title: Emodin induces cytotoxic effect in human breast carcinoma MCF-7 cell through modulating the expression of apoptosis-related genes.
abstract: BACKGROUND
  The poor prognostic outcome of breast cancer is largely due to its resistance to cancer therapies. Development of therapeutic agents that can inhibit growth and induce apoptosis in breast cancer cells can help solve the problem. Emodin is an active anthraquinone that has been reported to have diverse biological effects.
  
  
  OBJECTIVE
  In this study, the anticancer effects of emodin on growth inhibition, apoptosis induction and the expression of apoptosis-related genes in MCF-7 cells were investigated.
  
  
  METHODS
  Growth inhibition induced by emodin was investigated by the MTS assay and the colony formation assay; while emodin-induced apoptosis was determined by the COMET assay and DNA fragmentation detection. Emodin (35 μM)-induced alterations in the expression of apoptotic-related genes were detected by using real-time PCR.
  
  
  RESULTS
  Emodin had significant growth inhibitory effects on MCF-7 cells with IC₅₀ = 7.22 µg/ml (∼30 μM). It also exerted a concentration-dependant inhibitory effect on the colony-forming ability of MCF-7 cells with IC₅₀ = 7.60 µg/ml (∼30 µM). Hallmarks of apoptosis, such as single-strand DNA breakage and DNA fragmentation, were observed in emodin-treated MCF-7 cells. The gene expression of Fas ligand (FASL) was up-regulated (p < 0.01) but those of MCL1, CCND1 and C-MYC were down-regulated (p < 0.05) in emodin-treated MCF-7 cells.
  
  
  CONCLUSIONS
  This study indicated that emodin could induce growth inhibition and apoptosis in MCF-7 cells through the modulation of the expression of apoptosis-related genes. The growth inhibitory effects of emodin might involve both the intrinsic and the extrinsic apoptotic pathways and cell cycle arrest.
authors.affiliation: Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, China.
authors.forename: Wing-Yan
authors.initials: WY
authors.lastname: Li
authors.forename: Robbie Yat-Kan
authors.initials: RY
authors.lastname: Chan
authors.forename: Peter Hoi-Fu
authors.initials: PH
authors.lastname: Yu
authors.forename: Shun-Wan
authors.initials: SW
authors.lastname: Chan
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000188:drug therapy*; D002277:Carcinoma / Q000188:drug therapy*; D002400:Cathartics / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D019938:Cyclin D1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D053904:DNA Breaks, Single-Stranded / Q000187:drug effects; D053938:DNA Fragmentation; D004642:Emodin / Q000494:pharmacology*; D053222:Fas Ligand Protein / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D020128:Inhibitory Concentration 50; D061986:MCF-7 Cells; D064549:Myeloid Cell Leukemia Sequence 1 Protein / Q000037:antagonists & inhibitors / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000187:drug effects; D016271:Proto-Oncogene Proteins c-myc / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D051017:Apoptosis Regulatory Proteins; C530104:CCND1 protein, human; D002400:Cathartics; C505661:FASLG protein, human; D053222:Fas Ligand Protein; C579095:MCL1 protein, human; C489427:MYC protein, human; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D016271:Proto-Oncogene Proteins c-myc; D019938:Cyclin D1; D004642:Emodin