MyMedR

Displaying all 4 publications

Abstract:

Sort:

Fulltext Sphingosine 1-phosphate receptor 2 (S1P2) attenuates reactive oxygen species formation and inhibits cell death: implications for otoprotective therapy

Herr DR, Reolo MJ, Peh YX, Wang W, Lee CW, Rivera R, et al.

Sci Rep, 2016 Apr 15;6:24541.
PMID: 27080739 DOI: 10.1038/srep24541

Ototoxic drugs, such as platinum-based chemotherapeutics, often lead to permanent hearing loss through apoptosis of neuroepithelial hair cells and afferent neurons of the cochlea. There is no approved therapy for preventing or reversing this process. Our previous studies identified a G protein-coupled receptor (GPCR), S1P2, as a potential mediator of otoprotection. We therefore sought to identify a pharmacological approach to prevent cochlear degeneration via activation of S1P2. The cochleae of S1pr2(-/-) knockout mice were evaluated for accumulation of reactive oxygen species (ROS) with a nitro blue tetrazolium (NBT) assay. This showed that loss of S1P2 results in accumulation of ROS that precedes progressive cochlear degeneration as previously reported. These findings were supported by in vitro cell-based assays to evaluate cell viability, induction of apoptosis, and accumulation of ROS following activation of S1P2 in the presence of cisplatin. We show for the first time, that activation of S1P2 with a selective receptor agonist increases cell viability and reduces cisplatin-mediated cell death by reducing ROS. Cumulatively, these results suggest that S1P2 may serve as a therapeutic target for attenuating cisplatin-mediated ototoxicity.

Matched MeSH terms: Cell Death/genetics
Identification and validation of mRNA profiles linked to ATP- induced cell death represent a novel prognostic model for breast cancer

Zhang Z, Zhang H, Zhang Z, Sandai D, Lu P, Zhang H, et al.

Front Immunol, 2024;15:1483498.
PMID: 39555060 DOI: 10.3389/fimmu.2024.1483498

BACKGROUND: Cell death mechanisms are integral to the pathogenesis of breast cancer (BC), with ATP-induced cell death (AICD) attracting increasing attention due to its distinctive specificity and potential therapeutic applications.
METHODS: This study employed genomic methodologies to investigate the correlation between drug sensitivity and types of AICD in BC. Initially, data from TCGA were utilized to construct a prognostic model and classification system for AICD. Subsequently, a series of bioinformatics analyses assessed the prognostic and clinical significance of this model within the context of BC.
RESULTS: Analysis revealed a cohort of 18 genes associated with AICD, exhibiting prognostic relevance. Survival analyses indicated that overall survival rates were significantly lower in high-risk populations compared to their low-risk counterparts. Furthermore, prognostic indicators linked to AICD demonstrated high accuracy in predicting survival outcomes in BC. Immunological assessments indicated heightened expression of anti-tumor infiltrating immune cells and immune checkpoint molecules in low-risk populations, correlating with various anti-tumor immune functions. Ultimately, a comprehensive prognostic model related to AICD was developed through univariate analysis, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analysis. As Adenosine triphosphate (ATP) concentration increased, the viability of BC cells exhibited a general decline at each time point. Notably, ATP diminished the mitochondrial membrane potential in BC cells while enhancing it in normal breast epithelial cells. Additionally, ATP inhibited the migration of BC cells and promoted their apoptosis. ATP also stimulated reactive oxygen species (ROS) production in MCF-10A cells, with implications for the immune response in BC cells. Compared to the control group, expression levels of CLIC6, SLC1A1, and CEMIP were significantly reduced in the ATP intervention group, whereas ANO6 expression was elevated. ANO6, CEMIP, and CLIC6 share genetic variants with BC, while SLC1A1 does not exhibit genetic causal variation with the disease.
CONCLUSION: A valuable prognostic model associated with AICD has been established, capable of accurately predicting BC prognosis. The induction of cell death by ATP appears to play a protective role in BC progression. These findings carry significant implications for the implementation of personalized and tailored treatment strategies for BC patients.

Matched MeSH terms: Cell Death/genetics
Fulltext Bcl-xL silencing induces alterations in hsa-miR-608 expression and subsequent cell death in A549 and SK-LU1 human lung adenocarcinoma cells

Othman N, In LL, Harikrishna JA, Hasima N

PLoS One, 2013;8(12):e81735.
PMID: 24339958 DOI: 10.1371/journal.pone.0081735

Bcl-xL is an anti-apoptotic protein that is frequently found to be overexpressed in non-small cell lung cancer leading to an inhibition of apoptosis and poor prognosis. Recently, the role of miRNAs in regulating apoptosis and cell survival during tumorigenesis has become evident, with cancer cells showing perturbed expression of various miRNAs. In this study, we utilized miRNA microarrays to determine if miRNA dysregulation in bcl-xL silenced lung adenocarcinoma cells could be involved in regulating cell death. Short interfering RNA-based transfection of A549 and SK-LU1 lung adenocarcinoma cells was successful in inducing a reduction in bcl-xL expression levels, resulting in a decrease in cell viability. A total of 10 miRNAs were found to be significantly differentially expressed when compared between siRNA-transfected and non-transfected cells including hsa-miR-181a, hsa-miR-769-5p, hsa-miR-361-5p, hsa-miR-1304 and hsa-miR-608. When overexpression studies on hsa-miR-608 was performed via transfection of miRNA mimics, cell death was found to be induced in A549 and SK-LU1 cells in comparison to untreated cells. This effect was reversed when knockdown studies involving anti-sense inhibitors were introduced. Combination of siRNA based silencing of bcl-xL (siBcl-xL) followed by anti-sense inhibitor transfection led to a decrease in the apoptotic population of A549 and SK-LU1 cells in comparison to cells only treated with siBcl-xL, illustrating the connection between bcl-xL, hsa-miR-608 and cell death. Gene target prediction analysis implicated the PI3K/AKT, WNT, TGF-β, and ERK signaling pathways as targets of bcl-xL induced miRNA alterations. We have demonstrated that bcl-xL silencing in A549 and SK-LU1 cells leads to the occurrence of cell death through the dysregulation of specific miRNAs. This study also provides a platform for anti-sense gene therapy whereby miRNA expression can be exploited to increase the apoptotic properties in lung adenocarcinoma cells.

Matched MeSH terms: Cell Death/genetics
Fulltext Genome wide transcriptome profiling of a murine acute melioidosis model reveals new insights into how Burkholderia pseudomallei overcomes host innate immunity

Chin CY, Monack DM, Nathan S

BMC Genomics, 2010;11:672.
PMID: 21110886 DOI: 10.1186/1471-2164-11-672

At present, very little is known about how Burkholderia pseudomallei (B. pseudomallei) interacts with its host to elicit melioidosis symptoms. We established a murine acute-phase melioidosis model and used DNA microarray technology to investigate the global host/pathogen interaction. We compared the transcriptome of infected liver and spleen with uninfected tissues over an infection period of 42 hr to identify genes whose expression is altered in response to an acute infection.

Matched MeSH terms: Cell Death/genetics