This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lichtenauer, U. D. Articles by Beuschlein, F. Search for Related Content PubMed PubMed Citation Articles by Lichtenauer, U. D. Articles by Beuschlein, F.

Side Population Does Not Define Stem Cell-Like Cancer Cells in the Adrenocortical Carcinoma Cell Line NCI h295R

Institute of Molecular Medicine and Cell Research (U.D.L., I.S., F.B.), Department of Internal Medicine I (K.G.), Life Imaging Center (R.N.), Centre for Systems Biology, and Department of General and Visceral Surgery (K.-D.R.), Albert-Ludwigs-University Freiburg, D-79085 Freiburg, Germany; Clinical Endocrinology (M.Q.), Department of Internal Medicine, Charite Campus Mitte, Charite University Medicine Berlin, D-10117 Berlin, Germany; Department of Internal Medicine I (M.F.), Endocrine and Diabetes Unit, University of Wuerzburg, D-97074 Wuerzburg, Germany; and Medical Clinic (F.B.), University Hospital Innenstadt, Ludwig Maximilians University, D-80336 Munich, Germany

Address all correspondence and requests for reprints to: Felix Beuschlein, M.D., Division of Endocrine Research, Department of Medicine Innenstadt, University Hospital Munich, Ziemssenstrasse 1, D-80336 Munich, Germany. E-mail: felix.beuschlein{at}med.uni-muenchen.de.

Recent evidence suggests the existence of a stem cell-like subpopulation of cells in hematological and solid tumor entities, which determine the malignant phenotype of a given tumor through their proliferative potential and chemotherapy resistance. A recently used technique for the isolation of this cell population is through exclusion of the vital dye Hoechst 33342, which defines the so-called side population (SP). Herein we demonstrate the presence of SP cells in a variety of adrenal specimens, including primary cultures of human adrenocortical tumors and normal adrenal glands as well as established human and murine adrenocortical cancer cell lines by fluorescence-activated cell sorter analysis and confocal microscopy. On a functional level, SP cells from the human adrenocortical tumor cell line NCI h295R revealed an expression pattern consistent with a less differentiated phenotype, including lower expression of steroidogenic enzymes such as steroid acute regulatory protein (StAR) and side-chain cleavage enzyme (P450scc) in comparison with non-SP cells. However, proliferation between SP and non-SP cells did not differ (105.6 ± 18.1 vs. 100.0 ± 3.5%). Furthermore, re-sorting and tracing experiments revealed the capacity for both cell types to give rise to the original SP- and non-SP-containing cell population. Similarly to the baseline growth kinetics, no survival benefit was evident in SP cells after treatment with cytotoxic agents commonly used in adrenocortical carcinomas. Taken together, these findings provide evidence that Hoechst dye exclusion, in contrast to what has been reported for other tumor entities, is not a major tumor stem cell defining marker in adrenocortical NCI h295R tumor cells.