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6199582 
Journal Article 
FTIR imaging of MCF-7 colonies and their vicinity in Matrigel-embedded 3D cultures 
Goormaghtigh, E; Smolina, M 
2016 
155-166 
BACKGROUND:It is now recognized that tumor cells can actively alter their microenvironment and that this remodelled microenvironment can subsequently play a critical role in cancer progression and influence therapeutic responses. To date, the molecular heterogeneity within a 3D cancer cell colony and its influence on the extracellular matrix have not been studied by infrared imaging. OBJECTIVE:The objective of this study is to investigate by mid-infrared imaging 3D Matrigel-embedded colonies of pure MCF-7 human mammary adenocarcinoma cell line and the surrounding microenvironment after undergoing formalin fixation and paraffin embedding (FFPE). METHODS:In order to better reproduce the procedure used for preservation and storage of clinical tissue specimens for pathologic analysis, 7- and 10-day MCF-7 colonies embedded and grown in Matrigel were FFPE-treated; 4- mu m-thick sections were cut, mounted on barium fluoride window and deparaffinized. The Fourier transform infrared (FTIR) images of 4096 spectra were collected in transmission mode using a FPA-based FTIR imaging system. They were pre-processed and analysed by principal component and K-mean cluster analyses. RESULTS:At 1654 cm-1 and 1234 cm-1, the intensity of absorption in the colonies is significantly higher than in Matrigel. It can be also noted, on the one hand, that there is a spectral heterogeneity in the intracolonial distribution of the absorbances at 1654, 1644, 1640 and 1634 cm-1 (Amide I range) possibly due to changes in protein secondary structures. On the other hand, we observe that Matrigel close to MCF-7 colonies appears altered with respect to more distant Matrigel matrix. CONCLUSIONS:FTIR imaging allowed us to highlight changes in the chemical content in MCF-7 colonies and their direct vicinity in Matrigel-embedded 3D cultures. 
Biotechnology and Bioengineering Abstracts; FTIR imaging; 3D cell culture; extracellular matrix; Adenocarcinoma; Cell culture; Spectroscopy; Preservation; Tumor cells; Colonies; Embedding; Tumor cell lines; Paraffin; Secondary structure; Formaldehyde; Fluoride; Microenvironments; Protein structure; W 30910:Imaging