title: Induction of apoptosis and the regulation of ErbB signaling by laminarin in HT-29 human colon cancer cells.
abstract: Laminarin, found in marine brown algae, is used as a carbohydrate reserve for phytoplankton; however, it is also used in traditional Chinese medicine, and has been shown to have several biological activities, including anticancer activities. In this study, we examined the mechanisms through which laminarin from Laminaria digitata induces apoptosis in HT-29 colon cancer cells, as well as the involvement of the ErbB signaling pathway. Cell viability assay revealed that laminarin induced cell death in a dose-dependent manner. Cell cycle analysis revealed that laminarin increased the percentage of cells in the sub-G1 and G2-M phase. Western blot analysis demonstrated that laminarin inhibited the heregulin-stimulated phosphorylation of ErbB2. A decrease in cellular proliferation was also observed; this was found to be dependent on ErbB, which activates c-Jun N-terminal kinase. These findings demonstrate the important role of the epidermal growth factor receptor in colon cancer tumorigenesis, and suggest the potential of laminarin as a bio-functional food with anticancer effects on human colon cancer.
authors.affiliation: Department of Food and Life Science, Pukyong National University, Nam-gu, Busan 608-737, Republic of Korea.
authors.forename: Hee-Kyoung
authors.initials: HK
authors.lastname: Park
authors.forename: In-Hye
authors.initials: IH
authors.lastname: Kim
authors.forename: Joongkyun
authors.initials: J
authors.lastname: Kim
authors.forename: Taek-Jeong
authors.initials: TJ
authors.lastname: Nam
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism*; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005936:Glucans; D019073:HT29 Cells; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D020890:Neuregulin-1 / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011134:Polysaccharides / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D000970:Antineoplastic Agents; D018797:Cell Cycle Proteins; D005936:Glucans; D020890:Neuregulin-1; D011134:Polysaccharides; C008247:laminaran; C512478:EGFR protein, human; D066246:ErbB Receptors; D051057:Proto-Oncogene Proteins c-akt