casticin and Urinary-Bladder-Neoplasms

Casticin shows anti-cancer effects in many types of cancer. However, there is no information regarding its role in DNA damage in human bladder cancer. The aim of this study was to investigate the effects of casticin on TSGH-8301 cells in vitro.. Viability of cells was assayed by flow cytometry. DNA damage was assayed by DAPI staining, comet assay, and gel electrophoresis. Protein levels were examined by western blotting and confocal laser microscopy.. Casticin decreased viability of cells and induced DNA damage. Furthermore, casticin decreased expression of p-ATM, p-ATR, MDC1 and MGMT levels after 48 h of treatment, however, it increased p-ATR and MGMT levels after 12 h. In contrast, casticin increased the levels of p-p53, p-H2A.X, and PARP after 48 h of treatment. As shown by confocal microscopy, casticin affected the translocation of DNA-PKcs and p-p53 to the nucleus of TSGH-8301 cells.. Casticin decreased viability of human bladder cancer cells through DNA damage.

Topics: Active Transport, Cell Nucleus; Adaptor Proteins, Signal Transducing; Antineoplastic Agents, Phytogenic; Ataxia Telangiectasia Mutated Proteins; Cell Cycle Proteins; Cell Line, Tumor; Cell Survival; DNA Damage; DNA Modification Methylases; DNA Repair; DNA Repair Enzymes; DNA-Activated Protein Kinase; Flavonoids; Histones; Humans; Nuclear Proteins; Phosphorylation; Poly(ADP-ribose) Polymerases; Trans-Activators; Tumor Suppressor Protein p53; Tumor Suppressor Proteins; Urinary Bladder Neoplasms

The p53 family protein p73 plays an important role in apoptosis induced by chemotherapeutic drugs. Transcriptionally active (TA) p73 (TAp73) substitutes for p53 in the response to stress. XIAP associated factor 1 (XAF1) is a novel predictive and prognostic factor in patients with bladder cancer, but the association between TAp73 and XAF1 expression in bladder cancer cells is poorly understood. Here, we investigated the status of TAp73 and XAF1 in T24 bladder cancer cells to identify molecular mechanisms in casticin‑exposed T24 cells. Casticin induced activation of JNK/p38 MAPK that preceded activation of the caspase cascade and disruption of the mitochondria membrane potential (∆ψm). Expression of XAF1 and TAp73 was also upregulated in casticin-treated T24 cells. Casticin treatment of T24 cells induced receptor-interacting protein (RIP) kinase expression and increased intracellular production of reactive oxygen species (ROS). Casticin-mediated ROS induced an increase in phosphorylated JNK/p38 MAPK, resulting in progressive upregulation of TAp73, which in turn led to XAF1 expression. Our data suggest that the apoptotic activity of casticin in T24 cells is mediated by activation of the TAp73-XAF1 signaling pathway through RIP kinase-mediated ROS production.

Topics: Adaptor Proteins, Signal Transducing; Apoptosis; Apoptosis Regulatory Proteins; Caspases; Cell Line, Tumor; Flavonoids; Humans; Intracellular Signaling Peptides and Proteins; JNK Mitogen-Activated Protein Kinases; Membrane Potential, Mitochondrial; Mitochondria; Neoplasm Proteins; Phosphorylation; Reactive Oxygen Species; Receptor-Interacting Protein Serine-Threonine Kinases; Signal Transduction; Tumor Protein p73; Tumor Suppressor Protein p53; Up-Regulation; Urinary Bladder Neoplasms