ABSTRACT
Apoptosis has an important role in maintaining tissue homeostasis in cellular stress responses such as inflammation, endoplasmic reticulum stress, and oxidative stress. T-cell death-associated gene 51 (TDAG51) is a member of the pleckstrin homology-like domain family and was first identified as a pro-apoptotic gene in T-cell receptor-mediated cell death. However, its pro-apoptotic function remains controversial. In this study, we investigated the role of TDAG51 in oxidative stress-induced apoptotic cell death in mouse embryonic fibroblasts (MEFs). TDAG51 expression was highly increased by oxidative stress responses. In response to oxidative stress, the production of intracellular reactive oxygen species was significantly enhanced in TDAG51-deficient MEFs, resulting in the activation of caspase-3. Thus, TDAG51 deficiency promotes apoptotic cell death in MEFs, and these results indicate that TDAG51 has a protective role in oxidative stress-induced cell death in MEFs.
Subject(s)
Apoptosis , Embryo, Mammalian/cytology , Fibroblasts/metabolism , Oxidative Stress , Reactive Oxygen Species/metabolism , Transcription Factors/deficiency , Animals , Fibroblasts/enzymology , Fibroblasts/pathology , Gene Expression Regulation , Intracellular Space/metabolism , Mice , Mitogen-Activated Protein Kinases/metabolism , NF-kappa B/metabolism , Oxidative Stress/genetics , Signal Transduction , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
Magneto-fluorescent silica nanoparticles were conjugated with cetuximab for the targeting and imaging of colon cancer. In this study, cetuximab-conjugated magneto-fluorescent nanoparticles (MFSN-Ctx) could specifically target colon cancer cells that expressed EGFR on their cell membranes, and specific fluorescence was detected. MFSN-Ctx produced significant MRI signal changes in a human colon cancer xenograft mouse model. Intravenous injection of MFSN-Ctx resulted in faster uptake as compared to intraperitoneal injection, indicating that MFSN-Ctx had different kinetic properties in tumors based on the method of injection. The local concentration of MFSN-Ctx in a tumor was amplified by the use of an external magnetic field. These results demonstrate the potential application of MFSN-Ctx for the detection of EGFR-expressing colon cancer using in vivo imaging approaches.
