Evaluation of Cytotoxic Potentials of Novel Cyclooxygenase-2 Inhibitor against ALL Lymphocytes and Normal Lymphocytes and Its Anticancer Effect through Mitochondrial Pathway.

In the present study, we searched selective cytotoxicity and mitochondria mediated apoptosis of novel COX-2 inhibitor 2-(4-(Methylsulfonyl)phenyl)imidazo[1,2-a] pyridine-8-carboxylic acid on B-lymphocytes and their mitochondria isolated from normal subjects and acute lymphoblastic leukemia (ALL) patients' blood. Our results showed this compound can selectively induce cellular and mitochondrial toxicity on ALL B-lymphocytes and mitochondria without any toxic effects on normal B-lymphocytes and their mitochondria. Taken together, the results of this study suggest that cancerous mitochondria are a potential target for the ALL B-lymphocytes. Selective toxicity of COX-2 inhibitor in cancerous mitochondria could be an attractive therapeutic option for the effective clinical management of therapy-resistant ALL.

Novel Colchicine Analogues Target Mitochondrial PT Pores Using Free Tubulins and Induce ROS-Mediated Apoptosis in Cancerous Lymphocytes.

B-acute lymphoblastic leukemia (B-ALL) is the frequent pediatric malignity. Chemotherapy is the most practical approaches to deal with such malignancies. Microtubule-targeted agents are one of the most strategic drugs which formerly used in chemotherapy. Although colchicine-binding anti-tubulin agents exhibited promising effects in clinical trials, their exact mechanism of action is not fully understood. In this study, the effects of two newly synthesized of colchicine derivatives were investigated on cell viability of cancerous and normal lymphocytes. The viability test was carried out by MTT assay. Apoptosis vs. necrosis was measured by double staining with annexin V/PI, and caspase-3 as the ultimate mediator of apoptotic measured through the colorimetric assay. Parameters of mitochondrial damage (ROS formation, MMP (Mitochondrial Membrane Potential) decline, mitochondrial swelling, and cytochrome c release following treatment by colchicine derivatives. By focusing on mitochondrial parameters, we showed that following treatment by two newly synthesized colchicine derivatives, apoptosis is triggered in cancerous B-lymphocytes. We demonstrated these compounds could activate apoptosis in cancerous lymphocytes by augmentation of reactive oxygen species (ROS), a decline in mitochondrial membrane potential (MMP), mitochondrial swelling, release of cytochrome c, and also caspase-3 activation. Considering the obtained evidence, these inhibitors could be the new therapeutic strategies in ALL treatment.

Targeting the mitochondrial apoptosis pathway by a newly synthesized COX-2 inhibitor in pediatric ALL lymphocytes.

AIM: Acute lymphoblastic leukemia (ALL) is known as a barely curable malignancy. Particular mutations involved in apoptosis may have a main role in the onset of ALL in the pediatric patients. It has been proven that cycloxygenase-2 is capable of impairing the apoptosis pathway through mitochondria in tumor cells. METHODOLOGY: In this study, we investigated selective toxicity of a newly synthesized chalconeferrocenyl derivative as a selective cycloxygenase-2 inhibitor in ALL and healthy B-lymphocytes, and also isolated mitochondria obtained from them. For this purpose, we evaluated the cellar parameters like viability, apoptosis/necrosis, caspase-3 activation and ATP content, and also mitochondrial parameters like mitochondrial membrane potential decline, reactive oxygen species formation, cytochrome C release and mitochondrial swelling. CONCLUSION: Our results implied that this compound can selectively induce cellular and mitochondrial toxicity in cancerous ALL B-lymphocytes and obtained mitochondria from them without any detrimental effects on healthy subjects.

Perfluorooctanesulfonate (PFOS) Induces Apoptosis Signaling and Proteolysis in Human Lymphocytes through ROS Mediated Mitochondrial Dysfunction and Lysosomal Membrane Labialization.

Perfluorinated compounds (PFCs) such as perfluorooctanesulfonate (PFOS) are stable chemicals that accumulate in biological matrix. Toxicity of these compounds including immunotoxicity has been demonstrated in experimental models and wildlife. Although limited number of studies examined the effects of PFOS on human lymphocytes but so far no research has investigated the complete mechanisms of PFOS cytotoxicity toward human lymphocytes. The main goal of this investigation was to find out the mechanisms underlying the cytotoxic effect of PFOS toward human lymphocytes using accelerated cytotoxicity mechanisms screening (ACMS) technique. Human lymphocytes were isolated from blood of healthy donors using Ficoll-paquePLUS standard method. Cell viability was determined following 12 h of incubation of human lymphocytes with 100-500 µM PFOS. Our results showed that IC50 concentration (163.5 µM) of PFOS reduced viability of human lymphocytes approximately 50% via increased ROS formation, lipid peroxidation, glutathione depletion and damage to cell sub organelles such as mitochondria and lysosomes. Besides, in this study we demonstrated involvement of cellular proteolysis and activation of caspase-3 in PFOS induced lymphocyte cytotoxicity. We finally concluded that at environmentally related concentration, PFOS can induce toxic effect toward human lymphocytes through induction of oxidative stress and damage to cell sub organelles.

Selective Cytotoxicity of α-Santonin from the Persian Gulf Sponge Dysidea Avara on Pediatric ALL B-lymphocytes via Mitochondrial Targeting

Background: Acute lymphoblastic leukemia (ALL) is one of the most dominant malignancies among children, characterized by production of immature and dysfunctional blasts which are resistant to cytotoxic chemotherapeutic agents. Therefore, research protocols are currently focusing on discovery of novel anti-cancer agents to enhance survival rates and decrease unwanted side effects. Approximately two-thirds of the planet is covered by oceans with a massive range of marine organisms of interest to scientists in pharmaceutical fields. Methods: Among marine resources, sponges are known to have beneficial effects in the treatment of numerous malignancies. One fraction of crude extracts containing α-Santonin was made from the Persian Gulf marine sponge, Dysidea avara, and investigated for anticancer effects. Results: Treatment of ALL B-lymphocytes with the Dysidea avara extract caused augmentation in ROS generation, decline in mitochondrial membrane potential, mitochondrial swelling, release of cytochrome c from mitochondria and activation of caspase-3 only in mitochondria isolated from B-ALL lymphocytes. Conclusion: In brief, our results suggest that Dysidea avara extracts may selectively induce apoptosis in malignant pediatric lymphocytes.

Matrine Induction of ROS Mediated Apoptosis in Human ALL B-lymphocytes Via Mitochondrial Targeting

Background: Acute lymphoblastic leukemia (ALL) is one of the most common malignancies among children, characterized by mass production of leukemic blasts. Chemotherapy is the first step in routine treatment, although it may evoke considerable side effects. Matrine, an alkaloid extracted from a Chinese herb, Sophora alopecuroides flavescens Ait, may be protective. Several investigations have indicated pro-apoptotic and anti-proliferative effects in a diverse range of cancer cells. Methods: Matrine's anti-cancer effects and associated mechanisms were assessed in human ALL B-lymphocytes, focusing on parameters of inflammatory change and apoptosis. Results: Treatment of ALL B-lymphocytes with matrine augmented ROS generation, and caused mitochondrial swelling and a decline in mitochondrial membrane potential. Significant up-regulation of the pro-apoptotic protein Bax and down-regulation of the anti-apoptotic Bcl-2 were also noted. Conclusion: Our results suggest that matrine may be a potential anticancer agent. However, additional studies are needed to clarify involved mechanisms.

Analysis of cytotoxic effects of nickel on human blood lymphocytes.

Nickel compounds possess many applications in different industrial processes. Human beings are exposed to nickel commonly through occupational exposure and food. Although a few studies so far have investigated the effects of nickel compounds on human lymphocytes, the complete mechanism of cytotoxicity of this metal on human lymphocytes is yet to be determined. The intention of this paper was to determine the cytotoxicity mechanism of water soluble NiCl2 toward human lymphocytes using the accelerated cytotoxicity mechanisms screening (ACMS) technique. Human lymphocytes were isolated from the blood of healthy subjects based on Ficoll-Paque PLUS standard method. For the assessment of cell viability, lymphocytes were incubated with 0.05-1 mM NiCl2 for 12 h. Determination of mechanistic parameters was performed 2, 4 and 6 h after treatment of cells with ½ EC5012h, EC5012h and 2EC5012h of NiCl2. Our results demonstrate that cytotoxicity of NiCl2 on human lymphocytes is associated with increased ROS formation, mitochondrial membrane potential collapse, glutathione depletion, lysosomal membrane damage, cellular proteolysis and activation of caspase-3 before cytotoxicity ensued.

A Newly Synthetized Ferrocenyl Derivative Selectively Induces Apoptosis in ALL Lymphocytes through Mitochondrial Estrogen Receptors.

BACKGROUND: Estrogens, as the main female steroid hormones have multiple proven effects on reproductive and non- reproductive systems. Expression of ERα and ERß, two dominant estrogen receptors, in peripheral blood mononuclear cells in certain B-cell malignancies and the existence of estrogens receptors on mitochondria is open to question that estrogen likely has an impact on the cancerous lymphocytes life span. Acute Lymphoblastic Leukemia (ALL) is the frequent pediatric malignity which is recurrent and hardly curable in many cases. The malignant cells are generally resistant to apoptosis caused the severe lymphocytes accumulation in the peripheral blood. METHODS: By focusing on mitochondria as a life/death center of the cell; in the current research we compared cytotoxicity effects of a new ferrocenyl derivative with raloxifene as well-known SERMs considering the apoptotic process and survival of cancerous lymphocytes. RESULTS: We demonstrated that both ferrocenyl derivative and raloxifene could cause mitochondrial lesion and initiate the apoptosis process by caspase activation and cytochrome c release. CONCLUSION: In brief, the ferrocenyl derivative could induce estrogen-related selective apoptosis on cancerous lymphocytes by affecting mitochondrial receptors.

A Comparison of Hepatocyte Cytotoxic Mechanisms for Docetaxel and PLGA-Docetaxel Nanoparticls.

Docetaxel (DTX) is one of the most widely used drugs in oncology due to its high efficacy against several cancers. Though, its routine clinical administration, formulated in tween 80, causes serious side effects. Polylactide-co-glycolide (PLGA), biodegradable polyester synthesized and approved for human use, is employed to overcome these problems. In this investigation, we compare the cytotoxic mechanisms of DTX and PLGA-DTX in isolated rat hepatocytes. Cytotoxicity of DTX and PLGA-DTX were associated with reactive oxygen species formation, activation of caspases cascade, collapse of mitochondrial membrane potential (MMP), lysosomal membrane leakiness and ATP depletion. Our results also showed that CYP2E1 is involved in the oxidative stress cytotoxicity mechanism and both drugs are detoxified via phase II metabolic methylation. Furthermore, we concluded that PLGA-DTX is bioactivated by GSH. It could also potentiate hepatocyte toxicity through a mitochondrial/lysosomal toxic cross-talk. In addition to these observed differences, it is likely that mode of hepatocyte membrane penetration is different between these compounds.

Ichthyotoxic Cochlodinium polykrikoides Induces Mitochondrial Mediated Oxidative Stress and Apoptosis in Rat Liver Hepatocytes.

In this research, we investigated the cytotoxic mechanisms of Cochlodinium polykrikoidescell lysate on isolated rat liver hepatocytes.This micro algae is responsible for a severe and widespread harmful algal bloom in the Persian Gulf and Gulf of Oman (2008-2009). Isolated hepatocytes were obtained by collagenase perfusion of Sprague-Dawley rat liver.According to our results, incubation of algal lysate with isolated rat hepatocytescaused hepatocyte membrane lysis, reactive oxygen species (ROS) formation, glutathione depletion, collapse of mitochondrial membrane potential,ATP depletion and increase in ADP/ATP ratio, cytochrome c release in to the hepatocyte cytosol,activation of caspase-3 (final mediator of apoptosis) and appearance of apoptosis phenotype. On the other hand, pre-treatment of antioxidants (α-tocopherol succinate and BHT), radical scavengers (mannitol and DMSO), mitochondrial permeability transition (MPT) pore sealing agents (cyclosporine A, carnitine and trifluoperazine), NADPH P450 reductase inhibitor (Diphenyliodonium chloride), CYP2E1 inhibitors (Phenylimidazole and 4-Methylpyrazole) and ATP generators (L-glutamine, Fructose and Xylitol)inhibitedcaspase-3 activation and cell death in algal lysate treated hepatocytes.Our data also confirmed that algal lysate activates apoptosis signaling via oxidative stress and mitochondrial pathway. Thus, ROS formation caused by the lysate exposure could directly be involved in mitochondrial MPT pore opening and activation of caspase-3 leading to C.polykrikoides lysateinduced apoptosis on rat hepatocytes. These findings contribute to a better understanding of C.polykrikoides-toxic effects on mammalian liver cells.