title: Ganoderma lucidum polysaccharides in human monocytic leukemia cells: from gene expression to network construction.
abstract: BACKGROUND
  Ganoderma lucidum has been widely used as a herbal medicine for promoting health and longevity in China and other Asian countries. Polysaccharide extracts from Ganoderma lucidum have been reported to exhibit immuno-modulating and anti-tumor activities. In previous studies, F3, the active component of the polysaccharide extract, was found to activate various cytokines such as IL-1, IL-6, IL-12, and TNF-alpha. This gave rise to our investigation on how F3 stimulates immuno-modulating or anti-tumor effects in human leukemia THP-1 cells.
  
  
  RESULTS
  Here, we integrated time-course DNA microarray analysis, quantitative PCR assays, and bioinformatics methods to study the F3-induced effects in THP-1 cells. Significantly disturbed pathways induced by F3 were identified with statistical analysis on microarray data. The apoptosis induction through the DR3 and DR4/5 death receptors was found to be one of the most significant pathways and play a key role in THP-1 cells after F3 treatment. Based on time-course gene expression measurements of the identified pathway, we reconstructed a plausible regulatory network of the involved genes using reverse-engineering computational approach.
  
  
  CONCLUSIONS
  Our results showed that F3 may induce death receptor ligands to initiate signaling via receptor oligomerization, recruitment of specialized adaptor proteins and activation of caspase cascades.
authors.affiliation: Department of Life Science, National Taiwan University, Taipei 106, Taiwan. jerekcheng@gmail.com
authors.forename: Kun-Chieh
authors.initials: KC
authors.lastname: Cheng
authors.forename: Hsuan-Cheng
authors.initials: HC
authors.lastname: Huang
authors.forename: Jenn-Han
authors.initials: JH
authors.lastname: Chen
authors.forename: Jia-Wei
authors.initials: JW
authors.lastname: Hsu
authors.forename: Hsu-Chieh
authors.initials: HC
authors.lastname: Cheng
authors.forename: Chern-Han
authors.initials: CH
authors.lastname: Ou
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Yang
authors.forename: Shui-Tein
authors.initials: ST
authors.lastname: Chen
authors.forename: Chi-Huey
authors.initials: CH
authors.lastname: Wong
authors.forename: Hsueh-Fen
authors.initials: HF
authors.lastname: Juan
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D020869:Gene Expression Profiling; D006801:Humans; D007948:Leukemia, Monocytic, Acute / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011134:Polysaccharides / Q000737:chemistry / Q000494:pharmacology*; D053218:Receptors, Death Domain / Q000235:genetics / Q000378:metabolism; D020940:Reishi / Q000737:chemistry*; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000502:physiology
chemical_list: D016207:Cytokines; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D011134:Polysaccharides; D053218:Receptors, Death Domain