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Xue H, Yuan G, Guo X, Liu Q, Zhang J, Gao X, Guo X, Xu S, Li T, Shao Q, Yan S, Li G. A novel tumor-promoting mechanism of IL6 and the therapeutic efficacy of tocilizumab: Hypoxia-induced IL6 is a potent autophagy initiator in glioblastoma via the p-STAT3-MIR155-3p-CREBRF pathway. Autophagy 2016; 12:1129-52. [PMID: 27163161 PMCID: PMC4990999 DOI: 10.1080/15548627.2016.1178446] [Citation(s) in RCA: 104] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Hypoxia induces protective autophagy in glioblastoma cells and new therapeutic avenues that target this process may improve the outcome for glioblastoma patients. Recent studies have suggested that the autophagic process is upregulated in glioblastomas in response to extensive hypoxia. Hypoxia also induces the upregulation of a specific set of proteins and microRNAs (miRNAs) in a variety of cell types. IL6 (interleukin 6), an inflammatory autocrine and paracrine cytokine that is overexpressed in glioblastoma, has been reported to be a biomarker for poor prognosis because of its tumor-promoting effects. Here, we describe a novel tumor-promoting mechanism of IL6, whereby hypoxia-induced IL6 acts as a potent initiator of autophagy in glioblastoma via the phosphorylated (p)-STAT3-MIR155-3p pathway. IL6 and p-STAT3 levels correlated with the abundance of autophagic cells and HIF1A levels in human glioma tissues and with the grade of human glioma, whereas inhibition of exogenous or endogenous IL6 repressed autophagy in glioblastoma cells in vitro. Knockdown of endogenous MIR155-3p inhibited IL6-induced autophagy, and enforced expression of MIR155-3p restored the anti-autophagic activity of IL6 inhibitors. We show that the hypoxia-IL6-p-STAT3-MIR155-3p-CREBRF-CREB3-ATG5 pathway plays a central role in malignant glioma progression, with blockade of the IL6 receptor by tocilizumab demonstrating a certain level of therapeutic efficacy in a xenograft model in vivo, especially in combination with temozolomide. Moreover, tocilizumab inhibits autophagy by promoting tumor apoptosis. Collectively, our findings provide new insight into the molecular mechanisms underlying hypoxia-induced glioma cell autophagy and point toward a possible efficacious adjuvant therapy for glioblastoma patients.
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Affiliation(s)
- Hao Xue
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China.,b Brain Science Research Institute, Shandong University , Jinan , Shandong Province , China
| | - Guang Yuan
- c Department of Neurosurgery , Central Hospital of Zibo City , Zibo , Shandong Province , China
| | - Xing Guo
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China.,b Brain Science Research Institute, Shandong University , Jinan , Shandong Province , China
| | - Qinglin Liu
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China
| | - Jinsen Zhang
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China.,b Brain Science Research Institute, Shandong University , Jinan , Shandong Province , China
| | - Xiao Gao
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China
| | - Xiaofan Guo
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China
| | - Shugang Xu
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China.,d Department of Neurosurgery , Dezhou People's Hospital , Dezhou , Shandong Province , China
| | - Tong Li
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China
| | - Qianqian Shao
- e Institute of Basic Medical Sciences and Key Laboratory of Cardiovascular Proteomics of Shandong Province, Qilu Hospital of Shandong University , Jinan , Shandong Province , China
| | - Shaofeng Yan
- b Brain Science Research Institute, Shandong University , Jinan , Shandong Province , China
| | - Gang Li
- a Department of Neurosurgery , Qilu Hospital of Shandong University , Jinan , Shandong Province , China.,b Brain Science Research Institute, Shandong University , Jinan , Shandong Province , China
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Itakura G, Kobayashi Y, Nishimura S, Iwai H, Takano M, Iwanami A, Toyama Y, Okano H, Nakamura M. Control of the Survival and Growth of Human Glioblastoma Grafted Into the Spinal Cord of Mice by Taking Advantage of Immunorejection. Cell Transplant 2014; 24:1299-311. [PMID: 24818989 DOI: 10.3727/096368914x681711] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Recent studies have demonstrated that transplantation of induced pluripotent stem cell-derived neurospheres can promote functional recovery after spinal cord injury in rodents, as well as in nonhuman primates. However, the potential tumorigenicity of the transplanted cells remains a matter of apprehension prior to clinical applications. As a first step to overcome this concern, this study established a glioblastoma multiforme xenograft model mouse. The feasibility of controlling immune suppression to ablate the grafted cells was then investigated. The human glioblastoma multiforme cell line U251 MG was transplanted into the intact spinal cords of immunodeficient NOD/SCID mice or into those of immunocompetent C57BL/6J H-2kb mice treated with or without immunosuppressants [FK506 plus anticluster of differentiation (CD) 4 antibody (Ab), or FK506 alone]. In vivo bioluminescent imaging was used to evaluate the chronological survival of the transplanted cells. The graft survival rate was 100% (n = 9/9) in NOD/SCID mice, 0% (n = 6/6) in C57BL/6J mice without immunosuppressant treatment, and 100% (n = 37/37) in C57BL6/J mice with immunosuppressant treatment. After confirming the growth of the grafted cells in the C57/BL6J mice treated with immunosuppressants, immune suppression was discontinued. The grafted cells were subsequently rejected within 3 days in C57BL/6J mice treated with FK506 alone, as opposed to 26 days in C57BL/6J mice treated with FK506 plus anti-CD4 Ab. Histological evaluation confirmed the ablation of the grafted cells. Although this work describes a xenograft setting, the results suggest that this immunomodulatory strategy could provide a safety lock against tumor formation stemming from transplanted cells.
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Affiliation(s)
- Go Itakura
- Department of Orthopaedic Surgery, Keio University School of Medicine, Shinjuku, Tokyo, Japan
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Vasco C, Canazza A, Rizzo A, Mossa A, Corsini E, Silvani A, Fariselli L, Salmaggi A, Ciusani E. Circulating T regulatory cells migration and phenotype in glioblastoma patients: an in vitro study. J Neurooncol 2013; 115:353-63. [DOI: 10.1007/s11060-013-1236-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 08/25/2013] [Indexed: 12/20/2022]
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