Lei Zhang, Xiaopeng Ding, Jin Huang, Chen Jiang, Boqiang Cao, Yu Qian, Chao Cheng, Minchao Dai, Xiaoyi Guo and Junfei Shao Pages 119 - 125 ( 7 )
Within the last decade, extensive research has revealed that curcumin can increase the sensitivity of tumor cells to high-energy X-ray radiation in vitro and dual-specificity phosphatase (DUSPs) are implicated in cancer, obesity, diabetes, inflammation and Alzheimer’s disease. To date, the article about the radiosensitizing effect of curcumin via enhancement of the DUSP-2 pathway was rarely reported. Here, we discuss the radiosensitizing effects of curcumin on suppressing glioma vivo growth. BALB-c nude mice bearing subcutaneous U87 xenografts were treated with curcumin and/or local radiation to assess their vivo response. Tumor growth, real-time PCR, western blotting, immunohistochemical assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) were performed to explore the possible mechanism involved. Curcumin in combination with irradiation significantly enhanced the tumor-suppressive effect in vivo compared with local radiotherapy alone. Both mRNA and protein levels of DUSP-2 were significantly upregulated in the curcumin in combination with radiation treatment group. Curcumin pretreatment inhibited radiationinduced extracellular signal-regulated kinases (ERK)/c-Jun N-terminal kinases (JNK) phosphorylation and enhanced radiation-induced tumor cell apoptosis in subcutaneous xenografts. In conclusion, curcumin significantly increased the radiosensitivity of U87 human glioma cells in vivo. The radiosensitizing effect of curcumin was found to be closely related to its pro-apoptosis activity via enhancement of the DUSP-2 pathway.
Apoptosis, curcumin, dual specificity phosphatase 2, glioma, radiosensitization.
Department of Neurosurgery, Nanjing Medical University Affiliated Wuxi People’s Hospital, 299 Qingyang Road, Wuxi 214194, China.