title: Silibinin down-regulates expression of secreted phospholipase A2 enzymes in cancer cells.
abstract: BACKGROUND
  Silibinin, a naturally-occurring flavonoid produced by milk thistle, possesses antioxidant, anti-inflammatory and cancer-preventive activities. In the current study, we examined the effects of silibinin on the expression of secreted phospholipase A2 (sPLA2) enzymes, especially those of group IIA (hGIIA), which play a crucial role in inflammation and carcinogenesis.
  
  
  METHODS
  The effects of silibinin on sPLA2 expressions in human HepG2 hepatoma and PC-3 prostate cancer cells were analyzed using quantitative reverse transcription-polymerase chain reaction and enzyme linked immunosorbent assay technique.
  
  
  RESULTS
  Silibinin inhibited the expression of hGIIA in unstimulated and cytokine-primed HepG2 and PC-3 cells. The mRNA levels of sPLA2 of groups IB, III and V were also significantly decreased by silibinin. Analyses of transcription factor activation suggest that nuclear factor-κB, but not specificity protein 1 (SP1) is implicated in the silibinin-mediated down-regulation of hGIIA.
  
  
  CONCLUSIONS
  Silibinin exhibits inhibitory effects on basal and cytokine-induced expression of sPLA2s in cancer cells and therefore, may have the potential to protect against up-regulation of hGIIA and other sPLA2 isoforms during inflammation and cancer.
authors.affiliation: Fetscherstrasse 74, D 01307 Dresden, Germany. Albert.Hagelgans@uniklinikum-dresden.de.
authors.forename: Albert
authors.initials: A
authors.lastname: Hagelgans
authors.forename: Brit
authors.initials: B
authors.lastname: Nacke
authors.forename: Maria
authors.initials: M
authors.lastname: Zamaraeva
authors.forename: Gabriele
authors.initials: G
authors.lastname: Siegert
authors.forename: Mario
authors.initials: M
authors.lastname: Menschikowski
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000378:metabolism; D054497:Phospholipases A2, Secretory / Q000235:genetics* / Q000378:metabolism; D059368:RNA Isoforms; D015398:Signal Transduction / Q000187:drug effects; D000077385:Silybin; D012838:Silymarin / Q000494:pharmacology*; D016329:Sp1 Transcription Factor / Q000378:metabolism; D014410:Tumor Stem Cell Assay
chemical_list: D000970:Antineoplastic Agents; D059368:RNA Isoforms; D012838:Silymarin; D016329:Sp1 Transcription Factor; D000077385:Silybin; D054497:Phospholipases A2, Secretory
keywords: Secreted phospholipase A2; cancer cells; signaling pathways; silibinin