp. 2771-2777 ◽  
Author(s):  
Beatriz Bellosillo ◽  
Neus Villamor ◽  
Armando López-Guillermo ◽  
Silvia Marcé ◽  
Jordi Esteve ◽  
...  

Abstract Mechanisms involving the in vitro effect of rituximab in cells from 55 patients with B-cell lymphoproliferative disorders were investigated. No cytotoxic effect was observed when cells were incubated with rituximab alone, but in the presence of human AB serum rituximab induced complement-dependent cell death (R-CDC). A cytotoxic effect was observed in cells from 9 of 33 patients with B-cell chronic lymphocytic leukemia, 16 of 16 patients with mantle-cell lymphoma, 4 of 4 patients with follicular lymphoma, and 2 of 2 patients with hairy-cell leukemia. R-CDC was observed in cells from patients expressing more than 50 × 103 CD20 molecules per cell, and directly correlated with the number of CD20 molecules per cell. Preincubation with anti-CD59 increased the cytotoxic effect of rituximab and sensitized cells from nonsensitive cases. Neither cleavage of poly-ADP ribose polymerase (PARP) nor activation of caspase-3 was observed in R-CDC. In addition, no cells with a hypodiploid DNA content were detected and R-CDC was not prevented by a broad-spectrum caspase inhibitor, suggesting a caspase-independent mechanism. Incubation with rituximab in the presence of AB serum induced a rapid and intense production of reactive oxygen species (ROS). R-CDC was blocked by the incubation of cells with N-acetyl-L-cysteine (NAC) or Tiron, 2 ROS scavengers, indicating that the cytotoxic effect was due to the generation of superoxide (O2−) radicals. In conclusion, the results of the present study suggest that CD20, CD59, and complement have a role in the in vitro cytotoxic effect of rituximab, which is mediated by a caspase-independent process that involves ROS generation.

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Amnah M. Alshangiti ◽  
Eszter Tuboly ◽  
Shane V. Hegarty ◽  
Cathal M. McCarthy ◽  
Aideen M. Sullivan ◽  
...  

Neuroblastoma is an embryonal malignancy that arises from cells of sympathoadrenal lineage during the development of the nervous system. It is the most common pediatric extracranial solid tumor and is responsible for 15% of childhood deaths from cancer. Fifty percent of cases are diagnosed as high-risk metastatic disease with a low overall 5-year survival rate. More than half of patients experience disease recurrence that can be refractory to treatment. Amplification of the MYCN gene is an important prognostic indicator that is associated with rapid disease progression and a poor prognosis, highlighting the need for new therapeutic approaches. In recent years, there has been an increasing focus on identifying anticancer properties of naturally occurring chalcones, which are secondary metabolites with variable phenolic structures. Here, we report that 4-hydroxychalcone is a potent cytotoxin for MYCN-amplified IMR-32 and SK-N-BE (2) neuroblastoma cells, when compared to non-MYCN-amplified SH-SY5Y neuroblastoma cells and to the non-neuroblastoma human embryonic kidney cell line, HEK293t. Moreover, 4-hydroxychalcone treatment significantly decreased cellular levels of the antioxidant glutathione and increased cellular reactive oxygen species. In addition, 4-hydroxychalcone treatment led to impairments in mitochondrial respiratory function, compared to controls. In support of this, the cytotoxic effect of 4-hydroxychalcone was prevented by co-treatment with either the antioxidant N-acetyl-L-cysteine, a pharmacological inhibitor of oxidative stress-induced cell death (IM-54) or the mitochondrial reactive oxygen species scavenger, Mito-TEMPO. When combined with the anticancer drugs cisplatin or doxorubicin, 4-hydroxychalcone led to greater reductions in cell viability than was induced by either anti-cancer agent alone. In summary, this study identifies a cytotoxic effect of 4-hydroxychalcone in MYCN-amplified human neuroblastoma cells, which rationalizes its further study in the development of new therapies for pediatric neuroblastoma.


Drug Research ◽  
2019 ◽  
Vol 69 (10) ◽  
pp. 528-536
Author(s):  
Najat Bouchmaa ◽  
Reda Ben Mrid ◽  
Youness Boukharsa ◽  
Youssef Bouargalne ◽  
Mohamed Nhiri ◽  
...  

Abstract Background In cancer cells, the intracellular antioxidant capacity and the redox homeostasis are mainly maintained by the glutathione- and thioredoxin-dependent systems which are considered as promising targets for anticancer drugs. Pyridazinones constitute an interesting source of heterocyclic compounds for drug discovery. The present investigation focused on studying the in-vitro antitumor activity of newly synthesized Pyridazin-3(2h)-ones derivatives against P815 (Murin mastocytoma) cell line. Methods The in-vitro cytotoxic activities were investigated toward the P815 cell line using tetrazolium-based MTT assay. Lipid peroxidation and the specific activities of antioxidant enzymes were also determined. Results The newly compounds had a selective dose-dependent cytotoxic effect without affecting normal cells (PBMCs). Apoptosis was further confirmed through the characteristic apoptotic morphological changes and DNA fragmentation. Two compounds (6f and 7h) were highly cytotoxic and were submitted to extend biological testing to determine the likely mechanisms of their cytotoxicity. Results showed that these molecules may induce cytotoxicity via disturbing the redox homeostasis. Importantly, the anticancer activity of 6f and 7h could be due to the intracellular reactive oxygen species hypergeneration through significant loss of glutathione reductase and thioredoxin reductase activities. This eventually leads to oxidative stress-mediated P815 cell apoptosis. Furthermore, the co-administration of 6f or 7h with Methotrexate exhibited a synergistic cytotoxic effect. Conclusions considering their significant anticancer activity and chemosensitivity, 6f and 7h may improve the therapeutic efficacy of the current treatment for cancer.


Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 403 ◽  
Author(s):  
Jiaye Wu ◽  
Yue Zhang ◽  
Ruizhi Hao ◽  
Yuan Cao ◽  
Xiaoyi Shan ◽  
...  

Lead is a heavy metal known to be toxic to both animals and plants. Nitric oxide (NO) was reported to participate in plant responses to different heavy metal stresses. In this study, we analyzed the function of exogenous and endogenous NO in Pb-induced toxicity in tobacco BY-2 cells, focusing on the role of NO in the generation of reactive oxygen species (ROS) as well as Pb2+ and Ca2+ fluxes using non-invasive micro-test technology (NMT). Pb treatment induced BY-2 cell death and rapid NO and ROS generation, while NO burst occurred earlier than ROS accumulation. The elimination of NO by 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) resulted in a decrease of ROS, and the supplementation of NO by sodium nitroprusside (SNP) caused an increased accumulation of ROS. Furthermore, the addition of exogenous NO stimulated Pb2+ influx, thus promoting Pb uptake in cells and aggravating Pb-induced toxicity in cells, whereas the removal of endogenous NO produced the opposite effect. Moreover, we also found that both exogenous and endogenous NO enhanced Pb-induced Ca2+ effluxes and calcium homeostasis disorder. These results suggest that exogenous and endogenous NO played a critical regulatory role in BY-2 cell death induced by Pb stress by promoting Pb2+ influx and accumulation and disturbing calcium homeostasis.


2007 ◽  
Vol 67 (11) ◽  
pp. 5408-5417 ◽  
Author(s):  
Angelo De Milito ◽  
Elisabetta Iessi ◽  
Mariantonia Logozzi ◽  
Francesco Lozupone ◽  
Massimo Spada ◽  
...  

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1183
Author(s):  
Sheelu Monga ◽  
Nunzio Denora ◽  
Valentino Laquintana ◽  
Rami Yashaev ◽  
Abraham Weizman ◽  
...  

Parkinson’s disease (PD) is a progressive neurodegenerative disorder which is characterized by the degeneration of dopaminergic neurons in substantia nigra (SN). Oxidative stress or reactive oxygen species (ROS) generation was suggested to play a role in this specific type of neurodegeneration. Therapeutic options which can target and counteract ROS generation may be of benefit. TSPO ligands are known to counteract with neuro-inflammation, ROS generation, apoptosis, and necrosis. In the current study, we investigated an in vitro cellular PD model by the assessment of 6-hydroxydopamine (6-OHDA, 80 µM)-induced PC12 neurotoxicity. Simultaneously to the exposure of the cells to 6-OHDA, we added the TSPO ligands CB86 and CB204 (25 µM each) and assessed the impact on several markers of cell death. The two ligands normalized significantly (57% and 52% respectively, from 44%; whereas the control was 68%) cell proliferation at different time points from 0–24 h. Additionally, we evaluated the effect of these two TSPO ligands on necrosis using propidium iodide (PI) staining and found that the ligands inhibited significantly the 6-OHDA-induced necrosis. As compared to control, the red count was increased up to 57-fold whereas CB86 and CB204 inhibited to 2.7-fold and 3.2-fold respectively. Necrosis was also analyzed by LDH assay which showed significant effect. Both assays demonstrated similar potent anti-necrotic effect of the two TSPO ligands. Reactive oxygen species (ROS) generation induced by 6-OHDA was also inhibited by the two TSPO ligand up to 1.3 and 1.5-fold respectively, as compared to 6-OHDA group. CB86 and CB204 inhibited also normalized the cell viability up to 1.8-fold after the exposure to 6-OHDA, as assessed by XTT assay. The two TSPO ligands also inhibited apoptosis significantly (1.3-fold for both) as assessed by apopxin green staining. In summary, it appears that the two TSPO ligands CB86 and CB204 can suppress cell death of PC12 induced by 6-OHDA. The results may be relevant to the use of these two TSPO ligands as therapeutic option neurodegenerative diseases like PD.


Author(s):  
Mariachiara Buccarelli ◽  
Quintino Giorgio D’Alessandris ◽  
Paola Matarrese ◽  
Cristiana Mollinari ◽  
Michele Signore ◽  
...  

Abstract Background Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor in adults, characterized by a poor prognosis mainly due to recurrence and therapeutic resistance. It has been widely demonstrated that glioblastoma stem-like cells (GSCs), a subpopulation of tumor cells endowed with stem-like properties is responsible for tumor maintenance and progression. Moreover, it has been demonstrated that GSCs contribute to GBM-associated neovascularization processes, through different mechanisms including the transdifferentiation into GSC-derived endothelial cells (GdECs). Methods In order to identify druggable cancer-related pathways in GBM, we assessed the effect of a selection of 349 compounds on both GSCs and GdECs and we selected elesclomol (STA-4783) as the most effective agent in inducing cell death on both GSC and GdEC lines tested. Results Elesclomol has been already described to be a potent oxidative stress inducer. In depth investigation of the molecular mechanisms underlying GSC and GdEC response to elesclomol, confirmed that this compound induces a strong increase in mitochondrial reactive oxygen species (ROS) in both GSCs and GdECs ultimately leading to a non-apoptotic copper-dependent cell death. Moreover, combined in vitro treatment with elesclomol and the alkylating agent temozolomide (TMZ) enhanced the cytotoxicity compared to TMZ alone. Finally, we used our experimental model of mouse brain xenografts to test the combination of elesclomol and TMZ and confirmed their efficacy in vivo. Conclusions Our results support further evaluation of therapeutics targeting oxidative stress such as elesclomol with the aim of satisfying the high unmet medical need in the management of GBM.


2019 ◽  
Author(s):  
Sorush Niknamian

The aim of this study is to mention the effectiveness of Glutathione supplementation for the prevention of cancer. Glutathione (GSH) is an important antioxidant in plants, animals, fungi, and some bacteria and archaea. As we mentioned in our several researches, the prime cause of cancer is increasing the amounts of ROS in cells which damage the mitochondrial cristae and also due to the butterfly effect, it causes the cells to become cancerous instead of apoptosis. The studies in humans and mice shows the relation between increasing the amounts of GSH in vivo and in vitro, and decreasing ROS level in cells.


2021 ◽  
Vol 12 (6) ◽  
pp. 7342-7355

The present study focuses on exploring the antilithiatic potential of Didymocarpus pedicellata, which is valuable in managing renal disorders. Urolithiasis is an idiopathic disorder with a high recurrence and an incidence rate and is of major concern worldwide due to partial and unsatisfactory relief. Calcium oxalate crystals in contact with renal epithelial cells (HK2), causing reactive oxygen species overproduction, oxidative stress, apoptosis resulting in crystal adhesion and internalization. Crystals were modulated by cotreatment with ethanolic extract of D. pedicellata. Cell toxicity assay was assessed using flow cytometry. Cell-crystal interaction, adhesion, and internalization were visualized through Scanning electron microscopy (SEM) analysis and hematoxylin-eosin staining. The lithogenic induction caused impairment of renal function due to oxidative stress, measured by ROS levels. Cell death assays were detected by dual staining methods. Fluorimeter evaluation pointed to active caspase 3 mediated cell death (apoptotic) in oxalate injured cells was attenuated by Didymocarpus pedicellata extract. Alterations in cell adhesion were observed by immunocytochemistry. The current study revealed that the Didymocarpus pedicellata was endowed with antiurolithiatic activity as it displayed increased viability, reduced oxidative stress due to lowered production of intracellular reactive oxygen species (ROS), and decreased apoptosis when oxalate injured HK2 cells were cotreated with the extract.


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