PSK induces apoptosis through the inhibition of activated STAT3 in human esophageal carcinoma cells
PSK, a protein-bound polysaccharide, is widely used in Japan as an immunopotentiating biological response modifier for cancer patients. PSK exerts antitumor activities through stimulation of the host's immune response; however, few studies have addressed the direct actions of PSK on tumor cells. Recently, it has been found that STAT3 is aberrantly activated in various types of malignancies, and plays a crucial role in tumor cell proliferation and survival. In the present study, STAT3 was constitutively activated in KYSE170 and TE13 esophageal carcinoma cells, and PSK inhibited proliferation and induced apoptosis in these cells in a dose-dependent manner. Based on these findings, the relationship between STAT3 and apoptosis in these cells was investigated. Results showed that PSK inhibited the expression of activated STAT3 and stimulated the expression of pro-apoptotic Bax in a dose-dependent manner, without affecting the expression of anti-apoptotic Bcl-xL and Mcl-1. These results indicate that PSK may induce apoptosis in esophageal carcinoma cells by inhibiting the expression of activated STAT3.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Affiliations: Division of Digestive Surgery, Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
Publication date: January 1, 2012
More about this publication?
- The International Journal of Oncology provides an international forum for the publication of the latest, cutting-edge research in the broad area of oncology and cancer treatment. The journal accepts original high quality works and reviews on all aspects of oncology research including carcinogenesis, metastasis, epidemiology, chemotherapy and viral oncology. Through fair and efficient peer review, the journal is dedicated to publishing top tier research in the field, offering authors rapid publication as well as high standards of copy-editing and production. The International Journal of Oncology is published on a monthly basis in both print and early online.
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Information for Advertisers
- Terms & Conditions
- Ingenta Connect is not responsible for the content or availability of external websites