Frede S, Freitag P, Geuting L, Konietzny R, Fandrey J. Oxygen-regulated expression of the erythropoietin gene in the human renal cell line REPC. Blood. 2011;117(18):4905-4914.

The Editors of Blood wish to retract the above-mentioned publication.

The paper reported on a permanent human renal cell line, which was established from the tumor-free renal tissue of an anonymized male patient suffering from a kidney tumor. The cells, which were capable of hypoxia-inducible erythropoietin production and therefore termed renal erythropoietin producing cells (REPC), showed features of neuronal cells and were negative for hepatitis virus B.

After publication, the authors have freely provided the cells to a number of researchers who requested them. One of the collaborators has brought to the authors’ attention that the REPC were contaminated with human Hep3B cells. Upon this, the authors have externally tested the cells including frozen aliquots of the youngest passage that were left after treating all REPC for mycoplasma infection. DNA profiling using 8 different and highly polymorphic short tandem repeat (STR) loci revealed that the REPC were cross-contaminated with Hep3B. STR profiles of the used cells matched the STR reference profile of the cell line Hep3B as indicated by a search of the STR database from the cell banks ATCC (United States), HPACC (United Kingdom), JCRB (Japan), RIKEN (Japan), KCLB (Korea) and DSMZ (Germany). Upon this, all groups who received cells were immediately informed about the contamination and have been asked to send back aliquots of the cells. These were again externally tested, but the contamination was confirmed. One collaborating group had identified different cell phenotypes in the REPC cultures by immunohistochemistry and tried to isolate single clones from the phenotypically different-appearing cells. The latest STR profiling of the 2 clones, however, also revealed persisting cross-contamination with Hep3B.

Thus, the authors notified Blood that they can currently neither provide cells that were described in the original publication nor reproduce the original results due to the lack of the cells. Because the cells should have served as an important new in vitro model or renal cells to study erythropoietin production, the authors and the Journal feel obliged to retract the above publication to avoid any further confusion about the existence of a permanent human renal erythropoietin-producing cell line. The authors apologize for any inconvenience that the research community may have faced with REPC obtained directly from them or from other sources.

All authors agree to the retraction.