Han-Xiang Zhan and Lin Cong contributed equally to this work.
Activated mTOR/P70S6K signaling pathway is involved in insulinoma tumorigenesis†
Article first published online: 18 JUN 2012
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Surgical Oncology
Volume 106, Issue 8, pages 972–980, 15 December 2012
How to Cite
Zhan, H.-X., Cong, L., Zhao, Y.-P., Zhang, T.-P., Chen, G., Zhou, L. and Guo, J.-C. (2012), Activated mTOR/P70S6K signaling pathway is involved in insulinoma tumorigenesis. J. Surg. Oncol., 106: 972–980. doi: 10.1002/jso.23176
- Issue published online: 14 NOV 2012
- Article first published online: 18 JUN 2012
- Manuscript Accepted: 10 MAY 2012
- Manuscript Received: 6 FEB 2012
Insulinoma was a rare tumor and its pathogenesis was poorly understood. There had no study that focused on the role of mTOR signaling pathway in insulinoma tumorigenesis.
Materials and Methods
Expression of p-mTOR and its downstream p-P70S6K in insulinoma and normal pancreatic tissue was evaluated by immunohistochemical staining and Western blotting. In vitro study, an insulinoma cell line (INS-1) was treated with inhibitors of mTOR (rapamycin) or dual PI3K/mTOR inhibitor (NVP-BEZ235), RT-PCR, and Western blotting were applied to evaluate their influence on the expression of mTOR and P70S6K. Cell proliferation was evaluated by MTT test, cell cycle and apoptosis were analyzed by flow cytometry, insulin secretion level was evaluated by GSIS method.
Positive expression of p-mTOR and p-P70S6K was much higher in insulinoma tumor specimens than the normal pancreatic islet (P < 0.05). mTOR inhibitors can induce decreased expression of mTOR and P70S6K, which resulting in inhibiting INS-1 cell proliferation, insulin secretion and inducing apoptosis. NVP-BEZ235 had better influence on inhibiting the cell proliferation and inducing apoptosis than rapamycin.
mTOR/P70S6K signaling pathway is involved in tumorigenesis of insulinoma, NVP-BEZ235 and rapamycin offer a promising role as novel drugs in treatment of insulinoma. J. Surg. Oncol. 2012; 106: 972–980. © 2012 Wiley Periodicals, Inc.