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

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.

Fu J ，Rodova M ，Roy SK ，Sharma J ，Singh KP ，Srivastava RK ，Shankar S ... -  《-》

Sulforaphane regulates self-renewal of pancreatic cancer stem cells through the modulation of Sonic hedgehog-GLI pathway.

Li SH ，Fu J ，Watkins DN ，Srivastava RK ，Shankar S ... -  《-》

NPV-LDE-225 (Erismodegib) inhibits epithelial mesenchymal transition and self-renewal of glioblastoma initiating cells by regulating miR-21, miR-128, and miR-200.

Fu J ，Rodova M ，Nanta R ，Meeker D ，Van Veldhuizen PJ ，Srivastava RK ，Shankar S ... -  《-》

Sanguinarine inhibits pancreatic cancer stem cell characteristics by inducing oxidative stress and suppressing sonic hedgehog-Gli-Nanog pathway.

Sonic hedgehog pathway is highly activated in pancreatic cancer stem cells (CSC) which play crucial roles in cancer initiation, progression and metastasis. However, the molecular mechanisms by which sanguinarine regulates pancreatic CSC characteristics is not well understood. The objectives of this study were to examine the molecular mechanisms by which sanguinarine regulates pancreatic CSC characteristics. Sanguinarine inhibited cell proliferation and colony formation and induced apoptosis through oxidative damage. Sanguinarine inhibited self-renewal capacity of pancreatic CSCs isolated from human and KrasG12D mice. Furthermore, sanguinarine suppressed epithelial-mesenchymal transition (EMT) by up-regulating E-cadherin and inhibiting N-cadherin. Significant decrease in expression level of Snail, Slug and Zeb1 corroborated the suppression of EMT in sanguinarine treated pancreatic CSCS. The ability of sanguinarine to inhibit pluripotency maintaining factors and CSC markers suggest that sanguinarine can be an effective agent for inhibiting pancreatic cancer growth and development by targeting CSCs. Furthermore, sanguinarine inhibited Shh-Gli pathway leading to modulation of Gli target genes in pancreatic CSCs. Chromatin immunoprecipitation assay demonstrated that Nanog directly binds to promoters of Cdk2, Cdk6, FGF4, c-Myc and Oct4, and sanguinarine inhibits the binding of Nanog with these genes, suggesting the direct involvement of Nanog in cell cycle, pluripotency and self-renewal. To further investigate the role of Shh-Gli-Nanog pathway, we regulated Shh signaling either by Shh protein or Nanog overexpression. Enforced activation of Shh or overexpression of Nanog counteracted the inhibitory effects of sanguinarine on pancreatic CSC proliferation, suggesting the actions of sanguinarine are mediated, at least in part, through Shh-Gli-Nanog pathway. Our studies suggest that sanguinarine can be used for the treatment and/or prevention of pancreatic cancer by targeting CSCs.

Ma Y ，Yu W ，Shrivastava A ，Alemi F ，Lankachandra K ，Srivastava RK ，Shankar S ... -  《-》

PI3K/AKT/mTOR and sonic hedgehog pathways cooperate together to inhibit human pancreatic cancer stem cell characteristics and tumor growth.

Sharma N ，Nanta R ，Sharma J ，Gunewardena S ，Singh KP ，Shankar S ，Srivastava RK ... -  《Oncotarget》