Local alignment vectors reveal cancer cell-induced ECM fiber remodeling dynamics

Abstract

Invasive cancer cells interact with the surrounding extracellular matrix (ECM), remodeling ECM fiber network structure by condensing, degrading, and aligning these fibers. We developed a novel local alignment vector analysis method to quantitatively measure collagen fiber alignment as a vector field using Circular Statistics. This method was applied to human non-small cell lung carcinoma (NSCLC) cell lines, embedded as spheroids in a collagen gel. Collagen remodeling was monitored using second harmonic generation imaging under normal conditions and when the LKB1-MARK1 pathway was disrupted through RNAi-based approaches. The results showed that inhibiting LKB1 or MARK1 in NSCLC increases the collagen fiber alignment and captures outward alignment vectors from the tumor spheroid, corresponding to high invasiveness of LKB1 mutant cancer cells. With time-lapse imaging of ECM micro-fiber morphology, the local alignment vector can measure the dynamic signature of invasive cancer cell activity and cell-migration-induced ECM and collagen remodeling and realigning dynamics.

The use of mixed collagen-Matrigel matrices of increasing complexity recapitulates the biphasic role of cell adhesion in cancer cell migration: ECM sensing, remodeling and forces at the leading edge of cancer invasion

“…Our quantification of ECM remodeling showed that collagen fiber alignment was higher in Matrigel-containing hydrogels (CM and CM+) compared to collagen only hydrogels (C), indicating that hydrogel composition and stiffness are crucial determinants of the extent of matrix remodeling. Indeed, H1299 cells were able to align the collagen fibers in all three hydrogels, a phenomenon that has been associated with malignancy and cell invasiveness [40]. These results are similar to previous studies reported for different types of cancer including glioblastoma (U87 tumor spheroids) [41] and breast cancer (tumors in vivo) [42].…”

Collective forces of tumor spheroids in three-dimensional biopolymer networks

“…The motivation for this extension is that tumor spheroids are able to replicate the main structural and functional properties of solid tumors 10 , including the individual and collective invasion into the surrounding matrix 11 . In particular, it has been hypothesized that the collective traction force of a whole tumor may alter the mechanics of the extracellular matrix and facilitate invasion by aligning collagen fibers radially away from the tumor [12][13][14] . However, current 3D finite element force reconstruction methods for single cells, especially in a non-linear material such as collagen, are computationally too slow for analyzing large (∼0.5 mm) tumor spheroids.…”

Role of tumor-associated neutrophils in regulation of tumor growth in lung cancer development: A mathematical model

“…In this work, we did not specifically consider many other microenvironmental players such as signaling networks [131], human neutrophil elastase as a therapeutic target in the absence [132, 133] and presence [134] of LPS, endogenous NK immune dynamics [40, 135], angiogenesis from blood vessels [136–138], ECM remodeling [139], or growth factors such as epidermal growth factor (EGF) [140, 141], and CSF-1 [7, 142]. These factors may play critical roles in cancer progression.…”