Probing single-tumor cell interactions with different-age type I collagen networks by synchrotron-based Fourier transform infrared microspectroscopy

Marie Guilbert,Gianfelice Cinque,Christophe Eklouh-Molinier,Pierre Jeannesson,Ying Yang,Josep Sulé-Suso,Ganesh D Sockalingum,Katia Wehbe

doi:10.1117/1.jbo.19.11.111612

Abstract

We report here on a first study using synchrotron radiation-based Fourier transform infrared microspectroscopy and imaging to investigate HT1080 human fibrosarcoma cells grown onto different-aged type I collagen networks. Spectral images were analyzed with k-means and fuzzy C-means (FCM) clustering algorithms. K-means delineated tumor cells from their surrounding collagen networks and the latter as a function of age mainly due to specific changes in the sugar absorption region. The FCM analysis gave a better nuance of the spectral images. A progression of the biochemical information was observed upon going from the cellular compartments to the pericellular contact regions and to the intact collagens of the different age groups. Two spectral markers based on sugar and protein bands via the intensity ratio (I1032/I1655) and band area ratio (Asugar/Aamide II), showed an increase in advanced glycation endproducts (AGEs) with age. A clear-separation of the three age groups was obtained for spectra originating from the peripheral contact areas mainly due to changes in protein band intensities. The above-described markers decreased to constant levels for the three conditions indicating a masking of the biochemical information. These results hold promises to better understand the impact of age on tumor progression processes while highlighting new markers of the tumor cell invasion front.

Highlights

Studying individual cancer cells represents an increasing area of major interest in the understanding of mechanisms implicated in tumor progression
We investigated the tumor cells grown on different-age collagen networks by synchrotron-based Fourier transform infrared (S-FTIR) microspectroscopy with the objective to gain insights into the cell/matrix interactions regions
This study demonstrates the potential of synchrotron-based infrared microspectroscopy to map single-tumor cells grown on a matrix substrate, in a direct, label-free, and noninvasive way

Summary

Introduction

Studying individual cancer cells represents an increasing area of major interest in the understanding of mechanisms implicated in tumor progression. Investigating tumor cell migration requires considering the cell microenvironment since in vivo, cells develop specific interactions with their counterparts and with extracellular matrix (ECM) proteins to promote cell adhesion, proliferation, and migration.[1] Most studies are performed in classical cell culture systems where cells are seeded on plane and rigid substrates, such as plastic or glass, which do not take into account the matrix components. Dynamic interactions between tumor cells and matrix proteins are a key determinant in the tumor progression and metastases dissemination, which represent the main uncontrolled problem in cancer therapeutics.[2] Among these ECM proteins, type I collagen represents the major component in the body connective tissues through which tumor cells usually migrate to form metastases, and which can be used as a preintravasation microenvironment.[3] specific sites of type I collagen are recognized by integrins to promote cell attachment to the matrix fibrillar network,[4] enabling the trigger migration cycle of cells

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