Displaying publications 81 - 100 of 1070 in total

Abstract:
Sort:
  1. Poh YW, Gan SY, Tan EL
    Exp Oncol, 2012 Jul;34(2):85-9.
    PMID: 23013758
    The aim of this study is to investigate whether IL-6, IL-10 and TGF-β are able to confer resistance to apoptosis in nasopharyngeal carcinoma cells by upregulating the expression of survivin.
    Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/genetics; Inhibitor of Apoptosis Proteins/antagonists & inhibitors; Inhibitor of Apoptosis Proteins/genetics*
  2. Zhang J, Ming C, Zhang W, Okechukwu PN, Morak-Młodawska B, Pluta K, et al.
    Drug Des Devel Ther, 2017;11:3045-3063.
    PMID: 29123378 DOI: 10.2147/DDDT.S144415
    The asymptomatic properties and high treatment resistance of ovarian cancer result in poor treatment outcomes and high mortality rates. Although the fundamental chemotherapy provides promising anticancer activities, it is associated with severe side effects. The derivative of phenothiazine, namely, 10H-3,6-diazaphenothiazine (PTZ), was synthesized and reported with ideal anticancer effects in a previous paper. In this study, detailed anticancer properties of PTZ was examined on A2780 ovarian cancer cells by investigating the cytotoxicity profiles, mechanism of apoptosis, and cell invasion. Research outcomes revealed PTZ-induced dose-dependent inhibition on A2780 cancer cells (IC50 =0.62 µM), with significant less cytotoxicity toward HEK293 normal kidney cells and H9C2 normal heart cells. Generation of reactive oxygen species (ROS) and polarization of mitochondrial membrane potential (ΔΨm) suggests PTZ-induced cell death through oxidative damage. The RT2 Profiler PCR Array on apoptosis pathway demonstrated PTZ-induced apoptosis via intrinsic (mitochondria-dependent) and extrinsic (cell death receptor-dependent) pathway. Inhibition of NF-κB and subsequent inhibition of (BIRC6-XIAP) complex activities reduced the invasion rate of A2780 cancer cells penetrating through the Matrigel™ Invasion Chamber. Lastly, the cell cycle analysis hypothesizes that the compound is cytostatic and significantly arrests cell proliferation at G2/M phase. Hence, the exploration of the underlying anticancer mechanism of PTZ suggested its usage as promising chemotherapeutic agent.
    Matched MeSH terms: Apoptosis/drug effects*; Inhibitor of Apoptosis Proteins/metabolism; X-Linked Inhibitor of Apoptosis Protein/metabolism
  3. Vijayarathna S, Gothai S, Jothy SL, Chen Y, Kanwar JR, Sasidharan S
    Asian Pac J Cancer Prev, 2015;16(17):7435-9.
    PMID: 26625740
    A failure of a cell to self destruct has long been associated with cancer progression and development. The fact that tumour cells may not instigate cell arrest or activate cell death mechanisms upon cancer drug delivery is a major concern. Autophagy is a mechanism whereby cell material can be engulfed and digested while apoptosis is a self-killing mechanism, both capable of hindering multiplication after cell injury. In particular situations, autophagy and apoptosis seem to co-exist simultaneously or interdependently with the aid of mutual proteins. This review covers roles of microRNAs and chemopreventive agents and makes an attempt at outlining possible partnerships in maximizing cancer cell death with minimal normal cell damage.
    Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/genetics
  4. Haris K, Ismail S, Idris Z, Abdullah JM, Yusoff AA
    Asian Pac J Cancer Prev, 2014;15(11):4499-505.
    PMID: 24969876
    Glioblastoma, the most aggressive and malignant form of glioma, appears to be resistant to various chemotherapeutic agents. Hence, approaches have been intensively investigated to targeti specific molecular pathways involved in glioblastoma development and progression. Aloe emodin is believed to modulate the expression of several genes in cancer cells. We aimed to understand the molecular mechanisms underlying the therapeutic effect of Aloe emodin on gene expression profiles in the human U87 glioblastoma cell line utilizing microarray technology. The gene expression analysis revealed that a total of 8,226 gene alterations out of 28,869 genes were detected after treatment with 58.6 μg/ml for 24 hours. Out of this total, 34 genes demonstrated statistically significant change (p<0.05) ranging from 1.07 to 1.87 fold. The results revealed that 22 genes were up-regulated and 12 genes were down-regulated in response to Aloe emodin treatment. These genes were then grouped into several clusters based on their biological functions, revealing induction of expression of genes involved in apoptosis (programmed cell death) and tissue remodelling in U87 cells (p<0.01). Several genes with significant changes of the expression level e.g. SHARPIN, BCAP31, FIS1, RAC1 and TGM2 from the apoptotic cluster were confirmed by quantitative real-time PCR (qRT-PCR). These results could serve as guidance for further studies in order to discover molecular targets for the cancer therapy based on Aloe emodin treatment.
    Matched MeSH terms: Apoptosis/drug effects; Apoptosis/genetics
  5. Basri DF, Xian LW, Abdul Shukor NI, Latip J
    Biomed Res Int, 2014;2014:461756.
    PMID: 24783205 DOI: 10.1155/2014/461756
    Stilbenoids have been considered as an alternative phytotherapeutic treatment against methicillin-resistant Staphylococcus aureus (MRSA) infection. The combined effect of ε-viniferin and johorenol A with the standard antibiotics, vancomycin and linezolid, was assessed against MRSA ATCC 33591 and HUKM clinical isolate. The minimum inhibitory concentration (MIC) value of the individual tested compounds and the fractional inhibitory concentration index (FICI) value of the combined agents were, respectively, determined using microbroth dilution test and microdilution checkerboard (MDC) method. Only synergistic outcome from checkerboard test will be substantiated for its rate of bacterial killing using time-kill assay. The MIC value of ε -viniferin against ATCC 33591 and johorenol A against both strains was 0.05 mg/mL whereas HUKM strain was susceptible to 0.1 mg/mL of ε-viniferin. MDC study showed that only combination between ε-viniferin and vancomycin was synergistic against ATCC 33591 (FICI 0.25) and HUKM (FICI 0.19). All the other combinations (ε-viniferin-linezolid, johorenol A-vancomycin, and johorenol A-linezolid) were either indifferent or additive against both strains. However, despite the FICI value showing synergistic effect for ε-viniferin-vancomycin, TKA analysis displayed antagonistic interaction with bacteriostatic action against both strains. As conclusion, ε-viniferin can be considered as a bacteriostatic stilbenoid as it antagonized the bactericidal activity of vancomycin. These findings therefore disputed previous report that ε-viniferin acted in synergism with vancomycin but revealed that it targets similar site in close proximity to vancomycin's action, possibly at the bacterial membrane protein. Hence, this combination has a huge potential to be further studied and developed as an alternative treatment in combating MRSA in future.
    Matched MeSH terms: Apoptosis/drug effects; Apoptosis/physiology
  6. Pai YJ, Abdullah NL, Mohd-Zin SW, Mohammed RS, Rolo A, Greene ND, et al.
    PMID: 22945349 DOI: 10.1002/bdra.23072
    Adhesion and fusion of epithelial sheets marks the completion of many morphogenetic events during embryogenesis. Neural tube closure involves an epithelial fusion sequence in which the apposing neural folds adhere initially via cellular protrusions, proceed to a more stable union, and subsequently undergo remodeling of the epithelial structures to yield a separate neural tube roof plate and overlying nonneural ectoderm. Cellular protrusions comprise lamellipodia and filopodia, and studies in several different systems emphasize the critical role of RhoGTPases in their regulation. How epithelia establish initial adhesion is poorly understood but, in neurulation, may involve interactions between EphA receptors and their ephrinA ligands. Epithelial remodeling is spatially and temporally correlated with apoptosis in the dorsal neural tube midline, but experimental inhibition of this cell death does not prevent fusion and remodeling. A variety of molecular signaling systems have been implicated in the late events of morphogenesis, but genetic redundancy, for example among the integrins and laminins, makes identification of the critical players challenging. An improved understanding of epithelial fusion can provide insights into normal developmental processes and may also indicate the mode of origin of clinically important birth defects.
    Matched MeSH terms: Apoptosis/genetics; Apoptosis/physiology
  7. Tee TT, Cheah YH, Hawariah LP
    Anticancer Res, 2007 Sep-Oct;27(5A):3425-30.
    PMID: 17970090
    F16 is a plant-derived pharmacologically active fraction extracted from Eurycoma longifolia Jack. Previously, we have reported that F16 inhibited the proliferation of MCF-7 human breast cancer cells by inducing apoptotic cell death while having some degree of cytoselectivity on a normal human breast cell line, MCF-10A. In this study, we attempted to further elucidate the mode of action of F16. We found that the intrinsic apoptotic pathway was invoked, with the reduction of Bcl-2 protein. Then, executioner caspase-7 was cleaved and activated in response to F16 treatment. Furthermore, apoptosis in the MCF- 7 cells was accompanied by the specific proteolytic cleavage of poly(ADP-ribose) polymerase-1 (PARP-1). Surprisingly, caspase-9 and p53 were unchanged with F16 treatment. We believe that the F16-induced apoptosis in MCF-7 cells occurs independently of caspase-9 and p53. Taken together, these results suggest that F16 from E. longifolia exerts anti-proliferative action and growth inhibition on MCF-7 cells through apoptosis induction and that it may have anticancer properties.
    Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/physiology
  8. Dhurga DB, Suresh KG, Tan TC, Chandramathi S
    Trans R Soc Trop Med Hyg, 2012 Dec;106(12):725-30.
    PMID: 23141370 DOI: 10.1016/j.trstmh.2012.08.005
    Previous studies have shown that apoptosis-like features are observed in Blastocystis spp., an intestinal protozoan parasite, when exposed to the cytotoxic drug metronidazole (MTZ). This study reports that among the four subtypes of Blastocystis spp. investigated for rate of apoptosis when treated with MTZ, subtype 3 showed the highest significant increase after 72h of in vitro culture when treated with MTZ at 0.1mg/ml (79%; p<0.01) and 0.0001mg/ml (89%; p<0.001). The close correlation between viable cells and apoptotic cells for both dosages implies that the pathogenic potential of these isolates has been enhanced when treated with MTZ. This suggests that there is a mechanism in Blastocystis spp. that actually regulates the apoptotic process to produce higher number of viable cells when treated. Apoptosis may not just be programmed cell death but instead a mechanism to increase the number of viable cells to ensure survival during stressed conditions. The findings of the present study have an important contribution to influence chemotherapeutic approaches when developing drugs against the emerging Blastocystis spp. infections.
    Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/physiology
  9. Fakiruddin KS, Lim MN, Nordin N, Rosli R, Zakaria Z, Abdullah S
    Cancers (Basel), 2019 08 28;11(9).
    PMID: 31466290 DOI: 10.3390/cancers11091261
    Mesenchymal stem cells (MSCs) are emerging as vehicles for anti-tumor cytotherapy; however, investigation on its efficacy to target a specific cancer stem cell (CSC) population in non-small cell lung cancer (NSCLC) is lacking. Using assays to evaluate cell proliferation, apoptosis, and gene expression, we investigated the efficacy of MSCs expressing tumour necrosis factor (TNF)-related apoptosis inducing ligand (MSC-TRAIL) to target and destroy CD133+ (prominin-1 positive) NSCLC-derived CSCs. Characterization of TRAIL death receptor 5 (DR5) revealed that it was highly expressed in the CD133+ CSCs of both H460 and H2170 cell lines. The human MSC-TRAIL generated in the study maintained its multipotent characteristics, and caused significant tumor cell inhibition in NSCLC-derived CSCs in a co-culture. The MSC-TRAIL induced an increase in annexin V expression, an indicator of apoptosis in H460 and H2170 derived CD133+ CSCs. Through investigation of mitochondria membrane potential, we found that MSC-TRAIL was capable of inducing intrinsic apoptosis to the CSCs. Using pathway-specific gene expression profiling, we uncovered candidate genes such as NFKB1, BAG3, MCL1, GADD45A, and HRK in CD133+ CSCs, which, if targeted, might increase the sensitivity of NSCLC to MSC-TRAIL-mediated inhibition. As such, our findings add credibility to the utilization of MSC-TRAIL for the treatment of NSCLC through targeting of CD133+ CSCs.
    Matched MeSH terms: Apoptosis; Receptors, TNF-Related Apoptosis-Inducing Ligand; TNF-Related Apoptosis-Inducing Ligand
  10. Tengku Din TADAA, Abdul Jalal MI, Seeni A, Shamsuddin S, Jaafar H
    Malays J Pathol, 2018 Dec;40(3):303-312.
    PMID: 30580361
    INTRODUCTION: This study focused on PF4 effects on caspase-3,-6, -7, -8 and -9 which regulate the apopotosis process in breast cancer.

    MATERIALS AND METHODS: Breast tumours were induced in forty 21-day-old female Sprague Dawley rats (SDRs) using MNU until tumour size reached 14.5 mm (SD: 0.5 mm). The rats were then divided into two groups: Group 1 (control injected with 0.9% saline; n = 20), and Group 2 (platelet factor 4 (PF4); n = 20). PF4 was administered through focal intralesional injection at 20 μg/lesion dose. Following 5-day treatment, the SDRs were sacrificed. Subsequently, representative sections from the tumour were obtained for haematoxylin and eosin (H&E) staining. The expressions of caspase-3, -6, -7, -8 and -9 were evaluated using immunohistochemistry (IHC) staining.

    RESULTS: The majority of breast tumour specimens were of aggressive types [ncontrol = 13 (65%); nPF4 = 12 (60%)]. Invasive ductal carcinoma not otherwise specified (IDC-NOS) was the most commonly observed breast tumour histology for control and PF4 groups (n = 8 (40%) in respective groups). PF4-treated group exhibited significant differences in the caspase-3, -6 and -8 expression levels compared to the control group (all p < 0.001). There were no significant differences in caspase-7 (p = 0.347) and caspase-9 (p = 0.373) expression levels between both groups.

    CONCLUSION: This study found that PF4 acts via the caspase-mediated extrinsic apoptosis pathway without the involvement of the intrinsic pathway.
    Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/physiology
  11. Tan SN, Sim SP
    BMC Med Genomics, 2019 01 15;12(1):9.
    PMID: 30646906 DOI: 10.1186/s12920-018-0465-4
    BACKGROUND: It has been found that chronic rhinosinusitis (CRS) increases the risk of developing nasopharyngeal carcinoma (NPC). CRS can be caused by gastro-oesophageal reflux (GOR) that may reach nasopharynx. The major component of refluxate, bile acid (BA) has been found to be carcinogenic and genotoxic. BA-induced apoptosis has been associated with various cancers. We have previously demonstrated that BA induced apoptosis and gene cleavages in nasopharyngeal epithelial cells. Chromosomal cleavage occurs at the early stage of both apoptosis and chromosome rearrangement. It was suggested that chromosome breaks tend to cluster in the region containing matrix association region/scaffold attachment region (MAR/SAR). This study hypothesised that BA may cause chromosome breaks at MAR/SAR leading to chromosome aberrations in NPC. This study targeted the AF9 gene located at 9p22 because 9p22 is a deletion hotspot in NPC.

    METHODS: Potential MAR/SAR sites were predicted in the AF9 gene by using MAR/SAR prediction tools. Normal nasopharyngeal epithelial cells (NP69) and NPC cells (TWO4) were treated with BA at neutral and acidic pH. Inverse-PCR (IPCR) was used to identify chromosome breaks in SAR region (contains MAR/SAR) and non-SAR region (does not contain MAR/SAR). To map the chromosomal breakpoints within the AF9 SAR and non-SAR regions, DNA sequencing was performed.

    RESULTS: In the AF9 SAR region, the gene cleavage frequencies of BA-treated NP69 and TWO4 cells were significantly higher than those of untreated control. As for the AF9 non-SAR region, no significant difference in cleavage frequency was detected between untreated and BA-treated cells. A few breakpoints detected in the SAR region were mapped within the AF9 region that was previously reported to translocate with the mixed lineage leukaemia (MLL) gene in an acute lymphoblastic leukaemia (ALL) patient.

    CONCLUSIONS: Our findings suggest that MAR/SAR may be involved in defining the positions of chromosomal breakages induced by BA. Our report here, for the first time, unravelled the relation of these BA-induced chromosomal breakages to the AF9 chromatin structure.

    Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/genetics
  12. Sarmadi VH, Ahmadloo S, Boroojerdi MH, John CM, Al-Graitte SJR, Lawal H, et al.
    Cell Transplant, 2020 2 7;29:963689719885077.
    PMID: 32024378 DOI: 10.1177/0963689719885077
    Treatment of leukemia has become much difficult because of resistance to the existing anticancer therapies. This has thus expedited the search for alternativ therapies, and one of these is the exploitation of mesenchymal stem cells (MSCs) towards control of tumor cells. The present study investigated the effect of human umbilical cord-derived MSCs (UC-MSCs) on the proliferation of leukemic cells and gauged the transcriptomic modulation and the signaling pathways potentially affected by UC-MSCs. The inhibition of growth of leukemic tumor cell lines was assessed by proliferation assays, apoptosis and cell cycle analysis. BV173 and HL-60 cells were further analyzed using microarray gene expression profiling. The microarray results were validated by RT-qPCR and western blot assay for the corresponding expression of genes and proteins. The UC-MSCs attenuated leukemic cell viability and proliferation in a dose-dependent manner without inducing apoptosis. Cell cycle analysis revealed that the growth of tumor cells was arrested at the G0/G1 phase. The microarray results identified that HL-60 and BV173 share 35 differentially expressed genes (DEGs) (same expression direction) in the presence of UC-MSCs. In silico analysis of these selected DEGs indicated a significant influence in the cell cycle and cell cycle-related biological processes and signaling pathways. Among these, the expression of DBF4, MDM2, CCNE2, CDK6, CDKN1A, and CDKN2A was implicated in six different signaling pathways that play a pivotal role in the anti-tumorigenic activity exerted by UC-MSCs. The UC-MSCs perturbate the cell cycle process of leukemic cells via dysregulation of tumor suppressor and oncogene expression.
    Matched MeSH terms: Apoptosis/genetics; Apoptosis/physiology
  13. Sok SP, Arshad NM, Azmi MN, Awang K, Ozpolat B, Hasima Nagoor N
    PLoS One, 2017;12(2):e0171329.
    PMID: 28158287 DOI: 10.1371/journal.pone.0171329
    Autophagy plays a role in deciding the fate of cells by inducing either survival or death. 1'S-1-acetoxychavicol acetate (ACA) is a phenylpropanoid isolated from rhizomes of Alpinia conchigera and has been reported previously on its apoptotic effects on various cancers. However, the effect of ACA on autophagy remains ambiguous. The aims of this study were to investigate the autophagy-inducing ability of ACA in human non-small cell lung cancer (NSCLC), and to determine its role as pro-survival or pro-death mechanism. Cell viability assay was conducted using MTT. The effect of autophagy was assessed by acridine orange staining, GFP-LC3 punctate formation assay, and protein level were analysed using western blot. Annexin V-FITC/PI staining was performed to detect percentage of cells undergoing apoptosis by using flow cytometry. ACA inhibits the cell viability and induced formation of cytoplasmic vacuoles in NSCLC cells. Acidic vesicular organelles and GFP-LC3 punctate formation were increased in response to ACA exposure in A549 and SK-LU-1 cell lines; implying occurrence of autophagy. In western blot, accumulation of LC3-II accompanied by degradation of p62 was observed, which further confirmed the full flux of autophagy induction by ACA. The reduction of Beclin-1 upon ACA treatment indicated the Beclin-1-independent autophagy pathway. An early autophagy inhibitor, 3-methyaldenine (3-MA), failed to suppress the autophagy triggered by ACA; validating the existence of Beclin-1-independent autophagy. Silencing of LC3-II using short interfering RNA (siRNA) abolished the autophagy effects, enhancing the cytotoxicity of ACA through apoptosis. This proposed ACA triggered a pro-survival autophagy in NSCLC cells. Consistently, co-treatment with lysosomal inhibitor, chloroquine (CQ), exerted a synergistic effect resulting in apoptosis. Our findings suggested ACA induced pro-survival autophagy through Beclin-1-independent pathway in NSCLC. Hence, targeting autophagy pathway using autophagy inhibitor such as CQ represented a novel promising approach to potentiate the cytotoxicity of ACA through apoptosis in NSCLC.
    Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/genetics
  14. Fakiruddin KS, Ghazalli N, Lim MN, Zakaria Z, Abdullah S
    Int J Mol Sci, 2018 07 27;19(8).
    PMID: 30060445 DOI: 10.3390/ijms19082188
    Tapping into the ability of engineered mesenchymal stem cells (MSCs) to mobilise into the tumour has expanded the scope of cancer treatment. Engineered MSCs expressing tumour necrosis factor (TNF)-related apoptosis inducing ligand (MSC-TRAIL) could serve as a platform for an efficient and targeted form of therapy. However, the presence of cancer stem cells (CSCs) that are resistant to TRAIL and apoptosis may represent a challenge for effective treatment. Nonetheless, with the discovery of small molecular inhibitors that could target CSCs and tumour signalling pathways, a higher efficacy of MSC-TRAIL mediated tumour inhibition can be achieved. This might pave the way for a more effective form of combined therapy, which leads to a better treatment outcome. In this review, we first discuss the tumour-homing capacity of MSCs, its effect in tumour tropism, the different approach behind genetically-engineered MSCs, and the efficacy and safety of each agent delivered by these MSCs. Then, we focus on how sensitisation of CSCs and tumours using small molecular inhibitors can increase the effect of these cells to either TRAIL or MSC-TRAIL mediated inhibition. In the conclusion, we address a few questions and safety concerns regarding the utilization of engineered MSCs for future treatment in patients.
    Matched MeSH terms: TNF-Related Apoptosis-Inducing Ligand/genetics; TNF-Related Apoptosis-Inducing Ligand/metabolism*
  15. Lambuk L, Iezhitsa I, Agarwal R, Bakar NS, Agarwal P, Ismail NM
    Neurotoxicology, 2019 01;70:62-71.
    PMID: 30385388 DOI: 10.1016/j.neuro.2018.10.009
    OBJECTIVE: N-methyl-D-aspartate (NMDA) excitotoxicity has been proposed to mediate apoptosis of retinal ganglion cells (RGCs) in glaucoma. Taurine (TAU) has been shown to have neuroprotective properties, thus we examined anti-apoptotic effect of TAU against retinal damage after NMDA exposure.

    METHODOLOGY: Sprague-Dawley rats were divided into 5 groups of 33 each. Group 1 was administered intravitreally with PBS and group 2 was similarly injected with NMDA (160 nmol). Groups 3, 4 and 5 were injected with TAU (320 nmol) 24 hours before (pre-treatment), in combination (co-treatment) and 24 hours after (post-treatment) NMDA exposure respectively. Seven days after injection, rats were sacrificed; eyes were enucleated, fixed and processed for morphometric analysis, TUNEL and caspase-3 staining. Optic nerve morphology assessment was done using toluidine blue staining. The estimation of BDNF, pro/anti-apoptotic factors (Bax/Bcl-2) and caspase-3 activity in retina was done using ELISA technique.

    RESULTS: Severe degenerative changes were observed in retinae after intravitreal NMDA exposure. The retinal morphology in the TAU pre-treated group appeared more similar to the control retinae and demonstrated a higher number of nuclei than the NMDA group both per 100 μm length (by 1.5-fold, p 

    Matched MeSH terms: Apoptosis/drug effects*; Apoptosis/physiology
  16. Tan SN, Sim SP, Khoo ASB
    BMC Mol. Biol., 2018 12 04;19(1):15.
    PMID: 30514321 DOI: 10.1186/s12867-018-0116-5
    BACKGROUND: Oxidative stress is known to be involved in most of the aetiological factors of nasopharyngeal carcinoma (NPC). Cells that are under oxidative stress may undergo apoptosis. We have previously demonstrated that oxidative stress-induced apoptosis could be a potential mechanism mediating chromosome breakages in nasopharyngeal epithelial cells. Additionally, caspase-activated DNase (CAD) may be the vital player in mediating the chromosomal breakages during oxidative stress-induced apoptosis. Chromosomal breakage occurs during apoptosis and chromosome rearrangement. Chromosomal breakages tend to cluster in certain regions, such as matrix association region/scaffold attachment region (MAR/SAR). We hypothesised that oxidative stress-induced apoptosis may result in chromosome breaks preferentially at the MAR/SAR sites. The AF9 gene at 9p22 was targeted in this study because 9p22 is a deletion site commonly found in NPC.

    RESULTS: By using MAR/SAR recognition signature (MRS), potential MAR/SAR sites were predicted in the AF9 gene. The predicted MAR/SAR sites precisely match to the experimentally determined MAR/SARs. Hydrogen peroxide (H2O2) was used to induce apoptosis in normal nasopharyngeal epithelial cells (NP69) and NPC cells (HK1). Nested inverse polymerase chain reaction was employed to identify the AF9 gene cleavages. In the SAR region, the gene cleavage frequency of H2O2-treated cells was significantly higher than that of the non-treated cells. A few chromosomal breakages were detected within the AF9 region which was previously found to be involved in the mixed lineage leukaemia (MLL)-AF9 translocation in an acute lymphoblastic leukaemia patient. As for the non-SAR region, no significant difference in the gene cleavage frequency was found between the untreated control and H2O2-treated cells. Furthermore, H2O2-induced cleavages within the SAR region were reduced by caspase-3 inhibitor, which indirectly inhibits CAD.

    CONCLUSIONS: These results reaffirm our previous findings that oxidative stress-induced apoptosis could be one of the potential mechanisms underlying chromosome breakages in nasopharyngeal epithelial cells. MAR/SAR may play a vital role in defining the location of chromosomal breakages mediated by oxidative stress-induced apoptosis, where CAD is the major nuclease.

    Matched MeSH terms: Apoptosis/drug effects; Apoptosis/genetics
  17. Angelopoulou E, Paudel YN, Bougea A, Piperi C
    J Neurosci Res, 2021 Sep;99(9):2117-2133.
    PMID: 34115895 DOI: 10.1002/jnr.24895
    The pathogenesis of Parkinson's disease (PD) remains elusive. There is still no available disease-modifying strategy against PD, whose management is mainly symptomatic. A growing amount of preclinical evidence shows that a complex interplay between autophagy dysregulation, mitochondrial impairment, endoplasmic reticulum stress, oxidative stress, and excessive neuroinflammation underlies PD pathogenesis. Identifying key molecules linking these pathological cellular processes may substantially aid in our deeper understanding of PD pathophysiology and the development of novel effective therapeutic approaches. Emerging preclinical evidence indicates that apelin, an endogenous neuropeptide acting as a ligand of the orphan G protein-coupled receptor APJ, may play a key neuroprotective role in PD pathogenesis, via inhibition of apoptosis and dopaminergic neuronal loss, autophagy enhancement, antioxidant effects, endoplasmic reticulum stress suppression, as well as prevention of synaptic dysregulation in the striatum, excessive neuroinflammation, and glutamate-induced excitotoxicity. Underlying signaling pathways involve phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin, extracellular signal-regulated kinase 1/2, and inositol requiring kinase 1α/XBP1/C/EBP homologous protein. Herein, we discuss the role of apelin/APJ axis and associated molecular mechanisms on the pathogenesis of PD in vitro and in vivo and provide evidence for its challenging therapeutic potential.
    Matched MeSH terms: Apoptosis/drug effects; Apoptosis/physiology
  18. Mai CW, Kang YB, Nadarajah VD, Hamzah AS, Pichika MR
    Phytother Res, 2018 Jun;32(6):1108-1118.
    PMID: 29464796 DOI: 10.1002/ptr.6051
    In this study, a series of 20 structurally similar vanilloids (Vn) were tested for their antiproliferative effects against 12 human cancer cells: human breast (MCF-7 and MDA-MB-231), cervical (HeLa), ovarian (Caov-3), lung (A549), liver (HepG2), colorectal (HT-29 and HCT116), nasopharyngeal (CNE-1 and HK-1), and leukemic (K562 and CEM-SS) cancer cells. Among all the tested vanilloids, Vn16 (6-shogaol) exhibited the most potent cytotoxic effects against human colorectal cancer cells (HT-29). The apoptotic induction effects exhibited by Vn16 on HT-29 cells were confirmed using dual staining fluorescence microscopy and enzyme-linked immunosorbent assay. The effects of Vn16 on regulation of 43 apoptotic-related markers were determined in HT-29. The results suggested that 8 apoptotic markers (caspase 8, BAD, BAX, second mitochondrial-derived activator, caspase 3, survivin, bcl-2, and cIAP-2) were either upregulated or downregulated. These results further support the chemopreventive properties of foods that contain vanilloids.
    Matched MeSH terms: Apoptosis; Inhibitor of Apoptosis Proteins/metabolism*
  19. Wang L, Li Y, Huang G, Zhang X, Pingguan-Murphy B, Gao B, et al.
    Crit Rev Biotechnol, 2016 Jun;36(3):553-65.
    PMID: 25641330 DOI: 10.3109/07388551.2014.993588
    Natural cellular microenvironment consists of spatiotemporal gradients of multiple physical (e.g. extracellular matrix stiffness, porosity and stress/strain) and chemical cues (e.g. morphogens), which play important roles in regulating cell behaviors including spreading, proliferation, migration, differentiation and apoptosis, especially for pathological processes such as tumor formation and progression. Therefore, it is essential to engineer cellular gradient microenvironment incorporating various gradients for the fabrication of normal and pathological tissue models in vitro. In this article, we firstly review the development of engineering cellular physical and chemical gradients with cytocompatible hydrogels in both two-dimension and three-dimension formats. We then present current advances in the application of engineered gradient microenvironments for the fabrication of disease models in vitro. Finally, concluding remarks and future perspectives for engineering cellular gradients are given.
    Matched MeSH terms: Apoptosis
  20. Tan SN, Sim SP, Khoo AS
    Cell Biosci, 2016;6:35.
    PMID: 27231526 DOI: 10.1186/s13578-016-0103-9
    Genetic aberrations have been identified in nasopharyngeal carcinoma (NPC), however, the underlying mechanism remains elusive. There are increasing evidences that the apoptotic nuclease caspase-activated deoxyribonuclease (CAD) is one of the players leading to translocation in leukemia. Oxidative stress, which has been strongly implicated in carcinogenesis, is a potent apoptotic inducer. Most of the NPC etiological factors are known to induce oxidative stress. Although apoptosis is a cell death process, cells possess the potential to survive apoptosis upon DNA repair. Eventually, the surviving cells may carry rearranged chromosomes. We hypothesized that oxidative stress-induced apoptosis may cause chromosomal breaks mediated by CAD. Upon erroneous DNA repair, cells that survive apoptosis may harbor chromosomal rearrangements contributing to NPC pathogenesis. This study focused on the AF9 gene at 9p22, a common deletion region in NPC. We aimed to propose a possible model for molecular mechanism underlying the chromosomal rearrangements in NPC.
    Matched MeSH terms: Apoptosis
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links