We report that MDM2, a negative regulator of p53, can bind to EBNA-5. Using GST pull-down assay, immunoprecipitation, surface plasmon resonance and immunostaining of lymphoblastoid cells, we found that trimolecular complexes are formed between EBNA-5, MDM2 and p53, where MDM2 serves as a bridge. The EBNA-5 binding to MDM2 counteracted destabilizing effect of the latter on the p53. In ubiquitination and degradation assays in vitro, EBNA-5 inhibited p53 polyubiquitination (but not monoubiquitination) in a concentration-dependent manner. This resembles the effect of p14ARF on p53. Moreover, EBNA-5 was found to inhibit the degradation of p53 in vitro. High levels of p53 expression were maintained in LCLs. The binding of EBNA-5 to MDM2 also could impair the functional activity of p53. The p53-dependent genes P21 and VDR were not induced in EBV-infected, in contrast to mitogen-activated cells. This may explain the tolerance of established LCLs to high levels of p53 without undergoing apoptosis.
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http://dx.doi.org/10.1002/ijc.25414 | DOI Listing |
Naunyn Schmiedebergs Arch Pharmacol
January 2025
Key Laboratory of Marine Pharmaceutical Compound Screening, College of Pharmacy, Jiangsu Ocean University, Lianyungang, China.
Triple-negative breast cancer (TNBC) is characterized by high aggressiveness and recurrence rates due to the lack of effective treatment options. Piperine, a natural alkaloid extracted from black pepper, has demonstrated significant anticancer potential in recent years. Therefore, developing piperine derivatives to enhance its anticancer effects holds critical clinical significance.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, China.
Liver disease poses a significant threat to global public health, with arsenic (As) recognized as a major environmental toxin contributing to liver injury. However, the specific mechanisms and the protective effects of α-lipoic acid (LA) remain unclear. Therefore, this study employs network toxicology and network pharmacology to comprehensively analyze the hepatotoxic mechanism of As and the hepatoprotective mechanism of LA, and further verifies the mechanisms of peroxisomal β-oxidation and lipophagy in the process.
View Article and Find Full Text PDFFront Oncol
January 2025
Department of Biotherapy, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.
Objective: To investigate the optimal cut-off value of immunohistochemical marker Ki67 as a prognostic factor to predict the recurrence of non-muscle invasive bladder urothelial carcinoma (NMIBUC).
Methods: A total of 331 patients diagnosed with NMIBUC who underwent surgery in the Yongchuan Hospital and the Second Affiliated Hospital of Chongqing Medical University from January 2012 to January 2020 were finally included in this study. The optimal cut-off value of Ki67 for predicting recurrence of NMIBUC was calculated by ROC curve and Youden index.
Toxicol Rep
June 2025
National Research Center, Therapeutic Chemistry Department, Al Bohouth Street, Egypt.
Resistance of cancer cells, especially breast cancer, to therapeutic medicines represents a major clinical obstacle that impedes the stages of treatment. Carcinoma cells that acquire resistance to therapeutic drugs can reprogram their own metabolic processes as a way to overcome the effectiveness of treatment and continue their reproduction processes. Despite the recent developments in medical research in the field of drug resistance, which showed some explanations for this phenomenon, the real explanation, along with the ability to precisely predict the possibility of its occurrence in breast cancer cells, still necessitates a deep consideration of the dynamics of the tumor's response to treatment.
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