scholarly journals Pardaxin Activates Excessive Mitophagy and Mitochondria-Mediated Apoptosis in Human Ovarian Cancer by Inducing Reactive Oxygen Species

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1883
Author(s):  
Yen-Po Chen ◽  
Po-Chang Shih ◽  
Chien-Wei Feng ◽  
Chang-Cheng Wu ◽  
Kuan-Hao Tsui ◽  
...  

Most ovarian cancer (OC) patients are diagnosed with stage III or higher disease, resulting in a poor prognosis. Currently, paclitaxel combined with carboplatin shows the best treatment outcome for OC. However, no effective drug is available for patients that do not respond to treatment; thus, new drugs for OC are needed. We evaluated the antimicrobial peptide, pardaxin, in PA-1 and SKOV3 cells. Pardaxin induced apoptosis as determined by MTT and TUNEL assays, as well as activation of caspases-9/3, Bid, t-Bid, and Bax, whereas Bcl-2 was downregulated. The IC50 values for pardaxin were 4.6–3.0 μM at 24 and 48 h. Mitochondrial and intracellular reactive oxygen species (ROS) were overproduced and associated with disrupted mitochondrial membrane potential and respiratory capacity. Additionally, the mitochondrial network was fragmented with downregulated fusogenic proteins, MFN1/2 and L-/S-OPA1, and upregulated fission-related proteins, DRP1 and FIS1. Autophagy was also activated as evidenced by increased expression of autophagosome formation-related proteins, Beclin, p62, and LC3. Enhanced mitochondrial fragmentation and autophagy indicate that mitophagy was activated. ROS-induced cytotoxicity was reversed by the addition of N-acetylcysteine, confirming ROS overproduction as a contributor. Taken together, pardaxin demonstrated promising anticancer activity in OC cells, which warrants further preclinical development of this compound.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Sophia R. Chaudhry ◽  
Jaime Lopes ◽  
Nancy K. Levin ◽  
Hasini Kalpage ◽  
Michael A. Tainsky

AbstractApproximately 25% of all cases of ovarian cancer (OVCA) cases are associated with inherited risk. However, accurate risk assessment is limited by the presence of variants of unknown significance (VUS). Previously, we performed whole-exome sequencing on 48 OVCA patients with familial predisposition, yet negative for pathogenic BRCA1/2 mutations. In our cohort, we uncovered thirteen truncating mutations in genes associated with apoptosis (~35% of our patient cohort). The TP53I3 p.S252X premature stop gain was identified in two unrelated patients. TP53I3 is transcriptionally activated by p53 and believed to play a role in DNA damage response and reactive oxygen species-induced apoptosis. In addition, nonsense variants in apoptosis-related genes TP53AIP1, BCLAF1, and PIK3C2G were identified in our cohort; highlighting the potential relevance of genes involved in apoptotic processes to hereditary cancer. In the current study, we employed functional assays and demonstrated that cells expressing TP53I3 p.S252X displayed decreased homologous recombination repair efficiency and increased sensitivity to chemotherapeutic drugs bleomycin, mitomycin c, and etoposide. In addition, in the presence of oxidative stress from hydrogen peroxide or etoposide we observed a reduction in the formation of reactive oxygen species, an important precursor to apoptosis with this variant. Our findings suggest that the combination of in silico and wet laboratory approaches can better evaluate VUSs, establish novel germline predisposition genetic loci, and improve individual cancer risk estimates.


2014 ◽  
Vol 32 (5) ◽  
pp. 2150-2158 ◽  
Author(s):  
YU WANG ◽  
JUN MA ◽  
HAORAN SHEN ◽  
CHENGJIE WANG ◽  
YUEPING SUN ◽  
...  

2001 ◽  
Vol 280 (1) ◽  
pp. L10-L17 ◽  
Author(s):  
Han-Ming Shen ◽  
Zhuo Zhang ◽  
Qi-Feng Zhang ◽  
Choon-Nam Ong

Alveolar macrophages (AMs) are the principal target cells of silica and occupy a key position in the pathogenesis of silica-related diseases. Silica has been found to induce apoptosis in AMs, whereas its underlying mechanisms involving the initiation and execution of apoptosis are largely unknown. The main objective of the present study was to examine the form of cell death caused by silica and the mechanisms involved. Silica-induced apoptosis in AMs was evaluated by terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling assay and cell cycle/DNA content analysis. The elevated level of reactive oxygen species (ROS), caspase-9 and caspase-3 activation, and poly(ADP-ribose) polymerase (PARP) cleavage in silica-treated AMs were also determined. The results showed that there was a temporal pattern of apoptotic events in silica-treated AMs, starting with ROS formation and followed by caspase-9 and caspase-3 activation, PARP cleavage, and DNA fragmentation. Silica-induced apoptosis was significantly attenuated by a caspase-3 inhibitor, N-acetyl-Asp-Glu-Val-Asp aldehyde, and ebselen, a potent antioxidant. These findings suggest that apoptosis is an important form of cell death caused by silica exposure in which the elevated ROS level that results from silica exposure may act as an initiator, leading to caspase activation and PARP cleavage to execute the apoptotic process.


2009 ◽  
Vol 31 (2) ◽  
pp. 320-330 ◽  
Author(s):  
Martha Barba-Barajas ◽  
Georgina Hernández-Flores ◽  
José M. Lerma-Díaz ◽  
Pablo C. Ortiz-Lazareno ◽  
Jorge R. Domínguez-Rodríguez ◽  
...  

2018 ◽  
Vol 64 (7) ◽  
pp. 455-464 ◽  
Author(s):  
Géssika Silva Souza ◽  
Lais Pessanha de Carvalho ◽  
Edésio José Tenório de Melo ◽  
Valdirene Moreira Gomes ◽  
André de Oliveira Carvalho

Plant defensins are plant antimicrobial peptides that present diverse biological activities in vitro, including the elimination of Leishmania amazonensis. Plant defensins are considered promising candidates for the development of new drugs. This protozoan genus has great epidemiological importance and the mechanism behind the protozoan death by defensins is unknown, thus, we chose L. amazonensis for this study. The aim of the work was to analyze the possible toxic mechanisms of Vu-Defr against L. amazonensis. For analyses, the antimicrobial assay was repeated as previously described, and after 24 h, an aliquot of the culture was tested for viability, membrane perturbation, mitochondrial membrane potential, reactive oxygen species (ROS) and nitric oxide (NO) inductions. The results of these analyses indicated that after interaction with L. amazonensis, the Vu-Defr causes elimination of promastigotes from culture, membrane perturbation, mitochondrial membrane collapse, and ROS induction. Our analysis demonstrated that NO is not produced after Vu-Defr and L. amazonensis interaction. In conclusion, our work strives to help to fill the gap relating to effects caused by plant defensins on protozoan and thus better understand the mechanism of action of this peptide against L. amazonensis.


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