Displaying publications 21 - 40 of 62 in total

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  1. Fulltext Expression of senescence-associated microRNAs and target genes in cellular aging and modulation by tocotrienol-rich fraction
    Khee SG, Yusof YA, Makpol S
    Oxid Med Cell Longev, 2014;2014:725929.
    PMID: 25132913 DOI: 10.1155/2014/725929
    Emerging evidences highlight the implication of microRNAs as a posttranscriptional regulator in aging. Several senescence-associated microRNAs (SA-miRNAs) are found to be differentially expressed during cellular senescence. However, the role of dietary compounds on SA-miRNAs remains elusive. This study aimed to elucidate the modulatory role of tocotrienol-rich fraction (TRF) on SA-miRNAs (miR-20a, miR-24, miR-34a, miR-106a, and miR-449a) and established target genes of miR-34a (CCND1, CDK4, and SIRT1) during replicative senescence of human diploid fibroblasts (HDFs). Primary cultures of HDFs at young and senescent were incubated with TRF at 0.5 mg/mL. Taqman microRNA assay showed significant upregulation of miR-24 and miR-34a and downregulation of miR-20a and miR-449a in senescent HDFs (P < 0.05). TRF reduced miR-34a expression in senescent HDFs and increased miR-20a expression in young HDFs and increased miR-449a expression in both young and senescent HDFs. Our results also demonstrated that ectopic expression of miR-34a reduced the expression of CDK4 significantly (P < 0.05). TRF inhibited miR-34a expression thus relieved its inhibition on CDK4 gene expression. No significant change was observed on the expression of CCND1, SIRT1, and miR-34a upstream transcriptional regulator, TP53. In conclusion tocotrienol-rich fraction prevented cellular senescence of human diploid fibroblasts via modulation of SA-miRNAs and target genes expression.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  2. Fulltext Cellular Homeostasis and Antioxidant Response in Epithelial HT29 Cells on Titania Nanotube Arrays Surface
    Smn Mydin RB, Sreekantan S, Hazan R, Farid Wajidi MF, Mat I
    Oxid Med Cell Longev, 2017;2017:3708048.
    PMID: 28337249 DOI: 10.1155/2017/3708048
    Cell growth and proliferative activities on titania nanotube arrays (TNA) have raised alerts on genotoxicity risk. Present toxicogenomic approach focused on epithelial HT29 cells with TNA surface. Fledgling cell-TNA interaction has triggered G0/G1 cell cycle arrests and initiates DNA damage surveillance checkpoint, which possibly indicated the cellular stress stimuli. A profound gene regulation was observed to be involved in cellular growth and survival signals such as p53 and AKT expressions. Interestingly, the activation of redox regulator pathways (antioxidant defense) was observed through the cascade interactions of GADD45, MYC, CHECK1, and ATR genes. These mechanisms furnish to protect DNA during cellular division from an oxidative challenge, set in motion with XRRC5 and RAD50 genes for DNA damage and repair activities. The cell fate decision on TNA-nanoenvironment has been reported to possibly regulate proliferative activities via expression of p27 and BCL2 tumor suppressor proteins, cogent with SKP2 and BCL2 oncogenic proteins suppression. Findings suggested that epithelial HT29 cells on the surface of TNA may have a positive regulation via cell-homeostasis mechanisms: a careful circadian orchestration between cell proliferation, survival, and death. This nanomolecular knowledge could be beneficial for advanced medical applications such as in nanomedicine and nanotherapeutics.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  3. Fulltext Mechanisms of the anti-tumor activity of Methyl 2-(-5-fluoro-2-hydroxyphenyl)-1 H-benzo[d]imidazole-5-carboxylate against breast cancer in vitro and in vivo
    Hasanpourghadi M, Pandurangan AK, Karthikeyan C, Trivedi P, Mustafa MR
    Oncotarget, 2017 Apr 25;8(17):28840-28853.
    PMID: 28392503 DOI: 10.18632/oncotarget.16263
    Microtubule Targeting Agents (MTAs) induce cell death through mitotic arrest, preferentially affecting rapidly dividing cancer cells over slowly proliferating normal cells. Previously, we showed that Methyl 2-(-5-fluoro-2-hydroxyphenyl)-1H-benzo[d]imidazole-5-carboxylate (MBIC) acts as a potential MTA. In this study, we demonstrated that MBIC exhibits greater toxicity towards non-aggressive breast cancer cell-line, MCF-7 (IC50 = 0.73 ± 0.0 μM) compared to normal fibroblast cell-line, L-cells (IC50 = 59.6 ± 2.5 μM). The IC50 of MBIC against the aggressive breast cancer cell-line, MDA-MB-231 was 20.4 ± 0.2 μM. We hypothesized that the relatively high resistance of MDA-MB-231 cells to MBIC is associated with p53 mutation. We investigated p53 and three of its downstream proteins: survivin, cyclin dependent kinase (Cdk1) and cyclin B1. Following treatment with MBIC, survivin co-immunoprecipitated with caspases with higher affinity in MDA-MB-231 compared to MCF-7 cells. Furthermore, silencing survivin caused a 4.5-fold increase in sensitivity of MDA-MB-231 cells to MBIC (IC50 = 4.4 ± 0.3). In addition, 4 weeks of MBIC administration in MDA-MB-231 cells inoculated BALB/c nude mice resulted in 79.7% reduction of tumor volume compared to the untreated group with no severe sign of toxicity. Our results demonstrated MBIC has multiple anti-tumor actions and could be a potential drug in breast cancer therapy.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  4. Fulltext Nutlin-3 sensitizes nasopharyngeal carcinoma cells to cisplatin-induced cytotoxicity
    Voon YL, Ahmad M, Wong PF, Husaini R, Ng WT, Leong CO, et al.
    Oncol Rep, 2015 Oct;34(4):1692-700.
    PMID: 26252575 DOI: 10.3892/or.2015.4177
    The small-molecule inhibitor of p53-Mdm2 interaction, Nutlin-3, is known to be effective against cancers expressing wild-type (wt) p53. p53 mutations are rare in nasopharyngeal carcinoma (NPC), hence targeting disruption of p53-Mdm2 interaction to reactivate p53 may offer a promising therapeutic strategy for NPC. In the present study, the effects of Nutlin-3 alone or in combination with cisplatin, a standard chemotherapeutic agent, were tested on C666-1 cells, an Epstein-Barr virus (EBV)-positive NPC cell line bearing wt p53. Treatment with Nutlin-3 activated the p53 pathway and sensitized NPC cells to the cytotoxic effects of cisplatin. The combined treatment also markedly suppressed soft agar colony growth formation and increased apoptosis of NPC cells. The effect of Nutlin-3 on NPC cells was inhibited by knockdown of p53, suggesting that its effect was p53-dependent. Extended treatment with increasing concentrations of Nutlin-3 did not result in emergence of p53 mutations in the C666-1 cells. Collectively, the present study revealed supportive evidence of the effectiveness of combining cisplatin and Nutlin-3 as a potential therapy against NPC.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  5. Alterations of the p14ARF-p53-MDM2 pathway in oral squamous cell carcinoma: MDM2 overexpression is a common event
    Lim KP, Sharifah H, Lau SH, Teo SH, Cheong SC
    Oncol Rep, 2005 Oct;14(4):963-8.
    PMID: 16142358 DOI: 10.3892/or.14.4.963
    The majority of global incidences of oral cancer occur in Asia, and the aetiology of oral cancer is different in Asia as it is in the West. However, whereas there is a growing understanding of the molecular mechanisms of oral cancer progression in the West, there is little progress in this understanding in Asia. In particular, the role of the p53 pathway in modulating cancer progression in Asian oral cancer remains unclear. In this study, we micro-dissected and analysed 20 well-differentiated oral squamous cell carcinoma specimens for alterations in the p53 pathway. We found that 6/20 samples contained mutations in the p53 gene which occurred in three hotspots, at codon 203, 218 and 296. Furthermore, 6/20 samples had a homozygous deletion of p14ARF, but notably p14ARF deletion and p53 mutation events were often independent and mutually exclusive. Strikingly, MDM2 was upregulated in 20/20 samples, but not in 3/3 normal tissue specimens. Taken together, these data suggest that inactivation of the p53 pathway is a frequent event in oral squamous cell carcinoma, which occurs by an aberration in one of a number of players in the p53 pathway.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism*
  6. Pereskia bleo Leaves Extract Induces Cell Death via Cell Cycle Arrest and Apoptosis in Cervical Cancer Cells HeLa
    Mohd-Salleh SF, Wan-Ibrahim WS, Ismail N
    Nutr Cancer, 2020;72(5):826-834.
    PMID: 31433251 DOI: 10.1080/01635581.2019.1654530
    Introduction:Pereskia bleo is a leafy and edible plant, locally known as "Pokok Jarum Tujuh Bilah" which has anticancer properties. This study purposed to determine the cytotoxic effects of P. bleo leaves extracts on several well-known cancer cells and elucidate its underlying mechanism in inducing cell death.Methods: Cytotoxic activity on selected cell lines was determined using MTT assay. Mechanism of cell death was investigated through cell cycle and Annexin V assay. Expression of apoptotic proteins was measured by flow cytometry method.Results: Ethyl acetate extract of P. bleo leaves (PBEA) appeared to have the strongest IC50 value (14.37 ± 8.40 μg/ml) and most active against HeLa cells was further studied for apoptosis. The cell cycle investigation by flow cytometry evidenced the increment of PBEA treated HeLa cells in G0/G1 phase and apoptotic event was detected in Annexin V assay. Analysis of apoptotic protein showed pro-apoptotic proteins (Bax, p53 and caspase 3) were triggered where as anti-apoptotic protein Bcl-2 was suppressed in treated HeLa cells.Conclusions: Our findings demonstrated that PBEA treatment induced cell death in HeLa cells by p53-mediated mechanism through arresting cell cycle at G0/G1 phase and mitochondrial-mediated pathway with involvement of pro-apoptotic proteins, anti-apoptotic protein, and caspase 3.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  7. Development and structural characterisation of human scFv targeting MDM2 spliced variant MDM215kDa
    Lim CC, Chan SK, Lim YY, Ishikawa Y, Choong YS, Nagaoka Y, et al.
    Mol Immunol, 2021 07;135:191-203.
    PMID: 33930714 DOI: 10.1016/j.molimm.2021.04.016
    The murine double minute 2 (MDM2) protein is a major negative regulator of the tumour suppressor protein p53. Under normal conditions, MDM2 constantly binds to p53 transactivation domain and/or ubiquinates p53 via its role as E3 ubiquitin ligase to promote p53 degradation as well as nuclear export to maintain p53 levels in cells. Meanwhile, amplification of MDM2 and appearance of MDM2 spliced variants occur in many tumours and normal tissues making it a prognostic indicator for human cancers. The mutation or deletion of p53 protein in half of human cancers inactivates its tumour suppressor activity. However, cancers with wild type p53 have its function effectively inhibited through direct interaction with MDM2 oncoprotein. Here, we described the construction of a MDM2 spliced variant (rMDM215kDa) consisting of SWIB/MDM2 domain and its central region for antibody generation. Biopanning with a human naïve scFv library generated four scFv clones specific to rMDM215kDa. Additionally, the selected scFv clones were able to bind to the recombinant full length MDM2 (rMDM2-FL). Computational prediction showed that the selected scFv clones potentially bind to exon 7-8 of MDM2 while leaving the MDM2/SWIB domain free for p53 interaction. The developed antibodies exhibit good specificity can be further investigated for downstream biomedical and research applications.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  8. Dichloromethane fraction of Moringa oleifera leaf methanolic extract selectively inhibits breast cancer cells (MCF7) by induction of apoptosis via upregulation of Bax, p53 and caspase 8 expressions
    Mohd Fisall UF, Ismail NZ, Adebayo IA, Arsad H
    Mol Biol Rep, 2021 May;48(5):4465-4475.
    PMID: 34086162 DOI: 10.1007/s11033-021-06466-y
    Moringa oleifera is a well-known medicinal plant which has anti-cancer and other biological activities. This research aims to determine the cytotoxic and apoptotic effect of M. oleifera leave extract on the breast cancer (MCF7) cells. The extracts were prepared using hexane, dichloromethane, chloroform and n-butanol by fractionating the crude 80% methanol extract of the plant leaves. The cytotoxic effect of the extracts on MCF7 cells were determined using CellTiter 96® AQueous One Solution Cell Proliferation (MTS) assay. The apoptosis study was conducted using Annexin V-FITC analysis and confirmed by Western blotting using selected proteins, which are p53, Bax, cytochrome c and caspase 8. Our results showed that the dichloromethane (DF-CME-MOL) extract was selectively cytotoxic to MCF7 cells (5 μg/mL) without significantly inhibiting the non-cancerous breast (MCF 10A) cells. It had the highest selectivity index (SI) value of 9.5 among the tested extracts. It also induced early apoptosis and increased the expressions of pro-apoptotic proteins Bax, caspase 8 and p53 in MCF7 cells. Gas chromatography-mass spectrometry analysis (GC-MS) analysis showed that the major compounds found in DF-CME-MOL were benzeneacetonitrile, 4-hydroxy- and benzeneacetic acid, 4-hydroxy-, methyl ester among others that were detected. Thus, DF-CME-MOL extract was found to inhibit the proliferation of MCF7 cells by apoptosis induction, which is likely due to the activities of the detected phytochemical compounds of the extract.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism*
  9. Fulltext Nutlin-3, A p53-Mdm2 antagonist for nasopharyngeal carcinoma treatment
    Voon YL, Wong PF, Khoo ASB
    Mini Rev Med Chem, 2018;18(2):173-183.
    PMID: 28714398 DOI: 10.2174/1389557517666170717125821
    Nasopharyngeal carcinoma (NPC) is a form of head and neck cancer of multifactorial etiologies that is highly prevalent among men in the population of Southern China and Southeast Asia. NPC has claimed many thousands of lives worldwide; but the low awareness of NPC remains a hindrance in early diagnosis and prevention of the disease. NPC is highly responsive to radiotherapy and chemotherapy, but radiocurable NPC is still dependent on concurrent treatment of megavoltage radiotherapy with chemotherapy. Despite a significant reduction in loco-regional and distant metastases, radiotherapy alone has failed to provide a significant improvement in the overall survival rate of NPC, compared to chemotherapy. In addition, chemo-resistance persists as the major challenge in the management of metastatic NPC although the survival rate of advanced metastatic NPC has significantly improved with the administration of chemotherapy adjunctive to radiotherapy. In this regard, targeted molecular therapy could be explored for the discovery of alternative NPC therapies. Nutlin-3, a small molecule inhibitor that specifically targets p53-Mdm2 interaction offers new therapeutic opportunities by enhancing cancer cell growth arrest and apoptosis through the restoration of the p53-mediated tumor suppression pathway while producing minimal cytotoxicity and side effects. This review discusses the potential use of Nutlin-3 as a p53-activating drug and the future directions of its clinical research for NPC treatment.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  10. Effects of Alkoxy Chain Length and 1-Hydroxy Group on Anticolorectal Cancer Activity of 2-Bromoalkoxyanthraquinones
    Mekzali NW, Chee CW, Abdullah I, Lee YK, Rashid NN, Lee VS, et al.
    Med Chem, 2023;19(9):897-905.
    PMID: 37046198 DOI: 10.2174/1573406419666230410134213
    BACKGROUND: KRAS and p53 are two of the most common genetic alterations associated with colorectal cancer. New drug development targeting these mutated genes in colorectal cancer may serve as a potential treatment avenue to the current regimen.

    OBJECTIVE: The objective of the present study was to investigate the effects of alkoxy chain length and 1-hydroxy group on anticolorectal cancer activity of a series of 2-bromoalkoxyanthraquinones and corroborate it with their in silico properties.

    METHODS: In vitro anticancer activity of 2-bromoalkoxyanthraquinones was evaluated against HCT116, HT29, and CCD841 CoN cell lines, respectively. Molecular docking was performed to understand the interactions of these compounds with putative p53 and KRAS targets (7B4N and 6P0Z).

    RESULTS: 2-Bromoalkoxyanthraquinones with the 1-hydroxy group were proven to be more active than the corresponding counterparts in anticancer activity. Among the tested compounds, compound 6b with a C3 alkoxy chain exhibited the most promising antiproliferation activity against HCT116 cells (IC50 = 3.83 ± 0.05 μM) and showed high selectivity for HCT116 over CCD841 CoN cells (SI = 45.47). The molecular docking reveals additional hydrogen bonds between the 1-hydroxy group of 6b and the proteins. Compound 6b has adequate lipophilicity (cLogP = 3.27) and ligand efficiency metrics (LE = 0.34; LLE = 2.15) close to the proposed acceptable range for an initial hit.

    CONCLUSION: This work highlights the potential of the 1-hydroxy group and short alkoxy chain on anticolorectal cancer activity of 2-bromoalkoxyanthraquinones. Further optimisation may be warranted for compound 6b as a therapeutic agent against colorectal cancer.

    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  11. Fulltext A multi-resolution textural approach to diagnostic neuropathology reporting
    Fauzi MF, Gokozan HN, Elder B, Puduvalli VK, Pierson CR, Otero JJ, et al.
    J Neurooncol, 2015 Sep;124(3):393-402.
    PMID: 26255070 DOI: 10.1007/s11060-015-1872-4
    We present a computer aided diagnostic workflow focusing on two diagnostic branch points in neuropathology (intraoperative consultation and p53 status in tumor biopsy specimens) by means of texture analysis via discrete wavelet frames decomposition. For intraoperative consultation, our methodology is capable of classifying glioblastoma versus metastatic cancer by extracting textural features from the non-nuclei region of cytologic preparations based on the imaging characteristics of glial processes, which appear as anisotropic thin linear structures. For metastasis, these are homogeneous in appearance, thus suitable and extractable texture features distinguish the two tissue types. Experiments on 53 images (29 glioblastomas and 24 metastases) resulted in average accuracy as high as 89.7 % for glioblastoma, 87.5 % for metastasis and 88.7 % overall. For p53 interpretation, we detect and classify p53 status by classifying staining intensity into strong, moderate, weak and negative sub-classes. We achieved this by developing a novel adaptive thresholding for detection, a two-step rule based on weighted color and intensity for the classification of positively and negatively stained nuclei, followed by texture classification to classify the positively stained nuclei into the strong, moderate and weak intensity sub-classes. Our detection method is able to correctly locate and distinguish the four types of cells, at 85 % average precision and 88 % average sensitivity rate. These classification methods on the other hand recorded 81 % accuracy in classifying the positive and negative cells, and 60 % accuracy in further classifying the positive cells into the three intensity groups, which is comparable with neuropathologists' markings.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  12. Elephantopus scaber induces apoptosis through ROS-dependent mitochondrial signaling pathway in HCT116 human colorectal carcinoma cells
    Chan CK, Supriady H, Goh BH, Kadir HA
    J Ethnopharmacol, 2015 Jun 20;168:291-304.
    PMID: 25861953 DOI: 10.1016/j.jep.2015.03.072
    Elephantopus scaber also known as Elephant's foot (Asteraceae family) has a plethora of traditional applications including dysuria, diarrhea, dysentery, leukemia and cancer. This study aimed to investigate the apoptosis inducing effects of E. scaber and the underlying mechanisms in HCT116 colorectal cell line.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  13. Induction of cell cycle arrest and apoptosis by betulinic acid-rich fraction from Dillenia suffruticosa root in MCF-7 cells involved p53/p21 and mitochondrial signalling pathway
    Foo JB, Saiful Yazan L, Tor YS, Wibowo A, Ismail N, How CW, et al.
    J Ethnopharmacol, 2015 May 26;166:270-8.
    PMID: 25797115 DOI: 10.1016/j.jep.2015.03.039
    Dillenia suffruticosa (Family: Dilleniaceae) or commonly known as "Simpoh air" in Malaysia, is traditionally used for treatment of cancerous growth including breast cancer.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism*
  14. Fulltext Induction of apoptosis in cancer cells by NiZn ferrite nanoparticles through mitochondrial cytochrome C release
    Al-Qubaisi MS, Rasedee A, Flaifel MH, Ahmad SH, Hussein-Al-Ali S, Hussein MZ, et al.
    Int J Nanomedicine, 2013;8:4115-29.
    PMID: 24204141 DOI: 10.2147/IJN.S50061
    The long-term objective of the present study was to determine the ability of NiZn ferrite nanoparticles to kill cancer cells. NiZn ferrite nanoparticle suspensions were found to have an average hydrodynamic diameter, polydispersity index, and zeta potential of 254.2 ± 29.8 nm, 0.524 ± 0.013, and -60 ± 14 mV, respectively. We showed that NiZn ferrite nanoparticles had selective toxicity towards MCF-7, HepG2, and HT29 cells, with a lesser effect on normal MCF 10A cells. The quantity of Bcl-2, Bax, p53, and cytochrome C in the cell lines mentioned above was determined by colorimetric methods in order to clarify the mechanism of action of NiZn ferrite nanoparticles in the killing of cancer cells. Our results indicate that NiZn ferrite nanoparticles promote apoptosis in cancer cells via caspase-3 and caspase-9, downregulation of Bcl-2, and upregulation of Bax and p53, with cytochrome C translocation. There was a concomitant collapse of the mitochondrial membrane potential in these cancer cells when treated with NiZn ferrite nanoparticles. This study shows that NiZn ferrite nanoparticles induce glutathione depletion in cancer cells, which results in increased production of reactive oxygen species and eventually, death of cancer cells.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  15. Fulltext Emerging Anticancer Potentials of Selenium on Osteosarcoma
    Pang KL, Chin KY
    Int J Mol Sci, 2019 Oct 25;20(21).
    PMID: 31731474 DOI: 10.3390/ijms20215318
    Selenium is a trace element essential to humans and forms complexes with proteins, which exert physiological functions in the body. In vitro studies suggested that selenium possesses anticancer effects and may be effective against osteosarcoma. This review aims to summarise current evidence on the anticancer activity of inorganic and organic selenium on osteosarcoma. Cellular studies revealed that inorganic and organic selenium shows cytotoxicity, anti-proliferative and pro-apoptotic effects on various osteosarcoma cell lines. These actions may be mediated by oxidative stress induced by selenium compounds, leading to the activation of p53, proapoptotic proteins and caspases. Inorganic selenium is selective towards cancer cells, but can cause non-selective cell death at a high dose. This condition challenges the controlled release of selenium from biomaterials. Selenium treatment in animals inoculated with osteosarcoma reduced the tumour size, but did not eliminate the incidence of osteosarcoma. Only one study investigated the relationship between selenium and osteosarcoma in humans, but the results were inconclusive. In summary, although selenium may exert anticancer properties on osteosarcoma in experimental model systems, its effects in humans require further investigation.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  16. LPS-induced Apoptosis is Partially Mediated by Hydrogen Sulphide in RAW 264.7 Murine Macrophages
    George L, Ramasamy T, Sirajudeen K, Manickam V
    Immunol Invest, 2019 Jul;48(5):451-465.
    PMID: 30689461 DOI: 10.1080/08820139.2019.1566355
    Lipopolysaccharide (LPS) induces apoptosis in murine macrophages through the autocrine secretion of tumor necrosis factor (TNF)-α and nitric oxide (NO). LPS-induced inflammation in murine macrophages is associated with hydrogen sulfide (H2S) production. In this present study, we reported the novel role of H2S in LPS-induced apoptosis and its underlying molecular mechanism specifically at late phases in murine macrophage cells. Stimulation of RAW 264.7 macrophages with LPS resulted in a time- and dose-dependent induction of apoptosis. We observed that the LPS-induced early apoptosis (associated with TNF-α secretion) in macrophages was not inhibited in the presence of H2S inhibitor (DL-propargylglycine), whereas early apoptosis was absent in the presence of TNF receptor antibody. Interestingly, LPS-induced late apoptosis paralleled with H2S production was reduced in the presence of H2S inhibitor but not with TNF receptor antibody. The late apoptotic events mediated by H2S and not the TNF-α induced early apoptosis correlated significantly with the induction of p53 and Bax expression in LPS-induced macrophages. Thus, it is possible that RAW 264.7 murine macrophages treated with LPS mediated early apoptosis through TNF-α and the late apoptotic events through the production of H2S.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  17. Gene expression profiling of p53(+/-) knockout and wild-type mice following diethylstilbestrol administration
    Salleh MN, Ismail P, Abdullah AS, Taufiq-Yap YH, Carmichael P
    IUBMB Life, 2004 Jul;56(7):409-16.
    PMID: 15545218
    Studies with clastogenic carcinogen diethylstilbestrol (DES) resulted in a broad of spectrum of toxic and carcinogenic effects in humans and rodents, but the cellular and molecular mechanism(s) by which it induces cancer is not clear. To identify putative genetic targets for p53 in vivo, we applied the cDNA macroarray gene expression profiles associated with apoptosis by comparing p53+/- knockout mice and wild-type mice on the kidney and uterus of female mice. p53+/- knockout mice and wild-type mice were treated with DES (500 micromole kg(-1)) or vehicle i.p once daily for 4 days. Total RNAs were obtained from kidney and uterus of both control and DES-treated. The signal intensities of individual gene spots on the membrane were quantified and normalized to the expression level of the GAPDH gene as an internal control. Our results demonstrated that 16 genes; bad, bax, bcl-2, bcl-w, bcl-x, caspase-3, caspase-7, caspase-8, c-myc, E124, GADD45, mdm2, NKkappab1, p53, p21, Rb and trail were up-regulated and six genes; caspase-1, caspase-2, DR5, E2F1, FasL and iNOS did not changed in response to DES treatment in wild-type mice compared to p53+/- knockout mice. Most genes are involved in cell cycle regulation, signal transduction, apoptosis, or transcription. The greatest changes were seen in bad, bcl-x, mdm2, p53 and p21 gene expression in wild-type mice compared to p53+/- knockout mice. In comparing p53 and p21 gene expression in wild-type mice and p53+/- knockout mice, there was an 4.4-fold vs. 1.8-fold; 8-fold vs. 5.2-fold for kidney and 16-fold vs. 5.5-fold; 2.1-fold vs. 8.3-fold for uterus samples increase in induction (respectively). RT-PCR and densitometric analysis was used to confirm the biggest changes of p21, p53 and bax genes. Using this approach, we have identified apoptosis associated genes regulated in response to DES and have revealed putative differences between the isogenic parent strain and p53+/- knockout mice, which will contribute to a better understanding of toxicity/carcinogenicity mechanisms in this model.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism*
  18. Expression of retinoblastoma protein and P16 proteins in classic Hodgkin lymphoma: relationship with expression of p53 and presence of Epstein-Barr virus in the regulation of cell growth and death
    Kim LH, Peh SC, Poppema S
    Hum Pathol, 2006 Jan;37(1):92-100.
    PMID: 16360421
    Deregulation of several genes involved in cell cycle control has been reported in classic Hodgkin lymphoma (cHL). This study aimed to investigate the expression of tumor suppressor proteins (P16(INK4A), retinoblastoma protein, and p53) in cHL in relation to the proliferation and apoptosis of Hodgkin/Reed-Sternberg (H/RS) cells, correlating with the status of Epstein-Barr virus (EBV). A total of 66 cHL cases and 10 nonneoplastic reactive lymphoid tissues were retrieved from the archives. Immunohistochemistry technique was used for the detection of protein expression. Presence of EBV infection was detected by EBV early RNA in situ hybridization. p16(INK4A) gene deletion status was assessed by fluorescence in situ hybridization technique. Expression of P16(INK4A) was observed in 49.2% of the cases, whereas positive retinoblastoma protein and p53 expressions in the H/RS cells were detected in 89.1% and 81.5% of the cases, respectively. Epstein-Barr virus positivity was detected in 53.0% of the cases. Proliferation marker, Ki-67 expression, was observed in 86.7% of the cases. There was no significant correlation between the expression of the various tumor suppressor proteins and Ki-67. Retinoblastoma protein and p53 were also not associated with the presence of EBV. An inverse relationship was observed between the expression of P16(INK4A) and the presence of EBV. There were no significant homozygous or hemizygous deletions of the p16(INK4A) gene. However, an aberrant copy number of chromosome 9 with the loss of one or more p16(INK4A) loci was detected in all cases assessable by fluorescence in situ hybridization. Loss of function of one or more tumor suppressor proteins may be involved in defective cell regulation of H/RS cells. Epstein-Barr virus may have a role in inhibiting P16(INK4A) expression, thus resulting in a perturbed p16(INK4A)-Rb cell cycle checkpoint.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism*
  19. The effect of Metformin on endometrial tumor-regulatory genes and systemic metabolic parameters in polycystic ovarian syndrome--a proof-of-concept study
    Shafiee MN, Malik DA, Yunos RI, Atiomo W, Omar MH, Ghani NA, et al.
    Gynecol Endocrinol, 2015 Apr;31(4):286-90.
    PMID: 25495168 DOI: 10.3109/09513590.2014.989982
    The aim of this proof-of-concept study was to determine the effects of three-month Metformin therapy on the expression of tumor-regulatory genes (p53, cyclin D2 and BCL-2) in the endometrium of women with polycystic ovary syndrome (PCOS). A total of 40 women, aged between 21 and 45 years with PCOS (Rotterdam criteria) were recruited. The participants were assessed at pre- and 3-month-post-Metformin therapy for the menstrual regularities, weight reduction, Ferriman Galway scores, fasting blood glucose (FBG), total cholesterol, LDL, HDL and p53, BCL-2 and cyclin D2 gene expression. Five participants conceived spontaneously after the initial recruitment. Majority (68%) resumed regular menstrual cycles after Metformin. There were significant reduction in BMI (p = 0.001), weight (p = 0.001) and Ferriman Galway scores (p = 0.001). A significant improvement was seen in mean FBG (p = 0.002), total cholesterol (p = 0.001), LDL (p = 0.003) and HDL cholesterol levels (p = 0.015). Tumor suppressor gene (p53) was significantly up-regulated after Metformin (10 out of 14 women), with p value 0.016. BCL-2 and cyclin D2 (oncogenes) were slightly up-regulated without significant difference (p = 0.119 and 0.155, respectively). In conclusion, Metformin therapy improved clinical and metabolic parameters in women with PCOS and up-regulated p53 tumor suppressor gene significantly. Further studies are however required to independently validate our findings.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism
  20. Fulltext Mutant p53 cooperates with the SWI/SNF chromatin remodeling complex to regulate VEGFR2 in breast cancer cells
    Pfister NT, Fomin V, Regunath K, Zhou JY, Zhou W, Silwal-Pandit L, et al.
    Genes Dev., 2015 Jun 15;29(12):1298-315.
    PMID: 26080815 DOI: 10.1101/gad.263202.115
    Mutant p53 impacts the expression of numerous genes at the level of transcription to mediate oncogenesis. We identified vascular endothelial growth factor receptor 2 (VEGFR2), the primary functional VEGF receptor that mediates endothelial cell vascularization, as a mutant p53 transcriptional target in multiple breast cancer cell lines. Up-regulation of VEGFR2 mediates the role of mutant p53 in increasing cellular growth in two-dimensional (2D) and three-dimensional (3D) culture conditions. Mutant p53 binds near the VEGFR2 promoter transcriptional start site and plays a role in maintaining an open conformation at that location. Relatedly, mutant p53 interacts with the SWI/SNF complex, which is required for remodeling the VEGFR2 promoter. By both querying individual genes regulated by mutant p53 and performing RNA sequencing, the results indicate that >40% of all mutant p53-regulated gene expression is mediated by SWI/SNF. We surmise that mutant p53 impacts transcription of VEGFR2 as well as myriad other genes by promoter remodeling through interaction with and likely regulation of the SWI/SNF chromatin remodeling complex. Therefore, not only might mutant p53-expressing tumors be susceptible to anti VEGF therapies, impacting SWI/SNF tumor suppressor function in mutant p53 tumors may also have therapeutic potential.
    Matched MeSH terms: Tumor Suppressor Protein p53/metabolism*
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