beta-elemene and Glioma

Elemene is a second-line broad-spectrum anti-tumour drug that has been used in China for more than two decades. However, its main anti-tumour ingredient, β-elemene, has disadvantages, including excessive lipophilicity and relatively weak anti-tumour efficacy. To improve the anti-tumour activity of β-elemene, based on its minor molecular weight character, we introduced furoxan nitric oxide (NO) donors into the β-elemene structure and designed six series of new generation β-elemene NO donor hybrids. The synthesised compounds could effectively release NO

Topics: Animals; Antineoplastic Agents; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Glioma; Humans; Mice; Mice, Nude; Molecular Structure; Neoplasms, Experimental; Nitric Oxide; Oxadiazoles; Sesquiterpenes; Structure-Activity Relationship

Glioma is the most frequent primary central nervous system tumor. Although the current first-line medicine, temozolomide (TMZ), promotes patient survival, drug resistance develops easily. Thus, it is important to investigate novel therapeutic reagents to solidify the treatment effect. β-Elemene (bELE) is a compound from a Chinese herb whose anticancer effect has been shown in various types of cancer. However, its role in the inhibition of glioma stem-like cells (GSLCs) has not yet been reported. We studied both the in vitro and the in vivo inhibitory effect of bELE and TMZ in GSLCs and parental cells and their combined effects. The molecular mechanisms were also investigated. We also optimized the delivery methods of bELE. We found that bELE selectively inhibits the proliferation and sphere formation of GSLCs, other than parental glioma cells, and TMZ exerts its effects on parental cells instead of GSLCs. The in vivo data confirmed that the combination of bELE and TMZ worked better in the xenografts of GSLCs, mimicking the situation of tumorigenesis of human cancer. Notch1 was downregulated with bELE treatment. Our data also demonstrated that the continuous administration of bELE produces an ideal effect to control tumor progression. Our findings have demonstrated, for the first time, that bELE could compensate for TMZ to kill both GSLCs and nonstem-like cancer cells, probably improving the prognosis of glioma patients tremendously. Notch1 might be a downstream target of bELE. Therefore, our data shed light on improving the outcomes of glioma patients by combining bELE and TMZ. Stem Cells Translational Medicine 2017;6:830-839.

Topics: Animals; Carcinogenesis; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Down-Regulation; Drug Synergism; Glioma; Humans; Male; Mice, Nude; Neoplastic Stem Cells; Receptor, Notch1; Sesquiterpenes; Spheroids, Cellular; Temozolomide

β-elemene, extracted from herb medicine Curcuma wenyujin has potent anti-tumor effects in various cancer cell lines. However, the activity of β-elemene against glioma cells remains unclear. In the present study, we assessed effects of β-elemene on human glioma cells and explored the underlying mechanism.. Human glioma U87 cells were used. Cell proliferation was determined with MTT assay and colony formation assay to detect the effect of β-elemene at different doses and times. Fluorescence microscopy was used to observe cell apoptosis with Hoechst 33258 staining and change of glioma apoptosis and cell cycling were analyzed by flow cytometry. Real-time quantitative PCR and Western-blotting assay were performed to investigated the influence of β-elemene on expression levels of Fas/FasL, caspase-3, Bcl-2 and Bax. The experiment was divided into two groups: the blank control group and β-elemne treatment group.. With increase in the concentration of β-elemene, cytotoxic effects were enhanced in the glioma cell line and the concentration of inhibited cell viability (IC50) was 48.5 μg/mL for 24h. β-elemene could induce cell cycle arrest in the G0/G1 phase. With Hoechst 33258 staining, apoptotic nuclear morphological changes were observed. Activation of caspase-3,-8 and -9 was increased and the pro-apoptotic factors Fas/FasL and Bax were upregulated, while the anti-apoptotic Bcl-2 was downregulated after treatment with β-elemene at both mRNA and protein levels. Furthermore, proliferation and colony formation by U87 cells were inhibited by β-elemene in a time and does- dependent manner.. Our results indicate that β-elemene inhibits growth and induces apoptosis of human glioma cells in vitro. The induction of apoptosis appears to be related with the upregulation of Fas/FasL and Bax, activation of caspase-3,-8 and -9 and downregulation of Bcl-2, which then trigger major apoptotic cascades.

Topics: Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Caspases; Cell Line, Tumor; Down-Regulation; Drug Screening Assays, Antitumor; Fas Ligand Protein; fas Receptor; Glioma; Humans; In Vitro Techniques; Proto-Oncogene Proteins c-bcl-2; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sesquiterpenes; Up-Regulation

This study investigated the effects of β-elemene + methoxyamine, a DNA base-excision repair inhibitor, on the inhibition of glioma growth. We treated C6 and SHG44 glioma cells with β-elemene and methoxyamine individually or in combinations, and subsequently analyzed cellular survivals by MTT assay. Comet assay, γ-H2AX focus formation assay and Western-blot were performed to investigate whether the observed cytotoxicity was associates with DNA damages. Finally, a xenograft tumor model was established in nude mice with C6 cells to analyze in vivo tumor inhibition effects of β-elemene, which was followed by determination of the expression of anti-apoptotic protein Bcl-2 via immunohistochemistry staining. Results showed that β-elemene could significantly inhibit the growth of glioma cells in a dose- and time-dependent manner. The combination of methoxyamine with β-elemene could result in a greater extent of DNA injuries in vitro. Furthermore, in vivo tumors exhibited a marked shrinkage in volume in β-elemene + methoxyamine treatment group. Immunohistochemistry analysis of the tumor tissues showed a distinctive decrease in Bcl-2 staining in β-elemene (56 %) and β-elemene + methoxyamine (36 %) groups when compared with the negative control (77 %). In conclusion, β-elemene exhibits a significant cytotoxic effect against glioma cells both in vitro and in vivo, which is likely to be mediated by its potential to damage tumor cell DNA and activate apoptotic pathway. Such growth inhibition effect of β-elemene could be potentiated by methoxyamine co-administration. Therefore, a combination of the two agents as a novel chemotherapeutic option for glioma merits further investigations.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Blotting, Western; Cell Proliferation; Comet Assay; DNA Damage; DNA Repair; Female; Glioma; Humans; Hydroxylamines; Immunoenzyme Techniques; Mice; Mice, Nude; Sesquiterpenes; Tumor Cells, Cultured

β-elemene, extracted from the ginger plant, possesses antitumor activity against a broad range of cancers clinically. However, the mechanism underlying β-elemene-induced cytotoxicity remains incompletely understood. Here, we show that β-elemene promoted apoptotic cell death in human glioma cells, downregulated survivin gene expression, and induced caspase-9, -3 and -7 activities. Induction of apoptosis was associated with inhibition of survivin gene expression, and restoration of survivin levels remarkably attenuated β-elemene-induced glioma cell death. Moreover, we found that the interaction between surviving and HBXIP, a critical regulator of caspase-9 activity, was impaired by β-elemene treatment. The results, therefore, reveal a caspase-mediated apoptotic pathway induced by β-elemene in human glioma cells, which is associated with downregulation of survivin itself and the interaction between survivin and HBXP.

Topics: Adaptor Proteins, Signal Transducing; Apoptosis; Brain Neoplasms; Caspase 3; Caspase 7; Caspase 9; Cell Line, Tumor; Down-Regulation; Glioma; Humans; Inhibitor of Apoptosis Proteins; Plant Extracts; Poly(ADP-ribose) Polymerases; Sesquiterpenes; Survivin; Zingiber officinale