epidermal-growth-factor and parthenolide

The expression of cytokines, such as IL-1β, and the activation of the epidermal growth factor receptor (EGFR) are crucial regulators in the process of carcinogenesis. The correlation between growth factor and activated cytokine signals in the control of tumor development is a critical issue to be clarified. In our study, we found that the IL-1β gene and protein expression were induced by EGF in squamous cell carcinoma. To clarify the mechanism involved in EGF-regulated IL-1β expression, we examined the transcriptional activity and mRNA stability of IL-1β in EGF-treated cells. We found that EGF induced the expression of IL-1β and was mediated through transcriptional activation, but not through mRNA stability. The involvement of Akt and NF-κB signaling pathways in the EGF-induced IL-1β gene expression was confirmed by knockdown of RelA and Akt in cells or treating cells with Akt and NF-κB inhibitors, LY294002 and parthenolide, respectively. The expression of dominant negative IκB also repressed the activation of NF-κB and inhibited EGF-induced IL-1β expression. Using immunofluorescence staining assay, the EGF-stimulated nuclear translocation of NF-κB (p65) was inhibited by pre-treating cells with LY294002 and parthenolide. Furthermore, EGF increased the binding of NF-κB to the NF-κB binding site of the IL-1β promoter through the activation of the Akt/NF-κB pathway, which resulted in activating IL-1β promoter activity. The expression and secretion of IL-1β induced by EGF considerably reduced chemotherapeutic drug cisplatin-induced cell death. These results showed that EGF enhanced the expression of IL-1β, which was mediated by the Akt/NF-κB pathway. The activation of EGF signaling and increase of IL-1β contributed to chemotherapeutic resistance of cancer cells, suggesting that the expression of IL-1β may be used as a biomarker to evaluate successful cancer treatment.

Topics: Biomarkers, Tumor; Blotting, Western; Carcinoma, Squamous Cell; Chromones; Cisplatin; Cytotoxins; DNA Primers; Enzyme-Linked Immunosorbent Assay; Epidermal Growth Factor; ErbB Receptors; Flow Cytometry; Fluorescent Antibody Technique; Gene Expression Regulation, Neoplastic; Humans; Interleukin-1beta; Morpholines; NF-kappa B; Oncogene Protein v-akt; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA Interference; RNA, Small Interfering; Sesquiterpenes; Signal Transduction

The expression of major histocompatibility complex (MHC) on human neural stem cells (hNSCs) is tightly related to the fate of these cells in transplantation, therefore strategies to relieve rejection and promote graft survival are necessary to be applied. This study investigated the effect of carbamylated erythropoietin (CEPO) on MHC expression and differentiation of hNSCs with or without IFN-gamma incubation. Results showed that low levels of MHC molecules were expressed on hNSCs and increased by IFN-gamma. CEPO enhanced MHC-I antigens in both proliferative and differentiated hNSCs, but decreased MHC-II antigens in differentiated hNSCs and those cells exposed to IFN-gamma. Furthermore, CEPO promoted neural differentiation of hNSCs and outgrowth of neurites. Western blot analysis revealed activation of Stat3, Stat5 and Akt during these processes. These results suggest that CEPO may have immunoregulatory function in hNSCs besides its neuroprotection.

Topics: Androstadienes; Anti-Inflammatory Agents, Non-Steroidal; Cell Differentiation; Cells, Cultured; Cytokines; Embryonic Stem Cells; Epidermal Growth Factor; Erythropoietin; Fetus; Fibroblast Growth Factor 2; Flow Cytometry; Gene Expression Regulation, Developmental; Histocompatibility Antigens; Humans; Immunosuppressive Agents; Nerve Tissue Proteins; Neurites; Neurons; Sesquiterpenes; Wortmannin

Stromelysin-1 belongs to matrix metalloproteinases responsible for proteolytic degradation of extracellular matrix in many tissues during various diseases, especially those involving inflammation. We studied the induced expression of stromelysin-1 in primary cultures of mouse brain astrocytes stimulated with various cytokines and cellular growth factors. Interleukin-1-beta (IL-1beta), tumor necrosis factor alpha (TNFalpha) and a mixture of IL-1, TNF and epidermal growth factor (EGF) significantly increased the level of stromelysin-1 mRNA in mouse astrocytes while interferon-gamma (IFN-gamma) inhibited this response or was without effect. This accumulation of specific mRNA was preceded by activation of two examined transcription factors: NFkappaB and AP-1. However, experiments with known inhibitors of activation of these transcription factors: pyrrolidine dithiocarbamate (PDTC), parthenolide and curcumin, indicate that NFkappaB and AP-1 cannot be solely responsible for the cytokine induced expression of stromelysin-1 gene in mouse astrocytes.

Topics: Animals; Astrocytes; Brain; Brain Chemistry; Cell Culture Techniques; Curcumin; Cytokines; Drug Synergism; Epidermal Growth Factor; Gene Expression Regulation; Inflammation Mediators; Interferon-gamma; Interleukin-1; Matrix Metalloproteinase 3; Mice; NF-kappa B; Pyrrolidines; RNA, Messenger; Sesquiterpenes; Thiocarbamates; Time Factors; Transcription Factor AP-1; Tumor Necrosis Factor-alpha