Expression of the neural stem cell markers NG2 and L1 in human angiomyolipoma: are angiomyolipomas neoplasms of stem cells?
Angiomyolipomas are benign tumors of the kidney which express phenotypes of smooth muscle, fat, and melanocytes. These tumors appear with increased frequency in the autosomal dominant disorder tuberous sclerosis and are the leading cause of morbidity in adults with tuberous sclerosis. While benign, these tumors are capable of provoking life threatening hemorrhage and replacement of the kidney parenchyma, resulting in renal failure. The histogenesis of these tumors is currently unclear, although currently, we believe these tumors arise from "perivascular epithelioid cells" of which no normal counterpart has been convincingly demonstrated. Recently, stem cell precursors have been recognized that can give rise to smooth muscle and melanocytes. These precursors have been shown to express the neural stem cell marker NG2 and L1. In order to determine whether angiomyolipomas, which exhibit smooth muscle and melanocytic phenotypes, express NG2 and L1, we performed immunocytochemistry on a cell line derived from a human angiomyolipoma, and found that these cells are uniformly positive. Immunohistochemistry of human angiomyolipoma specimens revealed uniform staining of tumor cells, while renal cell carcinomas revealed positivity only of angiogenic vessels. These results support a novel histogenesis of angiomyolipoma as a defect in differentiation of stem cell precursors.
Lim
So Dug
SD
Department of Urology, Emory University School of Medicine, and Atlanta VA Medical Center, Georgia 30322, USA.
Stallcup
William
W
Lefkove
Benjamin
B
Govindarajan
Baskaran
B
Au
Kit Sing
KS
Northrup
Hope
H
Lang
Deborah
D
Fisher
David E
DE
Patel
Avani
A
Amin
Mahul B
MB
Arbiser
Jack L
JL
D018207:Angiomyolipoma / Q000737:chemistry* / Q000209:etiology* / Q000473:pathology; D000941:Antigens / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000737:chemistry* / Q000209:etiology* / Q000473:pathology; D039841:Leukocyte L1 Antigen Complex / Q000378:metabolism; D011509:Proteoglycans / Q000378:metabolism; D013539:Simian virus 40 / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D000099216:Chondroitin Sulfate Proteoglycan 4
D000941:Antigens; D014408:Biomarkers, Tumor; D039841:Leukocyte L1 Antigen Complex; D011509:Proteoglycans; D000099216:Chondroitin Sulfate Proteoglycan 4