title: Expression of CD133 and other putative stem cell markers in uveal melanoma.
abstract: 'Cancer stem cells' (CSCs) are tumor cells with stem cell properties hypothesized to be responsible for tumorigenesis, metastatis, and resistance to treatment, and have been identified in different tumors including cutaneous melanoma, using stem cell markers such as CD133. This study explored expression of CD133 and other putative stem cell markers in uveal melanoma. Eight uveal melanoma cell lines were subjected to flow-cytometric (fluorescence-activated cell sorting) analysis of CD133 and other stem cell markers. Eight paraffin-embedded tumors were analyzed by immunohistochemistry for CD133, Pax6, Musashi, nestin, Sox2, ABCB5, and CD68 expressions. Ocular, uveal melanoma, and hematopoietic stem cell distributions of C-terminal and N-terminal CD133 mRNA splice variants were compared by reverse-transcription PCR. Fluorescence-activated cell sorting analysis revealed a population of CD133-positive/nestin-positive cells in cell lines Mel270, OMM 2.3, and OMM2.5. All cell lines studied were positive for nestin, CXCR-4, CD44, and c-kit. Immunohistochemistry identified cells positive for CD133, Pax6, Musashi, nestin, Sox2, ABCB5, and CD68 predominantly at the invading tumor front. C-terminal primers interacting with CD133 splice variant s2 detected a novel variant lacking exon 27. Differential expression of CD133 splice variants was found in iris, ciliary body, retina, and retinal pigment epithelium/choroid as well as in uveal melanoma cell lines. mRNA for nestin, Sox2, and Musashi was present in all studied cell lines. Uveal melanoma such as cutaneous melanoma may therefore contain CSCs. Further experiments are needed to isolate stem cell marker-positive cells, to evaluate their functional properties and to explore therapeutical approaches to these putative CSCs in uveal melanoma.
authors: Department of Ophthalmology, Clinic for Stem Cell Transplantation, University Hospital Hamburg-Eppendorf, Hamburg, Germany. mthill@uke.uni-hamburg.de
authors: Michelle
authors: M
authors: Thill
authors: Marc Jean
authors: MJ
authors: Berna
authors: Rebecca
authors: R
authors: Grierson
authors: Inna
authors: I
authors: Reinhart
authors: Tobias
authors: T
authors: Voelkel
authors: Christoph
authors: C
authors: Piechaczek
authors: Peter
authors: P
authors: Galambos
authors: Martine J
authors: MJ
authors: Jager
authors: Gisbert
authors: G
authors: Richard
authors: Claudia
authors: C
authors: Lange
authors: Ursula M
authors: UM
authors: Gehling
mesh_terms: D000071916:AC133 Antigen; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis* / Q000235:genetics; D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000096:biosynthesis; D008297:Male; D008545:Melanoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D064231:Nestin; D010455:Peptides / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014604:Uveal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000098943:Uveal Melanoma
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D006023:Glycoproteins; D007381:Intermediate Filament Proteins; C577484:NES protein, human; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; C000606023:PROM1 protein, human; D010455:Peptides; C000606024:Prom1 protein, mouse; D012333:RNA, Messenger