Anticancer research on Ganoderma tsugae extractsI: Ganoderma tsugae extracts inhibit colorectal cancer cell growth via G2/M cell cycle arrestII: Ganoderma tsugae extracts inhibit expression of epidermal growth factor receptor and angiogenesis in human e

Autor: Shih-Chung Hsu, 許世忠
Druh dokumentu: 學位論文 ; thesis
Popis: 97
Ganoderma, known as Lingzhi or Reishi, has been traditionally administered throughout Asian countries for centuries as cancer therapeutics and for other medicinal purposes. In this study, we find G. tsugae extracts (GTE) inhibit colorectal cancer cell proliferation caused by accumulating cells in G2/M phase, and it may be through downregulation of cyclin A and B1 and upregulation of p21 and p27. Tumorigenesis study in nude mice reveals the extracts cause tumor shrinkage. We also examine the anti-angiogenic effects of GTE on human epidermoid carcinoma A-431 cells. Our data indicate that GTE inhibits the expression of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) in vitro and in vivo, and also inhibits the capillary-like tube formation of human umbilical vein endothelial cells (HUVECs). We also demonstrate that the suppression of VEGF expression by GTE can be restored by treatment with EGF. These results suggest that GTE inhibits VEGF expression via suppression of EGFR expression, resulting in the downregulation of VEGF secretion from epidermoid carcinoma A-431 cells. Therefore, these data provide new insights into the possible therapeutic use of G. tsugae for treating colorectal cancer and reveal a novel role for G. tsugae in inhibiting EGFR and VEGF expression, which are important for tumor angiogenesis and growth. This study provides molecular evidence that GTE exerts anti-tumor effects both in vitro and in vivo on colorectal adenocarcinoma and epidermoid carcinoma cells. Moreover, no significant physiological changes resulting from treatment with GTE on both colorectal cancer Colo205 and epidermoid carcinoma A-431 cells are observed in a safety assay using an animal model. Thus, G. tsugae may provide a potential therapeutic approach for anti-cancer treatment.
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