[Investigation of CD133 as putative marker of tumor-initiating cell in laryngeal carcinoma].
OBJECTIVE
To detect the expression of CD133 in human established larynx tumors cell line, Hep-2 cell line and observe tumorigenicity of CD133(+) tumorigenic cells, CD133(-) tumorigenic cells and unsorted Hep-2 cells in vivo. The marker of cancer stem cells in Hep-2 cell line was explored.


METHODS
Flow cytometry was used to detect the expression of putative tumor-initiating cell marker CD133 in Hep-2 cell line. The immunomagnetic beads separation was applied to purify CD133 positive cells. CD133(+) tumor cells , CD133(-) tumor cells and unsorted Hep-2 cells were injected to severe combined immune deficiency mice individually to observe their ability of forming new tumors. To determine whether the difference in tumorigenicity in subpopulation of Hep-2 cells was due to differences in cell growth activity and cell cycle. The growth of sorted cells in vitro was observed with HE stain and analyzed cell cycle of CD133(+) cells and unsorted cells by flow cytometry.


RESULTS
Only a small proportion (3.15 +/- 0.83)% of cells in Hep-2 cell line express CD133. Both unsorted cells and sorted cells were all consistent with the character of malignant tumor. Comparison of the cell cycle status of sorted and unsorted cancer cells after magnetic sorting revealed that both cells exhibited a similar cell cycle distribution. In 20 injection sites, 16 sites contained tumor in CD133(+) group, whereas only 10 sites in unsorted group, 7 sites in CD133(-) group contained tumor. Compared with CD133(-) group (X2 = 8.286, P = 0.004) and unsorted group (X2 = 3.956, P = 0.047), CD133 positive cells possessed a marked capacity for giving rise to new tumors in vivo.


CONCLUSIONS
CD133 is one of makers for cancer stem cell in human larynx tumors, Hep-2 cell line. Identification of it provides a powerful tool to investigate the tumorigenic process in the larynx and to develop therapies targeted to the tumor-initiating cell.
Department of Otorhinolaryngology Head and Neck Surgery, Fudan University Affiliated Eye Ear Nose and Throat Hospital, Shanghai 200031, China.
Xu-dong
XD
Wei
Liang
L
Zhou
Lei
L
Cheng
Jie
J
Tian
D000071916:AC133 Antigen; D000818:Animals; D015703:Antigens, CD / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D045744:Cell Line, Tumor; D005434:Flow Cytometry; D006023:Glycoproteins / Q000032:analysis*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000378:metabolism*; D008297:Male; D051379:Mice; D016513:Mice, SCID; D014411:Neoplastic Stem Cells / Q000378:metabolism*; D010455:Peptides / Q000032:analysis*
D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; C000606024:Prom1 protein, mouse