title: Transcriptional profiling of Chinese medicinal formula Si-Wu-Tang on breast cancer cells reveals phytoestrogenic activity.
abstract: BACKGROUND
  Si-Wu-Tang (SWT), comprising the combination of four herbs, Paeoniae, Angelicae, Chuanxiong and Rehmanniae, is one of the most popular traditional oriental medicines for women's diseases. In our previous study, the microarray gene expression profiles of SWT on breast cancer cell line MCF-7 were found similar to the effect of β-estradiol (E2) on MCF-7 cells in the Connectivity Map database.
  
  
  METHODS
  Further data analysis was conducted to find the main similarities and differences between the effects of SWT and E2 on MCF-7 gene expression. The cell proliferation assay on MCF-7 (ER-positive) and MDA-MB-231 (ER-negative) cells were used to examine such estrogenic activity. The estrogenic potency of SWT was further confirmed by estrogen-responsive element (ERE) luciferase reporter assay in MCF-7 cells.
  
  
  RESULTS
  Many estrogen regulated genes strongly up-regulated by E2 were similarly up-regulated by SWT, e.g., GREB1, PGR and EGR3. Of interest with regard to safety of SWT, the oncogenes MYBL1 and RET were strongly induced by E2 but not by SWT. Quantitative RT-PCR analysis revealed a highly concordant expression change in selected genes with data obtained by microarrays. Further supporting SWT's estrogenic activity, in MCF-7 but not in MDA-MB-231 cells, SWT stimulated cell growth at lower concentrations (< 3.0 mg/ml), while at high concentrations, it inhibits the growth of both cell lines. The growth inhibitory potency of SWT was significantly higher in MDA-MB-231 than in MCF-7 cells. The SWT-induced cell growth of MCF-7 could be blocked by addition of the estrogen receptor antagonist tamoxifen. In addition, SWT was able to activate the ERE activity at lower concentrations. The herbal components Angelicae, Chuanxiong and Rehmanniae at lower concentrations (< 3.0 mg/ml) also showed growth-inducing and ERE-activating activity in MCF-7 cells.
  
  
  CONCLUSIONS
  These results revealed a new mechanism to support the clinical use of SWT for estrogen related diseases and possibly for cancer prevention. This study also demonstrated the feasibility of using microarray transcriptional profiling to discover phytoestrogenic components that are present in natural products.
authors.affiliation: Department of Pharmaceutical Sciences and Center for Advancement of Drug Research, College of Pharmacy, Western University of Health Sciences, Pomona, CA, USA.
authors.forename: Mandy
authors.initials: M
authors.lastname: Liu
authors.forename: Jeffery
authors.initials: J
authors.lastname: Fan
authors.forename: Steven
authors.initials: S
authors.lastname: Wang
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Wang
authors.forename: Charles
authors.initials: C
authors.lastname: Wang
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zuo
authors.forename: Moses S S
authors.initials: MS
authors.lastname: Chow
authors.forename: Leming
authors.initials: L
authors.lastname: Shi
authors.forename: Zhining
authors.initials: Z
authors.lastname: Wen
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D048789:Phytoestrogens / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D004365:Drugs, Chinese Herbal; D048789:Phytoestrogens; C403258:si-wu-tang