Title:The Activation of β1-integrin by Type I Collagen Coupling with the Hedgehog Pathway Promotes the Epithelial-Mesenchymal Transition in Pancreatic Cancer
Volume: 14
Issue: 5
Author(s): Wanxing Duan, Jiguang Ma, Qingyong Ma, Qinhong Xu, Jianjun Lei, Liang Han, Xuqi Li, Zheng Wang, Zheng Wu, Shifang Lv, Zhenhua Ma, Mouzhu Liu, Fengfei Wang and Erxi Wu
Affiliation:
Keywords:
Desmoplastic reaction, epithelial–mesenchymal transition, extracellular matrix, hedgehog pathway, β1-integrin,
pancreatic cancer.
Abstract: Pancreatic ductal adenocarcinoma (PDAC) is characterized by the excessive deposition of extracellular matrix
(ECM), which is thought to contribute to this tumor’s malignant behavior. However, the detailed mechanism and the
contribution of excessive deposition of ECM in PDAC progression remain unclear. A better understanding of the
mechanism involved in this process is essential for the design of new effective therapies. In this study, we demonstrated
that pancreatic cancer cells exhibited increased proliferation and decreased apoptosis in response to type I collagen. In
addition, PDAC cells exposed to type I collagen lost the expression of E-cadherin and increased expression of
mesenchymal markers, including N-cadherin and vimentin. This epithelial- mesenchymal transition (EMT) was correlated
with enhanced cell migration and invasiveness. Knockdown of β1-integrin abolished the effects induced by type I
collagen, and further investigation revealed that type I collagen activates β1-integrin (marked by phosphorylation of
β1 integrin downstream effectors, focal adhesion kinase [FAK], AKT, and ERK) accompanied by markedly up-regulation
of Gli-1, a component of the Hedgehog (HH) pathway. Knockdown of Gli-1 reversed the effects of type I collagen on
PDAC invasion and EMT. These results suggest that there is cross-talk between the β1-integrin signaling pathway and the
HH pathway in pancreatic cancer and that activation of the HH pathway plays a key role in the type I collagen-induced
effects on pancreatic cancer.