IR spectral imaging of secreted mucus: a promising new tool for the histopathological recognition of human colonic adenocarcinomas.
OBJECTIVE
During colonic carcinogenesis, mucin-type glycoproteins are known to undergo quantitative and qualitative alterations. The aim of this study was to determine the value of infrared (IR) spectral histology for the histopathological recognition of colonic adenocarcinomas based on mucin-associated IR spectral markers.


RESULTS
Paraffin-embedded tissue sections of normal human colon and adenocarcinomas were analysed directly by IR-microspectroscopy (IR-MSP), without prior chemical dewaxing. IR-MSP imaging combined with multivariate analysis permitted the construction of IR colour-coded images of the tissue sections providing spatially resolved biochemical information. This allowed localization of mucin-rich areas and provided label-free spectral-based staining of secreted mucus related to the biochemical heterogeneity of its mucin content. IR images of secreted mucus display the same spectral clusters in both normal and adenocarcinomatous colonic tissues, but with significant differences in surface percentages. Such differences allow a distinction between these two tissue types. Spectral variations associated with changes of mucin secondary structure were the most accurate mucus spectral marker for discriminating between normal colon and adenocarcinomas in the sample set.


CONCLUSIONS
IR-MSP imaging provides a new type of histology, independent of visual morphology, presenting tremendous possibilities for discovery and clinical monitoring of cancer markers.
Travo
Adrian
A
CNRS UMR 6237, Faculté de Pharmacie, Université de Reims Champagne-Ardenne, Reims, France.
Piot
Olivier
O
Wolthuis
Rolf
R
Gobinet
Cyril
C
Manfait
Michel
M
Bara
Jacques
J
Forgue-Lafitte
Marie-Elisabeth
ME
Jeannesson
Pierre
P
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D016000:Cluster Analysis; D003106:Colon / Q000378:metabolism* / Q000473:pathology; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D003952:Diagnostic Imaging / Q000379:methods*; D006801:Humans; D009093:Mucus / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D018709:Statistics, Nonparametric