C/EBPβ-1 promotes transformation and chemoresistance in Ewing sarcoma cells.
CEBPB copy number gain in Ewing sarcoma was previously shown to be associated with worse clinical outcome compared to tumors with normal CEBPB copy number, although the mechanism was not characterized. We employed gene knockdown and rescue assays to explore the consequences of altered CEBPB gene expression in Ewing sarcoma cell lines. Knockdown of EWS-FLI1 expression led to a decrease in expression of all three C/EBPβ isoforms while re-expression of EWS-FLI1 rescued C/EBPβ expression. Overexpression of C/EBPβ-1, the largest of the three C/EBPβ isoforms, led to a significant increase in colony formation when cells were grown in soft agar compared to empty vector transduced cells. In addition, depletion of C/EBPβ decreased colony formation, and re-expression of either C/EBPβ-1 or C/EBPβ-2 rescued the phenotype. We identified the cancer stem cell marker ALDH1A1 as a target of C/EBPβ in Ewing sarcoma. Furthermore, increased expression of C/EBPβ led to resistance to chemotherapeutic agents. In summary, we have identified CEBPB as an oncogene in Ewing sarcoma. Overexpression of C/EBPβ-1 increases transformation, upregulates expression of the cancer stem cell marker ALDH1A1, and leads to chemoresistance.
Department of Pediatrics, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
Jamie D
JD
Gardiner
Department of Pediatrics, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
Lisa M
LM
Abegglen
Department of Pediatrics, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
Xiaomeng
X
Huang
School of Medicine, University of Utah, Salt Lake City, UT, USA.
Bryce E
BE
Carter
School of Medicine, University of Utah, Salt Lake City, UT, USA.
Elizabeth A
EA
Schackmann
Department of Pediatrics, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
Marcus
M
Stucki
ARUP Institute for Clinical and Experimental Pathology®, Salt Lake City, UT, USA.
Christian N
CN
Paxton
Department of Orthopaedic Surgery, Sarcoma Services, University of Utah, Salt Lake City, UT, USA.
R
R
Lor Randall
Department of Pediatrics, Internal Medicine and Molecular Biology, University of Texas Southwestern, Dallas, TX, USA.
James F
JF
Amatruda
Department of Pathology, University of Utah, Salt Lake City, UT, USA.
Angelica R
AR
Putnam
Children's Cancer Research Institute, St. Anna Kinderkrebsforschung, Vienna, Austria.
Heinrich
H
Kovar
Center for Childhood Cancer and Blood Disorders, Nationwide Children's Hospital, and the Division of Pediatric Heme/Onc/BMT, The Ohio State University, Columbus, OH, USA.
Stephen L
SL
Lessnick
Department of Pediatrics, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
Joshua D
JD
Schiffman
D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism; D000080924:Aldehyde Dehydrogenase 1 Family; D000970:Antineoplastic Agents / Q000494:pharmacology; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015514:Oncogene Proteins, Fusion / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D051789:Proto-Oncogene Protein c-fli-1 / Q000235:genetics / Q000378:metabolism; D034802:RNA-Binding Protein EWS / Q000235:genetics / Q000378:metabolism; D050697:Retinal Dehydrogenase; D012512:Sarcoma, Ewing / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*
D000970:Antineoplastic Agents; D022782:CCAAT-Enhancer-Binding Protein-beta; C545012:CEBPB protein, human; C106031:EWS-FLI fusion protein; D015514:Oncogene Proteins, Fusion; D051789:Proto-Oncogene Protein c-fli-1; D034802:RNA-Binding Protein EWS; D000080924:Aldehyde Dehydrogenase 1 Family; D000444:Aldehyde Dehydrogenase; C510223:ALDH1A1 protein, human; D050697:Retinal Dehydrogenase
ALDH1A1; C/EBPβ; Ewing sarcoma; biomarker; chemoresistance