Genome-wide screening reveals an EMT molecular network mediated by Sonic hedgehog-Gli1 signaling in pancreatic cancer cells.
OBJECTIVE
The role of sonic hedgehog (SHH) in epithelial mesenchymal transition (EMT) of pancreatic cancer (PC) is known, however, its mechanism is unclear. Because SHH promotes tumor development predominantly through Gli1, we sought to understand its mechanism by identifying Gli1 targets in pancreatic cancer cells.


METHODS
First, we investigated invasion, migration, and EMT in PC cells transfected with lentiviral Gli1 interference vectors or SHH over-expression vectors in vitro and in vivo. Next, we determined the target gene profiles of Gli1 in PC cells using cDNA microarray assays. Finally, the primary regulatory networks downstream of SHH-Gli1 signaling in PC cells were studied through functional analyses of these targets.


RESULTS
Our results indicate there is decreased E-cadherin expression upon increased expression of SHH/Gli1. Migration of PC cells increased significantly in a dose-dependent manner within 24 hours of Gli1 expression (P<0.05). The ratio of liver metastasis and intrasplenic miniature metastasis increased markedly upon activation of SHH-Gli1 signals in nude mice. Using cDNA microarray, we identified 278 upregulated and 59 downregulated genes upon Gli1 expression in AsPC-1 cells. The data indicate that SHH-Gli1 signals promote EMT by mediating a complex signaling network including TGFβ, Ras, Wnt, growth factors, PI3K/AKT, integrins, transmembrane 4 superfamily (TM4SF), and S100A4.


CONCLUSIONS
Our results suggest that targeting the molecular connections established between SHH-Gli1 signaling and EMT could provide effective therapies for PC.
Department of Gastroenterology, The Tenth People's Hospital of Shanghai, Tongji University, Shanghai, China.
Xuanfu
X
Xu
Yingqun
Y
Zhou
Chuangao
C
Xie
Shu-mei
SM
Wei
Huizhong
H
Gan
Shengli
S
He
Fan
F
Wang
Ling
L
Xu
Jie
J
Lu
Weiqi
W
Dai
Lei
L
He
Ping
P
Chen
Xingpeng
X
Wang
Chuanyong
C
Guo
D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D020869:Gene Expression Profiling; D053263:Gene Regulatory Networks; D018014:Gene Transfer Techniques; D053823:Hedgehog Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D015513:Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014161:Transduction, Genetic; D000071676:Zinc Finger Protein GLI1
D053823:Hedgehog Proteins; D015513:Oncogene Proteins; D015534:Trans-Activators; D000071676:Zinc Finger Protein GLI1