Cyclin D1 and cyclin E1, as vital regulatory factors of G1-S phase cell cycle progression, are frequently constitutive expressed and associated with pathogenesis and tumorigenesis in most human cancers and they have been regarded as promising targets for cancer therapy. In this study, we established NVP-BEZ235, a potent dual kinase inhibitor, could induce neuroblastoma cells proliferation inhibition without apoptosis activation. Moreover, we showed NVP-BEZ235 could induce neuroblastoma cells arrested at G0/G1 phase accompanied with significant reduction of the cyclin D1 and E1 proteins in a dose dependent manner at nanomole concentration. Additionally we found that GSK3β was dephosphorylated and activated by NVP-BEZ235 and then triggered cyclin D1 and cyclin E1 degradation through ubiquitination proteasome pathway, based on the evidences that NVP-BEZ235 induced downregulation of cyclin D1 and cyclin E1 were obviously recovered by proteasome inhibitor and the blockade of GSK3β contributed to remarkable rescue of cyclin D1 and cyclin E1. Analogous results about its anti-proliferation effects and molecular mechanism were observed on neuroblastoma xenograft mouse model in vivo. Therefore, these results indicate that NVP-BEZ235-induced cyclin D1 and cyclin E1 degradation, which happened through activating GSK3β, and GSK3β-dependent down-regulation of cyclin D1 and cyclin E1 should be available for anticancer therapeutics.
Gastric cancer cell are not particularly sensitive to Ara-C, a deoxycytidine analog that affects DNA synthesis. In the present study, AGS and MKN-45 gastric cancer cell lines were treated with Ara-C to determine its role in cell prolife-ration and apoptosis. The antiproliferative effect of Ara-C was assessed using the Cell Counting kit-8. Gelatinase zymography was utilized to detect the activity of MMP-2 and MMP-9, and an in vitro invasion assay was performed. Using RT-PCR, CD-147, MMP-2 and MPP-9 mRNA levels were assessed in AGS cells with various doses of Ara-C treatment. CD-147, MMP-2 and MMP-9 protein levels were analysed in Ara-C‑treated AGS and MKN-45 cells. AGS cells were treated with or without U-0126 or siRNA-CD147 and/or Ara-C for 24 h, and an in vitro invasion assay was performed. Although low-dose Ara-C had no obvious effect on cell proliferation, it upregulated the expression of MMP-2, MMP-9 and CD-147 and ERK activation. Low-dose Ara-C increased gastric cancer cell invasion. U-0126 and siRNA-CD-147 inhibited the induction of Ara-C in gastric cancer cell invasion. Therefore, Ara-C enhances the invasiveness of gastric cancer cells by expression of CD-147 /MMP-2 and MMP-9 via the ERK signaling pathway. The results are therefore useful in the prevention of Ara-C collateral damage associated with standard, conventional protocols of chemotherapy administration.
Abstract. The aberrant activation of PI3K/Akt/mTOR signaling pathway plays an important role in the oncogenesis, prognosis and chemotherapy resistance of neuroblastoma. However, NVP-BEZ235, a potent dual PI3K and mTOR inhibitor have not shown beneficial effects on neuroblastoma especially in terms of apoptosis induction as a single agent. We therefore attempted to explore an effective combination regimen to enhance the anticancer activity of NVP-BEZ235. Interestingly, we found that oridonin, a natural biologically active compound extracted from the Chinese medicinal herb Rabdosia rubescens, combined with NVP-BEZ235 markedly induced apoptosis of neuroblastoma cells. Notably, the synergistic activation of the apoptotic pathway was accompanied with enhanced autophagy as evidenced by significant decreased p62 expression as well as upregulated conversion of LC3-II. Suppression of the Beclin-1, a core component of the autophagy machinery, by means of shRNA resulted in diminished synergistic antitumor effect. Furthermore, the co-treatment with oridonin and NVP-BEZ235 was also much more effective than either agent alone in inhibiting the growth of neuroblastoma xenografts and in inducing tumor cells apoptosis. Taken together, our results suggest that the combination of NVP-BEZ235 and oridonin is a novel and potential strategy for neuroblastoma therapy.
Background: It is important to modulate the expression of glucocorticoids receptor (GR) in tress and maintain the immunity homeostasis in sepsis process. Rhubarb have been shown to have potential effects on anti-inflammatory and immune modulation. The present study was designed to investigate the effects of rhubarb on the expression of GR and cellular immunity in burn-induced septic rats. Methods: Sixty-six healthy male Sprague Dawley (SD) rats were randomized into sepsis group ( n = 24), rhubarb group ( n = 24), and control group ( n = 18); each group were further randomized into 12, 24, and 72 h subgroups according to different time points. During onset of the sepsis model, the rats in the rhubarb group were infused with 50 mg/kg rhubarb powder dissolved into 1 mL saline through gastric tube, while sepsis and control groups were treated with saline. The binding activity of GR in liver cytosol and binding capacity of GR in peripheral blood leucocyte were analyzed by radiation ligands binding assay. The percentages of CD4 + ,CD8 + ,CD4 + CD25 + T cells, CD19 + B cells as well as natural killer (NK) cells in the lymphocytes in peripheral blood were detected by flow cytometer. For assessing the differences among groups, one-way analysis of variance (ANOVA) with Scheffe multi-comparison techniques were employed. Comparisons between time-based measurements within each group were performed with ANOVA repeated measurement. Results: The binding activity of GR in liver cytosol and binding capacity of GR in peripheral blood leucocyte were significantly decreased in a time-dependent manner in sepsis group ( t = 23.045, P < 0.01; t = 24.395, P < 0.05, respectively), which were increased in a time-dependent manner after rhubarb administration ( t = 19.965, P < 0.05; t = 17.140, P < 0.05, respectively). Twelve hours after sepsis, the percentages of CD4 + T cells, CD4 + /CD25 + T cell ratio, and CD19 + B cells in the peripheral blood were significantly increased in the sepsis group ( t = −3.395, P < 0.01; t = 2.568, P < 0.05; t = 2.993, P < 0.05, vs. control mice, respectively). However, the percentage of NK cells in the peripheral blood were significantly decreased in the sepsis group ( t ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.