Pancreatic stellate cells reorganize matrix components and lead pancreatic cancer invasion via the function of Endo180

Abstract

Specific cell populations leading the local invasion of cancer are called "leading cells". However, the underlying mechanisms are unclear. Here, we identified leading cells in pancreatic cancer and determined how these cells lead and promote cancer cell invasion in the extracellular matrix (ECM). Using three-dimensional matrix remodeling assay, we found that pancreatic stellate cells (PSCs) frequently invaded the collagen matrix with pancreatic cancer cells (PCCs), which invaded behind the invading PSCs. In addition, invading PSCs changed the alignment of collagen fibers, resulting in ECM remodeling and an increase in the parallel fibers along the direction of invading PSCs. Endo180 expression was higher in PSCs than in PCCs, Endo180 knockdown in PSCs attenuated the invasive abilities of PSCs and co-cultured PCCs, and decreased the expression level of phosphorylated myosin light chain 2 (MLC2). In mouse models, Endo180-knockdown PSCs suppressed tumor growth and changes in collagen fiber orientation in co-transplantation with PCCs. Our findings suggest that PSCs lead the local invasion of PCCs by physically remodeling the ECM, possibly via the function of Endo180, which reconstructs the actin cell skeleton by phosphorylation of MLC2.

Impairment of a distinct cancer-associated fibroblast population limits tumour growth and metastasis

“…Consistent with the published literature [26][27][28][29] and immunohistochemical data showing that the Endo180 protein is predominantly localised to stromal fibroblasts in solid tumours ( Fig. 1a; Supplementary Fig.…”

“…The 180 kDa Endo180 receptor comprises an N-terminal cysteine-rich domain, a fibronectin type II (FNII) domain that has been shown to bind collagens 15-19 , 8 C-type lectin-like domains (CTLDs), of which only CTLD2 displays Ca 2+ -dependent binding of sugars 20 , a single pass transmembrane domain and a cytoplasmic domain that interacts with components of the clathrin-mediated internalisation machinery to drive constitutive recycling between the plasma membrane and intracellular endosomes 21,22 . Although Endo180 is expressed by some sarcomas 23 , glioblastomas 24 and metaplastic breast cancers 25 , in most solid tumours of epithelial origin, expression of Endo180 is predominantly restricted to CAFs with little or no expression by the tumour cells [26][27][28][29] . Functionally, Endo180 can mediate endosomal uptake of collagens for lysosomal degradation 15,18 and has been demonstrated to promote cell migration 16,17 via its ability to generate Rho-ROCK-MLC2-mediated contractility 30 .Here we report that Endo180 expression is associated with the subset of CAFs characterised by their expression of matrix components and matrix-modifying enzymes and that genetic deletion of Endo180, although having little phenotype in normal mice, severely limits the growth and metastatic colonisation of inoculated wildtype syngeneic tumour cells.…”

Overexpression of Gremlin�1 by sonic hedgehog signaling promotes pancreatic cancer progression

“…In the skin, Gremlin 1 is considered a marker of activated myofibroblasts and the tumor-stromal interface ( 55 ). PSCs are a type of myofibroblast-like cell, which are involved in fibrosis and are the main source of the extracellular matrix, which is essential for excessive fibrous tissue ( 56 ). Although the traditional view is that PSCs are likely of local origin, an emerging concept is that the bone marrow (BM) is also a source.…”

The impact of cancer-associated fibroblasts on major hallmarks of pancreatic cancer

“…Erdogan et al 62 showed that CAFs could produce and organize fibronectin-rich ECM with an anisotropic fiber orientation, guiding directional cancer cell migration in a 3D cell-derived matrices (CDMs) model. Koikawa et al 63 found that CAFs invaded together with PCCs and assisted in PCC invasion by remodeling the ECM by changing the alignment of collagen fibers in a 3D matrix remodeling assay. This assistance could be attenuated by knockdown of Endo180 (urokinase-type plasminogen activator receptor-associated protein) in CAFs, as shown by decreased invasiveness of both cocultured CAFs and PCCs and altered orientation of collagen fibers in coinjection mouse models; this finding suggests that CAFs could remodel the stroma to support tumor invasion, possibly through interaction with Endo180 to rebuild the actin cytoskeleton 63 .…”

“…Koikawa et al 63 found that CAFs invaded together with PCCs and assisted in PCC invasion by remodeling the ECM by changing the alignment of collagen fibers in a 3D matrix remodeling assay. This assistance could be attenuated by knockdown of Endo180 (urokinase-type plasminogen activator receptor-associated protein) in CAFs, as shown by decreased invasiveness of both cocultured CAFs and PCCs and altered orientation of collagen fibers in coinjection mouse models; this finding suggests that CAFs could remodel the stroma to support tumor invasion, possibly through interaction with Endo180 to rebuild the actin cytoskeleton 63 . CAFs can also create tunnels through the matrix using invadopodia to degrade the matrix 12 , 64 .…”