Natural antioxidants products are widely distributed in food and medicinal plants. These natural antioxidants, especially polyphenols, exhibit a wide range of biological activities including anti-cancer, anti-inflammatory, and anti-atherosclerosis activities. Pomegranate (Punica granatum L.) is a rich source of polyphenolic components. The purpose of this study was to characterize the phenolic composition and flavonoids and anthocyanin content of different parts (peel and aril) of the Sefri variety of pomegranate. Our results showed that Peel extract was richer in these compounds than that of the Arils, especially in Punicalagin (A and B). DPPH free radical scavenging, reducing power (FRAP), β-carotene bleaching, and hydrogen peroxide scavenging assays revealed a greater dose-dependent activity of pomegranate peel phenolic extract (PPPE) compared to pomegranate aril phenolic extract (PAPE). PPPE was also more potent than PAPE concerning its ability to inhibit conjugated diene formation and to reduce α-tocopherol disappearance induced by CuSO4-mediated LDL peroxidation. Interestingly, both extracts (PPPE and PAPE) significantly inhibited lipid peroxidation and the formation of reactive oxygen species (ROS) in stressed J82 human bladder cancer cells. These results reflect the protective effects that this Moroccan variety of pomegranate can provide against the development of metabolic disorder, cancer, atherosclerosis, and cardiovascular disease. Given these properties, further studies should be undertaken to investigate possible applications of Sefri pomegranate extracts in the fields of food preservation and health supplements.
5 May 2019 in Oxidative Medicine and Cellular Longevity
Bladder cancer (BC) is one of the most common tumors found in the urinary bladder for both male and female in western countries. In vitro and in vivo studies suggest that high levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and oxidative stress play a crucial role in human cancer. Low concentration of ROS and RNS is indispensable for cell survival and proliferation. However, high concentration of ROS and RNS can exert a cytotoxic effect. Increased oxidative stress is a result of either increased ROS/RNS production or a decrease of antioxidant defense mechanisms. A literature search was carried out on PubMed, Medline, and Google Scholar for articles in English published up to May 2018 using the following keywords: oxidative stress, antioxidants, reactive oxygen species, lipid peroxidation, paraoxonase, urinary bladder cancer, and nitric oxide. Literature data demonstrate that BC is associated with oxidative stress and with an imbalance between oxidants and antioxidant enzymes. Markers of lipid peroxidation, protein and nucleic acid oxidation are significantly higher in tissues of patients with BC compared with control groups. A decrease of activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione, and paraoxonase) has also been demonstrated. The imbalance between oxidants and antioxidants could have a potential role in the etiology and progression of bladder cancer.
30 April 2022 in Experimental and Molecular Pathology
Resistance to systemic therapy remains the defining challenge in the management of gastric cancer (GC) and esophageal adenocarcinoma (EAC). While genomic drivers of resistance are well characterized, traditional bulk profiling has failed to capture the physical rules governing tumor survival within the complex tissue ecosystem. Emerging data from 2024–2025, leveraging high-resolution spatial transcriptomics and multi-omics, have recontextualized resistance as a phenomenon of “spatial privilege” rather than solely an intrinsic cellular fate. This review summarizes recent evidence to define “architectural refuges”: distinct spatial niches that physically shield malignant clones from cytotoxic and targeted agents. We delineate three critical resistance domains common to upper gastrointestinal adenocarcinomas: (1) The “Excluded” Niche, where specific cancer-associated fibroblast (CAF) subpopulations (iCAFs vs. myCAFs) and stiffened extracellular matrix create hypovascular zones that limit drug delivery; (2) the “Immune-Tolerant” Niche, characterized by the spatial exclusion of CD8+ T cells and the recruitment of suppressive myeloid populations via the MIF/CD74 and USP14 axes; and (3) the “Metabolic” Niche, where mitochondrial heterogeneity and lipid metabolic symbiosis establish nutrient-deprived niches that select for stem-like, dormant states. By mapping these conserved spatial determinants from primary GEJ tumors to peritoneal and distant metastases, we argue that overcoming resistance requires an advancement: moving beyond targeting individual mutations to dismantling the multicellular architecture that sustains malignancy.
Esophageal adenocarcinoma (EAC) is an aggressive malignancy with poor patient outcomes and limited therapeutic options. WEE1, a G2/M checkpoint kinase, is often upregulated in cancers and associated with resistance to therapy. In this study, we identify a previously unrecognized cytoplasmic role of WEE1 in stabilizing the oncogenic transcription factor MYC and promoting drug resistance in EAC. WEE1 was found to be aberrantly overexpressed and mislocalized to the cytoplasm in EAC cell lines and patient samples. WEE1 depletion or inhibition by MK-1775 significantly reduced MYC protein levels and transcriptional activity by promoting proteasome-mediated degradation. Mechanistically, WEE1 inhibition activated GSK3β, leading to phosphorylation of MYC at threonine 58 and subsequent ubiquitin-dependent degradation. In contrast, overexpression of wild-type WEE1, but not a kinase-dead mutant (K328A), increased p-CDC2 (Y15) and MYC protein levels, confirming that WEE1's kinase activity is essential for maintaining MYC stability. WEE1 inhibition also downregulated the MYC-ABCC1 axis, decreased MRP1 expression, and impaired drug efflux. A high-throughput screen of 892 FDA-approved compounds identified the histone deacetylase inhibitor Panobinostat as a potent synergistic partner of MK-1775. Combination treatment induced robust apoptosis and markedly suppressed tumor growth in EAC organoids and patient-derived xenograft models. These findings reveal a novel cytoplasmic function of WEE1 in sustaining MYC stability and chemoresistance. Targeting WEE1 destabilizes MYC and enhances therapeutic response, supporting the combination of MK-1775 and Panobinostat as a promising treatment strategy for EAC.