posted on 2023-11-28, 15:03authored byAdrian
A. Shimpi, Erik D. Williams, Lu Ling, Tigist Tamir, Forest M. White, Claudia Fischbach
Increased fibrotic extracellular
matrix (ECM) deposition promotes
tumor invasion, which is the first step of the metastatic cascade.
Yet, the underlying mechanisms are poorly understood as conventional
studies of tumor cell migration are often performed in 2D cultures
lacking the compositional and structural complexity of native ECM.
Moreover, these studies frequently focus on select candidate pathways
potentially overlooking other relevant changes in cell signaling.
Here, we combine a cell-derived matrix (CDM) model with phosphotyrosine
phosphoproteomic analysis to investigate tumor cell migration on fibrotic
ECM relative to standard tissue culture plastic (TCP). Our results
suggest that tumor cells cultured on CDMs migrate faster and in a
more directional manner than their counterparts on TCP. These changes
in migration correlate with decreased cell spreading and increased
cell elongation. While the formation of phosphorylated focal adhesion
kinase (pFAK)+ adhesion complexes did not vary between TCP and CDMs,
time-dependent phosphoproteomic analysis identified that the SRC family
kinase LYN may be differentially regulated. Pharmacological inhibition
of LYN decreased tumor cell migration and cytoskeletal rearrangement
on CDMs and also on TCP, suggesting that LYN regulates tumor cell
migration on CDMs in combination with other mechanisms. These data
highlight how the combination of physicochemically complex in vitro
systems with phosphoproteomics can help identify signaling mechanisms
by which the fibrotic ECM regulates tumor cell migration.