title: Systems analysis reveals a transcriptional reversal of the mesenchymal phenotype induced by SNAIL-inhibitor GN-25.
abstract: BACKGROUND
  HMLEs (HMLE-SNAIL and Kras-HMLE, Kras-HMLE-SNAIL pairs) serve as excellent model system to interrogate the effect of SNAIL targeted agents that reverse epithelial-to-mesenchymal transition (EMT). We had earlier developed a SNAIL-p53 interaction inhibitor (GN-25) that was shown to suppress SNAIL function. In this report, using systems biology and pathway network analysis, we show that GN-25 could cause reversal of EMT leading to mesenchymal-to-epithelial transition (MET) in a well-recognized HMLE-SNAIL and Kras-HMLE-SNAIL models.
  
  
  RESULTS
  GN-25 induced MET was found to be consistent with growth inhibition, suppression of spheroid forming capacity and induction of apoptosis. Pathway network analysis of mRNA expression using microarrays from GN-25 treated Kras-HMLE-SNAIL cells showed an orchestrated global re-organization of EMT network genes. The expression signatures were validated at the protein level (down-regulation of mesenchymal markers such as TWIST1 and TWIST2 that was concurrent with up-regulation of epithelial marker E-Cadherin), and RNAi studies validated SNAIL dependent mechanism of action of the drug. Most importantly, GN-25 modulated many major transcription factors (TFs) such as inhibition of oncogenic TFs Myc, TBX2, NR3C1 and led to enhancement in the expression of tumor suppressor TFs such as SMAD7, DD1T3, CEBPA, HOXA5, TFEB, IRF1, IRF7 and XBP1, resulting in MET as well as cell death.
  
  
  CONCLUSIONS
  Our systems and network investigations provide convincing pre-clinical evidence in support of the clinical application of GN-25 for the reversal of EMT and thereby reducing cancer cell aggressiveness.
authors.affiliation: Department of Pathology, Karmanos Cancer Institute, Wayne State University School of Medicine, John R, HWCRC 732, Detroit, MI, 4100, USA. azmia@karmanos.org.
authors.forename: Asfar S
authors.initials: AS
authors.lastname: Azmi
authors.forename: Aliccia
authors.initials: A
authors.lastname: Bollig-Fischer
authors.forename: Bin
authors.initials: B
authors.lastname: Bao
authors.forename: Bum-Joon
authors.initials: BJ
authors.lastname: Park
authors.forename: Sun-Hye
authors.initials: SH
authors.lastname: Lee
authors.forename: Gyu
authors.initials: G
authors.lastname: Yong-Song
authors.forename: Gregory
authors.initials: G
authors.lastname: Dyson
authors.forename: Chandan K
authors.initials: CK
authors.lastname: Reddy
authors.forename: Fazlul H
authors.initials: FH
authors.lastname: Sarkar
authors.forename: Ramzi M
authors.initials: RM
authors.lastname: Mohammad
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects*; D020869:Gene Expression Profiling; D053263:Gene Regulatory Networks / Q000187:drug effects; D020868:Gene Silencing; D006801:Humans; D008648:Mesoderm / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009285:Naphthoquinones / Q000494:pharmacology*; D010641:Phenotype; D034741:RNA, Small Interfering / Q000235:genetics; D000071250:Snail Family Transcription Factors; D018874:Spheroids, Cellular / Q000166:cytology / Q000187:drug effects; D049490:Systems Biology; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection
chemical_list: C587449:GN25 compound; D009285:Naphthoquinones; D034741:RNA, Small Interfering; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors