1-Oxoeudesm-11(13)-eno-12,8a-lactone induces G2/M arrest and apoptosis of human glioblastoma cells in vitro

Abstract

Aim:To investigate the effects of 1-oxoeudesm-11(13)eno-12,8a-lactone (OEL), a novel eudesmane-type sesquiterpene isolated from Aster himalaicus, on the cell cycle and apoptosis in human glioblastoma cells in vitro. Methods: Human malignant glioblastoma cell lines U87 and A172 were used. The cytotoxicity of OEL was examined using the MTT assay. Cell apoptosis was assessed with DAPI staining and flow cytometry. DNA damage was determined by measuring the phosphorylation of H2AX using immunofluorescence staining and Western blotting. Cell cycle profiles were measured with flow cytometry. The mRNA expression of p53 and p21Waf1/Cip1 was investigated using real-time PCR. The protein expression of γ-H2AX, caspase-9, caspase-3, p53, p21Waf1/Cip1, cyclin B1, and cdc2 was analyzed with Western blotting. Results: Treatment of the malignant glioblastoma cells with OEL inhibited the cell growth in dose-and time-dependent manners (the values of IC 50 at 48 and 72 h were 29.5 and 16.99 μmol/L, respectively, in U87 cells; 7.2 and 9.5 μmol/L, respectively, in A172 cells). OEL (10-30μmol/L) induced apoptosis and G 2 /M phase arrest in both U87 and A172 cells. OEL induced the phosphorylation of cdc2, a G 2 /M phase cyclin-dependent kinase, and decreased the expression of cyclin B1 required for progression through the G 2 /M phase in U87 cells. The compound remarkably increased the phosphorylation of H2AX in U87 cells. Moreover, OEL increased the mRNA and protein levels of p53 and its target gene p21Waf1/Cip1 in U87 cells. The compound also induced p53 phosphorylation. Pretreatment with PFT-α, a specific inhibitor of p53 transcriptional activity, could partially reverse the inhibition of OEL on the viability of U87 and A172 cells. Conclusion: OEL suppresses the growth of human glioblastoma cells in vitro via inducing DNA damage, p53-mediated cell cycle arrest and apoptosis, thus warrants further studies as a lead compound of anti-glioblastoma drug.

Telekin suppresses human hepatocellular carcinoma cells in vitro by inducing G2/M phase arrest via the p38 MAPK signaling pathway

“…Cyclin B1 is likely the primary regulator of mammalian mitosis [28] . Some chemical compounds have been reported to induce G 2 /M phase arrest by decreasing the intracellular levels of Cyclin B1 [29,30] , which is consistent with our work. In this study, telekin induced a decrease in Cyclin B1 mRNA and protein levels.…”

Novel tetrahydroacridine and cyclopentaquinoline derivatives with fluorobenzoic acid moiety induce cell cycle arrest and apoptosis in lung cancer cells by activation of DNA damage signaling

“…38 Our results just showed that new acridine compounds activate p53 which can activate the transcription of a variety of apoptosis-associated genes including Bax when DNA damage exceeds the repair capacity of the cell to induce apoptosis. 30 Analysis of expression of these proteins in cancer cells treated with tested compounds demonstrated increased expression of pro-apoptotic protein Bax and down-regulation of anti-apoptotic protein Bcl-2. Our results also showed that changes in the levels of Bax and Bcl-2 expression were associated with the activation of p53 in A549 cells in response to treatment with all tested compounds.…”

“…p53 acts as a nuclear transcription factor and transactivates multiple genes involved in apoptosis and cell cycle regulation. 30 To evaluate the effect of new compounds on p53 activation, A549 cells were cultured in the presence of acridine derivatives for 0.5 and 1 h at IC 50 and 25 µM concentration. Western blotting results showed a significantly increased p53 phosphorylation at Ser15 in response to all compounds treatment in dose-dependent manner ( Figure 2).…”

Quercetin sensitizes human glioblastoma cells to temozolomide in vitro via inhibition of Hsp27

“…The prognosis for GBM patients remains poor, with a median overall survival of 9.9 to 10.2 months after surgery and an average survival time of only 12 to 15 months [1][2][3] , despite progress in the development of surgical techniques and even with the standard chemotherapy of temozolomide (TMZ) plus radiotherapy. TMZ is an orally delivered alkylating agent that is considered the most efficient drug in GBM therapy.…”