Prominin-1/CD133, a neural and hematopoietic stem cell marker, is expressed in adult human differentiated cells and certain types of kidney cancer.
Human prominin-1/CD133 has been reported to be expressed in neural and hematopoietic stem/progenitor cells and in embryonic, but not adult, epithelia. This lack of detection of human prominin-1, as defined by its glycosylation-dependent AC133 epitope, is surprising given the expression of the murine ortholog in adult epithelia. Here, we demonstrate, by using a novel prominin-1 antiserum (alphahE2), that the decrease of AC133 immunoreactivity observed during differentiation of the colonic adenocarcinoma-derived Caco-2 cells is not paralleled by a down-regulation of prominin-1. We have also shown that alphahE2 immunoreactivity, but not AC133 immunoreactivity, is present in several adult human tissues, such as kidney proximal tubules and the parietal layer of Bowman's capsule of juxtamedullary nephrons, and in lactiferous ducts of the mammary gland. These observations suggest that only the AC133 epitope is down-regulated upon cell differentiation. Furthermore, alphahE2 immunoreactivity has been detected in several kidney carcinomas derived from proximal tubules, independent of their grading. Interestingly, in one particular case, the AC133 epitope, which is restricted to stem cells in normal adult tissue, was up-regulated in the vicinity of the tumor. Our data thus show that (1) in adults, the expression of human prominin-1 is not limited to stem and progenitor cells, and (2) the epitopes of prominin-1 might be useful for investigating solid cancers.
Florek
Mareike
M
Medical Clinic and Polyclinic I, University Carl Gustav Carus, Fetscherstrasse 74, 01307 Dresden, Germany.
Haase
Michael
M
Marzesco
Anne-Marie
AM
Freund
Daniel
D
Ehninger
Gerhard
G
Huttner
Wieland B
WB
Corbeil
Denis
D
D000071916:AC133 Antigen; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D018952:Antigens, CD34 / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D016466:CHO Cells; D018938:Caco-2 Cells; D002454:Cell Differentiation; D006224:Cricetinae; D003412:Cricetulus; D000939:Epitopes; D006023:Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007106:Immune Sera; D007668:Kidney / Q000378:metabolism; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology; D042361:Mammary Glands, Human / Q000166:cytology / Q000378:metabolism*; D009417:Nerve Tissue / Q000166:cytology / Q000378:metabolism; D010455:Peptides / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism
D000071916:AC133 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D015415:Biomarkers; D000939:Epitopes; D006023:Glycoproteins; D007106:Immune Sera; C000606023:PROM1 protein, human; D010455:Peptides; D012333:RNA, Messenger