Open Access Highly Accessed Research article

Protein-bound polysaccharide from Phellinus linteus inhibits tumor growth, invasion, and angiogenesis and alters Wnt/β-catenin in SW480 human colon cancer cells

Kyoung-Sub Song1, Ge Li4, Jong-Seok Kim1, Kaipeng Jing1, Tae-Dong Kim1, Jin-Pyo Kim5, Seung-Bo Seo6, Jae-Kuk Yoo6, Hae-Duck Park7, Byung-Doo Hwang1, Kyu Lim123* and Wan-Hee Yoon1*

Author Affiliations

1 Department of Biochemistry, College of Medicine, Chungnam National University, Joong-gu, Daejeon 301-747, Korea

2 Cancer Research Institute, Chungnam National University, Joong-Ku, Daejeon 301-747, Korea

3 Infection Signaling Network Research Center, Chungnam National University, Joong-Ku, Daejeon 301-747, Korea

4 Department of General Surgery, Yanbian University Hospital, Jilin 133000, People's Republic of China

5 College of Pharmacy, Chungnam National University, Daejeon 301-747, Korea

6 Ja Kwang Research Institute, Hankook Sin Yak Pharmaceutical Company, Nonsan 320-854, Korea

7 Dr. Park's Breast Clinic, Daejeon, Korea

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BMC Cancer 2011, 11:307  doi:10.1186/1471-2407-11-307

Published: 22 July 2011

Abstract

Background

Polysaccharides extracted from the Phellinus linteus (PL) mushroom are known to possess anti-tumor effects. However, the molecular mechanisms responsible for the anti-tumor properties of PL remain to be explored. Experiments were carried out to unravel the anticancer effects of PL.

Methods

The anti-cancer effects of PL were examined in SW480 colon cancer cells by evaluating cell proliferation, invasion and matrix metallo-proteinase (MMP) activity. The anti-angiogenic effects of PL were examined by assessing human umbilical vein endothelial cell (HUVEC) proliferation and capillary tube formation. The in vivo effect of PL was evaluated in an athymic nude mouse SW480 tumor engraft model.

Results

PL (125-1000 μg/mL) significantly inhibited cell proliferation and decreased β-catenin expression in SW480 cells. Expression of cyclin D1, one of the downstream-regulated genes of β-catenin, and T-cell factor/lymphocyte enhancer binding factor (TCF/LEF) transcription activity were also significantly reduced by PL treatment. PL inhibited in vitro invasion and motility as well as the activity of MMP-9. In addition, PL treatment inhibited HUVEC proliferation and capillary tube formation. Tumor growth of SW480 cells implanted into nude mice was significantly decreased as a consequence of PL treatment, and tumor tissues from treated animals showed an increase in the apoptotic index and a decrease in β-catenin expression. Moreover, the proliferation index and microvessel density were significantly decreased.

Conclusions

These data suggest that PL suppresses tumor growth, invasion, and angiogenesis through the inhibition of Wnt/β-catenin signaling in certain colon cancer cells.