scholarly journals Cocaine Induces Alterations in Mitochondrial Membrane Potential and Dual Cell Cycle Arrest in Rat C6 Astroglioma Cells

2009 ◽  
Vol 35 (2) ◽  
pp. 288-297 ◽  
Author(s):  
Ramesh B. Badisa ◽  
Selina F. Darling-Reed ◽  
Carl B. Goodman
Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1452-1452
Author(s):  
Andrew A.G. Aprikyan ◽  
Nara A. Markosyan

Abstract Severe congenital neutropenia (SCN) is an inheritable hematopoietic disorder characterized by extremely low level of circulating neutrophils, ineffective intramedulary hematopoiesis with “maturation arrest” at the promyelocytic stage of differentiation, recurrent severe infections, and evolution to acute myelogenous leukemia (AML). Accelerated apoptosis of bone marrow-derived myeloid progenitor cells and cell cycle arrest of CD34+ cells was reported in SCN patients. We also reported that heterozygous mutations in the neutrophil elastase (NE) gene have been identified in approximately 80% of SCN patients. Transient expression of mutant but not normal NE triggered accelerated apoptotic cell death of human promyelocytic HL-60 cells supporting the causative role of mutant NE in pathogenesis of SCN. Here we present cellular model of SCN based on newly established tet-off HL-60 human promyelocytic cell line with inducible doxycycline-regulated expression of mutant NE with 8-amino acid deletion identified in a patient evolved to develop AML. Induced expression of mutant elastase in tet-off HL-60 cells treated with DMSO led to a block of differentiation or “maturation arrest” at the promyelocytic stage of differentiation with a significantly reduced proportion of differentiated cells (approximately 20% vs 70% in control) and higher proportion (~40%) of primitive undifferentiated cells compared with control DMSO-treated HL-60 cells expressing only normal NE (~10%). Flow cytometry analysis of annexin V-labeled cells repeatedly revealed approximately 2-fold higher rate of apoptosis in tet-off HL-60 cells with induced expression of mutant NE compared with control cells. FACS analysis of DAPI-labeled tet-off HL-60 cells with induced expression of mutant NE revealed abnormal cell cycle progression with gradual accumulation and apparent arrest of cells in G1-phase of the cell cycle similar to that reported for SCN patients. Interestingly, the apoptotic cell shrinking and swelling as determined by flow cytometry was observed in all phases of the cell cycle suggesting that accelerated apoptosis rather than cell cycle arrest is the primary abnormality caused by expression of mutant NE, and the abnormal cell cycle progression is a consequence of this impaired cell survival. Further analysis revealed a dramatic reduction in mitochondrial membrane potential of tet-off HL-60 cells expressing mutant NE compared with control cells. The reduced mitochondrial membrane potential as determined by FACS was observed as early as 24 hours of induction of mutant NE expression and before the accelerated apoptosis or cell cycle arrest was detected. Western blot analysis demonstrated that caspase-3 was not activated in the cells even after 3 days of mutant NE induction. Further analysis of apoptosis regulators revealed a down-regulation of Bcl-2 expression and up-regulation of Bax in cells with induced expression of mutant elastase. These data suggest that mutant elastase-mediated “maturation arrest” of human promyelocytic cells in patients with SCN and SCN/AML is associated with reduced expression of anti-apoptotic Bcl-2 and upregulation of pro-apoptotic Bax proteins that trigger a dramatic reduction in mitochondrial membrane potential and subsequent caspase-independent apoptosis and cell cycle arrest. Current studies focused on elucidating and characterizing specific molecular interactions mediating the pro-apoptotic effect of mutant neutrophil elastase in SCN.


2021 ◽  
Author(s):  
Sandeep Kumar ◽  
Alok Shukla ◽  
Praveen Kumar Verma ◽  
Rishi kant Singh ◽  
Naveen Kumar ◽  
...  

Abstract Cancer is a group of diseases characterised by abnormal and undifferentiated cell growth that has the potential to spread to other parts of the body. It is the world's second leading cause of death and morbidity. According to the GLOBOCAN 2020 report, out of 19.3 million new cancer cases and 10 million deaths reported, 544352 new cases and 259793 deaths occurred by non-Hodgkin lymphoma (NHLs). Although, numerous therapeutic approaches like, surgery, radiotherapy, chemotherapy and immunotherapy have been developed to treat cancer, limited success has been achieved, possibly due to severe side effects associated with the drugs used during chemotherapy. Therefore, deciphering the novel compound with least side effects and highly potent against cancer is urgently required. In the present study we used leaf extract of M. oleifera, well-known for its anti-cancer efficacy against different cancer cells, however, its effect on Dalton’s lymphoma, a type of spontaneously occurring T cell lymphoma originated in the thymus of DBA mice is seriously lacking. Therefore, present study was aimed to analyze the therapeutic efficacy of M. oleifera against DL cells. Our results show that leaf extract of M. oleifera (MOML) significantly induces morphological changes in DL cells followed by chromatin condensation, nuclear fragmentation, and ROS generation. We also found significant changes in mitochondrial membrane potential (ΔΨm) in a dose dependent manner. Furthermore, apoptosis of DL cells induced by cell cycle arrest at G2/M and S phase suggested that MOML could be used to treat NHL effectively


2020 ◽  
Vol 20 (10) ◽  
pp. 1188-1196
Author(s):  
Heriberto Torres-Moreno ◽  
Maria C. Marcotullio ◽  
Carlos Velazquez ◽  
Víctor M. Arenas-Luna ◽  
Salomón Hernández-Gutiérrez ◽  
...  

Background: Cucurbitacin IIb (CIIb) from Ibervillea sonorae has a high capacity to suppress cancer cell proliferation and induce apoptosis. This study investigated the molecular mechanisms related to the antiproliferative and apoptosis induction capacity of CIIb in HeLa cells. Materials and Methods: The cell viability and anti-proliferative effect of CIIb were evaluated by using the trypan blue exclusion assay. The effect of CIIb on the mitochondrial membrane potential was determined by flow cytometry using JC-1. The activity of caspase-3 and caspase-9 was evaluated by flow cytometry using commercial kits. The effect of CIIb on the cell cycle was investigated using Fluorescence-Activated Cell Sorting (FACS) analysis. Western blot analysis was used to evaluate both the inhibitory effect of CIIb on the STAT3 signaling pathway and cyclin –B1, and DNA damage by the comet assay. Results: CIIb triggers disruption of the mitochondrial membrane potential (Δψm) and consequently activated the caspases -3 and -9, as a result of the activation of the intrinsic pathway of the apoptosis. Likewise, the CIIbinduced cell cycle was arrested in S and G2/M after 24h of treatment. CIIb also reduced the expression of STAT3 and cyclin –B1. Finally, CIIb produced an antiproliferative effect at 48 and 72 h, inducing DNA damage. Conclusion: These results demonstrate CIIb-induced apoptosis and cell cycle arrest in HeLa through the inhibition of STAT3.


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