Expression of the Neural Stem Cell Markers NG2 and L1 in Human Angiomyolipoma: Are Angiomyolipomas Neoplasms of Stem Cells?

• Authors: So Dug Lim, Emory University; William Stallcup, The Burnham Institute for Medical Research; Benjamin Lefkove, Emory University; Baskaran Govindarajan, Emory University; Kit Sing Au, University of Texas Medical School at Houston; Hope Northrup, University of Texas Medical School at Houston; Deborah Lang, University of Texas Medical School at Houston; David E Fisher, Dana-Farber Cancer Institute; Avani Patel, Emory University; Mahul B Amin, Emory University; Jack Arbiser, Emory University
• Journal Title: Molecular Medicine
• Volume: Volume 13, Number 3-4
• Publisher: Feinstein Institute for Medical Research | 2007, Pages 160-165
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.2119/2006-00070.Lim
• Subjects: Health Sciences, General; Health Sciences, Oncology

Abstract

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.