CD133/CD166/Ki-67 Triple Immunofluorescence Assessment for
Putative Cancer Stem Cells in Colon Carcinoma*
Full Article (PDF file)
Claudiu Mărgaritescu1*, Daniel Pirici2*, Irina Cherciu3, Alexandru Bărbălan3, Tatiana Cârtână3, Adrian Săftoiu3,4
1) Department of Pathology;
2) Department of Research
of Medicine and Pharmacy
3) Department of
Center of Gastroenterology
and Hepatology, University
of Medicine and Pharmacy
4) Department of Endoscopy,
*These authors contributed
equally to the study.
Background & Aims: Colorectal cancer represents the third most common malignancy and the fourth most
common cause of cancer death worldwide. The existence of drug-resistant colon cancer stem cells is thought
to be one of the most important reasons behind treatment failure in colon cancer, their existence putatively
leading to metastasis and recurrences. The aim of our study was to investigate the immunoexpression patterns
of CD133 and CD166 in colon carcinoma, both individually and in combination, assessing their significance
as prognostic markers.
Methods. A total of 45 retrospective colon adenocarcinoma cases were investigated by enzymatic and multiple
fluorescence immunohistochemistry for their CD133 and CD166 expression and colocalization.
Results. Both CD133 and CD166 were expressed to different extents in all cancer specimens, with a
predominant cytoplasmic pattern for CD133 and a more obvious membranous-like pattern for CD166.
Overall, when comparing their reactivity for the tumoral tissue, CD166 expression areas seemed to be smaller
than those of CD133. However, there was a direct correlation between CD133 and CD166 expression levels
throughout the entire spectrum of lesions, with higher values for dysplastic lesions. Colocalization of CD133/
CD166 was obvious at the level of cells membranes, with higher coeficients in high grade dysplasia, followed
by well and moderate differentiated tumours.
Conclusions. CD133/CD166 colocalization is an early event occurring in colon tumorigenesis, with the
highest coeficients recorded for patients with high grade dysplasia, followed by well differentiated tumours.
Thus, we consider that the coexpression of these two markers could be useful for further prognostic and
therapeutically stratification of patients with colon cancer.
Key words: colon cancer - CD133 - CD166 - Ki-67 - colocalization coefficient - colon cancer stem cells.
Abbreviations: AJCC - American Joint Committee on Cancer; CCD - charge-coupled device camera sensor;
CD133 - prominin-1 (PROM1); CD166 - Activated Leukocyte Cell Adhesion Molecule (ALCAM); CRC -
colorectal cancer; CSC - cancer stem cells; DAB - 3,3'-diaminobenzidine chromogen; DAPI - 4',6-diamidino-
2-phenylindole; HE - Hematoxylin and eosin staining; HGD - high grade dysplasia; HRP - horseradish
peroxidase; LGD - low grade dysplasia; SDS - sodium dodecyl sulfate
*Part of this work has been accepted as a poster presentation at the Digestive Disease Week (DDW)
meeting, Chicago, IL, USA May 3-6, 2014