Colorectal Cancer
Copyright ©The Author(s) 2004. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 1, 2004; 10(11): 1569-1573
Published online Jun 1, 2004. doi: 10.3748/wjg.v10.i11.1569
Constitutive activation of Stat3 signaling pathway in human colorectal carcinoma
Xiang-Tao Ma, Shan Wang, Ying-Jiang Ye, Ru-Yu Du, Zhi-Rong Cui, Ma Somsouk
Xiang-Tao Ma, Shan Wang, Ying-Jiang Ye, Ru-Yu Du, Department of Surgery, Peking University People’s Hospital, Beijing 100044, China
Zhi-Rong Cui, Division of Surgical Oncology, Peking University People’s Hospital, Beijing 100044, China
Ma Somsouk, Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, 32 Fruit Street, Boston, MA 02114, USA
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Foundation of China, No. 30271269
Correspondence to: Dr. Shan Wang, Department of Surgery, Peking University People’s Hospital, Beijing 100044, China. shwang60@sina.com
Telephone: +86-10-68792772 Fax: +86-10-68318386
Received: October 24, 2003
Revised: December 4, 2003
Accepted: December 8, 2003
Published online: June 1, 2004
Abstract

AIM: Signal transducers and activators of transcription (STATs) are a family of transcription factors activated in response to cytokines and growth factors. Constitutive activation of Stat3 has been observed in a growing number of tumor-derived cell lines, as well as tumor specimens from human cancers. The purpose of this study was to investigate the expression of p-Stat3, activated form of Stat3, and its downstream mediators including cyclin D1 and Bcl-xL in colorectal carcinoma (CRC), and to explore the possible mechanism of Stat3 signaling pathway in the tumorigenesis of colorectal carcinoma.

METHODS: Tissue samples from 45 patients of primary colorectal carcinoma were selected for studying Stat3 signaling pathway protein expression. Western blot analysis was used to measure the expression of p-Stat3, cyclin D1, and Bcl-xL proteins in colorectal carcinomas. Furthermore, the expression patterns of these proteins were analyzed for their distribution at the cellular level by immunohistochemical staining of the tissues.

RESULTS: Protein levels of p-Stat3, cyclin D1, and Bcl-xL were increased in colorectal carcinomas compared with adjacent normal mucosae (P < 0.05). Elevated levels of p-Stat3 were correlated with the nodal metastasis and the stage (P < 0.05). Overexpression of cyclin D1 was associated with the nodal metastasis (P < 0.05). There was also a significant correlation between the expressions of p-Stat3 and cyclin D1 (r = 0.382, P < 0.05).

CONCLUSION: Constitutive activation of Stat3 may play an important role in the tumorigenesis of colorectal carcinoma, and the detailed mechanism of Stat3 signaling pathway in CRC deserves further investigation.

Keywords: $[Keywords]