title: Ergosterol peroxide from Chaga mushroom (Inonotus obliquus) exhibits anti-cancer activity by down-regulation of the β-catenin pathway in colorectal cancer.
abstract: OBJECTIVE
  In this study, we examined the effect of different fractions and components of Chaga mushroom (Inonotus Obliquus) on viability and apoptosis of colon cancer cells. Among them, one component showed the most effective growth inhibition and was identified as ergosterol peroxide by NMR analysis. We investigated the anti-proliferative and apoptosis mechanisms of ergosterol peroxide associated with its anti-cancer activities in human colorectal cancer (CRC) cell lines and tested its anti-tumor effect on colitis-induced CRC developed by Azoxymethane (AOM)/Dextran sulfate sodium (DSS) in a mouse model.
  
  
  METHODS
  We used MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, flow cytometry assays, Western blot analysis, colony formation assays, reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry (IHC), and AOM/DSS mouse models to study the molecular mechanism of metastatic activities in CRC cells.
  
  
  RESULTS
  Ergosterol peroxide inhibited cell proliferation and also suppressed clonogenic colony formation in HCT116, HT-29, SW620 and DLD-1 CRC cell lines. The growth inhibition observed in these CRC cell lines was the result of apoptosis, which was confirmed by FACS analysis and Western blotting. Ergosterol peroxide inhibited the nuclear levels of β-catenin, which ultimately resulted in reduced transcription of c-Myc, cyclin D1, and CDK-8. Ergosterol peroxide administration showed a tendency to suppress tumor growth in the colon of AOM/DSS-treated mice, and quantification of the IHC staining showed a dramatic decrease in the Ki67-positive staining and an increase in the TUNEL staining of colonic epithelial cells in AOM/DSS-treated mice by ergosterol peroxide for both prevention and therapy.
  
  
  CONCLUSIONS
  Our data suggest that ergosterol peroxide suppresses the proliferation of CRC cell lines and effectively inhibits colitis-associated colon cancer in AOM/DSS-treated mice. Ergosterol peroxide down-regulated β-catenin signaling, which exerted anti-proliferative and pro-apoptotic activities in CRC cells. These properties of ergosterol peroxide advocate its use as a supplement in colon cancer chemoprevention.
authors.affiliation: Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon 406-840 Republic of Korea; National Cancer Center, Goyang-si, Gyeonggi-do 410-769, Republic of Korea; Department of Food and Nutrition, School of Food Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do 456-756, Republic of Korea.
authors.forename: Ju-Hee
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon 406-840 Republic of Korea.
authors.forename: Jeong-Eun
authors.initials: JE
authors.lastname: Jang
authors.affiliation: Department of Zoology, School of Biological Sciences, Dr. Harisingh Gour Central University, Sagar 470003, India.
authors.forename: Siddhartha Kumar
authors.initials: SK
authors.lastname: Mishra
authors.affiliation: Korea Institute of Science and Technology (KIST), Gangneung Institute, Gangneung-si, Gangwon-do 210-340, Republic of Korea.
authors.forename: Hee-Ju
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Korea Institute of Science and Technology (KIST), Gangneung Institute, Gangneung-si, Gangwon-do 210-340, Republic of Korea.
authors.forename: Chu Won
authors.initials: CW
authors.lastname: Nho
authors.affiliation: Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon 406-840 Republic of Korea.
authors.forename: Dongyun
authors.initials: D
authors.lastname: Shin
authors.affiliation: College of Korean Medicine, Daejeon University, Daejeon 300-716, Republic of Korea.
authors.forename: Mirim
authors.initials: M
authors.lastname: Jin
authors.affiliation: National Cancer Center, Goyang-si, Gyeonggi-do 410-769, Republic of Korea.
authors.forename: Mi Kyung
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Department of Food and Nutrition, School of Food Science and Technology, Chung-Ang University, Anseong-si, Gyeonggi-do 456-756, Republic of Korea.
authors.forename: Changsun
authors.initials: C
authors.lastname: Choi
authors.affiliation: Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon 406-840 Republic of Korea. Electronic address: eyeball@hanmail.net.
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Oh
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D000363:Agaricales; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003092:Colitis / Q000150:complications; D003106:Colon / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D015536:Down-Regulation; D004875:Ergosterol / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008810:Mice, Inbred C57BL; D015398:Signal Transduction / Q000187:drug effects; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D051176:beta Catenin; C036071:ergosterol-5,8-peroxide; D004875:Ergosterol
keywords: AOM/DSS; Chaga mushroom; Colorectal cancer; Ergosterol peroxide; β-catenin