Search

Background: Temozolomide (TMZ)-based chemotherapy represents an effective way for treating human glioma. However, its clinical application is limited because of its side effects and resistance to standard chemotherapy. Hence, the search for novel chemosensitizers to augment their anticancer efficiency has attracted much attention. Natural borneol (NB) has been identified as a potential chemosensitizer in treating human cancers. However, the synergistic effect and mechanism of NB and TMZ in human glioma have not been investigated yet. Materials and methods: U251 human glioma cells were cultured, and the cytotoxicity and apoptosis of NB and/or TMZ were examined by MTT assay, flow cytometric analysis and Western blot. Nude mice tumor model was also employed to evaluate the in vivo anticancer effect and mechanism. Results: The results showed that the combined treatment of NB and TMZ more effectively inhibited human glioma growth via triggering mitochondria-mediated apoptosis in vitro, accompanied by the caspase activation. Combined treatment of NB and TMZ also caused mitochondrial dysfunction through disturbing Bcl-2 family expression. Further investigation revealed that NB enhanced TMZ-induced DNA damage through inducing reactive oxide species (ROS) overproduction. Moreover, glioma tumor xenograft growth in vivo was more effectively inhibited by the combined treatment with NB and TMZ through triggering apoptosis and anti-angiogenesis. Conclusion: Taken together, our findings validated that the strategy of using NB and TMZ could be a highly efficient way to achieve anticancer synergism. [ABSTRACT FROM AUTHOR]

NT157, a small-molecule tyrosine kinase inhibitor, exhibits broad-spectrum anti-tumor activity. However, NT157-mediated inhibition against glioma has not been explored yet. Herein, the anticancer effects and underlying mechanism of NT157 against human giloma growth were evaluated. The results showed that NT157 alone significantly inhibited glioma cells growth in vitro by lunching cell cycle arrest through up-regulating p21 and p27, and down-regulating cell cycle-related factors. NT157 alone also induced significant glioma cells apoptosis, followed by PARP cleavage and caspase-3 activation. Our findings further revealed that NT157 triggered significant DNA damage and dysfunction of PI3K/AKT, MAPKs and EGFR-STAT3 signaling pathways. Addition of several kinases inhibitors effectively abrogated NT157-induced DR5 up-regulation, which further confirmed the significant role of DR5 pathway. Moreover, combined treatment of NT157 and TRAIL showed enhanced apoptosis against U251 and U87 cells. However, Knockdown of DR5 expression significantly attenuated combined treatment-induced PARP cleavage and caspase-3 activation. Importantly, combined administration of NT157 and TRAIL in vivo effectively inhibited glioma xenograft growth of nude mice by inhibiting cell proliferation and angiogenesis, and inducing DNA damage and apoptosis. Taken together, our findings validated the rational design that combined strategy of NT157 and TRAIL to trigger DNA damage and apoptosis by up-regulating DR5 could be a high efficient way to combat human glioma. [Display omitted] • NT157 induced glioma cell cycle arrest and apoptosis. • NT157 enhanced TRAIL's anticancer effect by activating ROS and DR5 expression. [ABSTRACT FROM AUTHOR]

Due to the increasing incidence of malignant gliomas, particularly glioblastoma multiforme (GBM), a simple and reliable GBM diagnosis is needed to screen early the death-threaten patients. This study aimed to identify a protein that can be used to discriminate GBM from low-grade astrocytoma and elucidate further that it has a functional role during malignant glioma progressions. To identify proteins that display low or no expression in low-grade astrocytoma but elevated levels in GBM, glycoprotein fibronectin (FN) was particularly examined according to the mining of the Human Protein Atlas. Web-based open megadata minings revealed that FN was mainly mutated in the cBio Cancer Genomic Portal but dominantly overexpressed in the ONCOMINE (a cancer microarray database and integrated data-mining platform) in distinct tumor types. Furthermore, numerous different cancer patients with high FN indeed exhibited a poor prognosis in the PrognoScan mining, indicating that FN involves in tumor malignancy. To investigate further the significance of FN expression in glioma progression, tumor specimens from five malignant gliomas with recurrences that received at least two surgeries were enrolled and examined. The immunohistochemical staining showed that FN expression indeed determined the distinct progressions of malignant gliomas. Furthermore, the expression of vimentin (VIM), a mesenchymal protein that is strongly expressed in malignant cancers, was similar to the FN pattern. Moreover, the level of epithelial–mesenchymal transition (EMT) inducer transforming growth factor-beta (TGF-β) was almost recapitulated with the FN expression. Together, this study identifies a protein FN that can be used to diagnose GBM from low-grade astrocytoma; moreover, its expression functionally determines the malignant glioma progressions via TGF-β-induced EMT pathway. [ABSTRACT FROM AUTHOR]