Isolation and characterization of CD133+ cell population within human primary and metastatic colon cancer.
BACKGROUND
"Cancer stem cells" (CSC) have been identified as a minority of cancer cells responsible for tumor initiation, maintenance and spreading. Although a universal marker for CSC has not yet been identified, CD133 has been proposed as the hallmark of CSC in colon cancer. The aim of our study was to assess the presence of a CD133+ cell fraction in samples of colon cancer and liver metastasis from colon cancer and evaluate their potential as tumor-initiating cells.


METHODS
Tissue samples from 17 colon cancers and 8 liver metastasis were fragmented and digested using collagenase. Cell suspensions were characterized by flow cytometry using anti-CD133, CD45 and CD31 antibodies. CD133+ cells were also isolated by magnetic cell sorting and their tumor-initiating potential was assessed versus the remaining CD133- fraction by soft-agar assay.


RESULTS
Our results confirmed the existence of a subset of CD133+ tumor cells within human colon cancers. Interestingly, CD133+ cells were detectable in liver metastasis at a higher percentage when compared to primary tumors. Soft-agar assay showed that CD133+ cell fraction was able to induce larger and more numerous colonies than CD133-cells.


CONCLUSIONS
Our findings data that the CD133+ colon cancer cells might play an important role in both primary tumors as well as in metastatic lesions thus warranting further studies on the role(s) of this subset of cells in the metastatic process.
Puglisi
M A
MA
Department of Internal Medicine and Gastroenterology, Giovanni XXIII Cancer Research Center, Catholic University of the Sacred Heart, Rome, Italy.
Sgambato
A
A
Saulnier
N
N
Rafanelli
F
F
Barba
M
M
Boninsegna
A
A
Piscaglia
A C
AC
Lauritano
C
C
Novi
M L
ML
Barbaro
F
F
Rinninella
E
E
Campanale
C
C
Giuliante
F
F
Nuzzo
G
G
Alfieri
S
S
Doglietto
G B
GB
Cittadini
A
A
Gasbarrini
A
A
D000071916:AC133 Antigen; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000032:analysis*; D003110:Colonic Neoplasms / Q000473:pathology*; D005260:Female; D005434:Flow Cytometry; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism*; D014410:Tumor Stem Cell Assay
D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides