GANT-61 inhibits pancreatic cancer stem cell growth in vitro and in NOD/SCID/IL2R gamma null mice xenograft.

Abstract

Multiple lines of evidence suggest that the Sonic Hedgehog (Shh) signaling pathway is aberrantly reactivated in pancreatic cancer stem cells (CSCs). The objectives of this study were to examine the molecular mechanisms by which GANT-61 (Gli transcription factor inhibitor) regulates stem cell characteristics and tumor growth. Effects of GANT-61 on CSC's viability, spheroid formation, apoptosis, DNA-binding and transcriptional activities, and epithelial-mesenchymal transition (EMT) were measured. Humanized NOD/SCID/IL2R gamma(null) mice were used to examine the effects of GANT-61 on CSC's tumor growth. GANT-61 inhibited cell viability, spheroid formation, and Gli-DNA binding and transcriptional activities, and induced apoptosis by activation of caspase-3 and cleavage of Poly-ADP ribose Polymerase (PARP). GANT-61 increased the expression of TRAIL-R1/DR4, TRAIL-R2/DR5 and Fas, and decreased expression of PDGFRα and Bcl-2. GANT-61 also suppressed EMT by up-regulating E-cadherin and inhibiting N-cadherin and transcription factors Snail, Slug and Zeb1. In addition, GANT-61 inhibited pluripotency maintaining factors Nanog, Oct4, Sox-2 and cMyc. Suppression of both Gli1 plus Gli2 by shRNA mimicked the changes in cell viability, spheroid formation, apoptosis and gene expression observed in GANT-61-treated pancreatic CSCs. Furthermore, GANT-61 inhibited CSC tumor growth which was associated with up-regulation of DR4 and DR5 expression, and suppression of Gli1, Gli2, Bcl-2, CCND2 and Zeb1 expression in tumor tissues derived from NOD/SCID IL2Rγ null mice. Our data highlight the importance of Shh pathway for self-renewal and metastasis of pancreatic CSCs, and also suggest Gli as a therapeutic target for pancreatic cancer in eliminating CSCs.

• Authors: Junsheng Fu, Mariana Rodova, Sanjit K Roy, Jay Sharma, Karan P Singh, Rakesh K Srivastava, Sharmila Shankar
• Journal: Cancer letters (Cancer Lett) Vol. 330 Issue 1 Pg. 22-32 (Mar 01 2013) ISSN: 1872-7980 [Electronic] Ireland
• PMID: 23200667 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• GANT 61
• GLI1 protein, human
• GLI2 protein, human
• Hedgehog Proteins
• Kruppel-Like Transcription Factors
• Nuclear Proteins
• Pyridines
• Pyrimidines
• RNA, Small Interfering
• SHH protein, human
• Transcription Factors
• Zinc Finger Protein GLI1
• Zinc Finger Protein Gli2

Topics

• Animals
• Apoptosis (drug effects)
• Cell Growth Processes (drug effects)
• Cell Line, Tumor
• Down-Regulation (drug effects)
• Gene Expression Regulation, Neoplastic (drug effects)
• HEK293 Cells
• Hedgehog Proteins (metabolism)
• Humans
• Kruppel-Like Transcription Factors (genetics)
• Mice
• Mice, Inbred NOD
• Mice, SCID
• Neoplastic Stem Cells (drug effects, metabolism, pathology)
• Nuclear Proteins (genetics)
• Pancreatic Neoplasms (drug therapy, genetics, metabolism, pathology)
• Pyridines (pharmacology)
• Pyrimidines (pharmacology)
• RNA, Small Interfering (administration & dosage, genetics)
• Signal Transduction (drug effects)
• Transcription Factors (genetics)
• Transfection
• Xenograft Model Antitumor Assays
• Zinc Finger Protein GLI1
• Zinc Finger Protein Gli2