title: Sulforaphane regulates self-renewal of pancreatic cancer stem cells through the modulation of Sonic hedgehog-GLI pathway.
abstract: Sulforaphane (SFN), a component of dietary cruciferous vegetables has been characterized for its anti-proliferative properties. We have recently demonstrated that pancreatic CSCs display activation of sonic hedgehog pathway which are fundamental drivers of stem cell renewal, and SFN inhibits the self-renewal of pancreatic CSCs in vitro. Consistent with these observations, we sought to determine the chemopreventive potential of SFN in an in vivo setting. We show here for the first time that sulforaphane treatment resulted in a significant reduction in the tumor growth of orthotopically implanted primary pancreatic CSCs isolated from human pancreatic tumors into the pancreas of NOD/SCID/IL2Rgamma mice, which is mediated through the modulation of Sonic hedgehog-GLI signaling. Hedgehog pathway blockade by SFN at a dose of 20 mg/kg resulted in a 45 % reduction in growth of pancreatic cancer tumors and reduced expression of Shh pathway components, Smo, Gli 1, and Gli 2 in mouse tissues. Further, SFN inhibited the expression of pluripotency maintaining transcription factors Nanog and Oct-4 and angiogenic markers VEGF and PDGFRα which are downstream targets of Gli transcription. Furthermore, SFN treatment resulted in a significant reduction in EMT markers Zeb-1, which correlated with increase in E-Cadherin expression suggesting the blockade of signaling involved in early metastasis. Interestingly, SFN downregulated the expression of Bcl-2 and XIAP to induce apoptosis. These data demonstrate that, at a tolerable dose, inhibition of Shh pathway by SFN results in marked reduction in EMT, metastatic, angiogenic markers with significant inhibition in tumor growth in mice. Since aberrant Shh signaling occurs in pancreatic tumorigenesis, therapeutics that target Shh pathway may improve the outcomes of patients with pancreatic cancer by targeting CSCs, thus suggesting the use of sulforaphane to further improve preventive and therapeutic approaches in patients with this devastating disease.
authors.affiliation: Department of Pathology and Laboratory Medicine, The University of Kansas Cancer Center, The University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA.
authors.forename: Shih-Hui
authors.initials: SH
authors.lastname: Li
authors.forename: Junsheng
authors.initials: J
authors.lastname: Fu
authors.forename: Dara Nall
authors.initials: DN
authors.lastname: Watkins
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Srivastava
authors.forename: Sharmila
authors.initials: S
authors.lastname: Shankar
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D058750:Epithelial-Mesenchymal Transition; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D053823:Hedgehog Proteins / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D017879:Isothiocyanates; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D000071317:Nanog Homeobox Protein; D014411:Neoplastic Stem Cells / Q000187:drug effects / Q000502:physiology*; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000473:pathology*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013454:Sulfoxides; D013861:Thiocyanates / Q000494:pharmacology*; D014157:Transcription Factors / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D000071676:Zinc Finger Protein GLI1; D000075746:Zinc Finger Protein Gli2
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; C400551:GLI1 protein, human; C082593:GLI2 protein, human; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D017879:Isothiocyanates; D051741:Kruppel-Like Transcription Factors; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D009687:Nuclear Proteins; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; C509239:SHH protein, human; D013454:Sulfoxides; D013861:Thiocyanates; D014157:Transcription Factors; D042461:Vascular Endothelial Growth Factor A; D000071676:Zinc Finger Protein GLI1; D000075746:Zinc Finger Protein Gli2; C467480:vascular endothelial growth factor A, mouse; D020796:Receptor, Platelet-Derived Growth Factor alpha; C016766:sulforaphane